Polythiol composition and preparation process thereof

Abstract

The present invention relates to a process for preparing polythiols from polyenes, and to polythiol compositions obtained from alicyclic polyenes or isocyanurate-type polyenes. a) A step of reacting a polyene with a thiocarboxylic acid in the presence of oxygen (O2) and at least one organic solvent to obtain a reaction medium containing a polythioester and the at least one organic solvent, and b) A step of performing a deprotection step to obtain a polythiol, which includes step a), Steps a) and b) are carried out by one-pot synthesis. Preparation process for polythiols.

Description

Technical Field

[0001] The present invention relates to a process for preparing a polythiol composition and to a polythiol composition obtained by this process.

Background Art

[0002] Polythiols are industrially very important molecules. They are used, for example, as crosslinking agents, especially at low temperatures.

[0003] Currently, there are several synthetic routes for obtaining polythiols. Among the most widely used methods, mention may be made of the reaction between a polyol and a mercapto acid (for example, described in US Patent Application Publication No. 2005 / 0153231). This reaction is easy and makes it possible to obtain various polythiol structures, but the resulting product generally has low resistance to hydrolysis because of the large number of ester groups present.

[0004] Alternatively, a molecule having no hydrolyzable functional group can be obtained by direct addition of hydrogen sulfide to a polyene by an acid or a photocatalyst. This additive is described in particular in International Publication No. 2012 / 018757. However, in this method, a large amount of sulfur-containing compounds can be by-produced, and problems with conversion can occur depending on the reactants used. Therefore, the resulting molecule can contain a large number of unreacted double bonds, which causes stability problems and reduces the overall content of -SH groups. For example, when the starting reagent is of the triene type, this is reflected in particular by the presence of a large amount of monothiol and / or dithiol in the resulting composition.

[0005] In fact, controlling and / or reducing the formation of these by-products, such as monothiols and / or dithiols, is important depending on the intended application. This is because their content affects the degree of crosslinking of the subsequently prepared material, particularly thermosetting materials produced from resins and polythiol-type curing agents. Thus, the degree of crosslinking has been shown to affect the physical properties and viscoelastic characteristics of the polymer, such as polymer density, elastic modulus, elastic limit, or glass transition temperature (Tg). Tg is conventionally determined by differential scanning calorimetry (DSC) or dynamic mechanical analysis (DM(T)A). These parameters are directly related to the behavior of the material, such as hardness, elasticity, flexibility, or tear strength.

[0006] In particular, in order to obtain materials with higher heat resistance (i.e., materials that maintain their properties over a wider temperature range), it is necessary to obtain polymers with high glass transition temperatures.

[0007] Therefore, there is a need for industrial preparation processes for polythiols that can control, and even maximize, the conversion of the C=C double bond to the -SH group. There is also a need for preparation processes for polythiols that can control, and even reduce, the formation of by-products (e.g., monothiols and / or dithiols in the case of trithiols or sulfides).

[0008] One technical solution involves using a polythioester intermediate. That is, the C=C double bond is converted to a -R'-C(O)-SR” type functional group, which is then deprotected to obtain the desired polythiol. However, these polythioester intermediates are technically difficult to use industrially. They are generally very viscous compounds, and in fact even solid. Therefore, they are difficult to handle for the deprotection process. Thus, they present many practical problems at an industrial level and are rarely used in practice.

[0009] Furthermore, these polythioesters are conventionally obtained by the reaction of polyenes with thiocarboxylic acids, particularly thioacetic acid. However, this reaction involves the use of a large excess of thiocarboxylic acid that must be removed before the deprotection step. Therefore, in order to carry out the subsequent deprotection step, a further step of evaporation of this excess thiocarboxylic acid and / or purification of the polythioester is required.

[0010] Therefore, an improved process is needed for the preparation of polythiols via polythioesters. A polythiol composition is needed in which the -SH group content is controlled, and in fact even maximized. The term "-SH group content" is understood to mean the ratio of the total weight of -SH groups to the total weight of the composition. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] The object of the present invention is to provide an improved process for the preparation of polythiol compositions that simplifies industrial implementation. The object of the present invention is to provide an improved process for preparing polythiol compositions in which the -SH group content is controlled, and in fact even maximized. Another object of the present invention is to provide an improved polythiol composition in which the content of -SH groups is controlled, and in fact even maximized. In particular, an object of the present invention is to provide a trithiol composition having a controlled, or in fact, even reduced, amount of dithiol. The object of the present invention is to provide a polythiol composition used for the preparation of polymers, preferably thermosetting polymers.

[0012] The present invention addresses the above objectives, either in whole or in part. [Modes for carrying out the invention]

[0013] The inventors have surprisingly discovered that it is possible to employ a “one-pot” process for the synthesis of polythiols. The term “one-pot process” is understood to mean a process in which the reaction intermediate (i.e., a polythioester as described herein) is not isolated from the reaction medium in order to carry out subsequent deprotection steps. Such a one-pot process offers many advantages in the context of the industrial synthesis of polythiols.

[0014] In particular, the polythioester intermediate formation step (hereinafter referred to as step a)) according to the present invention allows for the acquisition of a very good conversion rate (especially a conversion rate of 90% to 100% of the polyene) while avoiding the excessive use of thiocarboxylic acid. In fact, in conventional processes, a large excess of thiocarboxylic acid is used, which not only reduces process efficiency but also generates a large amount of waste that requires separation and treatment. Furthermore, since such excess amounts must be removed before the deprotection step, it is difficult to achieve compatibility with a "one-pot" process. The present invention makes it possible to avoid these drawbacks and brings not only economic advantages but also environmental advantages.

