Method for preparing norbornene dicarbonitrile, and optical material intermediate composition comprising same

Abstract

The present invention relates to a method for preparing norbornene dicarbonitrile, which is an isocyanate intermediate, and an optical material norbornene dicarbonitrile intermediate composition comprising same. In particular, the present invention relates to: a method for preparing norbornene dicarbonitrile, which is used as an intermediate for preparing 2,3-bis (isocyanomethyl) bicyclo [2,2,1] heptane from among isocyanates; and an intermediate composition comprising norbornene dicarbonitrile.

Description

Method for producing norbornene dicarbonitrile and intermediate composition for optical materials containing the same

[0001] The present invention relates to a method for producing norbornene dicarbonitrile, an isocyanate intermediate, and a norbornene dicarbonitrile intermediate composition for optical materials comprising the same. In particular, the present invention relates to a method for producing norbornene dicarbonitrile, which is used as an intermediate for producing 2,3-bis(isocyanomethyl)bicyclo[2,2,1]heptane, among isocyanates, and an intermediate composition comprising norbornene dicarbonitrile.

[0002] Polyurethane resins are a type of important optical resin material, typically obtained through the polymerization reaction of a polyisocyanate composition and a polythiol compound. The diisocyanate typically used in the polyisocyanate composition is selected from a desired aliphatic or aromatic diisocyanate depending on the properties and desired reactivity required for the application. Among these diisocyanates, bis(isocyanomethyl)bicyclo(2,2,1)heptane (hereinafter referred to as "NBDI") has long been proposed and used as a transparent optical resin material due to its high refractive index and high pressure beta number, as well as excellent physical properties such as transparency, hardness, and heat resistance. Generally, NBDI refers to 2,5-NBDI and 2,6-NBDI rather than 2,3-NBD.

[0003] 2,3-Bis(isocyanomethyl)bicyclo[2,2,1]heptane (hereinafter referred to as “2,3-NBDI”) and its intermediates are disclosed in Patent Documents 1 to 3 and Non-Patent Document 1 described below.

[0004] (Patent Document 1) Japanese Patent Publication No. 1993-246973 mentions an aliphatic polycyclic diisocyanate compound of general formula (1) capable of synthesizing polyurethane having a structure in which two isocyanate groups are substituted, and a method for producing the same.

[0005] Here, only compounds where n = 1 in general formula (3) are mentioned, and compounds where n = 0 are not mentioned. Therefore, in order to obtain a diisocyanate suitable for an optical material, there is no indication in the above-mentioned prior literature as to the range within which the content ratio of the dinitrile compound of general formula (3) (here, when n = 0) should be limited, and there have been various problems in applying this as is for commercial mass production.

[0006] (Patent Document 2) Chinese Patent No. CN105016943 discloses an olefin polymerization solid catalyst that uses any diamide compound of general formula (I) as an internal electron donor. However, the process for obtaining 5-norbornene-2,3-dicaronitrile disclosed therein uses phosphorus pentoxide (P2O5), which is mainly used as a drying agent and dehydrating agent, as a catalyst, and carries out the reaction at a very high temperature of 305°C, so there have been various problems in commercial mass production, such as preparing a high-temperature reactor.

[0007] (Patent Document 3) Chinese Patent No. CN101671409 A discloses reacting 5-norbornene-2,3-dicarboxylic acid with urea, and purifying and removing unreacted 5-norbornene-2,3-dicarboxylic acid with ethanol. However, 5-norbornene-2,3-dicarboxylic acid undergoes a retro-Diels-Alder reaction (DA reaction) at about 190°C, and 5-norbornene-2,3-dicarboxamide undergoes a retro-DA reaction at about 140°C.

[0008] Therefore, under the above high temperature conditions, it is highly likely that the trans form and the cis form are mixed due to the Retro DA reaction, and it was confirmed that there is a limit to producing 2,3-NBDI in the trans form at the reaction temperature desired by the applicant.

[0009] According to the German paper (Non-patent Document 1), in the case of N,N'-disubstituted and unsubstituted fumaramides, addition is disclosed to occur only in highly polar solvents (e.g., alcohol, acetone, dimethylformamide, etc.) under thermal reaction conditions. However, this Non-patent Document 1 does not precisely disclose the yield and experimental method, and does not sufficiently disclose which analytical method was used to confirm the completion of the reaction, so there have been limitations in carrying out the method as is.

[0010] (Patent Document 1) Japanese Patent Publication No. 1993-246973 (published on September 24, 1993)

[0011] (Patent Document 2) Chinese Patent No. CN105016943 A (Published on November 4, 2015)

[0012] (Patent Document 3) Chinese Patent No. CN101671409 A (Published on November 4, 2015)

[0013] (Non-patent document 1) Monatshefte fur Chemie und verwandte Teile anderer Wissenschaften volume 96, pages 1928-1933 (1965)

[0014] The purpose of the present invention is to provide a method for producing norbornene dicarbonitrile, an intermediate capable of effectively producing 2,3-NBDI, and a composition comprising the same. After developing a method for producing such an intermediate, the present invention aims to produce 2,3-NBDI through an additional process, followed by a polymerization reaction with a polyol or polythiol, thereby providing an optical composition for a polyurethane optical resin.

