WO2011054770A1

WO2011054770A1 - Process for manufacturing an epoxy resin

Info

Publication number: WO2011054770A1
Application number: PCT/EP2010/066533
Authority: WO
Inventors: Patrick Gilbeau
Original assignee: Solvay Sa
Priority date: 2009-11-04
Filing date: 2010-10-29
Publication date: 2011-05-12
Also published as: CN102712738A; EP2496625A1; TW201124438A

Abstract

Process for manufacturing an epoxy resin, in which epichlorohydrin is reacted with at least one aromatic polyol so as to obtain the epoxy resin and a salt, and in which use is made of at least one non-halogenated, non-aromatic alcohol, as an additive, added to at least one step of the process or formed in at least one step of the process, in an additional amount relative to the amount of non-halogenated, non-aromatic alcohol possibly present as an impurity in the epichlorohydrin and/or in the aromatic polyol.

Description

Process for manufacturing an epoxy resin

The present application claims benefit of French patent applications n° 0957793 filed on November 04 2009 and n° 0959590 filed on December 24 2009, the content of which is incorporated herein by reference.

Should the disclosure of any of the patents, patent applications, and publications that are incorporated herein by reference conflict with the present specification to the extent that it might render a term unclear, the present specification shall take precedence.

The present invention relates to a process for manufacturing an epoxy resin.

Epoxy resins may be used in "coating" applications or "structural" applications.

"Coating" applications may be found in the marine field (corrosion- resistant coating for boats, for example), in the field of metal containers (cans for food use, for example), in the coil coating field, and in the field of coatings for motor vehicles, to name but a few of them.

"Structural" applications may be found in the field of composites

(reinforcing fibres based on glass, boron or graphite for example), in the civil engineering field, in the fields of floor coverings, of construction, of electrical laminates (printed circuits), of electrical and electronic applications

(transformers and insulators, for example), of adhesives, and of tooling

(prototypes and moulds, for example), to name but a few of them.

When the epoxy resin is a liquid epoxy resin, for example, a critical step of the manufacture lies in the difficulty of recovering said resin from a mixture containing the resin and inorganic salts, owing to the presence of solid organic by-products in the mixture. The recovery is generally carried out by treating the mixture containing the resin and the inorganic salts with a mixture of water and of an organic solvent, the solubility of which in water is limited. The organic phase obtained, which contains the liquid epoxy resin, and the aqueous phase obtained, which contains the salts, are separated by settling. The presence of a solid third phase at the interface of the organic and aqueous phases makes their separation difficult.

In patent application DD 216 471 Al, the resin is recovered by adding, to the mixture containing the resin and the inorganic salts, firstly toluene and then, after a minimum period of 15 min, water. This multi-step procedure does not completely solve the problem linked to the presence of the solid third phase and furthermore, it lengthens the time of the resin recovery step which reduces the productivity of the resin manufacturing process.

The objective of the invention is to solve the aforementioned problem by providing a process for manufacturing an epoxy resin, in which epichlorohydrin is reacted with at least one aromatic polyol so as to obtain the epoxy resin and a salt, and in which use is made of at least one non-halogenated, non-aromatic alcohol, as an additive, added to at least one step of the process or formed in at least one step of the process, in an additional amount relative to the amount of non-halogenated, non-aromatic alcohol possibly present as an impurity in the epichlorohydrin and/or in the aromatic polyol.

In the process according to the invention, by step of the process, one intends to denote any step including the supply of the raw materials and the recovery of the epoxy resin. The steps of the process can for instance be:

■ pretreatment of the reactants, such as the epichlorohydrin, the aromatic polyol and the basic agent for example;

■ chemical reactions that make it possible to transform the reactants into the epoxy resin, such as neutralization, condensation and dehydrochlorination reactions, for example;

■ physical treatments for removing reactants and/or products of the reaction, such as the azeotropic removal of the water by distillation, the removal of the unreacted epichlorohydrin by distillation, the filtration of the salt formed, the addition of solvents in order to dissolve the salt and the resin, the settling of the resulting solutions of epoxy resins and salt, for example;

■ recycling of unreacted raw materials and of solvents;

■ purification of effluents.

One of the essential features of the invention consists in using a non- halogenated, non-aromatic alcohol in the process for manufacturing the epoxy resin.

A non-halogenated, non-aromatic alcohol is an alcohol in which the molecule does not contain a bond between an aromatic carbon atom and a hydroxyl group -OH and does not contain a halogen atom.

There are many advantages linked to the use of such an alcohol as an additive: ■ increase in the epoxy resin yield of the process;

■ possibility of choosing from several procedures for recovery of the epoxy resin;

■ better use of the raw material;

■ reduction in the amount of releases to be treated and removed;

■ overall reduction in the cost of the process;

■ improvement in the productivity of the process;

■ simplification of the equipment.

More specifically, when the epoxy resin is a liquid epoxy resin, the addition of the non-halogenated, non-aromatic alcohol makes it possible to carry out the reaction under conditions such that the recovery of the resin may be performed easily, for example by adding to the mixture containing the resin and inorganic salts, a mixture of water and of an organic solvent, the solubility of which in water is limited, and by separating the aqueous and organic phases obtained by settling.

