Method for obtaining bio-derived polyepoxides with improved properties

Abstract

The present invention relates to a method for preparing an epoxy prepolymer composition containing a glycidyl ether, the method comprising the steps of: a) contacting a dianhydrohexitol with another alcohol to obtain a composition of alcohols; b) reacting the alcohol composition obtained in step a) with epihalohydrin to obtain a reaction mixture containing a glycidyl ether; c) recovering the epoxy prepolymer composition containing the glycidyl ether from the reaction mixture obtained at the end of step b). The present invention also relates to an epoxy prepolymer composition obtainable by the method, a curable composition comprising the epoxy prepolymer composition, a polyepoxide obtainable by curing the curable composition, and a composite material, coating, or adhesive comprising the polyepoxide.

Description

Technical Field

[0001] The present disclosure relates to the field of polyepoxides, and more particularly to a method for preparing epoxy prepolymers containing glycidyl ethers of dianhydrohexitol units and glycidyl ethers of other alcohol units.

Background Art

[0002] Prior Art Polyepoxides, also called epoxide polymers or commonly referred to as "epoxies", are widely used, for example, as surface materials in the manufacture of adhesives or coatings, and also as structural materials, for example, as matrices of composite materials.

[0003] Polyepoxides are obtained by curing curable compositions containing epoxy prepolymers.

[0004] For the purposes of the present invention, an epoxy prepolymer is a mixture of molecules containing epoxide functional groups that can subsequently be polymerized to give a polyepoxide. Epoxy prepolymers may or may not contain an oligomer fraction. They may or may not contain a polymer fraction.

[0005] Most curable compositions containing epoxy prepolymers, which are particularly used for manufacturing adhesives, coatings, or matrices of composite materials, contain, in addition to the epoxy prepolymer, at least one curing agent and / or at least one accelerator.

[0006] When a curable composition containing an epoxy prepolymer is cured, chemical bonds are formed between the molecules of the epoxy prepolymer and / or between the epoxy prepolymer and the curing agent by the ring-opening reaction of the epoxide functional groups of the epoxy prepolymer. Thereby, a three-dimensional polymer network is formed.

[0007] The term "accelerator" is understood to mean a compound that causes a homopolymerization reaction between two epoxide functional groups or a reaction between an epoxide functional group and a catalyzed curing agent. Lewis acids, Lewis bases, and photoinitiators are examples of such compounds.

[0008] The term "curing agent" is understood to mean any compound distinct from the epoxy prepolymer that reacts with the epoxide functional groups of the prepolymer to form a three-dimensional network. Examples include amines, amidoamines, Mannich bases, organic acids (including polyesters with terminal carboxylic acid functional groups), organic acid anhydrides, and latent curing agents (such as cyanamides and imidazole types).

[0009] In single-component curable compositions, the accelerator and / or curing agent are directly incorporated into the epoxy prepolymer composition: refer to the 1K system. In two-component curable compositions, the accelerator and / or curing agent are packaged separately from the epoxy prepolymer composition and mixed only when the curable composition is molded: refer to the 2K system.

[0010] Curable compositions containing epoxy prepolymers may also contain organic or inorganic fillers (such as silica, sand, aluminum oxide, talc, and calcium carbonate), pigments, plasticizers, stabilizers, and thixotropes.

[0011] Bisphenol A diglycidyl ether (BADGE) of formula (i) is a chemical compound that is currently very widely used as an epoxy prepolymer.

[0012] [C1] [ka]

[0013] BADGE is a product derived from petroleum, which is disadvantageous in situations of rising prices and / or shortages of petroleum resources.

[0014] Furthermore, bisphenol A is now recognized as an endocrine disruptor.

[0015] Therefore, handling bisphenol A-based epoxy prepolymers, or contact with polyepoxides obtained from BADGE, may be harmful to health.

[0016] In recent years, it has become known that BADGE can be replaced by a mixture containing isosorbide diglycidyl ether, which is a biologically derived product and has the following structure (formula (ii)).

[0017] [C2] [ka]

[0018] This compound, belonging to a more common class of dianhydrohexitol diglycidyl ethers, is now widely known and, as with its synthesis methods, is documented in the literature. For example, U.S. Patent Nos. 3,272,845, 4,770,871, International Publication Nos. 2008 / 147472, 2008 / 147473, U.S. Patent No. 3,041,300, International Publication Nos. 2012 / 157832, and International Publication Nos. 2015 / 110758 disclose methods for synthesizing dianhydrohexitol diglycidyl ethers.

[0019] By carrying out any one of the methods described in the aforementioned literature, an epoxy prepolymer composition is actually obtained that contains dianhydrohexitol monoglycidyl ether, in addition to dianhydrohexitol diglycidyl ether, and an oligomer comprising a dianhydrohexitol unit and a glyceryl unit, wherein these oligomers contain one or more glycidyl ether groups supported on the dianhydrohexitol unit and / or glyceryl unit.

[0020] In the present application, the "alcohol-based epoxy prepolymer" refers to an epoxy prepolymer in which the epoxide functional group is essentially contained in a glycidyl ether group, and the glycidyl ether group is essentially carried by the alcohol unit or a glyceryl unit that is itself bonded to the alcohol unit.

[0021] For example, in an isosorbide-based epoxy prepolymer, the glycidyl ether group is essentially carried by the isosorbide unit and the glyceryl unit bonded to the isosorbide unit. Therefore, the glycidyl ether group is, for example, in the form of isosorbide mono- or di-glycidyl ether, or in the form of a glycidyl ether-isosorbide-... unit in an oligomer.