[0015] In order to achieve the purpose of the present invention, the present invention was completed by intensively studying methods for producing various isocyanates:

[0016] The present invention is directed to 2,3-NBDI, not 2,5-NBDI and 2,6-NBDI (hereinafter referred to as '2,5(6)-NBDI'). However, if we first look at the manufacturing process of 2,5(6)-NBDI, it proceeds according to the following reaction scheme:

[0017] .

[0018] [Figure 1] Synthesis of 2,5-NBDI and 2,6-NBDI

[0019] On the other hand, the manufacturing process of 2,3-NBDI proceeds according to the following reaction scheme:

[0020] .

[0021] [Figure 2] 2,3-NBDI synthesis

[0022] Thus, the manufacturing process of 2,3-NBDI differs significantly from that of 2,5(6)-NBDI in terms of starting materials and reaction conditions. 2,3-NBDI exists as structural isomers, including tran-2,3-NBDI and cis-2,3-NBDI, and will typically exist as a mixture of these. Among them, cis-2,3-NBDI also exists as exo and endo stereoisomers, as follows:

[0023] .

[0024] [Figure 3] Structural isomers of 2,3-NBDI

[0025] Typically, 2,3-NBDI compounds are obtained from the intermediate norbornene dicarbonitrile, which in turn is obtained from fumaroamide. The process of obtaining norbornene dicarbonitrile from fumaroamide will be obtained through the Diels-Alder reaction, which has been known for a long time. This Diels-Alder reaction is one of the few reactions useful for creating cyclic molecules made of carbon. In particular, it can form hexagonal carbon-carbon bonds, and it is very useful in organic synthesis because it does not require any other process other than heating. The Diels-Alder reaction is very reactive and can proceed immediately at room temperature, and through this reaction, most dienes react with most dienophiles to form products.

[0026] The present inventors, through intensive research on prior art methods for producing isocyanates, have confirmed that there is a correlation between the activity of the dienophile component and the polarity of the solvent during the diene synthesis reaction between fumaramide and cyclopentadiene. In particular, fumaramide, the starting material for producing norbornene dicarbonitrile, has extremely low solubility in any solvent, further confirming that the desired reaction cannot proceed effectively with a single solvent.

[0027] In organic chemistry, the distinction between polar and non-polar solvents is typically based on the dielectric constant. The dielectric constant is determined based on the state of a charged particle entering the solvent. For example, if a positively charged particle enters a solvent, the δ portion of the solvent will surround the positively charged particle, resulting in a net positive charge cancellation. If this cancellation occurs effectively, significantly reducing the electric field strength of the positively charged particle, the solvent is said to have a high dielectric constant.

[0028] Polar solvents are also divided into protic solvents and aprotic solvents, and the standard for division is usually electronegativity. Protic solvents such as ethanol and methanol often have hydrogen atoms attached to highly electronegative oxygen atoms. This allows them to donate H+ when dissolved. Conversely, aprotic solvents are solvents that do not donate protons H+. High-boiling-point polar solvents are selected from the group consisting of polar aprotic solvents and mixtures thereof. Those skilled in the art consider solvents with a dielectric constant of 5 or higher, especially 15 or higher, to be polar, and solvents that do not contain hydrogen atoms that can be donated for hydrogen bonding are considered aprotic. Nonpolar aprotic solvents in which all hydrogen atoms (if present) are covalently bonded to carbon atoms are preferred.

[0029] The inventors of the present invention completed the present invention by considering various factors such as dielectric constant, which is a criterion for dividing polar and nonpolar solvents, electronegativity, which is a criterion for dividing protic and aprotic solvents, and characteristics of co-solvents in order to increase the solubility of fumaramide in a solvent.

[0030] As one aspect of the present invention, the present invention provides a method according to the following reaction scheme:

[0031] (1) A step of synthesizing 5-norbornene-2,3-diamide by reacting fumaramide with dicyclopentadiene (DCPD) or cyclopentadiene (CPD) in a high boiling point polar solvent; and

[0032] (2) A method for producing 2,3-NBCN is provided, comprising the step of reacting the synthesized 5-norbornene-2,3-diamide with phosphazeniun chloride in a nonpolar organic solvent to synthesize 5-norbornene-2,3-dicarbonitrile (2,3-NBCN).

[0033] Equation (1)

[0034] Equation (2)

[0035] Here, R1, R2, R3, R4, R5 and R6 are C1 to C, respectively. 10 is independently selected from the alkyl group of .

[0036] In the present invention, the high boiling point polar solvent is preferably a glycol, which may be selected from ethylene glycol, diethylene glycol, triethylene glycol, or a combination thereof.

[0037] As one embodiment of the present invention, the phosphazenium chloride can be prepared by reacting HMPA (hexamethylphosphoramide) in which substituents R1 to R6 are each methyl with a chlorinating agent:

[0038] .

