Isocyanate composition comprising chlorinated derivative, and optical resin comprising same

Abstract

The present invention relates to an isocyanate composition and a polyurethane optical resin comprising the composition. In particular, the present invention relates to: a 2,3-bis (isocyanomethyl) bicyclo (2,2,1) heptane (hereinafter, referred to as "2,3-NBDI") composition comprising first and / or second chlorinated derivatives generated during preparation of 2,3-NBDI; and a polyurethane optical resin obtained by polymerizing the composition and a polythiol.

Description

Isocyanate composition containing chlorinated derivative and optical resin containing the same

[0001] The present invention relates to an isocyanate composition and a polyurethane optical resin comprising the composition. In particular, the present invention relates to a 2,3-NBDI composition comprising a chlorinated derivative generated during the process of manufacturing 2,3-bis(isocyanomethyl)bicyclo[2,2,1]heptane (or 'bis(isocyanatomethyl)norbornane'; hereinafter referred to as '2,3-NBDI'), and a polyurethane optical resin obtained by polymerizing such a composition with a polythiol.

[0002] Polyurethane, polyurea, and polythiourea products, more specifically paints, adhesives, transparent polymer materials, and glass fiber materials, are manufactured by polycondensing various diisocyanates with various polyols, polyamines, or polythiols.

[0003] Polyurethane resin is a key optical resin material, typically obtained through the polymerization of a polyisocyanate composition and a polythiol compound. Depending on the type and location of the functional groups in the polyisocyanate composition, polyisocyanate compositions with different structures can be produced. Optical distortion and clouding occurring during the production process of polyurethane resin lenses can affect the optical performance of the final lens, lowering the lens production acceptance rate. Consequently, the industry has conducted extensive research into the mechanisms of optical distortion and clouding and methods for resolving them.

[0004] A representative diisocyanate used in polyisocyanate compositions is xylylene diisocyanate (abbreviated as XDI), which has the molecular formula R(NCO)2 (where R is a dimethylbenzene ring). Although XDI can be classified as an aliphatic (or aromatic) diisocyanate, its properties are intermediate between diisocyanate (cyclo)aliphatic compounds such as hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) and aromatic diisocyanates such as toluene diisocyanate (TDI) or diphenyl-methane diisocyanate (MDI).

[0005] Diisocyanates are selected from aliphatic or aromatic isocyanates depending on the properties required for the application and the desired reactivity. Cycloaliphatic diisocyanates (HDI, IPDI) exhibit high yellowing resistance, which is associated with low reactivity, whereas aromatic diisocyanates (TDI, MDI) are much more reactive but yellow quickly. The advantage of XDI is that it has excellent yellowing resistance to aromatic isocyanates on the one hand, and on the other hand, it has an isocyanate functional group with an intermediate reactivity between aliphatic and aromatic isocyanates.

[0006] Patent Documents 1 and 2 described below disclose 2,3-NBDI, and Patent Document 3 discloses a process for producing various isocyanates including 'bis(isocyanatomethyl)norbornene'. In addition, Patent Documents 4 and 5 disclose an isocyanate composition comprising xylylene diisocyanate and chloromethylbenzyl isocyanate as a chlorinated derivative. Meanwhile, Patent Document 6, a prior patent application filed by the same applicant as the present applicant, discloses a method for converting a chlorinated derivative generated during the production of xylylene diisocyanate into a non-chlorinated derivative.

[0007] In relation to the present invention, the problems of the prior art inventions of Patent Documents 1 to 6 will be specifically examined in the paragraph 'Means for solving the problem' of the present invention described below.

[0008] Prior art literature

[0009] (Patent Document)

[0010] (Patent Document 1) Japanese Patent Publication No. 2012-214568A (published on November 8, 2012)

[0011] (Patent Document 2) International Publication No. WO 2012 / 153509 (Published on November 15, 2012)

[0012] (Patent Document 3) International Publication No. WO 2007 / 010996 (Published on January 25, 2007)

[0013] (Patent Document 4) International Publication No. WO 2017 / 179575 (Published on October 19, 2017)

[0014] (Patent Document 5) International Publication No. WO 2018 / 190290 (Published on October 18, 2018)

[0015] (Patent Document 6) Korean Patent Publication No. 10-2020-0113074 (Published on October 6, 2020)

[0016] Polyurethane optical resin products are obtained through the polymerization of diisocyanate and polythiol compounds, but sometimes the products cause optical deformation, which adversely affects the performance of the optical material. The purpose of the present invention is to increase the storage stability of a 2,3-NBDI composition by controlling the content range of a chlorinated derivative of 2,3-NBDI. Accordingly, the present invention provides a 2,3-NBDI composition capable of effectively reducing the occurrence of optical deformation of a polyurethane resin due to a chlorinated derivative of 2,3-NBDI, and an optical composition comprising the same.