[0022] Therefore, the epoxy prepolymer composition obtained by implementing the method described in the foregoing document is an epoxy prepolymer based on dianhydrohexitol or isosorbide.

[0023] In the present application, the "alcohol-based polyepoxide" refers to a polyepoxide obtained by curing the alcohol-based epoxy prepolymer.

[0024] When a monoglycidyl ether compound and / or an oligomer is present in a diol-based epoxy prepolymer in addition to the diglycidyl ether compound, the crosslink density in the three-dimensional polymer network obtained by curing the curable composition containing the epoxy prepolymer is reduced as compared with that obtained when the curable composition contains the diglycidyl ether of the pure diol as the epoxy prepolymer.

[0025] This crosslink density is related to the glass transition temperature (Tg) of the polyepoxide. A high crosslink density can provide a material having a higher glass transition temperature (Tg) and being more chemically and mechanically resistant.

[0026] The presence of oligomers and / or monoglycidyl ethers in an epoxy prepolymer is directly related to the epoxy equivalent weight (EEW), defined as the mass of an epoxy prepolymer containing 1 equivalent of glycidyl ether groups. For example, pure isosorbide diglycidyl ether (Formula II) having a molecular weight of 258 g / mol and containing two glycidyl ether groups has an epoxy equivalent weight of 129 g / eq.

[0027] In a diol-based epoxy prepolymer, the EEW is at a minimum when the epoxy prepolymer is the diglycidyl ether of the pure diol. As the content of oligomers and / or monoglycidyl ethers of the diol in the epoxy prepolymer increases, the EEW of the epoxy prepolymer increases.

[0028] A polyepoxide was prepared from an epoxy prepolymer based on isosorbide diglycidyl ether.

[0029] However, it remains difficult to obtain a bio-derived polyepoxide having performance capabilities equivalent to those of polyepoxides obtained from petroleum-derived compounds such as BADGE.

[0030] U.S. Patent Application Publication No. 2015 / 0353676A1 describes, inter alia, polyepoxides based on isosorbide and cis-4-cyclohexene-1,2-dicarboxylic acid as a curing agent.

[0031] U.S. Patent Application Publication No. 2018 / 0230261A1 describes polyepoxides based on isosorbide and polyamides as curing agents.

[0032] International Publication No. 2015 / 110758A1 describes polyepoxides based on isosorbide and isophoronediamine as a curing agent. These polyepoxides have a glass transition temperature of about 95 to 100 °C.

[0033] Similarly, U.S. Patent Application Publication No. 2017 / 0253692 and Japanese Patent No. 2014189713 describe isosorbide-based polyepoxides containing various curing agents.

[0034] A recurring problem encountered with isosorbide-based polyepoxides is their significant water absorption; in other words, water molecules readily diffuse into the three-dimensional polymer network of the polyepoxide. Therefore, in the presence of moisture or liquid water, these polyepoxides tend to absorb water easily, particularly causing them to plasticize (lowering their glass transition temperature), swell, and reduce their tackiness or adhesive properties.

[0035] Therefore, significant water absorption makes polyepoxides unsuitable for many applications (particularly adhesives and matrices for composite materials), and this is one of the major obstacles to the current widespread use of dianhydrohexitol-based polyepoxides.

[0036] One solution to this problem developed by the applicant consists of preparing polyepoxides from a mixture of dianhydrohexitol-based epoxy prepolymers and other alcohol-based epoxy prepolymers.

[0037] The objective is to combine the properties of dianhydrohexitol-based polyepoxides with those of other alcohol-based polyepoxides, thereby compensating for the shortcomings of each.

[0038] While continuing this research, the applicant's company discovered that when dianhydrohexitol and other alcohols were mixed before the process of synthesizing the epoxy prepolymer, the resulting polyepoxides exhibited better properties, particularly lower water absorption, than polyepoxides obtained from mixtures of epoxy prepolymers synthesized separately from dianhydrohexitol and other alcohols. This remarkable effect is the subject of the present invention. [Overview of the project]

[0039] This disclosure relates to the preparation of an epoxy prepolymer containing dianhydrohexitol glycidyl ether, which can be used to obtain a polyepoxide with improved water absorption.

[0040] Therefore, we propose a method for preparing an epoxy prepolymer composition containing glycidyl ether, the method comprising the following steps: a. A step of contacting dianhydrohexitol with another alcohol to obtain an alcohol composition. b. A step of reacting the alcohol composition obtained in step a) with an epihalohydrin to obtain a reaction mixture containing glycidyl ether. c. The process includes recovering an epoxy prepolymer composition containing glycidyl ether from the reaction mixture obtained at the end of step b).

[0041] In another embodiment, we propose an epoxy prepolymer composition that can be obtained by the method of the present invention.

[0042] In another embodiment, we propose a curable composition comprising the epoxy prepolymer composition of the present invention, characterized by further comprising at least one accelerator and / or at least one curing agent.

[0043] In another embodiment, we propose a polyepoxide obtained by curing the curable composition of the present invention.

[0044] In another embodiment, the present invention proposes a composite material, coating, or adhesive comprising a polyepoxide.

[0045] Further features and advantages of the present invention will be revealed by the following detailed description. [Modes for carrying out the invention]

[0046] In this patent application, the expression "included in..." should be understood to include boundary values.

[0047] We propose a method for preparing an epoxy prepolymer composition containing glycidyl ether, and this method consists of the following steps: a) A step of contacting dianhydrohexitol with another alcohol to obtain an alcohol composition, b) A step of reacting the alcohol composition obtained in step a) with an epihalohydrin to obtain a reaction mixture containing glycidyl ether. c) The process includes recovering an epoxy prepolymer composition containing glycidyl ether from the reaction mixture obtained at the end of step b).

