Xylylene diisocyanate composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polyurethane modification, in particular to a xylylene diisocyanate composition as well as a preparation method and application thereof.The xylylene diisocyanate composition provided by the invention contains 1-1000 ppm of a compound shown in the formula (I), and resin prepared from the xylylene diisocyanate composition has excellent homogeneity, effectively inhibits stripes from occurring in the resin, and has the advantages of being good in mechanical property, good in mechanical property and the like. And the light transmittance consistency is obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane modification, and particularly to a xylylene diisocyanate composition, a preparation method thereof and an application thereof. Background Art

[0002] As an important isocyanate monomer, xylylene diisocyanate (XDI) contains a benzene ring and a methylene group in its molecular structure, and has excellent reactivity and chemical stability, and is widely used in the fields of polyurethane, coatings, adhesives, etc. In recent years, researchers have tried to introduce XDI into the preparation process of resin lenses in order to improve the performance of the lenses. However, in actual applications, the use of XDI in resin lenses still has poor uniformity, resulting in uneven phenomena in the lenses, such as streaks, which limits its further promotion and application.

[0003] For example, for the polyurethane resin manufactured from xylylene diisocyanate described in the patent application GB1194459A, sometimes sufficient uniformity cannot be ensured, and the prepared optical material has streaks. Patent CN109824843A improves the uniformity of resin lenses by adding an isocyanate prepolymer, however, it increases the cost and the difficulty of process operation.

[0004] Therefore, there is an urgent need in the art to provide a xylylene diisocyanate raw material capable of stably manufacturing a polyurethane resin with excellent uniformity. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor uniformity of polyurethane resin in the prior art, so as to provide a xylylene diisocyanate composition, a preparation method thereof and an application thereof.

[0006] To this end, in a first aspect, the present application provides a xylylene diisocyanate composition, and the xylylene diisocyanate composition comprises xylylene diisocyanate and 1-1000 ppm of a compound represented by the following formula (I);

[0007]

[0008] Wherein, R1, R2 or R3 are independently selected from or

[0009] In some embodiments, the content of the compound represented by formula (I) in the xylylene diisocyanate composition is 1-350 ppm.

[0010] In some embodiments, the content of xylylene diisocyanate in the xylylene diisocyanate composition is greater than 98 wt%.

[0011] In some embodiments, the compound represented by formula (I) is selected from or

[0012] In some embodiments, the benzenedimethylenediisocyanate includes any one or at least two combinations of 1,2-benzenedimethylenediisocyanate, 1,3-benzenedimethylenediisocyanate, or 1,4-benzenedimethylenediisocyanate, preferably 1,3-benzenedimethylenediisocyanate and / or 1,4-benzenedimethylenediisocyanate, more preferably 1,3-benzenedimethylenediisocyanate.

[0013] In a second aspect, the present application provides a method for preparing the benzenedimethylenediisocyanate composition described in any one of the above,

[0014] (1) Isocyanate chemical process: subjecting xylylenediamine or xylylenediamine hydrochloride to an isocyanation reaction with phosgene in the presence of a reaction solvent;

[0015] (2) Separation process: separating and purifying the reaction product obtained in step (1) to obtain the benzenedimethylenediisocyanate composition;

[0016] wherein the color number of xylylenediamine is less than or equal to 15 Hazen.

[0017] The present application also provides a method for preparing the benzenedimethylenediisocyanate composition described in any one of the above, the preparation method including mixing the benzenedimethylenediisocyanate and the compound represented by formula (I).

[0018] In a third aspect, the present invention provides a modified composition of a benzenedimethylenediisocyanate composition, the modified composition being a modified composition obtained by modifying the benzenedimethylenediisocyanate composition described in any one of the first aspect or the benzenedimethylenediisocyanate composition prepared by the preparation method described in the second aspect, the modified composition containing any one or at least two combinations of the following groups (a)-(i): (a) isocyanurate group, (b) uretidione group, (c) biuret group, (d) carbamate group, (e) urea group, (f) iminooxadiazinedione group, (g) urethane group, (h) uretonimine group, or (i) carbodiimide group.

[0019] In a fourth aspect, the present invention provides a resin composition, the resin composition including the benzenedimethylenediisocyanate composition described in any one of the first aspect or the benzenedimethylenediisocyanate composition prepared by the preparation method described in the second aspect or the modified composition of the benzenedimethylenediisocyanate composition described in the third aspect and a substance containing an active hydrogen group.