[0015] Another advantage of the present invention is that the reaction medium containing the polythioester intermediate obtained at the end of step a) can be easily stirred and handled. This can take the form of a viscous or slightly viscous liquid or suspension. Thus, handling difficulties at an industrial level are avoided. The reaction medium containing the polythioester intermediate is also compatible with the deprotection step (hereinafter referred to as step b), thereby simplifying the process. Therefore, steps a) and b) according to the present invention are carried out as a "one-pot" reaction. Consequently, intermediate steps for removing excess thiocarboxylic acid and / or purifying the polythioester intermediate, such as extraction, recrystallization and / or distillation, are unnecessary, and the process is significantly improved.

[0016] The polythiol compositions obtained by the process of the present invention are novel and are characterized by having a controlled, and in some cases maximized, -SH content. In particular, they have a high weight ratio as defined below.

number

[0017] Therefore, the present invention relates to a process for preparing polythiols, comprising the following steps. a) A step of reacting a polyene with a thiocarboxylic acid in the presence of oxygen (O2) and at least one organic solvent to obtain a reaction medium containing a polythioester and the at least one organic solvent, and b) A step of obtaining a polythiol by carrying out a deprotection step of the polythioester obtained in step a). Steps a) and b) are performed using a one-pot synthesis method.

[0018] The present invention also relates to a polythiol composition A obtained from an alicyclic polyene containing x C=C double bonds, wherein the composition is - A polythiol corresponding to the alicyclic polyene containing x -SH groups, and A thiol corresponding to the alicyclic polyene containing -(x-1) -SH groups, weight ratio

number

[0019] The present invention relates to a polythiol composition B obtained from an isocyanurate represented by the following general formula (I), [Chemical formula 1]

Chemical formula

Number

[0020] The term "alkyl" is understood to mean, in particular, a saturated, linear, branched or cyclic hydrocarbon radical containing 1 to 10, preferably 1 to 4 carbon atoms. The term "aryl" is understood to mean, in particular, a cyclic (monocyclic, bicyclic or tricyclic) aromatic hydrocarbon radical containing 6 to 10 carbon atoms, preferably phenyl or naphthyl, more preferably phenyl. The term "aralkyl" is understood to mean, in particular, an alkyl substituted by aryl, for example benzyl.

[0021] Polyene The term "polyene" is understood to mean any organic compound containing at least three C=C double bonds. The number of C=C double bonds in the polyene is hereafter referred to as "x," where x is an integer of 3 or more. Preferably, x is 3 to 10, more preferably 3 to 6, and more preferably 3 to 5. The polyene can be functionalized (i.e., it contains one or more chemical groups). The polyene may optionally contain one or more heteroatoms, such as halogens, silicon, oxygen, nitrogen, sulfur and / or phosphorus, and may optionally contain one or more chemical groups selected from halogens, -OH, -C(O)-, amines, amides, esters, ethers, ureas, thioethers, sulfoxides, sulfones, carbamates or thiocarbamates, preferably -OH or ethers, representing a linear, branched, cyclic or branched cyclic hydrocarbon chain.

[0022] Examples of such chemical groups include -OH, -C(O)-, -NH2, -NHR8, -NR8R9, -C(O)NH2, -C(O)NHR8, -C(O)NR8R9, -C(O)OH, -C(O)OR8, -NH-C(O)-NH2, -NH-C(O)-NHR8, -NH-C(O)-NR8R9, -NR7-C(O)-NH2, -NR7-C(O)-NHR8, and -NR7-C(O)-N Examples include R8R9, -NH-C(O)-OR8, -NR7-C(O)-OR8, -OC(=S)-NH2, -OC(=S)-NHR8, -OC(=S)-NR8R9, -SC(=O)-NH2, -SC(=O)-NHR8, -SC(=O)-NR8R9, -S(=O)R8, or -S(=O)2R8, where R7, R8, and R9 are independently selected from the alkyl groups defined above. The polyene may contain 4 to 40 carbon atoms, for example, 4 to 30, preferably 4 to 20, and more preferably 10 to 15 carbon atoms. It is particularly aliphatic (i.e., non-aromatic). Preferably, the polyene is The polyenes are selected from the aforementioned alicyclic polyenes and polyenes of general formula (I) as defined below.

[0023] Alicyclic polyene The term "alicyclic polyene" is understood to mean non-aromatic cyclic polyenes. They can be cyclic and branched, as in the case of trivinylcyclohexane. Preferably, they are not branched, and therefore their C=C double bonds are intraring double bonds. In particular, they are preferably formed from hydrocarbon chains containing 7 to 15 carbon atoms. Preferably, the alicyclic polyene is 1,5,9-cyclododecatriene (hereinafter referred to as 1,5,9-CDT or CDT). In particular, the isomers represented by the following formula can be cited. [ka] The cis, trans, trans-1,5,9-cyclododecatriene of the following formula is particularly preferred. [ka]

[0024] The following isocyanurate-type polyenes of general formula (I) [Chemical formula 1] [ka] In the formula, R is a linear or branched hydrocarbon chain containing at least one C=C double bond, which may optionally contain one or more heteroatoms such as oxygen, nitrogen, sulfur and / or phosphorus, and may optionally contain one or more chemical groups (in particular, the chemical groups described above). Preferably, R comprises a single C=C double bond and may optionally contain one or more heteroatoms, particularly oxygen. Preferably, R contains 2 to 15 carbon atoms, for example, 2 to 5 carbon atoms.