Without wishing to be tied to any one theoretical explanation, it is believed that the addition of such a non-halogenated, non-aromatic alcohol inhibits the adsorption of hydroxylated organic by-products, for example hydrolysis products of epoxy resins, on the salt formed, which would be responsible for the aforementioned separation difficulties when the epoxy resin is a liquid epoxy resin.

In the process according to the invention, the expression "epoxy resin" is understood to mean Type I Grade 1 Classes A to H, Type II Grade 1 Classes A to F and Type VI Grade 1 Class A resins, as defined in the ASTM D 1763 - 00 (2005) standard entitled "Standard Specifications for Epoxy Resins".

In the process according to the invention, the epoxy resin is preferably a liquid epoxy resin. The expression "liquid epoxy resin" is understood to mean Type I Grade 1 Classes A and B, Type II Grade 1 Classes A, B and C and Type VI Grade 1 Class A resins, as defined in the ASTM D 1763 - 00 (2005) standard entitled "Standard Specifications for Epoxy Resins".

Bisphenol A diglycidyl ether is one example of an epoxy resin.

Examples of chemical formulae of epoxy resins are presented in Figure 1 , when n is greater than or equal to zero, preferably greater than zero.

When n is greater than zero, the epoxy resin may be a polymer, the chemical formula of which contains at least one oxirane group, preferably a 2,3- epoxypropyloxy group. The term "polymer" is understood to mean molecules comprising several units joined to one another by covalent bonds, often in a repeating manner, these units being referred to as repeating units. The number of repeating units is greater than zero. A polymer contains at least one type of repeating unit. When the polymer contains only a single type of repeating unit, it is known as a homopolymer. When the polymer contains more than a single type of repeating unit, it is known as a copolymer. The copolymer may be of statistical, alternating or block type, as described in "Polymer Science Dictionary, M.S.M., Elsevier Applied Science, London and New York, 1989, page 86".

In the process according to the invention, the non-halogenated, non- aromatic alcohol preferably has a solubility in water that is greater than or equal to 10 g/kg at 25°C, more preferably greater than or equal to 50 g/kg, even more preferably greater than or equal to 100 g/kg, more preferably still greater than or equal to 150 g/kg, yet preferably greater than or equal to 200 g/kg, very particularly preferably greater than or equal to 500 g/kg. A non-halogenated, non-aromatic alcohol that is miscible with water in all proportions at 25°C is particularly suitable.

In the process according to the invention, the non-halogenated, non- aromatic alcohol preferably has a boiling point at a pressure of 1 bar absolute that is less than or equal to 100°C, more preferably less than or equal to 90°C, and most preferably lower than or equal to 80 °C.

In the process according to the invention, the non-halogenated, non- aromatic alcohol preferably forms a binary azeotrope with water, the boiling point of which at a pressure of 1 bar absolute is generally less than or equal to 100°C, and preferably less than 95 °C.

In the process according to the invention, the non-halogenated, non- aromatic alcohol comprises at least 1 carbon atom, preferably at least 2 carbon atoms and more preferably at least 3 carbon atoms. This non-halogenated, non- aromatic alcohol preferably comprises at most 12 carbon atoms, more preferably at most 8 carbon atoms and even more preferably at most 6 carbon atoms.

In the process according to the invention, the non-halogenated, non- aromatic alcohol may be of linear, branched, cyclic or branched cyclic structure.

In the process according to the invention, the non-halogenated, non- aromatic alcohol may be selected from non-halogenated, non-aromatic monoalcohols, non-halogenated, non-aromatic polyols and mixtures of at least two of them. In the process according to the invention, the non-halogenated, non aromaticalcohol is preferably a non halogenated, non aromatic polyol.

In the process according to the invention, the non-halogenated, non- aromatic monoalcohol is preferably selected from methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, iert-butanol, 1-pentanol, 2- pentanol, 3-pentanol, 3 -methyl- 1-butanol, 2 -methyl- 1-butanol, 2-methyl-2- butanol, 3-methyl-2-butanol, 2,2-dimethyl- 1-propanol, cyclopentanol, cyclohexanol, hydroxy acetone, allyl alcohol, glycidol and any mixture thereof.

In the process according to the invention, the non-halogenated, non- aromatic polyol is preferably selected from ethylene glycol, 1 ,2-propanediol, 1,3- propanediol, 1 ,2-butanediol, 1,2,3-propanetriol (glycerol), sorbitol, mannitol, maltitol, erythritol, xylitol, glycerol methyl ether, glycerol ethyl ether, linear glycerol oligomers, branched glycerol oligomers, cyclic glycerol oligomers, glyceraldehyde, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, dihydroxy acetone, erythrulose, ribulose, xylulose, psicose, fructose, tagatose, sucrose, lactose, lactulose, maltose, trehalose, turanose, cellobiose and mixtures of at least two of them. An example of linear glycerol oligomers is 3-(2,3- dihydroxypropoxy)propan-l,2-diol. Branched diglycerol oligomers are, for example, 3-(2-hydroxy-l-hydroxymethylethoxy)propan-l,2-diol and 2-(2- hydroxy-l-hydroxymethylethoxy)propan-l,3-diol). Branched glycerol oligomers are, for example, cis- and trans-2,5-bis(hydroxymethyl)-l,4-dioxane, cis- and trans-2,6-bis(hydroxymethyl)-l,4-dioxane, cis- and trans-6-hydroxy-2- hydroxymethyl-l,4-dioxepane and cis- and trans-3,7-dihydroxy-l,5-dioxocane.