[0020] Fifth aspect, the present invention provides a polyurethane resin, which is prepared by reacting a terephthalylidene diisocyanate composition according to any one of the first aspect, or a terephthalylidene diisocyanate composition prepared by the preparation method of the second aspect, or a modified composition of the terephthalylidene diisocyanate composition of the third aspect with a substance containing an active hydrogen group.

[0021] Sixth aspect, the present invention provides an optical material, which is polymerized from a terephthalylidene diisocyanate composition according to any one of the first aspect, or a terephthalylidene diisocyanate composition prepared by the preparation method of the second aspect, or a modified composition of the terephthalylidene diisocyanate composition of the third aspect and a polythiol compound.

[0022] In some embodiments, the optical material includes a plastic lens material, an automobile headlamp cover material, or a transparent roof material.

[0023] The technical solution of the present invention has the following advantages:

[0024] The terephthalylidene diisocyanate composition provided by the present invention contains 1 - 1000 ppm of the compound of formula (I). The resin prepared therefrom has excellent homogeneity, effectively inhibits the appearance of streaks in the resin, and significantly improves the consistency of light transmittance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is the device flow for preparing the terephthalylidene diisocyanate composition in the specific embodiment of the present invention;

[0027] 1. Salt formation kettle, 2. First photochemical kettle, 3. Second photochemical kettle, 4. Third photochemical kettle, 5. Phosgene stripping tower, 6. Solvent stripping tower, 7. Tar remover, 8. Rectification tower. SPECIFIC EMBODIMENTS

[0028] The following embodiments are provided to better further understand the present invention. They are not limited to the best embodiments, and do not limit the content and protection scope of the present invention. Any product obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with those of other prior arts and being the same as or similar to the present invention falls within the protection scope of the present invention.

[0029] For those not specifying specific experimental procedures or conditions in the examples, the operations or conditions of the conventional experimental procedures described in the literature in this field can be followed. For the reagents or instruments not specifying the manufacturers, they are all conventional reagent products that can be obtained through commercial purchase.

[0030] The technical problem to be solved by the present invention is to overcome the defect of poor homogeneity existing in polyurethane resins in the prior art, so as to provide a xylylene diisocyanate composition, a preparation method thereof and an application thereof.

[0031] To achieve this purpose, the following technical solutions are adopted:

[0032] In a first aspect, the present application provides a xylylene diisocyanate composition, and the xylylene diisocyanate composition includes xylylene diisocyanate and 1 - 1000 ppm of a compound represented by the following formula (I);

[0033]

[0034] wherein, R1, R2 or R3 are independently selected from, or

[0035] In the present invention, the xylylene diisocyanate composition is denoted as the XDI composition, the xylylene diisocyanate is denoted as XDI, and the compound represented by the formula (I) is denoted as XIT.

[0036] Regarding the content of XIT, based on the total mass of the XDI composition, the content of XIT is 1 - 1000 ppm (such as 1 ppm, 5 ppm, 6 ppm, 10 ppm, 12 ppm, 15 ppm, 20 ppm, 40 ppm, 50 ppm, 60 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 1000 ppm, etc.).

[0037] The researchers of the present invention found in the research that when the xylylene diisocyanate composition contains 1 - 1000 ppm of the compound of the formula (I), the prepared resin has excellent homogeneity, effectively inhibits the appearance of streaks in the resin, and the consistency of the light transmittance is significantly improved. When the content is less than 1 ppm or higher than 1000 ppm, the homogeneity will become poor.

[0038] The xylylene diisocyanate composition of the present invention is a substantially single compound (i.e., xylylene diisocyanate) containing more than 98 wt%, optionally 98 wt% - 99.8 wt% (such as 98 wt%, 98.5 wt%, 98.6 wt%, 98.8 wt%, 99 wt%, 99.2 wt%, 99.4 wt%, 99.6 wt%, 99.8 wt%, etc.) of xylylene diisocyanate as the main component. However, since it contains the compound shown in the chemical formula (I) as a minor component, it is defined as a xylylene diisocyanate composition.

[0039] Furthermore, the content of the compound shown in the formula (I) in the xylylene diisocyanate composition is 1 - 350 ppm.