[0017] In order to achieve the purpose of the present invention, the inventors intensively studied the characteristics of 2,3-NBDI and its chlorinated derivatives with reference to the above-mentioned patent documents, as described below.

[0018] Although several methods for producing XDI have been proposed in the past, the phosgenation method is generally being developed in various ways. The phosgene method produces an isocyanate by reacting an organic primary amine with phosgene in an inert solvent. In this method, an aromatic primary amine can be converted into a high-purity aromatic isocyanate relatively easily by passing phosgene gas through a suspension of free aromatic amine, carbonate, or hydrochloride thereof in a solvent.

[0019] Although it contains an aromatic ring, XDI, which is classified as an aliphatic isocyanate, is produced by reacting xylylene diamine with phosgene, and many side reactions occur during the reaction, generating various chlorinated derivatives as byproducts.

[0020] (Patent Document 1) discloses a diisocyanate compound represented by the following general formula:

[0021]

[0022] (Here, n1 represents 0 or 1).

[0023] Here, only specific diisocyanates are disclosed, and no description or allusion is made to their chlorinated derivatives generated during their manufacture.

[0024] (Patent Document 2) also discloses a method for producing an isocyanate compound of the following chemical formula:

[0025]

[0026] However, only specific diisocyanates are disclosed here, and there is no description or hint at any effect of chlorinated derivatives generated during the manufacturing process of 2,3-NBDI on the performance of optical materials.

[0027] (Patent Document 3) discloses that, as an isocyanate, various chain-chain aliphatic, cyclic aliphatic, and sulfur-containing chain-chain aliphatic isocyanates, and bis(isocyanatomethyl)norbornene and the like are particularly preferable. However, the 'bis(isocyanatomethyl)norbornene' exemplified here is a different compound from 'bis(isocyanatomethyl)norbornene', i.e., '2,3-bis(isocyanatomethyl)bicyclo[2,2,1]heptane'. In particular, Examples 4, 5, and 7, and Comparative Examples 2 and 4 only disclose 'bis(isocyanatomethyl)norbornene' together with chloromethylisocyanatomethylnorbornene (hereinafter abbreviated as CNi) as a chlorinated derivative.

[0028] (Patent Document 4) discloses that when the content ratio of chloromethylbenzyl isocyanate as a chlorinated derivative is within a specific range, a resin can be stably manufactured from an XDI composition, or a resin with improved resistance to yellowing can be obtained. In particular, it is disclosed that the polyisocyanate component contains a xylylene diisocyanate composition as an essential component, while it may contain other polyisocyanates, for example, aliphatic, alicyclic, araliphatic, aromatic polyisocyanates, etc., as optional components, but 2,3-NBDI is not disclosed or implied at all.

[0029] (Patent Document 5) discloses dichloromethylbenzyl isocyanate (DCI) and chloromethylbenzyl isocyanate (CBI) as chlorinated derivatives generated during the manufacturing process of XDI. In addition, it is emphasized that the XDI composition may further contain other by-products such as dichloromethaneiminomethylbenzyl isocyanate, xylylene dichloride (XDC), and cyanobenzyl isocyanate (MCN). However, 2,3-NBDI is not disclosed or implied at all.

[0030] (Patent Document 6) is the same as the applicant of the present application, but is limited to a method of manufacturing an isocyanate that includes both an unreduced chlorinated derivative and a reduced non-chlorinated derivative together with XDI by directly converting a chlorinated derivative generated in the process of manufacturing XDI into a non-chlorinated derivative through a reduction reaction.

[0031] The present inventors, after reviewing the above-mentioned patent documents, confirmed the differences between aromatic and alicyclic isocyanates and the principle of production of chlorinated derivatives, and created the present invention through the following process.

[0032] (1) Generally, NBDI is commonly used as 2,5-NBDI and 2,6-NBDI. However, 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'). The manufacturing process of 2,5(6)-NBDI proceeds according to the following reaction scheme:

[0033] [Figure 1] Synthesis of 2,5-NBDI and 2,6-NBDI

[0034]

[0035] On the other hand, the manufacturing process of 2,3-NBDI proceeds according to the following reaction scheme:

[0036] [Figure 2] 2,3-NBDI synthesis

[0037]

[0038] 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 stereoisomers, including tran-2,3-NBDI and cis-2,3-NBDI, and typically exists as a mixture of these. Among them, cis-2,3-NBDI also exists as exo and endo stereoisomers, as follows:

[0039] [Figure 3] Stereoisomer conformation of 2,3-NBDI

[0040]

[0041] (2) In addition, although 'bis(isocyanatomethyl)norbornene' is exemplified in the prior art patent (3) along with various chain-like aliphatic, cyclic aliphatic, and sulfur-containing chain-like aliphatic isocyanates, the difference in the chemical structure of norbornene and norbornane lies in the presence or absence of a double bond in the bicyclic portion. In the case of norbornene, a double bond exists in the bicyclic portion, and a retro-Diels-Alder reaction can occur if sufficient energy is received.