[0025] The following two compounds are particularly preferred. [Chemical formula 2] [ka] Triallyl isocyanurate (hereinafter referred to as TAIC) [Chemical formula 3] [ka] Trimetallyl isocyanurate In particular, the polyene is selected from CDT and TAIC.

[0026] Trien Preferably, the polyene is a triene. The term “triene” is understood to mean a polyene containing only three C=C double bonds (i.e., x=3), as defined above. This is specifically selected from the following: - Linear, branched, or alicyclic hydrocarbon trienes, and - A triene of general formula (I) as defined above, in which R contains a single C=C double bond. Specifically, within the Trien, Examples include trivinylcyclohexane, trivinylbenzene, cycloheptatriene, dimethylheptatriene, octatriene, cyclooctatriene, cyclododecatriene (CDT), triallyl isocyanurate (TAIC), triallyl cyanurate, trimetallyl isocyanurate, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, trimethylolpropane triallyl ether, and triallyamine. The preferred trienes according to the present invention are cyclododecatriene (CDT) and triallyl isocyanurate (TAIC).

[0027] Polythiol According to the present invention, the term "polythiol" refers to the polythiol corresponding to the starting polyene defined above. The term "corresponding to the starting polyene" is understood to mean that the structure of the starting polyene and the resulting polythiol are identical. However, C=C double bonds converted to -SH groups (i.e., -CH-C(SH)-) are an exception, and for x C=C double bonds in the starting polyene, x -SH groups are obtained (where x is defined above). The term "polythiol" also includes polythiols that are positional isomers of the double bonds of the starting polyene. The polythiols according to the present invention can also be called (x)thiols.

[0028] Polythioester intermediates The terms “polythioester intermediate” or “polythioester” are understood to mean the polythioester corresponding to the starting polyene. The term “corresponding to the starting polyene” is understood to mean that the structure of the starting polyene and the resulting polythioester are identical except for the C=C double bond converted to a -CH-C(SC(O)-R1)- group (R1 depends on the thiocarboxylic acid used, preferably R1 is methyl). For x C=C double bonds, x thioester groups are obtained, where x is defined above. The term “polythioester” also includes polythioesters that are positional isomers of the double bond of the starting polyene.

[0029] Process according to the present invention Process a) During step a), the polyene defined above is reacted with a thiocarboxylic acid in the presence of oxygen (O2) and at least one organic solvent to obtain a reaction medium containing the polythioester defined above and the at least one organic solvent. The reaction is as follows: R-CH=CH-R+R1-C(O)-SH → R-CH2-CH(SC(O)-R1)-R

[0030] Step a) is carried out in the presence of oxygen (O2), which acts as a reaction initiator. Therefore, step a) can be carried out in the presence of air, dilute air (a mixture of oxygen and nitrogen N2), or a mixture of oxygen and another inert gas. Oxygen can be introduced into the reaction medium by any technique. Oxygen may or may not be added throughout step a). In particular, oxygen is preferably blown into the reaction medium in the form of dilute air. For example, the dilute air passes through a frit or diffuser immersed in the reaction medium. Alternatively, oxygen can be bubbling into the reaction medium and nitrogen can be introduced into the gas phase of the reactor (i.e., the reactor headspace). The oxygen flow rate may be 0.01 to 100 Sl / h, preferably 0.05 to 10 Sl / h, more preferably 0.05 to 5 Sl / h, and particularly 0.05 to 2 Sl / h (standard liters / h). Step a) is carried out in the absence of any other reaction initiators, and more preferably in the absence of AIBN (azobisisobutyronitrile) and / or ultraviolet light.

[0031] Step a) is also carried out in the presence of an organic solvent or a mixture of organic solvents. A polar solvent or a mixture of polar solvents is particularly preferred. The solvent may be a polar protic solvent or a polar aprotic solvent. Among the usable solvents are alcohols, ethers (preferably cyclic ethers and glycol ethers, e.g., glycol dialkyl ethers), organochlorinating solvents, carboxylic acids, or mixtures thereof. Alcohols of the following general formula (IV) are particularly preferred. R4-OH (IV) In the formula, R4 represents an alkyl group as defined above. Preferably, the alcohol is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, n-butanol, butan-2-ol, isobutanol, and tert-butanol, and more preferably ethanol. Preferably, the solvent is selected from the group consisting of tetrahydrofuran (THF), 2-methyltetrahydrofuran (Me-THF), dioxane, chloroform, acetic acid, methanol, ethanol, isopropanol, n-propanol, n-butanol, butan-2-ol, isobutanol, tert-butanol, dimethoxyethane (also called grimm), diethoxyethane, dibutoxyethane, and mixtures thereof, with ethanol being more preferred.

[0032] The amount of solvent used is generally selected according to the desired viscosity of the reaction medium. Complete or partial dissolution can be achieved by those skilled in the art, depending on the target viscosity of the reaction medium. Preferably, 1 to 50 molar equivalents, more preferably 1 to 20 molar equivalents, of solvent is used relative to the polyene. The solvent can be added completely or partially from the beginning of step a). During step a), it may be added all at once, in multiple steps (semi-continuously), or in stages (continuously).

[0033] Thiocarboxylic acids are preferably represented by the following general formula (II). R1-C(O)-SH (II) During the ceremony, R1 represents an alkyl radical, aryl radical, or aralkyl radical as defined above. Preferably, R1 is selected from methyl, ethyl, and benzyl. Thioacetic acid in which R1 is methyl is very particularly preferred according to the present invention (hereinafter also referred to as TAA). For example, when thioacetic acid is used, polythioacetate is obtained as a polythioester intermediate.