In the process according to the invention, the non-halogenated, non- aromatic alcohol is preferably a non-halogenated, non-aromatic monoalcohol, such as isopropanol and glycidol, for example. Glycidol is most preferred.

In the process according to the invention, the non-halogenated, non- aromatic alcohol is preferably a non-halogenated, non-aromatic polyol of linear structure, such as glycerol or sorbitol, for example. Glycerol is most preferred.

In the process according to the invention, besides the epichlorohydrin, the aromatic polyol and the non-halogenated, non-aromatic alcohol, use may also be made of at least one basic compound. In the process according to the invention, besides the epichlorohydrin, the aromatic polyol and the non-halogenated, non- aromatic alcohol, use is also preferably made of at least one basic compound. The basic compound may be an organic or inorganic basic compound. Organic basic compounds are for example amines, phosphines and ammonium, phosphonium or arsonium hydroxides. Inorganic basic compounds are preferred. The expression "inorganic compounds" is understood to mean compounds which do not contain a carbon-hydrogen bond. The inorganic basic compound may be chosen from alkali and alkaline-earth metal oxides, hydroxides, carbonates, hydrogen carbonates, phosphates, hydrogen phosphates and borates, and mixtures thereof. Alkali and alkaline-earth metal oxides and hydroxides are preferred. The preferred basic compounds are in the form of concentrated aqueous solutions or suspensions of sodium hydroxide or calcium hydroxide or in the form of purified caustic brine. The expression "purified caustic brine" here means sodium hydroxide which contains sodium chloride such as, for example, that produced in a diaphragm electrolysis process.

In the process according to the invention, besides the epichlorohydrin, the aromatic polyol and the non-halogenated, non-aromatic alcohol, use may also be made of at least one monovalent substituted onium salt. The monovalent substituted onium salt may be chosen from the group constituted of quaternary ammonium, phosphonium or arsonium halides, phosphates, sulphates and arsenates, and mixtures of at least two of them.

In the process according to the invention, the aromatic polyol is preferably selected from the group constituted of bisphenol A (4,4'-dihydroxy-2,2- diphenylpropane, 4,4'-isopropylidenediphenol), tetrabromobisphenol A (4,4'- isopropylidenebis(2,6-dibromophenol)), bisphenol AF (4,4'-[2,2,2-trifluoro-l- (trifluoromethyl)ethylidene]bisphenol), hexafluorobisphenol A (4,4'-dihydroxy- 2,2-diphenyl- 1,1,1 ,3,3,3-hexafluoropropane), 1 , 1 ,2,2-tetra(p- hydroxyphenyl)ethane, tetramethylbisphenol (4,4 ' -dihydroxy-3 ,3 ',5,5'- tetramethylbisphenol), 1,5-dihydroxynaphthalene, 1,1 ',7,7'- tetrahydroxydinaphthylmethane, 4,4 ' -dihydroxy-a-methylstilbene, a

condensation product of phenol with formaldehyde, preferably bisphenol F (mixture of ο,ο', ο,ρ' and ρ,ρ' isomers of dihydroxydiphenylmethane), a condensation product of cresol with formaldehyde (mixture of ο,ο', ο,ρ' and ρ,ρ' isomers of methylhydroxydiphenylmethane), an alkylation product of phenol and of dicyclopentadiene (2,5-bis[(hydroxyphenyl]octahydro-4,7-methano-5H- indene), a condensation product of phenol and of glyoxal (tetrakis(4- hydroxyphenyl)ethane), a condensation product of phenol and of a

hydroxybenzaldehyde (e.g. tris(4-hydroxyphenyl)methane), l,l,3-tris(p- hydroxyphenyl)propane, and mixtures of at least two of them. Bisphenol A is more particularly preferred.

In the process according to the invention, the aromatic polyol is more preferably selected from the group constituted by bisphenol A, a condensation product of phenol with formaldehyde, a condensation product of cresol with formaldehyde and mixtures of at least two of them.

In one particularly preferred embodiment of the process according to the invention, the aromatic polyol is bisphenol A and the epoxy resin is a liquid epoxy resin of Type I Grade 1 Classes A and B, as defined in the ASTM D 1763 - 00 (2005) standard entitled "Standard Specifications for Epoxy Resins".

This resin generally has a viscosity at 25°C greater than or equal to 3000 cP and less than or equal to 40 000 cP, often greater than or equal to 3000 cP and less than or equal to 20 000 cP and frequently greater than or equal to 15 000 cP and less than or equal to 40 000 cP.