[0039] In the above reaction, the chlorinating agent may be selected from phosgene, diphosgene, triphosgene (BTC), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), thionyl chloride (SOCl2), oxalyl chloride (C2O2Cl2), phosphoryl chloride (POCl3) or a combination thereof.

[0040] In the present invention, the reaction temperature in the first step is maintained in the range of 150 to 175°C, preferably 155 to 170°C, and more preferably 160 to 165°C. In addition, the moisture content in the reactor in the first step is maintained in the range of 10 to 400 ppm, preferably 20 to 370 ppm, and more preferably 30 to 340 ppm, based on the total weight of the reactants.

[0041] As another aspect of the present invention, the method of the present invention may further include a step of removing 5-norbornene-2,3-dicarboximide of the following formula (1) produced as a side reaction in the first step:

[0042] Equation (1).

[0043] In another aspect of the present invention, the product 2,3-NBCN can be used in the step of synthesizing 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (2,3-NBDI) via the intermediate of bicyclo[2.2.1]heptane-2,3-dimethanamine (2,3-NBDA) according to the following reaction scheme:

[0044] .

[0045] As another aspect of the present invention, the present invention provides an intermediate composition for an optical material comprising norbornene-2,3-dicarbonitrile (2,3-NBCN),

[0046] A 2,3-NBCN intermediate composition comprising 5-norbornene-2,3-dicarboximide of the following chemical formula (1) is provided together with the above 2,3-NBCN:

[0047] Equation (1).

[0048] Here, 5-norbornene-2,3-dicarboximide of chemical formula (1) has a double bond that disappears through a reduction reaction, particularly a hydrogenation reaction, and can then be converted into a hydrolyzable chlorine compound through a reaction with a carboxylation agent (same as the above chlorination agent, such as phosgene, diphosgene, or triphosgene), so it is necessary to control its content in advance.

[0049] In the present invention, 5-norbornene-2,3-dicarboximide of the above chemical formula (1) may be included in a range of 0.1 to 500 ppm based on the total weight of the 2,3-NBCN intermediate composition.

[0050] Since the norbornene dicarbonitrile of the present invention is used as an intermediate for producing 2,3-NBDI, it is related to the effect of the 2,3-NBDI composition. Since the 2,3-NBDI composition is widely used in the field of optical materials, norbornene dicarbonitrile can play a significant role in improving quality and economic efficiency as an intermediate in the production of 2,3-NBDI, and thus has high value from a technological and industrial perspective.

[0051] Figure 1 is a schematic diagram of 5-norbornene-2,3-dicarboxamide. 1 This is a H-NMR graph.

[0052] Figure 2 is a schematic diagram of 5-norbornene-2,3-dicarboxnitrile (2,3-NBCN). 1 This is a H-NMR graph.

[0053] Figure 3 is for 5-norbornene-2,3-dicarboximide. 1 This is a H-NMR graph.

[0054] definition

[0055] All technical and scientific terms used in the description of the present invention have the same meaning as commonly understood by those skilled in the art to which this invention pertains, unless otherwise defined. All patent publications, application publications, and other papers cited as prior art are incorporated by reference in their entirety.

[0056] The term 'isocyanate' used in the description of the present invention refers to a substance used as a polyurethane material or a polyurea material, and these materials having different structures are synthesized depending on the number and position of functional groups. Here, 'isocyanate' is used to mean all of monoisocyanate, diisocyanate, or polyisocyanate.

[0057] The term '2,3-NBDI' refers to 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (or norbornane-2,3-diylbis(methylene)diisocyanate) as a whole, and all structural isomers, tran-2,3-NBDI, cis-2,3-NBDI, or mixtures thereof. Structural isomers will be specifically indicated as tran-2,3-NBDI, cis-2,3-NBDI, if necessary, and stereoisomers in the exo and endo forms will also be indicated.

[0058] As used herein, the term 'combination' includes blends, mixtures, reaction products, and the like.

[0059] In addition, specific numerical values ​​such as mixing ratio (content ratio), physical property value, and parameter described in the present invention may be replaced with the upper limit value (a numerical value defined as “below” or “less than”) or the lower limit value (a numerical value defined as “not less than” or “exceeds”) of the corresponding mixing ratio (content ratio), physical property value, and parameter described in the present invention. Meanwhile, “%” and ppm are based on mass unless specifically stated otherwise.

[0060] As used in the description and claims of the present invention, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "isocyanate" includes mixtures of two or more monoisocyanates, diisocyanates, and polyisocyanates.

[0061] Unless otherwise stated, each material disclosed in the description of the present invention is commercially available, and their production methods are known to those skilled in the art. Furthermore, unless otherwise stated in the description of the present invention, all test standards are the most recent standards in effect at the time of this application.

[0062] Unless otherwise specified, all numbers, values, and / or ratios expressing quantities of ingredients, reaction conditions, polymer compositions, and blends used herein are approximations that reflect various uncertainties in measurement and should therefore be understood as being modified in all instances by the term "about." In addition, when a numerical range is disclosed herein, such range is continuous and includes all values ​​from the minimum value to the maximum value within that range.