[0040] Furthermore, the compound shown in the formula (I) is selected from (denoted as 1,2-XIT), (denoted as 1,4-XIT) or (denoted as 1,3-XIT).

[0041] Furthermore, the xylylene diisocyanate includes any one or at least two combinations of 1,2-xylylene diisocyanate (o-xylylene diisocyanate, o-XDI, 1,2-XDI), 1,3-xylylene diisocyanate (m-xylylene diisocyanate, m-XDI, 1,3-XDI), or 1,4-xylylene diisocyanate (p-xylylene diisocyanate, p-XDI, 1,4-XDI). Preferably, it is 1,3-xylylene diisocyanate and / or 1,4-xylylene diisocyanate, and more preferably 1,3-xylylene diisocyanate.

[0042] In the present invention, XIT is produced as a by-product in the production of XDI described below. Of course, it can also be added artificially to obtain the required content.

[0043] In the present invention, the content ratio of XIT can be determined by analysis using liquid chromatography.

[0044] In a second aspect, the present application provides a method for preparing the xylylene diisocyanate composition according to any one of the above,

[0045] (1) Isocyanation step: subjecting xylylenediamine or xylylenediamine hydrochloride to an isocyanation reaction with phosgene in the presence of a reaction solvent;

[0046] (2) Separation step: separating and purifying the reaction product obtained in step (1) to obtain the xylylene diisocyanate composition;

[0047] Among them, the color number of xylylenediamine is less than or equal to 15 Hazen.

[0048] The isocyanate chemical process in step (1) can be called the phosgenation method. The isocyanation reaction is the phosgenation reaction. As the phosgenation method, specifically, for example, a method of directly reacting xylylenediamine with phosgene (also the cold and hot two-stage phosgenation method), a method of reacting the hydrochloride obtained by reacting xylylenediamine with hydrochloric acid (hydrogen chloride) with phosgene in a reaction solvent (also called the phosgenation method of amine hydrochloride), etc. are exemplified. The phosgenation method of reacting xylylenediamine hydrochloride with phosgene is preferred.

[0049] Preferably, the xylylenediamine hydrochloride is prepared through a salification process. The salification process includes: mixing xylylenediamine with hydrogen chloride in the presence of a reaction solvent to carry out a salification reaction to obtain the xylylenediamine hydrochloride. What is actually obtained in the salification process is a slurry containing xylylenediamine hydrochloride, and this slurry is directly applied to the isocyanate chemical process.

[0050] Preferably, the xylylenediamine (XDA) includes any one or at least two combinations of 1,2-xylylenediamine (o-xylylenediamine (o-XDA, 1,2-XDA)), 1,3-xylylenediamine (m-xylylenediamine (m-XDA, 1,3-XDA)), or 1,4-xylylenediamine (p-xylylenediamine (p-XDA, 1,4-XDA)).

[0051] Preferably, the salification process specifically includes: introducing hydrogen chloride gas (HCl gas) into the reaction solvent, then adding a solution containing xylylenediamine (abbreviated as xylylenediamine solution), and then stirring and mixing the hydrogen chloride gas and the xylylenediamine solution to carry out a salification reaction to obtain the xylylenediamine hydrochloride.

[0052] In the present invention, as the reaction solvent for the salification process or the solvent for the xylylenediamine solution, for example, aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as octane and decane, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane, halogenated aromatic hydrocarbons such as chlorotoluene, chlorobenzene, dichlorobenzene, dibromobenzene, and trichlorobenzene, nitrogen-containing compound classes such as nitrobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N'-dimethylimidazolinone, ethers such as dibutyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether, ketones such as heptanone, diisobutyl ketone, methyl isobutyl ketone, and methyl ethyl ketone, fatty acid esters such as ethyl acetate, butyl acetate, amyl acetate, and ethoxyethyl acetate, and aromatic carboxylic acid esters such as methyl salicylate, dimethyl phthalate, dibutyl phthalate, and methyl benzoate, etc. can be exemplified. The reaction solvent can be used alone or in combination of 2 or more kinds. Among the reaction solvents, halogenated aromatic hydrocarbons are preferred, and chlorobenzene and dichlorobenzene are more preferred.

[0053] Preferably, the content of xylylenediamine in the xylylenediamine solution is 1.0 wt.% or more, such as 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%, 14 wt.%, 15 wt.%, 16 wt.%, 17 wt.%, 18 wt.%, 19 wt.%, 20 wt.%, etc., and preferably 3.0 wt.% or more.