[0034] According to one embodiment, thiocarboxylic acids can be produced in situ (see U.S. Patent No. 3,270,063, Thompson Chemical Co., 1963, “Methods of Making Primary Mercaptans”), and thioacetic acid can be produced from acetic anhydride and hydrogen sulfide in the presence of a catalyst. Preferably, in order to carry out step a), the thiocarboxylic acid and solvent are first introduced into the reactor, and then oxygen is introduced, for example, by bubbling air. After that, the polyene can be added to the reaction medium. The temperature in step a) may be 5°C to 80°C, preferably 5°C to 50°C, more specifically 5°C to 25°C, for example 5°C to 10°C. Step a) is generally carried out at atmospheric pressure. The molar ratio of thiocarboxylic acid to double bond in the polyene may be 1 to 20, preferably 1 to 10, for example 1 to 5, and more preferably 1 to 3.

[0035] By step a), the polythioester intermediate defined above can be formed starting from a polyene. Therefore, the reaction medium obtained at the end of step a) may include the following: - The polythioester intermediate defined above, - The solvent or mixture of solvents as defined above, - By-products, such as (x-1) polythioesters, and - Cases where there are one or more unreacted reactants. The term "(x-1) polythioester" is understood to mean a compound containing x-1 thioester groups, where x is as defined above. This is a compound that retains a C=C double bond (i.e., an unreacted C=C double bond). Therefore, the reaction medium may contain 10% to 85% by weight of the polythioester intermediate relative to the total reaction medium. The reaction medium may contain 15% to 90% by weight of the solvent relative to the total amount of the reaction medium.

[0036] Step b) A polythiol can be obtained by deprotecting the polythioester intermediate obtained in step a) in step b). This can be done by any means known to those skilled in the art. Since steps a) and b) are carried out in a one-pot synthesis according to the present invention, it is understood that the reaction medium containing the polythioester obtained at the end of step a) is retained for carrying out the deprotection step b). Thus, steps a) and b) are carried out in the presence of the same solvent (or solvent mixture). The solvent (or solvent mixture) can be further added during step b). In particular, the process according to the present invention does not include a step of separation and / or extraction and / or washing of the (organic) phase containing the polythioester between steps a) and b). In particular, there is no intermediate step of purification of the polythioester. More specifically, there is no step of recrystallization and / or distillation of the polythioester.

[0037] Deprotection (b) can be carried out by conventional methods using a base or acid, a Dy(OTf)3 type catalyst (Liang et al., Asian J. Org. Chem., 10.1002 / ajoc.201700481), or a quaternary ammonium cyanide salt type compound (see U.S. Patent No. 7,173,156). Preferably, deprotection b) is basic deprotection in the presence of the alcohol defined above. This is generally carried out by adding an alkaline hydroxide, preferably NaOH or KOH. The addition can be done dropwise. The deprotection step b) may also preferably be acidic deprotection in the presence of the alcohol defined above. This can be done using hydrochloric acid, methanesulfonic acid, or methanesulfonic anhydride. When the deprotection is acidic, it is preferable to use the alcohol defined above as the solvent.

[0038] sulfonic acid The sulfonic acid is preferably an organic sulfonic acid, and preferably an anhydrous one. Sulfonic acids may be of the following general formula (III). R2-SO3H (III) In the formula, R2 represents the following: -1 or more identical or different halogen atoms are optionally substituted in whole or in part, preferably an alkyl radical as defined above, or - Preferably an aryl radical as defined above, which is optionally substituted with a linear or branched saturated hydrocarbon chain containing 1 to 4 carbon atoms. The halogen atom can be selected from fluorine, chlorine, and bromine. In particular, the alkyl can be perhalogenated, and more specifically, perfluorinated. Preferably, the sulfonic acid is an alkanesulfonic acid, which is preferably an anhydride (wherein R2 is alkyl).

[0039] Therefore, sulfonic acids (and their anhydrous forms) Methanesulfonic acid, ethanesulfonic acid, n-propanesulfonic acid, isopropanesulfonic acid, n-butanesulfonic acid, isobutanesulfonic acid, sec-butanesulfonic acid, tert-butanesulfonic acid, trifluoromethanesulfonic acid, para-toluenesulfonic acid, benzenesulfonic acid, and mixtures thereof in any proportion of two or more of these. You can choose from these options. In a particularly preferred embodiment, the sulfonic acid used in the context of the present invention is methanesulfonic acid (MSA) or methanesulfonic anhydride (AMSA).

[0040] The sulfonic acid may or may not be supported. Preferably, it is not supported. When supported, for example, a styrene-divinylbenzene copolymer type sulfonated resin, such as Amberlyst® 15 resin or Nafion®, can be used. For example, 0.1 to 10 equivalents of acid are used in polythioesters. For example, 3 to 60 equivalents (molar equivalents), preferably 3 to 20 equivalents of alcohol, are used in the polythioester.

[0041] The deprotection step b) can be carried out at a temperature of 10°C to 100°C, preferably 25°C to 80°C, and more preferably 40°C to 80°C. This is generally carried out at atmospheric pressure. Steps a) and b) can be carried out in the same reactor. For example, a batch reactor can be used.