[0042] [Figure 4]

[0043] .

[0044] On the other hand, in the case of nobornane, there is no double bond in the double ring, and the Retro Diels-Alder Reaction cannot occur even if sufficient energy is provided.

[0045] [Figure 5]

[0046] .

[0047] (3) Meanwhile, in the case of 2,3-NBDI produced on an industrial scale of several hundred kg, the influence of chlorinated derivatives had to be considered. The applicant succeeded in mass-producing 2,3-NBDI using a process developed in-house, and considered a method of reducing chlorinated derivatives to a specific range during the distillation process, which is a purification and separation process of 2,3-NBDI. In addition, the inventors of the present invention have also conducted a thorough study on how chlorinated derivatives negatively or positively affect optical lenses containing them. In particular, through various trials and errors in the development of a process for mass production, the present invention was completed regarding an isocyanate composition containing 2,3-NBDI in cis and trans forms, and containing a first chlorinated derivative and / or a second chlorinated derivative of these forms within a specific range.

[0048] A first aspect of the present invention is achieved by an isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (hereinafter referred to as '2,3-NBDI') of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2):

[0049] (1), (2).

[0050] The second aspect of the present invention is an isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2),

[0051] The above 2,3-NBDI is achieved by an isocyanate composition containing the trans form in a ratio of 99 mass% or more with respect to the total amount of the cis form and the trans form:

[0052] (1), (2).

[0053] The third aspect of the present invention is an isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2),

[0054] The above 2,3-NBDI contains the trans form at a ratio of 99 mass% or more with respect to the total amount of the cis form and the trans form;

[0055] The content of the first chlorinated derivative in the total mass of the isocyanate composition is achieved by an isocyanate composition of more than 0 ppm and less than or equal to 2,000 ppm:

[0056] (1), (2).

[0057] Meanwhile, the present invention relates to an isocyanate composition further containing a second chlorinated derivative of chemical formula (3) in an amount of more than 0 ppm and less than 200 ppm:

[0058] (3).

[0059] In addition, the isocyanate composition of the present invention preferably has 2,3-NBDI of chemical formula (1) as a trans stereoisomer of chemical formula (4), a cis-endo stereoisomer of chemical formula (5), a cis-exo stereoisomer of chemical formula (6), or a mixture thereof:

[0060] (4), (5), (6).

[0061] Furthermore, in the isocyanate composition of the present invention, the first chlorinated derivative is preferably a trans stereoisomer of the following chemical formula (7) or (8) or a mixture thereof:

[0062] (7), (8).

[0063] In the isocyanate composition of the present invention, it is preferable that the second chlorinated derivative is a trans stereoisomer of the following chemical formula (9):

[0064] (9).

[0065] In addition, it is preferable that the isocyanate composition of the present invention has a content ratio of 2,3-NBDI of the general formula (1) of 99 mass% or more.

[0066] In another aspect, the present invention relates to a polymerizable composition comprising the above-described isocyanate composition and a compound containing at least one isocyanate-reactive functional group. Here, the compound containing at least one isocyanate-reactive functional group is a polyol compound or a polythiol compound.

[0067] In addition, the polymerizable composition of the present invention preferably has a molar ratio of isocyanate (-NCO) / mercapto (-SH) of 0.8 to 3.0 as the molar ratio of the isocyanate composition and the polythiol compound.

[0068] Meanwhile, in another aspect, the present invention relates to a transparent optical resin obtained by reacting the above-described polymerizable composition. Here, the transparent optical resin includes an optical lens.

[0069] The 2,3-NBDI composition of the above chemical formula (1) is modified by a known method as needed and contained in an isocyanate component. The isocyanate component and the polyol compound or polythiol compound component are suitably used as raw materials for a polyurethane optical resin. The isocyanate component contains a 2,3-NBDI composition and / or a 2,3-NBDI modified composition in which the 2,3-NBDI composition is modified (hereinafter referred to as a 2,3-NBDI modified composition), and preferably consists of a 2,3-NBDI composition and / or a 2,3-NBDI modified composition.

[0070] In the present invention, the 2,3-NBDI composition may be an isocyanate modified composition containing at least one of the following functional groups (a) to (i):

[0071] (a) isocyanurate group, (b) allophanate group,

[0072] (c) Byureth period, (d) Urethe period, (e) Urea period,

[0073] (f) iminooxadiazine diion group, (g) urethdione group,

[0074] (h) uretonimine group, (i) carbodiimide group.