This resin generally has an epoxide equivalent weight greater than or equal to 170 and less than or equal to 226, often greater than or equal to 170 and less than or equal to 200, and frequently greater than or equal to 190 and less than or equal to 226. The epoxide equivalent weight is defined as the weight in grams of resin that contains one molar equivalent of epoxide functional group.

In this particularly preferred embodiment of the process according to the invention, besides the epichlorohydrin and the aromatic polyol, use may also be made of at least one basic compound, as defined above.

This embodiment is used in the process known under the name of the Phase Transfer Catalyst Process for manufacturing a liquid epoxy resin, and as described in Ullmann's Encyclopedia of Industrial Chemistry, Fifth Completely Revised Edition, Vol. A9, pages 548-549.

In this particularly preferred embodiment, besides the epichlorohydrin and the aromatic polyol, use may also be made of at least one basic compound and at least one quaternary ammonium salt. This embodiment is used in the process known under the name of the Phase Transfer Catalyst Process for manufacturing a liquid epoxy resin, and as described in Ullmann's Encyclopedia of Industrial Chemistry, Fifth Completely Revised Edition, Vol. A9, pages 548-549.

The various steps of the process according to the invention may be carried out in continuous mode or in batch mode.

In the process according to the invention, the non-halogenated, non- aromatic alcohol is used as an additive, added to at least one step of the process or formed in at least one step of the process, in an additional amount relative to the amount of this non-halogenated, non-aromatic alcohol possibly present as an impurity in the epichlorohydrm and/or in the aromatic polyol.

By possibly present as an impurity in the epichlorohydrm and/or in the aromatic polyol, one intends to denote that the non-halogenated, non-aromatic alcohol may be present or may not be present as an impurity in the

epichlorohydrm and/or in the aromatic polyol.

The non-halogenated, non-aromatic alcohol may be present as an impurity in the epichlorohydrm and/or in the aromatic polyol. In this case, and without wishing to be tied to any one theoretical explanation, it is believed that the amount of this non-halogenated, non-aromatic alcohol as an impurity in the epichlorohydrm and/or in the aromatic polyol is insufficient to inhibit the adsorption of hydroxylated organic by-products, for example hydrolysis products of epoxy resins, on the salt formed, which would be responsible for the aforementioned separation difficulties when the epoxy resin is a liquid epoxy resin, for example, and that it is needed to add or form an extra amount of that non-halogenated, non-aromatic alcohol.

The non-halogenated, non-aromatic alcohol may not be present as an impurity in the epichlorohydrm and/or in the aromatic polyol. The expression "not be present" is understood to mean situations where the content of non- halogenated, non-aromatic alcohol in the epichlorohydrm and/or in the aromatic polyol is less than 1 mg of non-halogenated, non-aromatic alcohol per kg of epichlorohydrm and/or less than 1 mg of non-halogenated, non-aromatic alcohol per kg of aromatic polyol.

The non-halogenated, non-aromatic alcohol may be added to or formed in at least one of the steps of the process according to the invention.

In the process according to the invention, the reaction between

epichlorohydrm and the aromatic polyol is generally carried out in a reaction medium.

In a first embodiment of the process according to the invention, the non- halogenated, non-aromatic alcohol is formed during the epichlorohydrm pretreatment step. This pretreatment step may consist of a partial hydrolysis of the epichlorohydrm. This partial hydrolysis may be carried out by addition of a defined amount of water or a defined amount of an aqueous mixture containing at least one basic agent as defined above. In this case the non-halogenated, non- aromatic alcohol is, for example, glycidol or glycerol, preferably glycerol. In a second embodiment of the process according to the invention, the non- halogenated, non-aromatic alcohol is added to at least one of the compounds chosen from epichlorohydrin, the aromatic polyol, the basic agent, the quaternary ammonium salt and mixtures of at least two of them.

In a third embodiment of the process according to the invention, the non- halogenated, non-aromatic alcohol is added to the reaction medium.

In a preferred variant of this third embodiment, the non-halogenated, non- aromatic alcohol is added during the reaction between the epichlorohydrin and the aromatic polyol. By the expression "during the reaction", one intends to denote during any step where both the epichlorohydrin and the aromatic polyol are present. In this variant, said reaction is preferably carried out at a

temperature greater than or equal to 25°C and less than or equal to 150°C.

In one preferred aspect of the preferred variant of this third embodiment, the non-halogenated, non-aromatic alcohol is added when the degree of conversion of the aromatic polyol, expressed as mol% of this compound, is greater than or equal to 50 mol%, preferably greater than or equal to 55 mol%, more preferably greater than or equal to 60 mol%, still more preferably greater than or equal to 65 mol%, yet more preferably preferably greater than or equal to 70 mol%, particularly preferably greater than or equal to 75 mol %, very particularly preferably greater than or equal to 80 mol%, most preferably greater than or equal to 85 %. and yet most preferably greater than or equal to 90 mol%. That degree of conversion of the aromatic polyol, expressed as mol% of this compound, is preferably lower than or equal to 99.9 mol%, more preferably lower than or equal to 99 mol%, still more preferably lower than or equal to 97.5 mol%, yet more preferably lower than or equal to 95 mol% and particularly preferably lower than or equal to 92.5 mol %.