[0048] Therefore, the first step (step a) of the method of the present invention consists of contacting dianhydrohexitol with another alcohol.

[0049] Dianhydrohexitol and other alcohols can be brought into contact by mixing the two compounds, for example by placing dianhydrohexitol and other alcohols in a solution, or by melting them if dianhydrohexitol and other alcohols are miscible in a liquid state, or by mixing them in a solid state, for example in powder form.

[0050] Dianhydrohexitols are heterocyclic compounds obtained by dehydrating two molecules of water from hexitol (e.g., iditol, mannitol, or sorbitol). Therefore, they are diols. Among dianhydrohexitols, isohexides correspond to 1,4:3,6-dianhydrohexitol and include isosorbide, isoidide, and isomannide.

[0051] In the method of the present invention, dianhydrohexitol is preferably isohexitol, more preferably selected from isosorbide, isomannide, and isoidide, with isosorbide being the most preferred.

[0052] In the method of the present invention, step b, in which the alcohol functional groups of dianhydrohexitol and other alcohols are reacted with an epihalohydrin, can be converted to glycidyl ether groups. In this step, oligomers can also be formed. Some of these oligomers contain dianhydrohexitol units or other alcohol units, while others contain mixtures of dianhydrohexitol units and other alcohol units.

[0053] Therefore, the reaction mixture at the end of step b contains an epoxy prepolymer composition comprising a glycidyl ether group supported by a dianhydrohexitol unit and a glycidyl ether group supported by another alcohol unit.

[0054] Unexpected effects can be obtained by mixing at least one dianhydrohexitol with at least one other alcohol in step a, or in other words, before step b, which involves reacting with the epihalohydrin.

[0055] In fact, the polyepoxide obtained by curing a curable composition containing the epoxy prepolymer composition obtained by the method of the present invention exhibits improved properties, such as water absorption properties, compared to the properties of the polyepoxide obtained by curing a corresponding curable composition obtained by mixing a dianhydrohexitol-based epoxy prepolymer with an epoxy prepolymer of another alcohol.

[0056] While we do not wish to limit the scope of the present invention to any theory, this unexpected improvement in polyepoxides can be considered to be related to the presence of oligomers containing both dianhydrohexitol units and other alcohol units in the epoxy prepolymer composition obtained by the method of the present invention.

[0057] In the method of the present invention, the other alcohol that is contacted with dianhydrohexitol in step a is preferably not dianhydrohexitol.

[0058] More preferably, other alcohols to be contacted with dianhydrohexitol in step a are the following alcohols, namely: - Trimethylolethane, - Trimethylolpropane, - Spiroglycol, - Tricyclodecane dimethanol, - Glycerol, - Hexane-1,6-diol, - C n Aliphatic diol, in the formula, n≧7, - Cyclohexane-1,m-dimethanol, where m=2,3 or 4, - Furan-p,q-dimethanol, where {p,q}={1,4}, {1,3} or {2,3}, - Thiophen-p,q-dimethanol, where {p,q}={1,4}, {1,3}, or {2,3}, - Isoborneol, - Dodecanol, or - Selected from Decanor.

[0059] In one embodiment of the method of the present invention, the other alcohol comprises at least two alcoholic functional groups.

[0060] If the other alcohol contains only one alcohol functional group, it may be incorporated only at the end of a chain in an oligomer containing both a dianhydrohexitol unit and the other alcohol unit, which is contained in the epoxy prepolymer composition obtained by the method of the present invention. If the other alcohol contains at least two alcohol functional groups, the epoxy prepolymer composition obtained by the method of the present invention may contain an oligomer containing a ...-dianhydrohexitol-glyceryl-other alcohol-glyceryl unit or a ...-dianhydrohexitol-glyceryl-other alcohol-glycidyl unit.

[0061] Preferably, the other alcohol to be contacted with dianhydrohexitol in step a of the method of the present invention is selected such that the polyepoxide based on the other alcohol has a lower water absorption rate than the polyepoxide based on dianhydrohexitol.

[0062] In other words, polyepoxides obtained by curing epoxy prepolymer compositions obtained by methods for etherification of other alcohols with epihalohydrins preferably have a lower water absorption rate than polyepoxides obtained by the same curing and etherification methods, except that other alcohols are replaced with dianhydrohexitol, which are measured by the same method.

[0063] In the method of the present invention, the other alcohol is preferably 1,4-cyclohexanedimethanol (CHDM).

[0064] In the method of the present invention, the ratio r(r=n) of the number of moles of dianhydrohexitol to the total number of moles of other alcohols and dianhydrohexitol is ジアンヒドロヘキシトール / (n ジアンヒドロヘキシトール +n 他のアルコール )) is preferably 0.05 to 0.95, more preferably 0.1 to 0.9.

[0065] In the method of the present invention, the epihalohydrin is preferably selected from epibromohydrin, epifluorohydrin, epiiodohydrin, and epichlorohydrin, with more preference being epichlorohydrin.

[0066] In the method of the present invention, step b, in which the alcohol functional group of dianhydrohexitol and other alcohols is reacted with an epihalohydrin, can be converted to a glycidyl ether group.

[0067] This can be done by any method known to those skilled in the art that can convert the alcohol functional group of dianhydrohexitol and other alcohols to a glycidyl ether group, for example, the method described in U.S. Patent No. 3,272,845, U.S. Patent No. 4,770,871, International Publication No. 2008 / 147472, International Publication No. 2008 / 147473, U.S. Patent Application Publication No. US3041,300, International Publication No. 2012 / 157832 and International Publication No. 2015 / 110758, preferably the method described in International Publication No. 2015 / 110758.