[0075] More specifically, the 2,3-NBDI modified composition containing the functional group (isocyanurate group) of (a) above contains a trimer of 2,3-NBDI and can be obtained, for example, by reacting an XDI composition in the presence of a known isocyanuration catalyst to isocyanurate (e.g., trimerize) 2,3-NBDI. The 2,3-NBDI modified composition containing the remaining functional groups (b) to (i) can also be obtained by a known method.

[0076] Meanwhile, the 2,3-NBDI modified composition may contain at least one functional group of the above (a) to (i), and may contain two or more types. Such a 2,3-NBDI modified composition is produced by appropriately combining the above reactions. In addition, the 2,3-NBDI modified composition may be used alone or in combination of two or more types.

[0077] Meanwhile, in another aspect, the present invention relates to a polymerizable composition comprising a modified composition of 2,3-NBDI of the chemical formula (1) described above and a polyol compound or a polythiol compound.

[0078] In another aspect, the present invention relates to (1) (chloromethyl)(isocyanatomethyl)bicyclo(2,2,1)heptane of the following chemical formula (2) as a first chlorinated derivative generated in the process of manufacturing 2,3-NBDI:

[0079] (2).

[0080] Here, the first chlorinated derivative may exist as a trans stereoisomer of the following chemical formula (7) or (8) or a mixture thereof:

[0081] (7), (8).

[0082] Since the 2,3-NBDI composition of the present invention is widely used in the field of optical materials, it is necessary to analyze the characteristics and appropriate content of chlorinated derivatives of 2,3-NBDI generated during the manufacturing process of 2,3-NBDI. Accordingly, the manufacturing efficiency and quality of optical lenses manufactured from 2,3-NBDI isocyanate can be improved, and thus, it has high technological and industrial value.

[0083] A 2,3-NBDI isocyanate composition containing a chlorinated derivative of 2,3-NBDI within an appropriate range is both economical and highly stable in storage. Furthermore, by using this composition, high-quality optical resins and optical products can be produced at high cost.

[0084] Figure 1 is the 13C-NMR data of the first chlorinated derivative obtained in the example.

[0085] definition

[0086] 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.

[0087] 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 have different structures that can be synthesized depending on the number and position of functional groups. Here, "isocyanate" is used to mean all of monoisocyanate, diisocyanate, or polyisocyanate.

[0088] The term '2,3-NBDI' refers to 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (or norbornene-2,3-diylbis(methylene)diisocyanate) as a whole, and all stereoisomers, tran-2,3-NBDI, cis-2,3-NBDI, or mixtures thereof. Stereoisomers will be specifically indicated as tran-2,3-NBDI, cis-2,3-NBDI, if necessary, and exo and endo stereoisomers will also be indicated.

[0089] The term "chlorinated derivative" refers to a process in which isocyanates can be produced by the direct method, the hydrochloride method, or the carbonate method, in which case impurities containing chlorine are generated by side reactions. In the present invention, the chlorinated impurities generated in the process of producing 2,3-NBDI include (1) a first chlorinated derivative, chloromethyl)(isocyanatomethyl)bicyclo(2,2,1)heptane; (2) a second chlorinated derivative, bis(chloromethyl)bicyclo(2,2,1)heptane; and (3) a third chlorinated derivative, chloromethyl(dichloromethyl)bicyclo(2,2,1)heptane, which rarely occurs; and a fourth chlorinated derivative, dichloromethyl(isocyanatomethyl)bicyclo(2,2,1)heptane.

[0090] The term "non-chlorinated derivative" is used to mean a substance in which chlorine is removed by replacing it with another atom or atomic group through a reduction reaction of the above "chlorinated derivative."

[0091] Additionally, the term "isocyanate-reactive functional group" means an "active hydrogen group-containing component" that reacts with isocyanates, such as a polyol component (a component mainly contained in a polyol having two or more hydroxyl groups), a polythiol component (a component mainly contained in a polythiol having two or more mercapto groups), a polyamine (a component mainly containing a polyamine having two or more amino groups), etc.

[0092] As used herein, the term “combination” includes blends, mixtures, reaction products, and the like.

[0093] 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, “%” is based on mass unless specifically stated otherwise.

[0094] As used in the description and claims of the present invention, the singular forms "singular" and "an" 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.

[0095] 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.

[0096] In the isocyanate composition of 2,3-NBDI of the present invention, the content ratio (purity) of 2,3-NBDI is, for example, 99.00 mass% or more, 99.50 mass% or more, preferably 99.70 mass% or more, 99.80 mass% or more, and more preferably 99.90 mass% or more, with respect to the total mass of the 2,3-NBDI composition.