This degree of conversion is the ratio between the amount of aromatic polyol that has been converted into epoxy resin in the process and the amount of aromatic polyol introduced during the process, before the addition of the non- halogenated, non-aromatic alcohol. This applies to continuous processes, semi- continuous processes and batch processes, whatever the number of steps to go from the raw materials to the final products.

In a fourth embodiment according to the process of the invention, the non- halogenated, non-aromatic alcohol is used as an additive, added to at least one step of the process or formed in at least one step of the process, when the degree of conversion of the aromatic polyol expressed as mol% of this compound is greater than or equal to 50 mol %, preferably greater than or equal to 55 mol%, more preferably greater than or equal to 60 mol%, still more preferably greater than or equal to 65 mol%, yet more preferably greater than or equal to 70 mol%, particularly preferably greater than or equal to 75 mol %, very particularly preferably greater than or equal to 80 mol%, still very particularly preferably greater than or equal to 80 mol%, most preferably greater than or equal to 85 % and yet most preferably greater than or equal to 90 mol%. In that embodiment, the degree of conversion of the aromatic polyol, expressed as mol% of this compound, is preferably lower than or equal to 99.9 mol%, more preferably lower than or equal to 99 mol%, still more preferably lower than or equal to

97.5 mol%, yet more preferably lower than or equal to 95 mol% and particularly preferably lower than or equal to 92.5 mol %.

In a first variant of that fourth embodiment, the non-halogenated, non- aromatic alcohol is used as an additive, added to at least one step of the process.

In a first aspect of the first variant of the fourth embodiment, the at least one step is a chemical reaction step.

In a second aspect of the first variant of the fourth embodiment, the at least one step is a physical treatment for removing reactants and/or products of the reaction. Such a treatment is for instance an operation to separate the epoxy resin from the other components of reaction medium, like for instance unreacted raw materials, reaction intermediates, and other products of the reaction. The separation operation can for instance be a liquid-liquid extraction of the reaction medium with a mixture of water and a solvent, preferably organic, with a limited solubility in water.

In a second variant of that fourth embodiment, the non-halogenated, non- aromatic alcohol is used as an additive, formed to at least one step of the process.

Without wishing to be tied to any one theoretical explanation, it is believed that this approach, in this aspect, makes it possible to prevent a degradation of the non-halogenated, non-aromatic alcohol which would limit its role of inhibiting the adsorption of hydroxylated organic by-products, for example hydrolysis products of epoxy resins, on the salt formed, which would be responsible for the aforementioned separation difficulties when the epoxy resin is a liquid epoxy resin for example.

In a fifth embodiment of the process according to the invention, which is preferred, the reaction between the epichlorohydrin and the aromatic polyol is carried out in a reaction medium and at least one portion of this reaction medium is subjected to at least one separation operation during which at least a first fraction containing unconverted epichlorohydrin and at least a second fraction, concentrated in epoxy resin and in salt, are obtained, in which said second fraction is subjected to at least one subsequent treatment, and in which at least one portion of the non-halogenated, non-aromatic alcohol is added to said second fraction before the subsequent treatment and/or during said subsequent treatment of said second fraction.

In a first variant of the fifth embodiment of the process according to the invention, which is more preferred, at least one portion of the reaction medium is subjected to at least one separation operation during which at least a first fraction containing unconverted epichlorohydrin and at least a second fraction, concentrated in epoxy resin and in salt, are obtained, and at least one portion of the non-halogenated, non-aromatic alcohol is added to said second fraction.

In a second variant of the fifth embodiment of the process according to the invention, the second fraction, to which the non-halogenated, non-aromatic alcohol has been added, is mixed with water and at least one organic solvent, the solubility of which in water is limited, so as to separate, by settling, a first part comprising the organic solvent and most of the epoxy resin included in the second fraction, to which the non-halogenated, non-aromatic alcohol has been added, before mixing and a second part comprising the water and most of the salt included in the second fraction, to which the non-halogenated, non-aromatic alcohol has been added, before mixing. The water and the organic solvent may be added to the second fraction, to which the non-halogenated, non-aromatic alcohol has been added, in any sequence, such as the water before the organic solvent, the organic solvent before the water, and the organic solvent at the same time as the water.

The expression "the solubility of which in water is limited" means that the solubility of the organic solvent in water at 25°C is less than 300 g of solvent per kg of water.

In a third variant of the fifth embodiment of the process according to the invention, which is also preferred, at least one portion of the reaction medium is subjected to at least one separation operation during which at least a first fraction containing unconverted epichlorohydrin and at least a second fraction, concentrated in epoxy resin and in salt, are obtained, and said second fraction is subjected to at least one subsequent treatment, and at least one portion of the non-halogenated, non-aromatic alcohol is added to said second fraction during said subsequent treatment.