[0063] The method for producing 2,3-NBCN of the present invention comprises, according to the following reaction scheme, (1) a step of synthesizing 5-norbornene-2,3-diamide by reacting fumaramide with dicyclopentadiene (DCPD) or cyclopentadiene (CPD) in a high-boiling-point polar solvent; and (2) a step of synthesizing 5-norbornene-2,3-dicarbonitrile (2,3-NBCN) by reacting the synthesized 5-norbornene-2,3-diamide with the following phosphazeniun chloride in a nonpolar organic solvent:

[0064] Equation (1)

[0065] Equation (2)

[0066] Here, R1, R2, R3, R4, R5 and R6 are C1 to C, respectively. 10 is independently selected from the alkyl group of .

[0067] The fumaramide used in the present invention is commercially available as a dry, finely powdered compound and can be purchased from Sigma-Aldrich. Furthermore, it can be directly prepared by reacting diethyl fumarate with concentrated ammonium hydroxide and ammonium chloride, according to the following reaction scheme in Non-Patent Document 1:

[0068] .

[0069] In the present invention, the term "high boiling point polar solvent" refers to a solvent having a boiling point higher than that of water and miscible with water. The high boiling point polar solvent may be selected from the group consisting of glycol, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and mixtures thereof. A particularly preferred glycol in the present invention may be selected from ethylene glycol, diethylene glycol, triethylene glycol, or a combination thereof.

[0070] In addition, if it is a non-polar organic solvent, it is not particularly limited, but toluene, benzene, cyclohexane, pentane, hexane, etc. are preferable as non-polar hydrocarbon solvents.

[0071] Cyclopentadiene (CPD) used in the present invention is an organic compound with the chemical formula C5H6, a colorless liquid with a strong, unpleasant odor. At room temperature, this cyclic diene dimerizes over several hours to produce dicyclopentadiene (DCPD) through the Diels-Alder reaction, which can be reconstituted upon heating to obtain the cyclopentadiene monomer.

[0072] Hexamethylphosphoramide (abbreviated as HMPA) used in the present invention is a phosphoramide (phosphoric acid amide) having the chemical formula [(CH3)2N]3PO, and is a useful reagent for organic synthesis. In addition, HMPA, like other phosphine oxides (e.g., triphenylphosphine oxide), has a highly polar tetrahedral core and P=O bond, and a significant negative charge exists on the oxygen atom.

[0073] In particular, the phosphazenium chloride can be prepared by reacting HMPA (hexamethylphosphoramide) in which the substituents R1 to R6 are each methyl with a chlorinating agent:

[0074] .

[0075] In addition, the chlorinating agent used in the present invention is selected from phosgene, diphosgene, triphosgene, phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), thionyl chloride (SOCl2), oxalyl chloride (C2O2Cl2), phosphoryl chloride (POCl3), or a combination thereof. In particular, phosgene gas is a common name for carbonyl chloride or carbonyl dichloride (COCl2), and is a colorless gas at room temperature, with a freezing point of 127.84°C and a boiling point of 7.84°C, and is generally produced by using a catalytic reaction of high-purity carbon monoxide to form anhydrous chlorine gas. The phosgene substitute and / or precursor used according to the present invention may include any phosgene equivalent, such as diphosgene, triphosgene, etc., and any combination thereof. The phosgene used in the present invention can be provided by thermal decomposition of a carbamate derivative using chloroformate, diphenyl carbamate, or N,N'-carbonyldiimidazole.

[0076] In the present invention, 2,3-NBCN used as an intermediate of 2,3-NBDI will be used in the step of synthesizing 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane(2,3-NBDI) via the intermediate of bicyclo[2.2.1]heptane-2,3-dimethanamine(2,3-NBDA) according to the following reaction scheme:

[0077] .

[0078] In addition, according to the present invention, an intermediate composition for an optical material of norbornene-2,3-dicarbonitrile (2,3-NBCN) comprising 5-norbornene-2,3-dicarboximide is claimed. Accordingly, as described below, (1) synthesis of 5-norbornene-2,3-dicarboxnitrile (2,3-NBCN), (2) synthesis of bicyclo[2.2.1]heptane-2,3-dimethanamine (2,3-NBDA), (3) synthesis of 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (2,3-NBDI), and (4) production of a lens using 2,3-NBDI using this intermediate composition will be specifically described in the examples described below.

[0079] According to the present invention, a polymerizable composition is provided, comprising the isocyanate composition described above and a polyol / polythiol.

[0080] The polymerizable composition may contain the isocyanate composition and the polyol / polythiol in a mixed state or in a separate state. That is, within the polymerizable composition, the isocyanate composition and the polyol / polythiol may be in a mixed state in contact with each other, or may be in a separate state so as not to contact each other.