[0054] Preferably, the content of xylylenediamine in the xylylenediamine solution is 50 wt.% or less, and preferably 30 wt.% or less.

[0055] Preferably, the salt formation temperature in the salt formation step is 0 °C or more, such as 1 °C, 5 °C, 10 °C, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, etc., and preferably 10 °C or more.

[0056] Preferably, the salt formation temperature in the salt formation step is 150 °C or less, preferably 140 °C or less, and more preferably 130 °C or less.

[0057] Preferably, the molar ratio of hydrogen chloride to xylylenediamine is 2:1 or more, such as 3:1, 4:1, 5:1, 6:1, 8:1, 10:1.

[0058] Preferably, the molar ratio of hydrogen chloride to xylylenediamine is 20:1 or less, and preferably 10:1 or less.

[0059] Preferably, the salt formation step is carried out under normal pressure or pressurized conditions.

[0060] Preferably, the pressure (gauge pressure) in the salt formation step is 0.01 MPaG or more, such as 0.1 MPaG, 0.2 MPaG, 0.5 MPaG, 0.6 MPaG, 0.7 MPaG, 0.8 MPaG, 0.9 MPaG, etc., and more preferably 0.02 MPaG or more.

[0061] Preferably, the pressure (gauge pressure) in the salt formation step is 1.0 MPaG or less, preferably 0.5 MPaG or less, and more preferably 0.4 MPaG or less.

[0062] Preferably, step (1) specifically includes: introducing phosgene gas into xylylenediamine hydrochloride to carry out an isocyanation reaction to obtain a reaction product containing xylylene diisocyanate and the compound shown in formula (I).

[0063] It should be noted that the content ratio of XIT in the XDI composition can also be adjusted by adding XIT to the XDI composition.

[0064] Preferably, the molar amount of phosgene is more than 4 times the molar amount of the phthalenediamine hydrochloride, such as 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 12 times, 14 times, 16 times, 18 times, 20 times, 22 times, 24 times, 26 times, 28 times, 30 times, 32 times, 34 times, 36 times, 38 times, 40 times, etc., and preferably more than 5 times.

[0065] Preferably, the molar amount of phosgene is 40 times or less the molar amount of the phthalenediamine hydrochloride, and preferably 30 times or less.

[0066] Preferably, the reaction temperature in the isocyanation process is 100 °C or higher, such as 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, etc., and preferably 110 °C or higher.

[0067] Preferably, the reaction temperature in the isocyanation process is 180 °C or lower, preferably 170 °C or lower, and more preferably 160 °C or lower.

[0068] Preferably, the time of the isocyanation reaction is 2 h or longer, such as 3 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, etc., and preferably 4 h or longer.

[0069] Preferably, the time of the isocyanation reaction is 25 h or shorter, and preferably 20 h or shorter.

[0070] Preferably, the isocyanation reaction is carried out under normal pressure or pressurized conditions.

[0071] Preferably, the pressure (gauge pressure) of the isocyanation reaction is 0 MPaG or higher, such as 0.0004 MPaG, 0.0008 MPaG, 0.001 MPaG, 0.002 MPaG, 0.006 MPaG, 0.01 MPaG, 0.02 MPaG, 0.03 MPaG, 0.05 MPaG, 0.1 MPaG, 0.2 MPaG, 0.3 MPaG, 0.4 MPaG, 0.5 MPaG, 0.6 MPaG, etc., preferably 0.0005 MPaG or higher, more preferably 0.001 MPaG or higher, further preferably 0.003 MPaG or higher, particularly preferably 0.01 MPaG or higher, especially preferably 0.02 MPaG or higher, and most preferably 0.03 MPaG or higher.

[0072] Preferably, the pressure (gauge pressure) of the isocyanation reaction is 0.6 MPaG or less, preferably 0.4 MPaG or less, and more preferably 0.2 MPaG or less.

[0073] Preferably, the isocyanation process is a batch process or a continuous process, preferably a continuous process.

[0074] The continuous process means that the slurry (XDA hydrochloride) generated in the stirring tank is continuously transported from the stirring tank to a reaction tank different from the stirring tank, and in the reaction tank, XDA hydrochloride reacts with phosgene, and the reaction liquid (reaction substance) is continuously taken out from the reaction tank. The present invention does not specifically limit the number of reaction kettles for the continuous process. Exemplarily, it can be two, three, four, five or more.