[0068] Therefore, in the method of the present invention, step b) of reacting the alcohol composition with the epihalohydrin is preferably the following step, namely, b1) A step of contacting an alcohol composition with an epihalohydrin to obtain a reaction mixture, b2) A step in which the reaction mixture obtained in step b1) is placed under vacuum to obtain a negative pressure of 100 millibars to 1,000 millibars. b3) The reaction mixture obtained in step b2) is heated at a temperature of 50°C to 120°C while maintaining the negative pressure, and the epihalohydrin is distilled. b4) The reaction mixture is maintained at the negative pressure and temperature, and a basic reagent is added to the reaction mixture obtained in step b3) over a period of 1 to 10 hours to perform azeotropic distillation of the water-epihalohydrin azeotropic mixture.

[0069] Step b1) of contacting the alcohol composition with the epihalohydrin is carried out in any apparatus known to those skilled in the art, which is capable of contacting chemical reagents and is equipped with heating and stirring components. For example, it may be a double-jacketed reactor. The apparatus in question must also be equipped with components for generating a partial vacuum and components for performing azeotropic distillation, such as a reverse Dean-Stark assembly with a condenser.

[0070] Epihalohydrins are preferably introduced in excess of the hydroxyl functional groups of the alcohols present in the alcohol composition (including dianhydrohexitol and other alcohols). Therefore, for every mole of hydroxyl functional groups, preferably 1 to 5 moles of epihalohydrins, more preferably about 2.5 moles of epihalohydrins are introduced.

[0071] Following this first step of contact (step b1), a vacuum pump is used to create a partial vacuum inside the apparatus, with a corresponding negative pressure of 100 millibars to 1,000 millibars (step b2). This means that the pressure inside the reactor is equal to the difference between atmospheric pressure (1,013 millibars) and the negative pressure (100 millibars to 1,000 millibars), or the pressure inside the reactor is 13 millibars to 913 millibars.

[0072] In one embodiment, step b2 is carried out to obtain a negative pressure of 300 to 900 millibars, particularly 500 to 800 millibars.

[0073] During step b3), the mixture is heated between the alcohol composition and the epihalohydrin at a temperature of 50°C to 120°C.

[0074] Preferably, the set temperature of the reactor's heating components must be adjusted to be at least equal to the boiling point of the epihalohydrin being used so that the distillation of the epihalohydrin begins. The boiling point to consider is the boiling point of the epihalohydrin at the pressure in the reactor.

[0075] During this first distillation step, the distillation is limited to the epihalohydrin. Furthermore, only a portion of the epihalohydrin is distilled. This distilled portion can be recovered, for example, in a reverse Dean-Stark and optionally reintroduced into the reaction mixture.

[0076] For example, epichlorohydrin has a boiling point of 116°C at atmospheric pressure, which is approximately equal to 80°C when the pressure in the reactor is 275 millibars (which corresponds to a negative pressure of 738 millibars). For convenience, the setpoint temperature of the reactor's heating components is adjusted to a temperature slightly higher (about 30°C higher) than the boiling point of the epichlorohydrin under consideration and the applied negative pressure.

[0077] During step b4), the basic reagent is added to the alcohol composition / epihalohydrin over a period of 1 to 10 hours.

[0078] The amount of the basic reagent is preferably a stoichiometric amount relative to the number of hydroxyl functional groups of the alcohol present in the alcohol composition. Nevertheless, it may be determined to be slightly in excess of this stoichiometric amount.

[0079] The basic reagent is preferably selected from lithium hydroxide, potassium hydroxide, calcium hydroxide, or sodium hydroxide, preferably in the form of an aqueous solution, and more preferably an aqueous solution of sodium hydroxide.

[0080] The OH group is introduced along with a basic reagent, depending on the number of moles of hydroxyl functional groups of the alcohol present in the alcohol composition. - The ratio of the number of moles is preferably 0.9 to 1.2.

[0081] As soon as the basic reagent is introduced (step b4), water is formed by the reaction between the alcohol composition and the epihalohydrin, just as additional water may be added by introducing the basic reagent in the form of an aqueous solution. Distillation is azeotropic distillation of the mixture of water and epihalohydrin. In other words, the water-epihalohydrin azeotropic mixture is distilled. After the distilled azeotropic mixture settles, the water is removed and the epihalohydrin is returned to the reaction medium. In the case of a reverse Dean-Stark apparatus, the water constitutes the upper phase from which it is removed, while the epihalohydrin in the lower phase is reintroduced into the reaction medium.

[0082] Azeotropic distillation is preferably continued until all water is removed. Therefore, the reaction medium is still heated for 30 minutes to 1 hour after the addition of the basic reagent is complete.

[0083] Preferably, a phase transfer catalyst is added during step b1). In this way, the viscosity of the produced product can be significantly reduced while maintaining a very high ratio of dianhydrohexitol diglycidyl ether to dianhydrohexitol monoglycidyl ether.

[0084] The phase transfer catalyst is preferably selected from tetraalkylammonium halides, sulfates, or bisulfates, and more preferably from tetrabutylammonium bromide or tetrabutylammonium iodide.

[0085] The amount of the phase transfer catalyst is preferably 0.01 to 5% by weight, more preferably 0.1 to 2% by weight, and even more preferably 1% by weight, relative to the total amount expressed by the sum of the masses of dianhydrohexitol and other alcohols. In this way, the EEW of the resulting epoxy prepolymer composition can be reduced very significantly.