[0097] In the present invention, 2,3-NBDI preferably contains the trans form in a ratio of 99 mass% or more based on the total amount of the cis form and the trans form, and more preferably, it can contain the trans form in a ratio of 99.5 mass% or more, 99.9 mass% or more, or 99.95 mass% or more.

[0098] In addition, if the isocyanate content in the isocyanate raw material exceeds a certain value, deformation, white solids, etc. occur as a result, which reduces the yield of the product. The content ratio of the first chlorinated derivative of 2,3-NBDI is, with respect to the total mass of the 2,3-NBDI composition, as a lower limit, for example, more than 0 ppm, 0.1 ppm or more, preferably more than 0 ppm, more preferably 50 ppm or more, and as an upper limit, for example, 2000 ppm or less, preferably 1500 ppm or less, more preferably 1000 ppm or less. In addition, the content ratio of the second chlorinated derivative of 2,3-NBDI is, with respect to the total mass of the 2,3-NBDI composition, as a lower limit, for example, more than 0 ppm, 0.1 ppm or more, preferably 5 ppm or more, and as an upper limit, for example, 200 ppm or less, preferably 150 ppm or less, more preferably 100 ppm or less. Therefore, in the present invention, by controlling the composition of the isocyanate raw material, the content of the chlorinated isocyanate derivative in the isocyanate raw material used can be effectively suppressed within the above-described range, thereby increasing storage stability and obtaining a transparent, high-refractive-index polyurethane optical resin with low optical strain.

[0099] The composition of the isocyanate of 2,3-NBDI will be described in detail in the examples described below, and a product manufactured using the obtained isocyanate composition can satisfy high optical properties, so that it can be used in the manufacture of optical materials, specifically, plastic optical lenses.

[0100] According to the present invention, a polymerizable composition is provided, comprising the isocyanate composition described above and a polyol / polythiol.

[0101] 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.

[0102] 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.

[0103] Low molecular weight polyols are compounds having two or more hydroxyl groups and a number average molecular weight of 60 to less than 400. Examples of low molecular weight polyols include ethylene glycol, propylene glycol, 1,3-propenediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentenediol, 1,6-hexenediol, diethylene glycol, triethylene glycol, dipropylene glycol, and mixtures thereof, 1,4-cyclohexenediol, dihydric alcohols such as hydrogenated bisphenol A and bisphenol A, trihydric alcohols such as glycerin, tetrahydric alcohols such as tetramethylol methane (pentaerythritol), pentahydric alcohols such as xylitol, and hexahydric alcohols such as sorbitol, mannitol, alitol, and iditol.

[0104] High molecular weight polyols are compounds 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. Examples of high molecular weight polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, silicone polyols, fluorine polyols, and vinyl monomer-modified polyols.

[0105] 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.

[0106] 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.

[0107] The internal release agent may be selected from among a fluorine-based nonionic surfactant having a perfluoroalkyl group, a hydroxyalkyl group, or a phosphate ester group; a silicone-based nonionic surfactant having a dimethylpolysiloxane group, a hydroxyalkyl group, or a phosphate ester group; an alkyl quaternary ammonium salt, i.e., trimethyl cetyl ammonium salt, trimethylstearyl, dimethylethyl cetyl ammonium salt, triethyldodecyl ammonium salt, trioctylmethyl ammonium salt, diethylcyclohexadodecyl ammonium salt; and an acidic phosphate ester, which may be used alone or in combination of two or more.

[0108] Benzophenone-based, benzotriazole-based, triazine-based, salicylate-based, cyanoacrylate-based, oxanilide-based, etc. can be used as the above ultraviolet absorber.

[0109] 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. In particular, as one of the electromagnetic wave absorbers, a near-infrared absorber having a high near-infrared absorption ability of 30% or more in the vicinity of 800 to 1000 nm can be used, and such a near-infrared absorber is preferably a mixture of a plurality of phthalocyanine pigments having different structures, and each of these pigments is a pigment having a minimum value of a spectral transmittance curve of less than 80% in the range of (i) a wavelength range of 800 nm to 850 nm, (ii) a wavelength range of 875 nm to 925 nm, and (iii) a wavelength range of 950 nm to 1000 nm. For example, PANAX FND-83, PANAX FND-88, PANAX FND-96, etc. can be used.

[0110] 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.

[0111] 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.

[0112] 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) an isocyanate composition and a thiol within the polymerizable composition. The polymerization reaction can be carried out so that the molar ratio of SH groups / NCO groups is 0.5 to 3.0, 0.7 to 2.0, preferably 0.8 to 1.5, and more preferably 0.9 to 1.1. Through such a molar ratio, a urethane resin having a well-balanced refractive index, impact resistance, dyeability, and heat resistance can be obtained.

[0113] 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.