[0042] The subsequent conventional recovery and / or purification steps of the polythiol obtained at the end of step b) can be carried out according to the desired degree of purity. For example, if deprotection is carried out by the addition of a base, the reaction medium may be subsequently acidified; conversely, if deprotection is carried out by the addition of an acid, the reaction medium may be basicized. Subsequently, the resulting organic phase containing various thiols (particularly polythiols and (x-1)thiols) can be extracted and, if desired, concentrated. Therefore, in particular, the resulting polythiol may be in the form of a polythiol composition described below.

[0043] Composition according to the present invention When preparing polythiols from polyenes having x C=C double bonds, the reaction in which these double bonds are converted to -SH groups generally does not proceed completely, and byproducts may be generated at each step, regardless of the process used. Therefore, according to the present invention, the term "polythiol" refers to a polythiol that corresponds to the starting polyene and contains x -SH groups. For example, trimercaptocyclododecane corresponds to cyclododecatriene. In this case, the x C=C double bonds of the starting material are completely converted to -SH groups.

[0044] According to the present invention, the term "(x-1) thiol" refers to a thiol containing (x-1) -SH groups that corresponds to the starting polyene. The term "corresponding to the starting polyene" is understood to mean that the structure of the resulting starting polyene and the (x-1) thiol are identical, except for the x C=C double bonds that have been converted into (x-1) -SH groups. In this case, the conversion of the C=C double bonds to -SH groups is incomplete, and one -SH group is missing. The C=C double bonds that are not converted to -SH groups can take the following forms in particular. - Still in the form of a C=C double bond, or - The form of the unprotected thioester group. Therefore, although (x-1) thiols can have different structures, unless otherwise specified, they are grouped under a general name characterized by the number of -SH groups. This includes (x-1) thiols that are positional isomers of the double bond of the starting polyene.

[0045] Therefore, a polythiol composition obtained from a polyene having x C=C double bonds, - A polythiol corresponding to the polyene containing x -SH groups, and -(x-1) -SH groups - a thiol corresponding to the polyene, A polythiol composition containing the above can be obtained. Such compositions may optionally contain other by-products or impurities (e.g., monothiols).

number

[0046] In particular, the trithiol composition can be obtained from trienes, and the trithiol composition is - The corresponding trithiol, and - Includes the corresponding dithiol. For example, in the case of a polythiol formed from cis, trans, or trans-1,5,9-cyclododecatriene as the starting polyene, the following dithioester can be obtained as a by-product from step a). [Chemical formula 4] [ka]

[0047] During step b), deprotection may not be completed. Therefore, according to the process of the present invention, it is possible to form the following: - (x-1) thiol from the (x-1) thioester formed in step a), and / or - (x-1) thiols from polythioesters that are not completely deprotected. Therefore, in the case of CDT, the following dithiols can be obtained at the end of step b). [Chemical formula 5] [ka]

[0048] Composition A obtained from an alicyclic polyene The present invention relates to a polythiol composition A obtained from an alicyclic polyene as defined above, which contains x C=C double bonds, wherein the polythiol composition is - A polythiol corresponding to the alicyclic polyene containing x -SH groups, and It contains a thiol corresponding to the alicyclic polyene containing (x-1) -SH groups (also referred to as an (x-1) thiol as described above), x is defined above. In particular, composition A contains at least 85% by weight, preferably at least 90% by weight, and more preferably at least 95% by weight of the polythiol, based on the total weight of composition A. In particular, composition A contains less than 9% by weight, preferably less than 5% by weight, and more preferably less than 1% by weight of the (x-1)thiol, based on the total weight of composition A.

[0049] Preferably, the weight ratio of composition A

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[0050] In particular, the present invention relates to a polythiol composition A obtained from the cyclododecatriene defined above, wherein the polythiol composition is - Trimercaptocyclododecane, - Dimercaptocyclododecene, and Contains -S-[bis(sulfanyl)cyclododecyl]ethanethioate. Therefore, the weight ratio [trimercaptocyclododecane / (dimercaptocyclododecene + S-[bis(sulfanyl)cyclododecyl]ethanethioate)] is as specifically defined above.

[0051] Composition B obtained from isocyanurate-type polyenes The present invention also relates to the polythiol composition B defined above, which is obtained from an isocyanurate of the following general formula (I). [Chemical formula 1] [ka] In the formula, R is a linear or branched hydrocarbon chain containing at least one C=C double bond, and may optionally contain one or more heteroatoms such as oxygen, nitrogen, sulfur and / or phosphorus, and may optionally contain one or more chemical groups. The aforementioned composition, - A polythiol corresponding to the isocyanurate containing x -SH groups, and The isocyanurate contains -(x-1) -SH groups, and the (x-1) thiol corresponds to the isocyanurate, x is defined as described above. In particular, composition B contains at least 70% by weight, preferably at least 80% by weight, and more preferably at least 90% by weight of the polythiol, for example, at least 95% by weight of the polythiol, based on the total weight of composition B. In particular, composition B contains less than 30% by weight, preferably less than 20% by weight, more preferably less than 10% by weight, for example less than 5% by weight, and in practice less than 1% by weight of the (x-1) thiol, based on the total weight of composition B.

[0052] Preferably, the weight ratio of composition B

number

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[0053] The preferred starting isocyanurate is triallyl isocyanurate. In particular, the above-defined polythiol composition B is obtained from triallyl isocyanurate, and the composition is -1,3,5-Tris(3-mercaptopropyl)-1,3,5-triazinan-2,4,6-trione and its isomers, and - Includes the corresponding dithiols (B1) and (B2) of the following formulas, as well as their isomers. [Chemical formula 6] [ka] [Chemical formula 7] [ka] Therefore, the weight ratio [(1,3,5-tris(3-mercaptopropyl)-1,3,5-triazinan-2,4,6-trione) / (B1+B2)] is as specifically defined above.