[0086] Preferably, step c) includes filtering the reaction medium obtained at the end of step b) to obtain a filtrate containing the epoxy prepolymer composition. This filtration step can remove salts formed during the reaction between the epihalohydrin and the alcohol composition, for example, sodium chloride in the case of epichlorohydrin. The salts separated by filtration are preferably washed again with epihalohydrin. The first filtrate and the washed epihalohydrin are then combined to form a filtrate containing the epoxy prepolymer composition.

[0087] After the filtration step (including washing off the removed salt), preferably, a filtrate concentration step and / or a filtrate purification step are performed.

[0088] The concentration process can remove, for example, unreacted epihalohydrins and / or washed epihalohydrins. This can be done, for example, by vacuum distillation, or in a rotary evaporator and / or wiped film evaporator apparatus. During this concentration process, the crude product or epoxy prepolymer composition is gradually heated to, for example, 140°C, and the pressure is reduced to, for example, 1 millibar (corresponding to a negative pressure of 1,012 millibars).

[0089] The purification process can be carried out, for example, by vacuum distillation (corresponding to a pressure <1 millibar and negative pressure >1,012 millibars), and can be performed using a wipe-type heat exchanger to separate the oligomeric compound from the dianhydrohexitol diglycidyl ether compound or other alcohols. This process is different from that described in the previous paragraph.

[0090] In another aspect of the present invention, we propose an epoxy prepolymer composition that can be obtained by the method of the present invention.

[0091] The epoxy prepolymer composition obtained by the method of the present invention has the advantage of lower viscosity compared to dianhydrohexitol-based epoxy prepolymers obtained by the same method without adding another alcohol to dianhydrohexitol.

[0092] Beneficially, the epoxy prepolymer compositions obtained by the method of the present invention have a Brookfield viscosity of less than 4,000 mPa.s, preferably less than 1,000 mPa.s, as measured at 25°C, without requiring a purification step to separate the oligomer compound from the diglycidyl ether compound.

[0093] Low viscosity facilitates the molding and processability of epoxy prepolymers. For example, it facilitates the production of composite materials containing polyepoxide as a matrix by casting, coating, injection, impregnation, lamination, injection molding, pultrusion, or filament winding. Low viscosity also facilitates thin-layer deposition, spray gun use, and roller use when using polyepoxide as a coating or adhesive, for example.

[0094] Viscosity is measured using a Brookfield DV-II+ viscometer. Measurements are taken after stabilizing the medium, which has been maintained at 25°C using a thermostat-controlled water bath. Viscosity measurements are obtained as torque, as a percentage of the viscometer's maximum torque between 10% and 100%.

[0095] This application does not specify the speed at which Brookfield viscosity is measured. Those skilled in the art will know how to adjust it with respect to the rotor selection so that it falls within the range of 10–100% of the viscometer's maximum torque.

[0096] After preparation, the epoxy prepolymer composition of the present invention can be crosslinked to form a cured polyepoxide. It may be preferable to add a curing agent and / or accelerator to initiate or accelerate crosslinking.

[0097] In another aspect of the present invention, a curable composition comprising the epoxy prepolymer composition of the present invention is proposed, characterized in that it further comprises at least one accelerator and / or at least one curing agent.

[0098] The term "curable composition" is intended to mean a liquid mixture that can polymerize to form a crosslinked (cured) resin. For example, a curable composition containing an epoxy prepolymer is a liquid mixture that can polymerize to form a polyepoxide, and by definition, a polyepoxide is a crosslinked resin.

[0099] Preferably, the curable composition contains an amine-type curing agent.

[0100] The amine curing agent can be selected from, for example, the following: - Linear aliphatic diamines, specifically 1,2-diaminomethane, 1,3-diaminopropane, butane-1,4-diamine, pentane-1,5-diamine, 1,6-diaminohexane, or 1,12-diaminododecane, - Cyclic aliphatic diamines, specifically isophorone diamine (IPDA), 4,4'-diaminodicyclohexylmethane (PACM), 1,2-diaminocyclohexane (DACH), menthanediamine, or 1,3-bis(aminomethyl)cyclohexane (1,3BAC), - Aromatic diamines, specifically 4,4'-methylenebis(2-aminophenyl)fluorene (BAFL), diethyltoluenediamine (DETDA), dimethylaminophenylfluorene (BAFL), diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DMTDA), 4,4'-methylenebis(2-ethylaniline) (MOEA), m-xylenediamine, m-phenylenediamine (MPDA), or 4,4'-diaminodiphenylmethane. - Triamines, specifically diethylenetriamine (DTA), - Tetramines, specifically triethylenetetramine, - Pentamines, specifically tetraethylenepentamine, - Diamines of fatty acid dimers, specifically Croda's Priamine® 1074, - Polyetheramines, specifically poly(oxypropylene)diamine (Jeffamine® D-230 from Huntsman Petrochemical LLC), or poly(oxypropylene)triamine (Jeffamine® T-403 from Huntsman Petrochemical LLC), or - Any other polyamine, specifically polyethyleneimine (e.g., BASF's Lupasol® FG), dipropenediamine, diethylaminopropylamine, N-aminoethylpiperazine, dicyandiamide (Dicy), - Or a mixture thereof.

[0101] Preferably, the curing agent is isophorone diamine.

[0102] The epoxy / amine system formed by the curable composition of the present invention may be stoichiometric, or it may contain an excess of amine functional groups or an excess of epoxy functional groups.