[0075] If necessary, for the reaction product of the isocyanation process, a degassing process, a solvent separation and purification process can be implemented. The remaining phosgene, hydrogen chloride and other gases generated as by-products are removed from the reaction product by using a known degassing tower. In the solvent separation and purification process, the reaction solvent is distilled off from the reaction liquid by using a known distillation tower. After the solvent is refined, most of it returns to the salification and isocyanation processes.

[0076] In the preferred technical solution of the present invention, the color number of XDA is controlled below 15 Hazen, which helps to obtain a composition with an XIT content in the range of 1-1000 ppm.

[0077] As the separation process, the reaction liquid (reaction mixture) in step (1) is subjected to a solvent removal process. In the solvent removal process, the inert solvent is distilled off from the reaction liquid by using a known distillation tower.

[0078] If necessary, a de-tarring process can be implemented for the reaction product after the solvent removal. The tar components are removed from the reaction liquid by using a known de-tarring device such as a short-path evaporator. It should be noted that the reaction substance from which the tar components have been removed through the de-tarring process is denoted as the intermediate substance. Additionally, if necessary, the intermediate substance can be purified. The purification method is not particularly limited and can be implemented by using industrial separation techniques such as distillation, rectification, crystallization, etc.

[0079] Preferably, the rectification is carried out in a rectification tower.

[0080] Preferably, the rectification tower includes a plate rectification tower or a packed rectification tower.

[0081] In the preferred technical solution of the present invention, the proportion of XIT can be adjusted to the above range by controlling the reaction conditions and separation conditions. It should be noted that the content ratio of XIT in the XDI composition can also be adjusted by adding XIT to the XDI composition.

[0082] Preferably, the number of theoretical plates of the rectification column is 2 or more, such as 4, 6, 8, 10, 14, 18, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, etc., preferably 5 or more.

[0083] Preferably, the number of theoretical plates of the rectification column is 60 or less, preferably 40 or less.

[0084] Preferably, the top pressure of the rectification column is 0.1 kPa or more, such as 0.2 kPa, 0.4 kPa, 0.6 kPa, 0.8 kPa, 1 kPa, 1.5 kPa, 2 kPa, 2.5 kPa, 3 kPa, 3.5 kPa, etc., preferably 0.15 kPa or more.

[0085] Preferably, the top pressure of the rectification column is 4 kPa or less, preferably 2.5 kPa or less.

[0086] Preferably, the top pressure of the rectification column is 100 - 500 Pa.

[0087] Preferably, the top reflux ratio of the rectification column is 0.01 or more, such as 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 18, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, etc., preferably 0.1 or more.

[0088] Preferably, the top reflux ratio of the rectification column is 60 or less, preferably 40 or less.

[0089] Preferably, the bottom temperature of the rectification column is 120 °C or more, such as 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, etc., preferably 145 - 155 °C.

[0090] Preferably, the top temperature of the rectification column is 80 °C or more, such as 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, etc., preferably 100 - 120 °C.

[0091] Preferably, the residence time of the rectification column is 2 h or more, such as 3 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, etc., preferably 4 h or more. The residence time of the rectification column is 2 - 6 h.

[0092] Specifically, first, a reaction solvent is charged into the salification kettle. Then, hydrogen chloride gas is continuously supplied to the bottom of the salification kettle through the hydrogen chloride supply line at the above-mentioned supply ratio (i.e., the controlled ratio of the mass of the above-mentioned xylylenediamine solution to the mass of the hydrogen chloride). Additionally, the above-mentioned xylylenediamine solution in which XDA is dissolved in the reaction solvent is continuously supplied to the top of the salification kettle through the amine supply line. Then, while maintaining the inside of the salification kettle at the above-mentioned salification temperature and salification pressure, the hydrogen chloride gas and the xylylenediamine solution are stirred and mixed by the stirring blades (salification process). Thereby, a slurry containing XDA hydrochloride is produced.

[0093] Then, the slurry containing XDA hydrochloride is continuously transported to the top of the phosgenation kettle through the hydrochloride transport line. That is, while continuously supplying hydrogen chloride gas and the xylylenediamine solution to the salification kettle, the slurry containing XDA hydrochloride is continuously taken out from the salification kettle and transported to the phosgenation kettle.