[0081] As a polyol component used in the polymerizable composition of the present invention, examples thereof include low molecular weight polyols and high molecular weight polyols. The polyols may be used alone or in combination of two or more.

[0082] A low molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of 60 or more and less than 400. A high molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of 400 or more, for example, 10,000 or less, preferably 5,000 or less.

[0083] As the polythiol component used in the polymerizable composition of the present invention, examples thereof include aliphatic polythiols, aromatic polythiols, heterocycle-containing polythiols, aliphatic polythiols containing sulfur atoms in addition to a mercapto group, aromatic polythiols containing sulfur atoms in addition to a mercapto group, and heterocycle-containing polythiols containing sulfur atoms in addition to a mercapto group. The thiol may be a thiol oligomer or a polythiol, and one type or two or more types may be used in combination. Specific examples of the above thiols include 3,3'-thiobis[2-[(2-mercaptoethyl)thio]-1-propanethiol, bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithioctane, 2,3-bis(2-mercaptoethylthio)propane-1-thiol, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, bis(2-mercaptoethyl)sulfide, tetrakis(mercaptomethyl)methane, 2-(2-mercaptoethylthio)propane-1,3-dithiol, 2-(2,3-bis(2-mercaptoethylthio)propylthio)ethanethiol, bis(2,3-dimercaptopropanyl)sulfide, Bis(2,3-dimercaptopropanyl)disulfide, 1,2-bis[(2-mercaptoethyl)thio]-3-mercaptopropane, 1,2-bis(2-(2-mercaptoethylthio)-3-mercaptopropylthio)ethane, 2-(2-mercaptoethylthio)-3-2-mercapto-3-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio-propane-1-thiol, 2,2-bis-(3-mercapto-propionyloxymethyl)-butyl ester, 2-(2-mercaptoethylthio)-3-(2-(2-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]ethylthio)ethylthio)propane-1-thiol, (4R,11S)-4,11-bis(mercaptomethyl)-3,6,9,12-tetrathiatetradecane-1,14-dithiol, (S)-3-((R-2,3-dimercaptopropyl)thio)propane-1,2-dithiol, (4R,14R)-4,14-bis(mercaptomethyl)-3,6,9,12,15-pentathiaheptane-1,17-dithiol,(S)-3-((R-3-mercapto-2-((2-mercaptoethyl)thio)propyl)thio)propyl)thio)-2-((2-mercaptoethyl)thio)propane-1-thiol, 3,3'-dithiobis(propane-1,2-dithiol), (7R,11S)-7,11-bis(mercaptomethyl)-3,6,9,12,15-pentathiaheptadecane-1,17-dithiol, (7R,12S)-7,12-bis(mercaptomethyl)-3,6,9,10,13,16-hexathiaoctadecane-1,18-dithiol, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 4,7-Dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, pentaerythritol tetrakis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), bispentaerythritol ether hexakis(3-mercaptopropionate), 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, pentaerythritol tetrakis(2-mercaptoacetate), Examples include pentaerythritol tetrakis(3-mercaptopropionate), 2-(2,2-bis(mercaptodimethylthio)ethyl)-1,3-dithiane, etc.

[0084] In addition, the above polymerizable composition may further include additives such as an internal release agent, an ultraviolet absorber, a near-infrared absorber, a polymerization initiator, a heat stabilizer, a color corrector, a chain extender, a crosslinking agent, a light stabilizer, an antioxidant, a filler, etc., as needed.

[0085] As the above internal release agent, a component selected from among a fluorine-based nonionic surfactant, a silicone-based nonionic surfactant, an alkyl quaternary ammonium salt, and an acidic phosphate ester may be used alone or in combination of two or more.

[0086] Benzophenone-based, benzotriazole-based, triazine-based, salicylate-based, cyanoacrylate-based, oxanilide-based, etc. can be used as the above ultraviolet absorber.

[0087] As the above near-infrared absorbent, azo-based, aminium-based, andraquinone-based, cyanine-based, polymethine-based, diphenylmethane-based, triphenylmethane-based, quinone-based, diimonium-based, dithiol metal complex-based, squarylium-based, phthalocyanine-based, naphthalocyanine-based, etc. can be used.

[0088] As the above polymerization initiator, amine-based, phosphorus-based, organotin-based, organocopper-based, organogallium-based, organozirconium-based, organozinc-based, organoaluminum-based, organobism-based, etc. can be used.

[0089] As the above heat stabilizer, one or more types of metal fatty acid salts, phosphorus salts, lead salts, organotin salts, etc. can be used in combination.

[0090] Furthermore, according to the present invention, a polythiourethane obtained from the polymerizable composition described above is provided. That is, the polythiourethane can be produced by polymerizing (and curing) the isocyanate composition and thiol within the polymerizable composition. The polymerization reaction can be carried out so that the molar ratio of SH groups / NCO groups is 0.8 to 1.3, and more specifically, 0.9 to 1.1.

[0091] Additionally, to control the reaction rate, a reaction catalyst commonly used in the production of polythiourethane may be added. A tin-based catalyst may be used as the curing catalyst (polymerization initiator), and examples thereof include dibutyltin dichloride, thibutyltin dilaurate, and dimethyltin dichloride.