In one particular aspect of this variant, the second fraction is mixed with water and at least one organic solvent, the solubility of which in water is limited, and a first part, comprising the organic solvent and most of the epoxy resin included in the medium before mixing, and a second part, comprising the water and most of the salt included in the medium before mixing, are separated by settling.

The organic solvent, the solubility of which in water is limited, may be selected from the group constituted by toluene, xylene, benzene, methyl isobutyl ketone, methyl ethyl ketone and mixtures of at least two of them. The water and the organic solvent may be added to the second fraction in any sequence, such as the water before the organic solvent, the organic solvent before the water, and the organic solvent at the same time as the water.

In this variant, the non-halogenated, non-aromatic alcohol may be added as is, or as a mixture with water, or as a mixture with the organic solvent or in any mixture with water and with at least one organic solvent.

In the fifth embodiment, the weight ratio between the amount of water added to the second fraction, concentrated in epoxy resin and in salt, and the amount of salt in said concentrated fraction is generally greater than or equal to 3 and preferably greater than or equal to 4. This ratio is generally less than or equal to 50, preferably less than or equal to 20 and more preferably less than or equal to 10.

In the fifth embodiment, the weight ratio between the amount of organic solvent added to the second fraction, concentrated in epoxy resin and in salt, and the amount of epoxy resin in said concentrated fraction is generally greater than or equal to 0.1 and preferably greater than or equal to 0.5 and more preferably greater than or equal to 0.8. This ratio is generally less than or equal to 10, preferably less than or equal to 5 and more preferably less than or equal to 2.

In the process according to the invention, the additional amount of the non- halogenated, non-aromatic alcohol preferably corresponds to at least one of the following conditions:

(a) the additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of epichlorohydrin used in the process expressed as g of non-halogenated, non-aromatic alcohol per kg of epichlorohydrin is greater than or equal to 0.005 and less than or equal to 500; (b) the additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of aromatic polyol used in the process expressed as g of non-halogenated, non-aromatic alcohol per kg of aromatic polyol is greater than or equal to 0.005 and less than or equal to 500.

Without wishing to be tied to any one theoretical explanation, it is believed that such conditions present the advantage of having a lower amount of the non- halogenated, non-aromatic alcohol to recover and to recycle in the process of the invention.

This additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of epichlorohydrin used in the process expressed as g of non-halogenated, non-aromatic alcohol per kg of epichlorohydrin is more preferably greater than or equal to 0.01, even more preferably greater than or equal to 0.1, more preferably still greater than or equal to 1 and very particularly preferably greater than or equal to 10. This content is more preferably less than or equal to 200, even more preferably less than or equal to 100, more preferably still less than or equal to 50, yet more preferably less than or equal to 30, particularly preferably less than or equal to 25, very particularly preferably less than or equal to 20 and most preferably less than or equal to 12. A content of less than or equal to 5 is also particularly convenient.

This additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of aromatic polyol used in the process expressed as g of non-halogenated, non-aromatic alcohol per kg of aromatic polyol is more preferably greater than or equal to 0.01, even more preferably greater than or equal to 0.1, more preferably still greater than or equal to 1 and very particularly preferably greater than or equal to 10. This content is more preferably less than or equal to 200, even more preferably less than or equal to 100, and more preferably still less than or equal to 50, yet more preferably less than or equal to 30, particularly preferably less than or equal to 25, very particularly preferably less than or equal to 20 and most preferably less than or equal to 12.

A content of less than or equal to 8, preferably of less than or equal to 5 and more preferably less than or equal to 3 is also particularly convenient.

The non-halogenated, non-aromatic alcohol may be added continuously or in batch mode.

In the process according to the invention, the epichlorohydrin may have been manufactured by any process. The epichlorohydrin may originate, for example, from a process for dehydrochlorination of dichloropropanol, for example via a basic compound, from an allyl chloride epoxidation process, or from the two processes. Among the allyl chloride epoxidation processes, the process for epoxidation via hydrogen peroxide is preferred.

In the process according to the invention, at least one portion of the epichlorohydrin is obtained by reaction between dichloropropanol and at least one basic compound. The basic compound may be as defined above.

In the process according to the invention, when the epichlorohydrin originates from a dichloropropanol dehydrochlorination process, the

dichloropropanol may itself be obtained by any process. The dichloropropanol may originate, for example, from an allyl chloride hypochlorination process, from a glycerol hydrochlorination process, from an allyl alcohol chlorination process, from a 1,3-dichloroacetone reduction process, from a 2,3- dichloropropanal reduction process or from a combination of at least two of these processes. The dichloropropanol is preferably obtained by a glycerol hydrochlorination process, by an allyl chloride hypochlorination process, or by a combination of the two.

In the process according to the invention, at least one portion of the dichloropropanol is more preferably obtained by a glycerol hydrochlorination process, and more specifically by reaction between glycerol and hydrogen chloride.

In the process according to the invention, at least one portion of the epichlorohydrin is preferably obtained by dehydrochlorination of

dichloropropanol via a basic compound, and at least one portion of said dichloropropanol being obtained by hydrochlorination of glycerol.