[0094] Next, at the above-mentioned supply ratio (i.e., the controlled ratio of the molar amount of the above-mentioned phosgene to the molar amount of the xylylenediamine hydrochloride), phosgene is continuously supplied to the tops of each of the first phosgenation kettle, the second phosgenation kettle, and the third phosgenation kettle in an inserted tube manner. Then, while maintaining the inside of the first phosgenation kettle at the above-mentioned reaction temperature and reaction pressure, the slurry and phosgene are stirred and mixed (the first-step isocyanate process). Thereby, XDA hydrochloride reacts with phosgene to generate XDI as the main component and XIT as a by-product. The total molar amount of phosgene and the molar amount of the xylylenediamine hydrochloride in the three phosgenation kettles are within the above range.

[0095] Then, the reaction liquid containing XDI, XIT, and the reaction solvent, etc. is continuously transported to the top of the second phosgenation kettle through the reaction substance transport line. That is, while continuously supplying the slurry and phosgene to the first phosgenation kettle, the primary phosgenation liquid is continuously taken out from the first phosgenation kettle and transported to the second phosgenation kettle.

[0096] Next, while maintaining the inside of the second phosgenation kettle at the above-mentioned reaction temperature and reaction pressure, the primary reaction substance and phosgene are stirred and mixed in the second phosgenation kettle (the second-step isocyanate process).

[0097] Similarly, in the third phosgenation kettle, the phosgenation reaction is carried out while inputting the secondary reaction substance (the third-step isocyanate process).

[0098] Thereby, the salification process and the isocyanate process are continuously carried out.

[0099] Then, a reaction liquid (phosgenation reaction liquid) containing XDI, XIT, or an intermediate thereof, and the reaction solvent, etc. is produced. It should be noted that the total residence time in the three-step isocyanate process is within the above-mentioned isocyanation reaction time range.

[0100] Next, the above-described photochemical reaction solution is continuously supplied to the middle part of the degassed phosgene tower through the reaction substance supply line. Through the degassed phosgene tower, the photochemical reaction solution is separated into a gas containing phosgene, hydrogen chloride, etc., and a degassed substance in a liquid state containing XDI, XIT or an intermediate thereof, and a reaction solvent (degassing step).

[0101] Next, the degassed substance is continuously supplied to the middle of the solvent removal tower through the degassed substance supply line. Then, using the solvent removal tower, the reaction solvent is distilled off from the degassed substance (solvent separation and purification step) to obtain a degassed substance containing XDI, XIT or an intermediate thereof.

[0102] Next, the degassed substance is continuously supplied to the upper part of the de-tarring device through the degassed substance supply line. Then, using the de-tarring device, the tar component is removed from the degassed substance to obtain an intermediate substance containing XDI and XIT (de-tarring step).

[0103] Next, the intermediate substance is continuously supplied to the middle of the distillation column through the intermediate substance supply line. Then, under the conditions of the above-described distillation step (bottom temperature, top temperature, top pressure, top reflux ratio, and residence time), the low-boiling components are distilled off from the intermediate substance, and the XDI composition is withdrawn from a position slightly below the middle of the column.

[0104] Thus, an XDI composition containing XDI and XIT can be continuously produced.

[0105] In a third aspect, the present invention provides a modified composition of a benzenedimethyl diisocyanate composition, wherein the modified composition is a modified composition obtained by modifying the benzenedimethyl diisocyanate composition provided in the first aspect, and the modified benzenedimethyl diisocyanate in the modified composition contains any one or at least two combinations of the following groups (a)-(i): (a) isocyanurate group, (b) uretdione group, (c) biuret group, (d) carbamate group, (e) urea group, (f) iminooxadiazinedione group, (g) urethane group, (h) uretonimine group, or (i) carbodiimide group.

[0106] Those skilled in the art can modify the XDI composition as needed using known methods to obtain an XDI modified composition, and the XDI modified composition is suitably used as a polyisocyanate component and a component containing an active hydrogen group as a raw material for a polyurethane resin.

[0107] More specifically, the modified XDI containing the functional group (isocyanurate group) of the above (a) is a trimer of XDI, and can be obtained, for example, by reacting an XDI composition in the presence of a known isocyanuration catalyst to carry out isocyanuration of XDI therein.