[0054] The above composition is novel and therefore forms part of the present invention. The present invention also relates to the polythiol composition that can be obtained, obtained, or directly obtained by the process according to the present invention. The present invention also relates to polythiols obtained by or directly by the process according to the present invention.

[0055] Unless a specific isomer is mentioned, the name of a compound is understood to include all of its possible positional isomers. A given range such as "X~X" is understood to include both an upper and lower limit. The following examples are given for illustrative purposes only and are not intended to limit the present invention. [Examples]

[0056] Example 1: One-pot synthesis of polythiol compositions from CDT according to the present invention, with basic deprotection. Process a) 155 g (2.04 mol) of TAA (thioacetic acid) is introduced into a 1-liter jacketed reactor. The medium is left to stand at 5°C with stirring, and then 28.4 g (0.62 mol) of ethanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, 100 g (0.62 mol) of 1,5,9-cyclododecatriene (CDT) is added dropwise via a peristaltic pump over approximately 1 hour. Once the addition is complete, 113.6 g (2.47 mol) of ethanol is added to the reaction medium. The reaction medium is stirred continuously at 5°C for almost an entire night. GC / FID analysis demonstrates the complete conversion of 1,5,9-cyclododecatriene. Cut off the air supply.

[0057] Basic deprotection step b) Next, 171 g of ethanol is added to the reaction medium. Then, the reaction medium is degassed under nitrogen for 1 hour, and then the temperature is raised to approximately 40°C. 177 g of 46% sodium hydroxide aqueous solution, which has been degassed beforehand, is added via a dropping funnel. The reaction medium is stirred under nitrogen at 40°C for 2-3 hours.

[0058] Recovery process Subsequently, the reaction medium is cooled to 20°C, and then 200 g (2.03 mol) of 37% HCl is added dropwise to the medium via a peristaltic pump. The organic phase containing thiols is removed. The aqueous phase is extracted with 105 g (1.24 mol) of dichloromethane. The organic phase is then combined, washed four times with 14.8 g (0.82 mol) of water, and then concentrated using a rotary evaporator.

[0059] GC / FID analysis demonstrates complete conversion of trithioacetate. The resulting composition contains the following: - 0.36% dithiol corresponding to CDT with one residual double bond, - 0.47% dithiol monothioacetate corresponding to CDT, -95.87% trimercaptocyclododecane, and - Remaining impurities (100%). weight ratio

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[0060] Example 2 One-pot synthesis of polythiol compositions from CDT according to the present invention using acidic (AMSA and ethanol) deprotection. Process a) 155 g (2.04 mol) of TAA is introduced into a 1-liter jacketed reactor. The medium is left to stand at 5°C with stirring, and then 29 g (0.63 mol) of ethanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, 100 g (0.62 mol) of 1,5,9-cyclododecatriene is added dropwise via a peristaltic pump over approximately 1 hour. Once the addition is complete, 113.6 g (2.47 mol) of ethanol is added to the reaction medium. The reaction medium is stirred continuously at 5°C for almost an entire night. GC / FID analysis demonstrates the complete conversion of 1,5,9-cyclododecatriene. Cut off the air supply.

[0061] Acidic deprotection step b) Raise the temperature of the reaction medium to 20°C and add 85 g (1.85 mol) of ethanol to the reaction medium. Add 74 g (0.77 mol) of methanesulfonic anhydride dropwise through a dropping funnel. Stir the medium under reflux under nitrogen for 10 hours.

[0062] Recovery process Subsequently, the reaction medium is cooled to 20°C, and then 154 g (0.77 mol) of a pre-degassed 20% NaOH solution is added dropwise to the medium via a peristaltic pump. The organic phase containing thiols is removed. The aqueous phase is extracted with 105 g (1.24 mol) of dichloromethane. The organic phases are combined, then washed four times with 14.8 g (0.82 mol) of water, and then concentrated using a rotary evaporator.

[0063] GC / FID analysis demonstrates complete conversion of trithioacetate. The resulting composition contains the following: - 5.26% dithiol corresponding to CDT with one residual double bond, - 0.58% dithiol monothioacetate corresponding to CDT, -90.60% trimercaptocyclododecane, and - Remaining impurities (100%). weight ratio

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[0064] Example 3: One-pot synthesis of polythiol compositions from TAIC according to the present invention, with basic deprotection. Process a) 101 g (1.33 mol) of TAA is introduced into a 1-liter jacketed reactor. The medium is left to stand at 5°C with stirring, and then 92 g (2.00 mol) of ethanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, 100 g (0.40 mol) of triallyl isocyanurate (TAIC) dissolved in 19 g (0.41 mol) of ethanol is added dropwise via a peristaltic pump over approximately 40 minutes. After the addition is complete, 148 g (3.21 mol) of ethanol is gradually added to the reaction medium. The reaction medium is stirred continuously at 5°C for approximately 6 hours. GC / FID or HPLC / UV analysis demonstrates the complete conversion of triallyl isocyanurate. Cut off the air supply.

[0065] Basic deprotection step b) Subsequently, the reaction medium is degassed with nitrogen for 1 hour, and then 115.1 g of a 46% sodium hydroxide aqueous solution, which has been degassed beforehand, is added dropwise through a dropping funnel. The reaction medium is stirred under nitrogen at 25°C for 5 hours, and then cooled to 10°C for approximately 17 hours.