[0114] Meanwhile, although the present invention has been described focusing on the problematic first and second chlorinated derivatives, it is expected that the third chlorinated derivative, chloromethyl(dichloromethyl)bicyclo(2,2,1)heptane, and the fourth chlorinated derivative, dichloromethyl(isocyanatomethyl)bicyclo(2,2,1)heptane, will also be produced. However, these chlorinated derivatives will be produced in trace amounts, and it is difficult to separate and purify them, and therefore they will not be considered in the present invention.

[0115] So far, the present invention has been described mainly with respect to a 2,3-NBDI composition comprising chlorinated derivatives thereof generated during the process of manufacturing 2,3-NBDI. However, such chlorinated derivatives may be extended and applied to other aliphatic (alicyclic) isocyanates. Examples of such extendable compounds include hexamethylene diisocyanate, isophorone diisocyanate, bis-(4-isocyanatocyclohexyl)methane, 1,3-,1,4-bis(isocyanatomethyl)cyclohexane, m-tetramethylxylylene diisocyanate, and the like, particularly diisocyanates having the following general formula:

[0116]

[0117] (Here, n1 is either 0 or 1).

[0118] Meanwhile, as mentioned, Patent Document 6 relates to a method for producing an isocyanate comprising a non-chlorinated derivative obtained by converting a chlorinated derivative generated in the process of producing XDI into a non-chlorinated derivative through a reduction reaction. This method can also be applied to the chlorinated derivative generated in the process of producing 2,3-NBDI of the present invention.

[0119] The inventors of the present invention are conducting additional experiments on a method for producing 2,3-NBDI comprising the first and second chlorinated derivatives generated during the process of producing 2,3-NBDI, which are then converted into non-chlorinated derivatives through a reduction reaction, and on a 2,3-NBDI composition comprising the obtained non-chlorinated derivatives. A separate application will be filed as soon as these experiments are completed.

[0120]

[0121] Afterwards, the analysis method and synthesis of chlorinated derivatives of isocyanates, the physical properties and measurement methods of lens products, etc. are described.

[0122] [2,3-NBDI Synthesis and Analysis Method]

[0123] (1) [Synthesis example]

[0124] (Synthesis Example 1) Synthesis of 2,3-NBDI

[0125] The trans form of 2,3-NBDI (purity 99.76%) used in Example 1 can be synthesized through the 2,3-NBDI synthesis process of [Figure 2] below and purified to a purity of approximately 99.76% before use:

[0126] [Figure 2]

[0127] .

[0128] Referring to the known method along with the above reaction scheme, bicyclo[2.2.1]heptane-2,3-dimethanamine was synthesized through hydrogenation of 5-norbornene-2,3-dicarbonitrile in the presence of a catalyst, and 2,3-NBDI was synthesized using the synthesized bicyclo[2.2.1]heptane-2,3-dimethanamine as a carbonylating agent such as phosgene.

[0129] (Synthesis Example 2) First chlorinated derivative of 2,3-NBDI

[0130] A standard substance of the first chlorinated derivative was obtained through column / vacuum distillation of crude 2,3-NBDI.

[0131] (Synthesis Example 3) Second chlorinated derivative of 2,3-NBDI

[0132] A standard substance of the second chlorinated derivative was obtained by reacting cyclopentadiene obtained by thermal decomposition of 1,4-dichloro-2-butene (TCI) with a purity of >95.0% (by GC) and dicyclopentadiene in a chloromethane solvent.

[0133] (Synthesis Example 4) Mixture of first and second chlorinated derivatives of 2,3-NBDI

[0134] Crude 2,3-NBDI was vacuum distilled to obtain a mixture containing the first chlorinated derivative and the second chlorinated derivative.

[0135] (2-1) Content of 2,3-NBDI

[0136] 2,3-NBDI with a purity of 99% prepared in the above-described Synthetic Example 1 was analyzed by gas chromatography under the following conditions as a standard material, and a calibration curve was created from the area value of the obtained gas chromatography, and then quantified, and the content of 2,3-NBDI was measured.

[0137] - Device: HP-6890 (HP)

[0138] - Column: DB-624 (30.0mx 250μm x 1.40μm)

[0139] - Inlet temperature: 180 ℃

[0140] - Detector temperature: 250 ℃

[0141] (2-2) Content of the first chlorinated derivative

[0142] Using the first chlorinated derivative (purity 99%) synthesized in Synthesis Example 2 as a standard material, the content of the first chlorinated derivative included in the composition of each example was calculated in the same manner as the 2,3-NBDI measurement method, and is shown in Table 1. The obtained first chlorinated derivative was analyzed by 13C-NMR (600 MHz, CDCl3) and MS, and the results are shown in Fig. 1. The fact that the 13C-NMR of Fig. 1 was not observed as a single peak is due to partial stereoisomers, and the specific data are as follows.