[0103] Therefore, the ratio of the number of NH bonds in the formula of the curing agent (D) to the number of epoxy groups in the epoxy prepolymer composition is equal to 1:2 to 2:1, particularly 2:3 to 3:2, and more specifically 1:1 (stoichiometric mixture).

[0104] For example, a primary amine functional group contains two NH bonds. Therefore, there are four NH bonds in one molecule of isophorone diamine.

[0105] Preferably, in the curable composition of the present invention, the accelerator is selected from Lewis acids, tertiary amines, or imidazoles and their derivatives.

[0106] In one embodiment, in the curable composition of the present invention, the accelerator and / or curing agent are directly incorporated into the epoxy prepolymer composition. Therefore, the curable composition of the present invention is a one-component type (1K system).

[0107] In one embodiment, in the curable composition of the present invention, the accelerator and / or curing agent are packaged separately from the epoxy prepolymer composition. Therefore, the curable composition of the present invention is a two-component type (2K system).

[0108] In another aspect of the present invention, a polyepoxide obtained by curing the curable composition of the present invention is proposed.

[0109] The curing (i.e., crosslinking) of the curable composition of the present invention may occur spontaneously or may require heating or irradiation with UV radiation.

[0110] Specifically, the curable composition of the present invention is crosslinked at a temperature of 5°C to 260°C.

[0111] More specifically, the curable composition of the present invention may optionally undergo a curing cycle that includes one or more heating times at increasing temperatures between 30°C and 260°C, after a time at ambient temperature. For example, the curable composition of the present invention may undergo a curing cycle of 1 hour at 80°C followed by 2 hours at 180°C.

[0112] Preferably, the polyepoxide of the present invention has a glass transition temperature (Tg) of 70°C or higher, particularly 70°C to 210°C, and more specifically 90°C to 200°C.

[0113] The glass transition temperature of the polyepoxide of the present invention can be determined by techniques known to those skilled in the art, particularly by differential scanning calorimetry (DSC), for example, using a DSC Q20 instrument in an open crucible with a heating / cooling / heating cycle from 0°C to 200°C at 10°C / min, or by dynamic viscoelasticity measurement (DMA), for example, using an Anton Paar MCR501 rheometer with a tension clamp at a controlled temperature from 25°C to 250°C at 5°C / min and a frequency of 1 Hz.

[0114] Furthermore, the polyepoxide of the present invention has a water absorption rate of 15% or less, particularly 0.1% to 11%, more specifically 0.5% to 9.5%, preferably 1% to 9%, more specifically 1.5% to 8.5%, and even more specifically 2% to 8%.

[0115] The water absorption rate of polyepoxide is determined by measuring the mass of the sample before and after saturation with water obtained by immersing it in water for a sufficient amount of time at ambient temperature. For example, the water absorption rate of polyepoxide can be determined for a 50 mm × 25 mm × 2 mm parallelepiped sample immersed in water for 96 hours at ambient temperature according to the following formula.

[0116] [Formula 1]

number

[0117] Another aspect of the present invention proposes a composite material, coating material, or adhesive material comprising the polyepoxide of the present invention.

[0118] The composite material of the present invention may be a polyepoxide / fiber type composite material, and the fibers may be selected in particular from glass fibers, carbon fibers, basalt fibers, and plant fibers (flax, hemp).

[0119] The composite material of the present invention may be useful in the manufacture of structurally functional components in fields such as automobiles, ships, aerospace, or even sports and leisure. [Examples]

[0120] The water absorption rate of the sample is determined by immersing a 50mm x 25mm x 2mm parallelepiped sample in water at ambient temperature for 96 hours, according to the following formula.

[0121] [Formula 2]

number

[0122] The glass transition temperature (Tg) is determined by differential scanning calorimetry (DSC) under the following conditions. Equipment: DSC Q20 Place 10-20 mg of the product in an open crucible. Perform a heating / cooling / heating cycle from 0°C to 200°C at a rate of 10°C / min.

[0123] Viscosity is measured using a Brookfield DV-II+ rotational viscometer. Measurements are taken after stabilizing the medium, which has been maintained at 25°C using a thermostat-controlled water bath. Viscosity measurements are obtained as torque, as a percentage of the viscometer's maximum torque between 10% and 100%.

[0124] The epoxy equivalent weight (EEW) is measured according to ISO 3001 or ASTM D1652 standards.

[0125] Example 1: 100% Isosorbide (Comparative Example)

[0126] 200 g of isosorbide, 633 g of epichlorohydrin (5 molar equivalents relative to the diol), and 2 g of tetraethylammonium bromide (TEAB, 1% by mass relative to the mass of the diol) are placed in a 2.5 L double-jacketed reactor equipped with a reverse Dean-Stark with stirring blades and a container. The reaction medium is heated under a partial vacuum of 275 millibars (corresponding to a negative pressure of 1,013 - 275 = 738 millibars) maintained by a vane pump (setpoint temperature: 110°C). After distilling enough epichlorohydrin to fill the reverse Dean-Stark, 230 g of 50% by mass aqueous sodium hydroxide solution is introduced over 3 hours using a peristaltic pump. During the addition of sodium sulfate, the water introduced and formed during the reaction can be removed by distillation of the water-epichlorohydrin azeotrope mixture and separation in the Dean-Stark. After the addition of sodium sulfate is complete, the medium is heated and distilled until it reaches a temperature of 90°C. Once this temperature is reached, heating is stopped and the medium is allowed to cool to ambient temperature. The medium is then stripped and the salt formed during the reaction is filtered using porosity 3 sintered glass. The salt cake is then washed with 150 g of acetone. The filtrate is collected. The washing solvent and residual epichlorohydrin are removed by distillation under vacuum using a rotary evaporator. 338 g of a yellow, homogeneous, viscous oil is obtained. The results of the analysis performed on the obtained epoxy prepolymer are shown in Table 1. [Table 1]