[0066] Recovery process The reaction medium is then cooled to 20°C, and 483 g (1.32 mol) of 10% HCl solution is added dropwise to the medium via a peristaltic pump. The organic phase containing thiols is removed. The aqueous phase is extracted three times with 68 g (0.80 mol) of dichloromethane. The organic phases are combined, then washed twice with 14.4 g (0.80 mol) of water, and then concentrated using a rotary evaporator.

[0067] GC / FID analysis demonstrates complete conversion of trithioacetate. A polythiol composition is obtained that contains 95% by weight of trithiol corresponding to the TAIC and approximately 0.2% by weight of dithiol corresponding to the TAIC, relative to the total weight of the composition. weight ratio

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[0068] Example 4 One-pot synthesis of polythiol compositions from CDT according to the present invention using acidic (HCl and methanol) deprotection. Process a) 155 g (2.04 mol) of TAA is introduced into a 3-liter jacketed reactor. The medium is left to stand at 5°C with stirring, and then 19.8 g (0.62 mol) of methanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, 100 g (0.62 mol) of 1,5,9-cyclododecatriene is added dropwise via a peristaltic pump over approximately 1 hour. After the addition is complete, 78.9 g (2.46 mol) of methanol is added to the reaction medium. The reaction medium is stirred continuously at 5°C for almost an entire night. GC / FID analysis demonstrates the complete conversion of 1,5,9-cyclododecatriene. Cut off the air supply.

[0069] Acidic deprotection step b) The reaction medium is heated to 20°C, and 1119 g (34.93 mol) of methanol is added to the reaction medium. The reaction medium is heated to 40°C, and 576.9 g (5.85 mol) of 37% HCl is added dropwise via a peristaltic pump. The reaction medium is then heated under nitrogen and refluxed for 48 hours.

[0070] Recovery process Subsequently, the reaction medium is cooled to 20°C, the organic phase containing thiols is removed, and then 105 g (1.24 mol) of dichloromethane is added to the aqueous phase. The organic phases are combined, then washed four times with 74 g (4.11 mol) of water, and then concentrated using a rotary evaporator.

[0071] GC / FID analysis demonstrates complete conversion of trithioacetate. A polythiol composition is obtained containing 96.28% trimercaptocyclododecane and 0.25% dithiol corresponding to CDT. weight ratio

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[0072] Example 5 One-pot synthesis of polythiol compositions from CDT according to the present invention using acidic deprotection (HCl and ethanol) Process a) 774.0 g (10.17 mol) of TAA is introduced into a 3-liter jacketed reactor. The reaction medium is stirred at 5°C, and then 142.0 g (3.08 mol) of ethanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, 500 g (3.08 mol) of 1,5,9-cyclododecatriene is added dropwise via a peristaltic pump over approximately 4 hours and 30 minutes. After the addition is complete, 851.7 g (18.49 mol) of ethanol is added to the reaction medium. The reaction medium is stirred continuously at 5°C for almost an entire night. GC / FID analysis demonstrates the complete conversion of 1,5,9-cyclododecatriene. Cut off the air supply.

[0073] Acidic deprotection step b) The temperature of the reaction medium is raised to 20°C, and 1478.6 g (30.81 mol) of 96% ethanol is added to the reaction medium. The reaction medium is heated to 40°C, and 910.9 g (9.24 mol) of 37% HCl is added dropwise via a peristaltic pump. The reaction medium is then heated under nitrogen and refluxed for 22 hours.

[0074] Recovery process Subsequently, the reaction medium was cooled to 30°C, the organic phase containing thiols was removed, and then 261.7 g (3.08 mol) of dichloromethane was added to it. Next, the obtained organic phase was washed four times with 110.9 g (6.16 mol) of water, and then concentrated using a rotary evaporator.

[0075] GC / FID analysis demonstrates complete conversion of trithioacetate. A polythiol composition is obtained containing 94.84% trimercaptocyclododecane and 5.17% dithiol corresponding to CDT. weight ratio

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[0076] Example 6 One-pot synthesis of polythiol compositions from TAIC according to the present invention using acidic deprotection (HCl and ethanol) Process a) 302.3 g (3.97 mol) of TAA is introduced into a 3-liter jacketed reactor. The reaction medium is stirred at 5°C, and then 166.3 g (3.61 mol) of ethanol is rapidly added. Air is blown into the reaction medium through the frit at a flow rate of approximately 0.4 Sl / h, and nitrogen is blown into the reactor headspace at a flow rate of approximately 4 Sl / h. Next, a solution of 27.7 g (0.60 mol) of ethanol and 300 g (1.20 mol) of triallyl isocyanurate is added dropwise through a peristaltic pump over approximately 1 hour and 15 minutes. Once the addition is complete, 221.8 g (4.81 mol) of ethanol is gradually added to the reaction medium. The reaction medium is stirred continuously at 5°C for approximately 6 hours. GC / FID or HLPC / UV analysis demonstrates the complete conversion of triallyl isocyanurate. Cut off the air supply.

[0077] Acidic deprotection step b) The temperature of the reaction medium is raised to 20°C, and 462.1 g (9.63 mol) of 96% ethanol is added to the reaction medium. The reaction medium is heated to 40°C, and 355.8 g (3.61 mol) of 37% HCl is added dropwise via a peristaltic pump. The reaction medium is then heated under nitrogen and refluxed for 28 hours.