[0092] [Physical properties of lenses made with 2,3-NBDI]

[0093] (1) Refractive index (ne) of the optical lens

[0094] The refractive index of the optical lens obtained by the composition of each example and comparative example described below was measured using a refractometer model DR-M4 manufactured by ATAGO at 20 o The refractive index (ne) at a wavelength of 546.1 nm (mercury e-line) was measured in C.

[0095] (2) Evaluation of heat resistance of optical lenses (Tg, 10℃)

[0096] The glass transition temperature (Tg) was measured using a thermomechanical analyzer, DSC N-650. The glass transition temperature was used as an indicator of heat resistance.

[0097] (3) Yellow Index (YI) of optical lenses

[0098] The yellowness for the optical lens was calculated using the chromaticity coordinates x and y using UV-2600 240V EN (Shimadzu), and the yellowness was expressed by Equation (1).

[0099] [Mathematical Formula 1] YI = (234x + 106y + 106) / y

[0100] (4) Cloudiness of optical lenses

[0101] This was evaluated by visual inspection using the following criteria.

[0102] Excellent: ◎, Average: ○, Poor: △, Poor: Ⅹ

[0103] (5) Strai of optical lenses

[0104] The optical lens was visually observed under a mercury lamp, and if any irregularities were observed, it was classified as having striae.

[0105] Excellent: ◎, Average: ○, Poor: △, Poor: Ⅹ

[0106]

[0107] [Analytical and synthetic methods for 2,3-NBDA and 2,3-NBCN]

[0108] (1) Analysis method of 5-norbornene-2,3-dicarboxamide

[0109] - The compound was analyzed by HPLC according to the following, and the results are shown in Figure 1 as NMR data:

[0110]

[0111] NMR: 1 H-NMR (600MHz, DMSO-D6) δ7.35(1H, s), 7.18 (1H, s), 6.77(1H, s), 6.69 (1H, s), 6.19~6.18(1H, m) 5.97~5.96(1H, m), 3.14(1H, s), 3.08~3.06(1H, m), 2.83~2.83(1H, m), 2.42~2.41(1H, m), 1.63~1.62(1H, m), 1.27~1.21(1H, m)

[0112] - MS: m / z=180(M+)

[0113] (2) Analysis method of 5-norbornene-2,3-dicarboxnitrile (2,3-NBCN)

[0114] - The compound was analyzed by GC according to the following, and the results are shown in Fig. 2.

[0115] - Device: HP-6890 (HP)

[0116] - Column: DB-624 (30.0mx 250μm x 1.40μm)

[0117] - Inlet temperature: 180 ℃

[0118] - Detector temperature: 250 ℃

[0119] - NMR: 1 H-NMR (600MHz, CDCl3)δ 6.38~6.36 (2H, m), 3.43~3.43(1H, d), 3.41~3.41(1H, s), 3.16~3.15(1H, m), 2.50~2.49(1H, m), 1.78~1.76(1H, s), 1.68~1.66(1H, d)

[0120] - MS: m / z=144(M + )

[0121] (3) Confirmation of 5-norbornene-2,3-dicarboximide

[0122] - The compound was analyzed by GC according to the following, and the results are shown in Fig. 3.

[0123] - NMR: 1 H-NMR (600MHz, DMSO-d6) δ 1.47~1.49(1H,d), 1.53~1.55(1H,m), 3.18~3.19(2H,m), 3.26~3.27(2H,m), 6.11~6.11(2H,m)

[0124] - MS: m / z=163(M + )

[0125] (4) Moisture analysis

[0126] - Moisture was measured using KYOTO ELECTEONICS MCU-710M / S.

[0127]

[0128] [Example]

[0129] (Synthesis Example 1) Synthesis of phosphazenium chloride

[0130] A thermometer, a mechanical stirrer, a condenser, and a dry ice trap were installed in a 4-port 2L double jacket reactor. 0.5 L of toluene was added to the reactor. 440 g of triphosgene (BTC) was dissolved in 0.5 L of toluene and prepared in advance. 400 g of HMPA (Hexamethylphosphoramide, Sigma-Aldrich) was added to the reactor and stirred. The internal temperature of the reactor was cooled to -10°C. At this temperature, BTC dissolved in toluene prepared in advance was slowly added dropwise. After the addition was completed, the internal temperature of the reactor was raised to 40°C and the reaction was performed for 10 hours. The solvent was removed by concentration, and 419 g of phosphazenium chloride in the form of a salt was obtained.

[0131] NMR: 31 P-NMR: (600MHz, CDCl3)δ 54.4

[0132]

[0133] The following Examples 1 to 6 were performed and the results are shown in Table 1.