[0127] Example 2: Isosorbide 25% / CHDM 75% (Example of the present invention)

[0128] 10 g of isosorbide, 29.3 g of CHDM, 126 g of epichlorohydrin (5 molar equivalents relative to the diol), and 400 mg of tetraethylammonium bromide (TEAB, 1% by mass relative to the diol) are placed in a 500 mL double-jacketed reactor equipped with a reverse Dean-Stark condenser and stirring blades. The reaction medium is heated under a partial vacuum of 275 millibars (corresponding to a negative pressure of 1,013 - 275 = 738 millibars) maintained by a vane pump (setpoint temperature: 110 °C). After distilling enough epichlorohydrin to fill the reverse Dean-Stark condenser, 45 g of 50% by mass aqueous sodium hydroxide solution is introduced over 3 hours using a peristaltic pump. During the addition of sodium sulfate, the water introduced and formed during the reaction can be removed by distillation of the water-epichlorohydrin azeotrope mixture and separation in the Dean-Stark condenser. After the addition of sodium sulfate is complete, the medium is heated and distilled until it reaches a temperature of 90°C. Once this temperature is reached, heating is stopped and the medium is allowed to cool to ambient temperature. The medium is then stripped and the salt formed during the reaction is filtered using porosity 3 sintered glass. The salt cake is then washed with 50 g of acetone. The filtrate is collected. The washing solvent and residual epichlorohydrin are removed by distillation under vacuum using a rotary evaporator. 67 g of a yellow, homogeneous, viscous oil is obtained. The results of the analysis performed on the obtained epoxy prepolymer are shown in Table 1.

[0129] Example 3: Isosorbide 75% / CHDM 25% (Example of the present invention)

[0130] 174.6 g of isosorbide, 58.2 g of CHDM, 644 g of epichlorohydrin (5 molar equivalents relative to the diol), and 2.32 g of tetraethylammonium bromide (TEAB, 1% by mass relative to the mass of the diol) are placed in a 2.5 L double-jacketed reactor equipped with a reverse Dean-Stark condenser with stirring blades and a condenser. The reaction medium is heated under a partial vacuum of 275 millibars (corresponding to a negative pressure of 1,013 - 275 = 738 millibars) maintained by a vane pump (setpoint temperature: 110°C). After distilling enough epichlorohydrin to fill the reverse Dean-Stark condenser, 235 g of 50% by mass aqueous sodium hydroxide solution is introduced over 3 hours using a peristaltic pump. During the addition of sodium sulfate, the water introduced and formed during the reaction can be removed by distillation of the water-epichlorohydrin azeotrope mixture and separation in the Dean-Stark condenser. After the addition of sodium sulfate is complete, the medium is heated and distilled until it reaches a temperature of 90°C. Once this temperature is reached, heating is stopped and the medium is allowed to cool to ambient temperature. The medium is then stripped and the salt formed during the reaction is filtered using porosity 3 sintered glass. The salt cake is then washed with 150 g of acetone. The filtrate is collected. The washing solvent and residual epichlorohydrin are removed by distillation under vacuum using a rotary evaporator. 352 g of a yellow, homogeneous, viscous oil is obtained. The results of the analysis performed on the obtained epoxy prepolymer are shown in Table 1.

[0131] The products from Examples 2 and 3 (25% isosorbide / 75% CHDM and 75% isosorbide / 25% CHDM, respectively) were crosslinked with isophoronediamine (IPDA).

[0132] Example 4: 5 grams of the product from Example 2 was mixed with 1.30 g of IPDA, followed by a curing cycle at 80°C for 1 hour, and then at 180°C for 2 hours.

[0133] Example 5: 5 grams of the product from Example 3 was mixed with 1.27 g of IPDA, followed by a curing cycle at 80°C for 1 hour, and then at 180°C for 2 hours.

[0134] The glass transition temperature and water absorption rate of the crosslinked product obtained in this manner were measured.

[0135] The results are shown in Table 2. [Table 2]

[0136] For comparison, crosslinking of an isosorbide / CHDM glycidyl ether mixture was performed. Therefore

[0137] Example 6: A 5-gram composition containing 25 mol% isosorbide diglycidyl ether (EEW ​​= 189 g / eq) and 75 mol% CHDM diglycidyl ether (EEW ​​= 159 g / eq) was vigorously mixed with 1.28 g of IPDA for 5 minutes, followed by a curing cycle in an oven at 80°C for 1 hour, followed by 180°C for 2 hours.

[0138] Example 7: A 5-gram composition containing 75 mol% isosorbide diglycidyl ether (EEW ​​= 189 g / eq) and 25 mol% CHDM diglycidyl ether (EEW ​​= 159 g / eq) was vigorously mixed with 1.17 g of IPDA for 5 minutes, followed by a curing cycle in an oven at 80°C for 1 hour, followed by 180°C for 2 hours.

[0139] The glass transition temperature and water absorption rate of the crosslinked product obtained in this manner were measured.

[0140] The results are shown in Table 2.

[0141] A comparison of the material of the present invention with a material manufactured from an epoxy prepolymer mixture shows that the first material has better water resistance (lower water absorption rate).