[0143] - 13C-NMR (100MHz, CDCl3) δ(21.7, 21.7) (29.5, 29.6) (36.7, 36.7), (38.8, 39.5), (40.0, 40.6) 44.3, (48.2, 48.4), (49.7, 49.9), (77.1, 77.3) (122.0, 122.2)

[0144] - MS: m / z=199(M+)

[0145] (2-3) Content of second chlorinated derivative

[0146] Using the 99% pure second chlorinated derivative synthesized in Synthesis Example 3 as a standard material, the content of the second chlorinated derivative included in the composition of each example was calculated in the same manner as the measurement method for 2,3-NBDI, and is shown in Table 1. The obtained second chlorinated derivative was analyzed by 13C-NMR (100 MHz, CDCl3) and MS.

[0147] - 13C-NMR (600MHz, CDCl3) δ28.2, 33.7, 38.3, 39.5, 47.9

[0148] - MS: m / z=192(M+)

[0149] (4) Refractive index (ne) of optical lens

[0150] 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.

[0151] (5) Evaluation of heat resistance of optical lenses (Tg, 10℃)

[0152] 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.

[0153] (6) Yellow Index (YI) of optical lenses

[0154] 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).

[0155] [Mathematical Formula 1] YI = (234x + 106y + 106) / y

[0156] (7) 2,3-NBDI composition and cloudiness of optical lenses

[0157] (a) Storage stability evaluation of 2,3-NBDI: The substances shown in Table 1 were added to 2,3-NBDI (purity 99.8), and the container was sealed with a stopper after nitrogen purging in a glass container and stored at 20°C. After storage for 180 days, the storage stability was evaluated by measuring whether the appearance became cloudy, which is the point at which transparency decreases, and this was evaluated visually according to the following criteria.

[0158] Excellent: ◎, Average: ○, Poor: △, Poor: Ⅹ

[0159] (b) Cloudiness of the lens itself: This was also evaluated visually, similar to the above, using the following criteria: Excellent: ◎, Average: ○, Poor: △, Poor: Ⅹ

[0160] (8) Strai of optical lenses

[0161] The optical lens was visually observed under a mercury lamp, and if any irregularities were observed, it was classified as having striae.

[0162] Excellent: ◎, Average: ○, Poor: △, Poor: Ⅹ

[0163] The present invention is illustrated by the following examples, but is not limited thereto. First, an example of the synthesis of a 2,3-NBDI chlorinated derivative and an isocyanate composition containing the same will be examined, followed by an example of an optical lens using such a composition.

[0164] (Example)

[0165] (Example 1)

[0166] In a stirred reactor, 56 parts by mass of trans-2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (2,3-NBDI, purity 99.76%) was added. Subsequently, 0.07 parts by mass of dibutyltin dichloride as a catalyst, 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 at 25°C. 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, it was cured to obtain an optical material, and the test results of the product are shown in Table 1.

[0167] (Examples 2 to 16, Comparative Examples 1 to 3)

[0168] In Examples 2 to 16 and Comparative Examples 1 to 3, the same polymerization process as in Example 1 was performed except that the chlorinated compounds containing the first chlorinated derivative and the second chlorinated derivative were used in the amounts shown in Table 1 below.

[0169]

[0170] * After storing the composition for 180 days, storage stability was evaluated by the presence or absence of cloudiness.

[0171]

[0172] According to the analysis results of [Table 1] above, it can be seen that the content of chlorine derivatives present in the isocyanate raw material has a significant effect on storage stability. When chlorinated derivatives are present, the occurrence of white turbidity was suppressed for 180 days. In particular, when the first chlorinated derivative was controlled within the range of 0 ppm to 2000 ppm, and when the second chlorinated derivative was also controlled within the range of 0 ppm to 200 ppm, it was shown that storage stability increased and the occurrence of white turbidity could be suppressed. In addition, white turbidity occurred when the first chlorinated derivative exceeded 2000 ppm, and white turbidity occurred when the second chlorinated derivative exceeded 200 ppm.

[0173] Meanwhile, in order to confirm the properties of lenses manufactured from 2,3-NBDI compositions according to the contents of the first chlorinated derivative and the second chlorinated derivative, separate Examples 21 to 30 and Comparative Examples 11 to 13 were performed as shown in Table 2 below, and the results are shown in Table 2 below.

[0174]

[0175] Although the 'cloudiness' in [Table 1] and [Table 2] are expressed by the same term, the cloudiness in [Table 2] is intended to evaluate the cloudiness of the lens itself after being molded into a lens. On the other hand, the cloudiness in [Table 1] is intended to evaluate the storage stability of only the 2,3-NBDI composition after 180 days of storage, and therefore, they should be distinguished.