In the process according to the invention, at least one portion of the epichlorohydrin is more preferably obtained by a process for

dehydrochlorination of dichloropropanol and at least one portion of said dichloropropanol is preferably obtained by hydrochlorination of glycerol, the dehydrochlorination and hydrochlorination processes possibly being carried out at the same manufacturing site as the process according to the invention or at different manufacturing sites.

In the process according to the invention, the epichlorohydrin is more preferably obtained by reaction between dichloropropanol and at least one basic compound, and at least one portion of said dichloropropanol is preferably obtained by reaction between glycerol and hydrogen chloride, and preferably at least one part of the glycerol has been obtained from renewable raw materials, such as in the production of biodiesel.

The processes for preparing the dichloropropanol and the epichlorohdyrin can be such as disclosed in International applications WO2005/054167, WO2006/100311, WO2006/100312, WO2006/100313, WO2006/100314, WO2006/100315, WO2006/100316, WO2006/100317, WO2006/106153, 2007054505, WO 2006/100318, WO2006/100319, WO2006/100320,

WO 2006/106154, WO2006/106155, WO 2007/144335, WO 2008/107468, WO 2008/101866, WO 2008/145729, WO 2008/110588, WO 2008/152045, WO 2008/152043, WO 2009/000773, WO 2009/043796, WO 2009/121853,

WO 2008/152044, WO 2009/077528, WO 2010/066660, WO 2010/029039 and WO 2010/029153, filed in the name of SOL V AY, the contents of which are incorporated herein by reference.

The examples below are intended to illustrate the invention without, however, limiting it.

Example 1 (not in accordance with the invention)

It was carried out as follows.

A mixture containing 4 mol of epichlorohydrin obtained by

dehydrochlorination of dichloropropanol by a basic compound, the

dichloropropanol having been obtained by hydrochlorination of glycerol using hydrogen chloride, 1 mol of commercial bisphenol A diglycidyl ether of 95% purity and 2 mol of sodium chloride, was heated at 90°C, with stirring, for 20 min and under a nitrogen atmosphere. The epichlorohydrin contained less than 50 ppm by weight of glycerol and less than 50 ppm by weight of glycidol. This mixture was then cooled to 85°C, and 0.025 mol of bisphenol A and 0.05 mol of sodium hydroxide, in the form of an aqueous solution containing 33% by weight of NaOH, were added thereto. The resulting mixture continued to be stirred for 1 hour at 85 °C. The epichlorohydrin was then evaporated by gradually reducing the pressure from 1 bar to around 200 mbar absolute, while gradually increasing the temperature of the mixture to 113°C. The temperature of the mixture resulting from the evaporation of the epichlorohydrin was then reduced to 55°C and a weight amount of methyl isobutyl ketone identical to the amount of bisphenol A diglycidyl ether used was added, with vigorous stirring,

continuously and over 20 min. An amount of water corresponding to 332 g of water per mol of NaCl introduced was then added, with vigorous stirring, continuously, over 12 min and at 55°C. The mixture obtained was then transferred to a separatory funnel and the three phases were separated after settling at 25°C for 20 h. The densest phase was a solution containing most of the salt present in the mixture before settling. The least dense phase was a solution containing most of the epoxy resin present in the mixture before settling. The phase of intermediate density contained a suspended solid. This phase was filtered under pressure through a polytetrafluoroethylene filter having a porosity of 5 μιη. On the filter, 4 g of wet solid were recovered per 100 g of bisphenol A diglycidyl ether used. The solid recovered was analysed by high performance liquid chromatography and contained 18.4% by weight of epoxy resin.

Example 2 (in accordance with the invention)

The operations from Example 1 were repeated except that, added to the mixture cooled to 85°C and containing the epichlorohydrin, the bisphenol A diglycidyl ether and the sodium chloride, were the bisphenol A, the 33% sodium hydroxide solution and 1.73 g of glycerol per mol of bisphenol A diglycidyl ether.

On the filter, 1.3 g of wet solid were recovered per 100 g of bisphenol A diglycidyl ether used. The solid recovered was analysed by high performance liquid chromatography and contained 17.5% by weight of epoxy resin.

Example 3 (in accordance with the invention)

The operations from Example 1 were repeated except that, added to the mixture cooled to 85°C and containing the epichlorohydrin, the bisphenol A diglycidyl ether and the sodium chloride, were the bisphenol A and 1.86 g of glycidol per mol of bisphenol A diglycidyl ether, and then the 33% sodium hydroxide solution.

On the filter, 1.6 g of wet solid were recovered per 100 g of bisphenol A diglycidyl ether used. The solid recovered was analysed by high performance liquid chromatography and contained 22.7% by weight of epoxy resin.

Claims

C L A I M S

1 - Process for manufacturing an epoxy resin, in which epichlorohydrin is reacted with at least one aromatic polyol so as to obtain the epoxy resin and a salt, and in which use is made of at least one non-halogenated, non-aromatic alcohol, as an additive, added to at least one step of the process or formed in at least one step of the process, in an additional amount relative to the amount of non-halogenated, non-aromatic alcohol possibly present as an impurity in the epichlorohydrin and/or in the aromatic polyol.