[0134] Example 1 (Synthesis of 5-norbornene-2,3-dicarboxamide (2,3-NBDA))

[0135]

[0136] After adding ethylene glycol (EG) to a 3L bottom flask equipped with a mechanical stirrer, thermometer, condenser, and Dean-Stark trap before synthesis, a small amount of toluene was added, and the internal temperature of the reaction was raised to 110°C to perform reflux, thereby performing pretreatment to remove toluene and moisture in the Dean-Stark trap.

[0137] A thermometer, a condenser, and a mechanical stirrer were installed in a 4-port 3L double jacket reactor. 1.5 L of ethylene glycol was added to the double jacket, followed by 186 g of fumaramide. 172 g of DCPD was added as a reactant. After adding the raw materials, the internal temperature of the reactor was raised to 160°C. The reactor was stirred for 4 hours while maintaining the temperature. After confirming the completion of the reaction, the solvent was removed through vacuum distillation. To remove the impurity 5-norbornene-2,3-dicarboximide (5-norbornene-2,3-dicarboximide), 500 mL of MeOH was added to the reactor, and the internal temperature of the reactor was raised to 70°C and refluxed for 30 minutes. The internal temperature of the reactor was cooled to 15°C and filtered. 250 g of 5-norbornene-2,3-dicarboxamide as a white solid was obtained. Contains 400 ppm of 5-norbornene-2,3-dicarboximide as an impurity.

[0138] [Examples 2-3]

[0139] The reaction was carried out under the same conditions as in Example 1, except that the solvent used was changed. The results are shown in Table 1.

[0140] [Examples 4-6]

[0141] The reaction was carried out under the same conditions as in Example 1, but the moisture content of ethylene glycol was changed. The results are shown in Table 1.

[0142] [Comparative Example 1]

[0143] The reaction was carried out under the same conditions as in Example 1, except that the solvent used was changed from ethylene glycol to 1,2-dichlorobenzene. The results are shown in Table 1.

[0144]

[0145] According to Table 1 above, when ethylene glycol was used as a cosolvent, satisfactory yields and conversion rates were obtained. Furthermore, considering the reaction temperature and time, among ethylene glycols, Example 4, which had a moisture content of 30 ppm, was the most satisfactory.

[0146]

[0147] Meanwhile, according to the present invention, a method for producing norbornene-2,3-dicarbonitrile (2,3-NBCN) containing 5-norbornene-2,3-dicarboximide and an intermediate composition for optical materials containing the same are claimed, and therefore, Examples 7 to 10 for producing a lens using such an intermediate composition are separately added.

[0148] [Example 7]

[0149] (Synthesis of 5-norbornene-2,3-dicarboxnitrile (2,3-NBCN))

[0150]

[0151] A thermometer, a condenser, a dry-ice trap, and a mechanical stirrer were installed in a 2L double jacketed 4-port reactor. 246.6 g of triphosgene (BTC) was dissolved in 500 g of toluene in advance. 800 g of toluene as a solvent was added to the reactor, and 150 g of 5-norbornene-2,3-dicarboxamide (purity 99%) prepared in Example 1 was additionally added. After adding 0.4 g of HMPA, the internal temperature of the reactor was increased to 90°C, and the previously prepared triphosgene solution in toluene was slowly added dropwise. The mixture was stirred for 6 hours while maintaining the temperature. It was confirmed that the solution had become clear. After cooling to room temperature, the solvent was concentrated and removed, and recrystallized using ethanol to obtain 118 g of 2,3-NBCN as a white solid.

[0152] [Example 8]

[0153] Synthesis of bicyclo[2.2.1]heptane-2,3-dimethanamine (2,3-NBDA)

[0154] Trans-2,3-NBCN 400g (containing 0.03 wt% of 5-norbornene-2,3-dicarboximide, 300ppm), 4g of Raney nickel catalyst, 4L of methanol solvent, and 1.2kg (17.65mol) of 25% ammonia water were introduced into an autoclave (hydrogenation device) with an internal volume of 30L. After the introduction, the interior of the autoclave was sufficiently purged with nitrogen. After the nitrogen purification was completed, hydrogen was supplied to the interior at a pressure of 10 bar, and the progress of the reaction was monitored through GC. After 20 minutes of reaction, no starting material, 2,3-NBCN, remained. The production of 2,3-NBDA with a GC purity of 99.8% was confirmed, the used Raney nickel catalyst was separated through filtration, and the solvent was removed through concentration under reduced pressure. 2,3-Norbornene dicarboximide ( ) was obtained as 384 g (90%) of 2,3-NBDA, a colorless transparent liquid containing about 270 ppm.