[0142] For comparison, isosorbide diglycidyl ether was crosslinked using IPDA. Therefore

[0143] Example 8: 5 grams of isosorbide diglycidyl ether (EEW ​​= 189 g / eq) was vigorously mixed with 1.12 g of IPDA for 5 minutes, followed by a curing cycle in an oven at 80°C for 1 hour, and then at 180°C for 2 hours.

[0144] A comparison of the material of the present invention with a polyepoxide obtained from isosorbide diglycidyl ether alone shows that the water resistance of the first material is significantly improved, while its heat resistance is reduced.

Claims

1. A method for preparing an epoxy prepolymer composition containing glycidyl ether, wherein the method comprises the following steps, namely, a) A step of contacting dianhydrohexitol with an alcohol selected from tricyclodecanedimethanol, hexane-1,6-diol, Cn aliphatic diol (wherein n≧7), and cyclohexane-1,m-dimethanol (wherein m=2, 3, or 4) to obtain an alcohol composition. b) A step of reacting the alcohol composition obtained in step a) with an epihalohydrin to obtain a reaction mixture containing glycidyl ether. c) A method comprising recovering the epoxy prepolymer composition containing glycidyl ether from the reaction mixture obtained at the end of step b).

2. The method according to claim 1, characterized in that the dianhydrohexitol is selected from isosorbide, isomannide, or isoidide.

3. The method according to claim 1 or 2, characterized in that the polyepoxide obtained by curing an epoxy prepolymer composition obtained by etherifying the alcohol composition with an epihalohydrin has a lower water absorption rate than the polyepoxide obtained by the same curing and etherification method except that all of the alcohols selected from tricyclodecanedimethanol, hexane-1,6-diol, Cn aliphatic diol (wherein n≧7), and cyclohexane-1,m-dimethanol (wherein m=2, 3, or 4) are replaced with dianhydrohexitol, as measured according to the method described below. (Method for measuring the water absorption rate of polyepoxides) For a 50 mm × 25 mm × 2 mm parallelepiped sample immersed in water at ambient temperature for 96 hours, the following formula is used to determine the result. Water absorption rate (%) = (Mass after immersion - Dry mass) / Dry mass

4. The epihalohydrin is characterized by being selected from epibromohydrin, epifluorohydrin, epiiodohydrin, epichlorohydrin, or a mixture thereof. The method described in any one of the requests 1 to 3.

5. Step b) of reacting the alcohol composition with an epihalohydrin is the following step, In other words, b1) A step of contacting the alcohol composition with an epihalohydrin to obtain a reaction mixture, b2) A step of placing the reaction mixture obtained in step b1) under vacuum to obtain a negative pressure of 100 millibars to 1,000 millibars. b3) The reaction mixture obtained in step b2) is heated at a temperature of 50°C to 120°C while maintaining the negative pressure, and the epihalohydrate is distilled. b4) The method according to any one of claims 1 to 4, comprising the step of adding a basic reagent to the reaction mixture obtained in step b3) over a period of 1 to 10 hours while maintaining the reaction mixture at the negative pressure and temperature, thereby performing azeotropic distillation of the water-epihalohydrin azeotropic mixture.

6. The method according to claim 5, characterized in that the basic reagent is selected from lithium hydroxide, potassium hydroxide, calcium hydroxide, or sodium hydroxide.

7. The method according to claim 5 or 6, characterized in that a phase transfer catalyst is added during step b1).

8. The method according to claim 7, characterized in that the phase transfer catalyst is selected from tetraalkylammonium halides, sulfuric acid, or bisulfate.

9. The method according to claim 7 or 8, characterized in that the amount of the phase transfer catalyst is 0.01 to 5% by weight of the total mass of dianhydrohexitol and an alcohol selected from tricyclodecanedimethanol, hexane-1,6-diol, Cn aliphatic diol (wherein n≧7), and cyclohexane-1,m-dimethanol (wherein m=2, 3, or 4).

10. The method according to any one of claims 1 to 9, characterized in that step c) includes filtering the reaction medium obtained at the end of step b) to obtain a filtrate containing the epoxy prepolymer composition.

11. A method for producing a curable composition containing an epoxy prepolymer composition, a) A step of contacting dianhydrohexitol with an alcohol selected from tricyclodecanedimethanol, hexane-1,6-diol, Cn aliphatic diol (wherein n≧7), and cyclohexane-1,m-dimethanol (wherein m=2, 3, or 4) to obtain an alcohol composition. b) A step of reacting the alcohol composition obtained in step a) with an epihalohydrin to obtain a reaction mixture containing glycidyl ether. c) A step of recovering the epoxy prepolymer composition containing glycidyl ether from the reaction mixture obtained at the end of step b), d) A step of obtaining a curable composition by adding at least one accelerator and / or at least one curing agent to the epoxy prepolymer composition obtained in step c), A method that includes this.

12. A method for producing polyepoxide, a) Dianhydrohexitol is converted to tricyclodecanedimethanol, hexane-1,6-diol, Cn aliphatic diol (wherein n≧7), and cyclohexane-1,m-dimethanol. A step of obtaining an alcohol composition by contacting it with an alcohol selected from (wherein m = 2, 3, or 4 in the formula), b) A step of reacting the alcohol composition obtained in step a) with an epihalohydrin to obtain a reaction mixture containing glycidyl ether. c) A step of recovering the epoxy prepolymer composition containing glycidyl ether from the reaction mixture obtained at the end of step b), d) A step of obtaining a curable composition by adding at least one accelerator and / or at least one curing agent to the epoxy prepolymer composition obtained in step c), e) A step of curing the curable composition to obtain a polyepoxide, A method that includes this.

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