2 - Process according to Claim 1 , in which the non-halogenated, non- aromatic alcohol has a solubility in water that is greater than or equal to 10 g/kg at 25°C.

3 - Process according to Claim 1 or 2, in which the non-halogenated, non- aromatic alcohol has a boiling point at a pressure of 1 bar absolute that is less than or equal to 100°C.

4 - Process according to any one of Claims 1 to 3, in which the non- halogenated, non-aromatic alcohol forms a binary azeotrope with water, the boiling point of which at a pressure of 1 bar absolute is less than or equal to 100°C.

5 - Process according to any one of Claims 1 to 4, in which the non- halogenated, non-aromatic alcohol is a non-halogenated, non-aromatic polyol.

6 - Process according to Claim 5, in which the non-halogenated, non- aromatic polyol is selected from ethylene glycol, 1 ,2-propanediol, 1,3- propanediol, 1 ,2-butanediol, 1,2,3-propanetriol, sorbitol, mannitol, maltitol, erythritol, xylitol, glycerol methyl ether, glycerol ethyl ether, linear glycerol oligomers, branched glycerol oligomers, cyclic glycerol oligomers,

glyceraldehyde, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, dihydroxy acetone, erythrulose, ribulose, xylulose, psicose, fructose, tagatose, sucrose, lactose, lactulose, maltose, trehalose, turanose, cellobiose and mixtures of at least two of them. 7 - Process according to claim 6, in which the non-halogenated, non- aromatic polyol is 1,2,3-propanetriol.

8 - Process according to any one of Claims 1 to 7, in which the additional amount of the non-halogenated, non-aromatic alcohol corresponds to at least one of the following conditions:

(a) the additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of epichlorohydrin used in the process, expressed as g of non-halogenated, non-aromatic alcohol per kg of epichlorohydrin is greater than or equal to 0.005 and less than or equal to 500;

(b) the additional amount of the non-halogenated, non-aromatic alcohol relative to the total amount of aromatic polyol used in the process expressed as g of non-halogenated, non-aromatic alcohol per kg of aromatic polyol is greater than or equal to 0.005 and less than or equal to 500.

9 - Process according to any one of Claims 1 to 8, in which the aromatic polyol is selected from the group constituted of bisphenol A (4,4'-dihydroxy-2,2- diphenylpropane, 4,4'-isopropylidenediphenol), tetrabromobisphenol A (4,4'- isopropylidenebis(2,6-dibromophenol)), bisphenol AF (4,4'-[2,2,2-trifluoro-l- (trifluoromethyl)ethylidene]bisphenol), hexafluorobisphenol A (4,4'-dihydroxy- 2,2-diphenyl- 1,1,1 ,3,3,3-hexafluoropropane), 1 , 1 ,2,2-tetra(p- hydroxyphenyl)ethane, tetramethylbisphenol (4,4 ' -dihydroxy-3 ,3 ',5,5'- tetramethylbisphenol), 1,5-dihydroxynaphthalene, 1,1 ',7,7'- tetrahydroxydinaphthylmethane, 4,4 ' -dihydroxy-a-methylstilbene, a

hydroxybenzaldehyde (e.g. tris(4-hydroxyphenyl)methane), l,l,3-tris(p- hydroxyphenyl)propane, and mixtures of at least two of them.

10 - Process according to Claim 9, in which the aromatic polyol is selected from the group constituted by bisphenol A, a condensation product of phenol with formaldehyde, a condensation product of cresol with formaldehyde and mixtures of at least two of them.

11 - Process according to any one of Claims 1 to 10, in which the non- halogenated, non-aromatic alcohol is added during the reaction between the epichlorohydrin and the aromatic polyol.

12 - Process according to any one of Claims 1 to 11, in which the non- halogenated, non-aromatic alcohol is added when the degree of conversion of the aromatic polyol, expressed as mol% of this compound, is greater than or equal to 50 mol%. 13 - Process according to any one of Claims 1 to 12, in which at least one portion of the epichlorohydrin has been obtained by a process for

dehydrochlorination of dichloropropanol and at least one portion of said dichloropropanol has been obtained by hydrochlorination of glycerol, and at least one part of the glycerol has been obtained from renewable raw materials. 14 - Process according to any one of Claims 1 to 13, in which the reaction between the epichlorohydrin and the aromatic polyol is carried out in a reaction medium and in which at least one portion of this reaction medium is subjected to at least one separation operation during which at least a first fraction containing unconverted epichlorohydrin and at least a second fraction, concentrated in epoxy resin and in salt, are obtained, in which said second fraction is subjected to at least one subsequent treatment, and in which at least one portion of the non- halogenated, non-aromatic alcohol is added to said second fraction before the subsequent treatment and/or during said subsequent treatment of said second fraction. 15 - Process according to Claim 14, in which the second fraction is mixed with water and at least one organic solvent, the solubility of which in water is less than 300 g of solvent per kg of water, and in which a first part, comprising the organic solvent and most of the epoxy resin included in the second fraction before mixing, and a second part, comprising the water and most of the salt included in the second fraction before mixing, are separated by settling.