[0176] According to the analysis results of [Table 2] above, it can be seen that the content of chlorinated derivatives present in the isocyanate raw material has a significant influence on the occurrence of optical deformation. In particular, when the content of the first chlorinated derivative in the isocyanate raw material is 2000 ppm or less, the physical properties of the optical lens obtained, such as refractive index, heat resistance, yellowness, cloudiness, and striae, are excellent or average, and the occurrence rate of deformation is low. In addition, when the content of the second chlorinated derivative is 200 ppm or less, the physical properties of the optical lens obtained, such as refractive index, heat resistance, yellowness, cloudiness, and striae, are excellent or average, and the occurrence rate of deformation is low. However, when the content of the first chlorinated derivative exceeds 2000 ppm, and when the content of the second chlorinated derivative exceeds 200 ppm, the physical properties of the lens, such as heat resistance and yellowness, are insufficient and poor, and the occurrence rate of optical deformation is high.

[0177] In summary, by using a 2,3-NBDI composition containing a specific range of 2,3-NBDI chlorinated derivatives, it is possible to obtain an optical product with high economic efficiency while improving storage stability and obtaining the quality of optical lenses required in the industry.

[0178] Meanwhile, those skilled in the art will understand that certain modifications or changes may be made to the present invention based on the above-described contents of this specification. However, it will also be understood that such modifications or changes fall within the scope defined by the claims of the present invention described below.

Claims

1. An isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane (hereinafter referred to as '2,3-NBDI') of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2): (1), (2).

2. An isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2), The above 2,3-NBDI is an isocyanate composition comprising a trans form in a ratio of 99 mass% or more based on the total amount of cis and trans forms: (1), (2).

3. An isocyanate composition comprising 2,3-bis(isocyanomethyl)bicyclo(2,2,1)heptane of the following chemical formula (1) and a first chlorinated derivative of the following chemical formula (2), An isocyanate composition wherein the content of the first chlorinated derivative in the total mass of the isocyanate composition is from more than 0 ppm to less than 2,000 ppm: (1), (2).

4. An isocyanate composition according to any one of claims 1 to 3, wherein the second chlorinated derivative of the following chemical formula (3) is additionally contained in an amount of more than 0 ppm and less than or equal to 200 ppm: (3).

5. An isocyanate composition according to any one of claims 1 to 3, wherein the 2,3-NBDI of the chemical formula (1) is a trans stereoisomer of the following chemical formula (4), a cis-endo stereoisomer of the following chemical formula (5), a cis-exo stereoisomer of the following chemical formula (6), or a mixture thereof: (4), (5), (6).

6. An isocyanate composition according to any one of claims 1 to 3, wherein the first chlorinated derivative is a trans stereoisomer of the following chemical formula (7) or (8) or a mixture thereof: (7), (8).

7. In the fourth paragraph, the isocyanate composition wherein the second chlorinated derivative is a trans stereoisomer of the following chemical formula (9): (9).

8. An isocyanate composition according to any one of claims 1 to 3, wherein the content ratio of 2,3-NBDI of the general formula (1) is 99 mass% or more.

9. A polymerizable composition comprising an isocyanate composition according to any one of claims 1 to 3 and a compound containing at least one isocyanate-reactive functional group.

10. A polymerizable composition according to claim 9, wherein the compound containing at least one isocyanate-reactive functional group is a polyol compound or a polythiol compound.

11. A polymerizable composition in claim 10, wherein the molar ratio of the isocyanate composition and the polythiol compound is 0.8 to 3.0 as the molar ratio of isocyanate (-NCO) / mercapto (-SH).

12. A transparent optical resin obtained by reacting the polymerizable composition described in Article 10.

13. In the 12th paragraph, the transparent optical resin is an optical resin including an optical lens.

14. A modified composition of the 2,3-NBDI composition of the chemical formula (1) described in any one of claims 1 to 3, A 2,3-NBDI modified composition characterized by containing at least one functional group of the following (a) to (i). (a) isocyanurate group, (b) allophanate group, (c) Byureth period, (d) Urethe period, (e) Urea period, (f) iminooxadiazine diion group, (g) urethdione group, (h) a uretonimine group, and (i) a carbodiimide group.

15. A modified composition of 2,3-NBDI of chemical formula (1) described in Article 14, and A polymerizable composition comprising a polyol compound or a polythiol compound. As the first chlorinated derivative generated in the manufacturing process of 16.2,3-NBDI, (chloromethyl)(isocyanatomethyl)bicyclo(2,2,1)heptane of the following chemical formula (2): (2).

17. In the 16th paragraph, the first chlorinated derivative is (chloromethyl)(isocyanatomethyl)bicyclo(2,2,1)heptane, which exists as a trans stereoisomer of the following chemical formula (7) or (8) or a mixture thereof: (7), (8).

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