[0155] - 13C-NMR (600MHz, CDCl2) = 21.85, 29.83, 36.63, 38.04, 39.40, 43.99, 47.18, 49.36, 51.68 (ppm)

[0156] - MS = 154(M + )

[0157] [Example 9]

[0158] Synthesis of 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (2,3-NBDI)

[0159] After preparing a stirrer, thermometer, condenser, and dry-ice trap in a 4-port 3L jacket reactor, 384 g (1.32 mol) of BTC and 1.9 kg (13.1 mol) of o-dichlorobenzene (ODCB) were added and stirred to dissolve them. When the solution became transparent, the reactor temperature was slowly cooled to 0 to 10°C, and when the temperature was reached, 240 g (1.56 mol) of 2,3-NBDA solution synthesized in Synthesis Example 2 was slowly added. Stirring was performed for 2 hours while maintaining the temperature, and the reactor temperature was initially increased to 70°C and then increased every 10°C. After maintaining the reactor temperature at 140 to 150°C and confirming that the solution became a light brown transparent solution, stirring was performed for 2 hours at the temperature, and the reaction temperature was cooled to vacuum distillation of the solvent and product. The following chemical formula ( ) was obtained as 298 g of a transparent liquid 2,3-NBDI containing about 230 ppm of chlorine compounds.

[0160] - 13 C-NMR (600 MHz, CDCl2) = 21.70, 29.48, 36.62, 38.80, 39.77, 44.27, 46.80, 47.10, 48.69, 122.04, 122.30 (ppm)

[0161] - MS = 206(M + )

[0162] [Example 10] (Manufacture of optical lens)

[0163] In a stirred reactor, 56 parts by mass of trans-2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (2,3-NBDI, purity 99.70%) obtained in Example 9 was added. Subsequently, 0.07 parts by mass of dibutyltin dichloride as a catalyst at 25°C, 0.13 parts by mass of an acidic phosphoric acid ester, 27.0 parts by mass of the polythiol compound 2,3-bis[(2-mercaptoethyl)thio]-1-propanethiol, and 28.4 parts by mass of pentaerythritol(3-mercaptopropionate) were added. These were mixed to form a polymeric raw material composition, and after degassing and molding as in a conventional optical lens molding method, the temperature was increased from 20°C to 120°C to polymerize and solidify for 24 hours, and after demolding, curing was performed to obtain an optical lens.

[0164] As a result of testing the properties of the obtained lens, the refractive index (n e )=1.59997, heat resistance (Tg,℃)=118.0, yellowness (YI)=0.94, and there was no cloudiness or streaking, so it was confirmed that there was no problem using it as a lens.

[0165] Meanwhile, the embodiments of the present invention described above should not be construed as limiting the technical concept of the present invention. The scope of protection of the present invention is limited only by the matters set forth in the claims, and those skilled in the art will be able to partially modify, improve, or alter the technical concept of the present invention in various forms. Therefore, it is understood that such partial modifications, improvements, or alterations, as long as they are obvious to those skilled in the art, will fall within the scope of protection of the present invention.

Claims

1. According to the reaction diagram below, (1) A step of synthesizing 5-norbornene-2,3-diamide by reacting fumaramide with dicyclopentadiene (DCPD) or cyclopentadiene (CPD) in a high boiling point polar solvent; and (2) A method for producing 2,3-NBCN, comprising: a step of reacting the synthesized 5-norbornene-2,3-diamide with phosphazeniun chloride in a nonpolar organic solvent to synthesize 5-norbornene-2,3-dicarbonitrile (2,3-NBCN); Equation (1) Equation (2) Here, R1, R2, R3, R4, R5 and R6 are C1 to C, respectively. 10 is independently selected from the alkyl group of .

2. A method according to claim 1, wherein the high boiling point polar solvent is glycol.

3. A method according to claim 2, wherein the glycol is a solvent selected from ethylene glycol, diethylene glycol, triethylene glycol, or a combination thereof.

4. In the first paragraph, the phosphazenium chloride is prepared by reacting HMPA (hexamethylphosphoramide) in which each of the substituents R1 to R6 is methyl with a chlorinating agent. .

5. A method according to claim 4, wherein the chlorinating agent is selected from phosgene, diphosgene, triphosgene (BTC), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), thionyl chloride (SOCl2), oxalyl chloride (C2O2Cl2), phosphoryl chloride (POCl3) or a combination thereof.

6. A method according to any one of claims 1 to 5, wherein the reaction temperature in the first step is maintained in a range of 150 to 175°C.

7. A method according to any one of claims 1 to 5, wherein the moisture content in the reactor in the first step is maintained in a range of 10 to 400 ppm based on the total weight of the reactants.

8. A method according to any one of claims 1 to 5, further comprising a step of reducing 5-norbornene-2,3-dicarboximide produced as a side reaction in the first step: .

9. In any one of paragraphs 1 to 5, the product 2,3-NBCN is used in the step of synthesizing 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane(2,3-NBDI) via the intermediate of bicyclo[2.2.1]heptane-2,3-dimethanamine(2,3-NBDA) according to the following reaction scheme: .

10. As an intermediate composition for norbornene-2,3-dicarbonitrile (2,3-NBCN) optical materials, A 2,3-NBCN intermediate composition comprising 5-norbornene-2,3-dicarboximide of the following chemical formula (1) together with the above 2,3-NBCN: (1).

11. In the 10th paragraph, the 5-norbornene-2,3-dicarboximide of the chemical formula (1) is included in a range of 0.1 to 500 ppm based on the total weight of the 2,3-NBCN intermediate composition.

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