[0078] Recovery process Subsequently, the reaction medium was cooled to 30°C, the organic phase containing thiols was removed, and then 102.2 g (1.20 mol) of dichloromethane was added to it. Next, the obtained organic phase is washed four times with 43 g (2.41 mol) of water, and then concentrated using a rotary evaporator.

[0079] HPLC / UV analysis demonstrates complete conversion of trithioacetate. A polythiol composition is obtained that contains a trithiol corresponding to 95.16% by weight and a dithiol corresponding to approximately 0.2% by weight, relative to the total weight of the composition. weight ratio

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[0080] Example 7 Application Test Two polythiol compositions derived from triallyl isocyanurate (TAIC) were prepared for application testing. The trithiol / dithiol mass ratio and -SH group content of these compositions are shown in the table below. [Table 1] Polythiol composition P1 was obtained according to Example 6. The same procedure as described in Example 6 was used, but instead of oxygen, AIBN (azobisisobutyronitrile) was used as an initiator, and the mixture was heated at 65°C during step a) to prepare polythiol composition P2.

[0081] Polythiol compositions P1 and P2 were used as curing agents for epoxy resin (Araldite® LY556, Huntsman) with a tertiary amine (DABCO® 33-LV, Sigma-Aldrich) as a catalyst. Curing was performed at room temperature (i.e., 25°C) using a stoichiometric amount of thiol groups relative to the epoxy groups. The amounts used are summarized in the table below. [Table 2]

[0082] The mixture was prepared in an aluminum cup. Specifically, the amounts of Araldite® LY556, polythiol, and amine were weighed separately. The mixture was quickly mixed with a spatula. The composition began to harden within minutes and was left at room temperature for 7 days. Rods were taken from each hardened composition and placed on a rectangular torsion assembly fixed to an ARES rheometer (Rheometer Scientific) for dynamic mechanical analysis (DMA). The samples underwent sinusoidal deformation at a frequency of 1 Hz over a temperature range varying from -50°C to 110°C. The glass transition temperature (Tg) was determined by the maximum value of the mechanical loss coefficient (tan delta). This value and the modulus of elasticity at the plateau were recorded and summarized in the table below. [Table 3]

[0083] Therefore, by using the polythiol composition P1 according to the present invention in epoxy resin, a crosslinked and high-density network can be obtained. The resin obtained in this way has a higher Tg and a higher plateau modulus.

Claims

1. a) Polyene, oxygen (O ２ ) and a step of reacting with a thiocarboxylic acid in the presence of at least one organic solvent to obtain a reaction medium containing a polythioester and the at least one organic solvent, b) A step of performing a deprotection step on the polythioester obtained in step a) to obtain a polythiol, Steps a) and b) are performed in one-pot synthesis. Preparation process for polythiols.

2. The deprotection step b) is basic deprotection, preferably carried out by the addition of an alkali hydroxide. The preparation process according to claim 1.

3. Deprotection step b) is preferably acidic deprotection in the presence of an alcohol. The preparation process according to claim 1.

4. The reaction medium contains 15% to 90% by weight of the solvent relative to the total amount of the reaction medium at the end of step a), The preparation process according to any one of claims 1 to 3.

5. The organic solvent is selected from the group consisting of alcohols, ethers, organochlorinating solvents, carboxylic acids, and mixtures thereof. The preparation process according to any one of claims 1 to 4.

6. The aforementioned organic solvent is of the following general formula (IV) R ４ -OH(U) Selected from the alcohols, In the formula, R ４ This represents a linear, branched, or cyclic saturated hydrocarbon group containing 1 to 10, preferably 1 to 4, carbon atoms. The preparation process according to any one of claims 1 to 5.

7. The thiocarboxylic acid is thioacetic acid. The preparation process according to any one of claims 1 to 6.

8. The aforementioned polyene is a triene. The preparation process according to any one of claims 1 to 7.

9. The aforementioned polyene is given by the following general formula (I) 【Chemistry 1】 Selected from alicyclic polyenes and isocyanurate polyenes, In the formula, R is a linear or branched hydrocarbon chain containing at least one C=C double bond, and may optionally contain one or more heteroatoms such as oxygen, nitrogen, sulfur and / or phosphorus, and may optionally contain one or more chemical groups. The preparation process according to any one of claims 1 to 8.

10. A polythiol composition A obtained from an alicyclic polyene containing x C=C double bonds, - A polythiol corresponding to the alicyclic polyene containing -x -SH groups, and A thiol corresponding to the alicyclic polyene containing -(x-1) -SH groups, weight ratio [Math 1] The ratios range from 10.1:1 to 50,000:

1. x is an integer greater than or equal to 3. Polythiol composition A.

11. The alicyclic polyene is cyclododecatriene, preferably its cis, trans, or trans-1,5,9-cyclododecatriene isomers. The polythiol composition A according to claim 10.

12. The following general formula (I) 【number】 Polythiol composition B obtained from isocyanurate, In the formula, R is a linear or branched hydrocarbon chain containing at least one C=C double bond, and may optionally contain one or more heteroatoms such as oxygen, nitrogen, sulfur and / or phosphorus, and may optionally contain one or more chemical groups. The aforementioned composition, - A polythiol corresponding to the isocyanurate containing -x -SH groups, and A thiol corresponding to the isocyanurate containing -(x-1) -SH groups, weight ratio [Math 2] The ratio is between 2:1 and 50,000:1, and x is an integer greater than or equal to 3. Polythiol composition B.

13. The isocyanurate is trially isocyanurate. The polythiol composition B according to claim 12.

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