[0108] The modified XDI containing the functional group (uretdione group) of the above (b) can be obtained by heating the XDI composition at about 90°C - 200°C, or by reacting it in the presence of a known uretdione-forming catalyst to cause uretdionization (e.g., dimerization) of XDI.

[0109] The modified XDI containing the functional group (biuret group) of the above (c) can be obtained by reacting the XDI composition with, for example, water, a tertiary alcohol (e.g., tert-butanol, etc.), a secondary amine (e.g., dimethylamine, diethylamine, etc.), etc., and then further reacting it in the presence of a known biuret-forming catalyst.

[0110] The modified XDI containing the functional group (urethane group) of the above (d) can be obtained by reacting the XDI composition with a polyol component (e.g., trimethylolpropane, etc.).

[0111] The modified XDI containing the functional group (urea group) of the above (e) can be obtained by reacting the XDI composition with water, a polyamine component (described later), etc.

[0112] The modified XDI (asymmetric trimer) containing the functional group (iminooxadiazinedione group) of the above (f) can be obtained by reacting the XDI composition in the presence of a known iminooxadiazinedionization catalyst to cause iminooxadiazinedionization (e.g., trimerization) of XDI.

[0113] The modified XDI containing the functional group (urethylenediurethane group) of the above (g) can be obtained by reacting the XDI composition with an alcohol and then further reacting it in the presence of a known urethylenediurethane-forming catalyst.

[0114] The modified XDI containing the functional group (uretonimine group) of the above (h) can be obtained by reacting the XDI composition in the presence of a known carbodiimidization catalyst to form a carbodiimide group, and then adding XDI to the carbodiimide group.

[0115] The modified XDI containing the functional group (carbodiimide group) of the above (i) can be obtained by reacting the XDI composition in the presence of a known carbodiimidization catalyst.

[0116] It should be noted that the XDI modified composition only needs to contain at least one of the above functional groups (a)-(i), and it can also contain two or more. Such an XDI modified composition can be generated by appropriately using the above reactions in combination. In addition, the XDI modified composition can be used alone or in combination of two or more.

[0117] Fourth aspect, the present invention provides a resin composition, which comprises the xylylene diisocyanate composition provided in the first aspect, or the xylylene diisocyanate composition prepared by the preparation method provided in the second aspect, or the modified composition of the xylylene diisocyanate composition provided in the third aspect, and a substance containing an active hydrogen group.

[0118] Fifth aspect, the present invention provides a polyurethane resin, which is formed by reacting the xylylene diisocyanate composition provided in the first aspect or the second aspect with a substance containing an active hydrogen group, or by reacting the modified composition provided in the third aspect with a substance containing an active hydrogen group.

[0119] Examples of the substance containing an active hydrogen group include a polyol component (a component mainly containing a polyol having two or more hydroxyl groups), a polythiol component (a component mainly containing a polythiol having two or more mercapto groups (thiol groups)), a polyamine component (a compound of a polyamine mainly containing two or more amino groups), and the like.

[0120] Examples of the polyol component include low molecular weight polyols and high molecular weight polyols.

[0121] The 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.

[0122] Examples of the low molecular weight polyol include diols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, alkane(7-22)diol, diethylene glycol, triethylene glycol, dipropylene glycol, 3-methyl-1,5-pentanediol, alkane-1,2-diol (C (carbon number, the same hereinafter) 17-20), isosorbide, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,4-cyclohexanediol, hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, bisphenol A; triols such as glycerol, trimethylolpropane; tetrols such as pentaerythritol, diglycerol; pentols such as xylitol; hexols such as sorbitol, mannitol, allitol, iditol, dulcitol, adonitol, inositol, dipentaerythritol; heptols such as perseitol; octols such as sucrose, etc.

[0123] In addition, polyalkylene oxides having a number average molecular weight of 60 or more and less than 400 (random and / or block copolymers containing two or more alkylene oxides) obtained by adding alkylene oxides such as ethylene oxide and propylene oxide using the above alcohols as initiators are also included in the low molecular weight polyols.

[0124] The high molecular weight polyol is a compound having two or more hydroxyl groups, a number average molecular weight of 400 or more, for example, 10,000 or less, preferably 5,000 or less. Examples of the high molecular weight polyol include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, polysiloxane polyols, fluorine polyols, and vinyl monomer-modified polyols.

[0125] Examples of the polyether polyol include polyoxy(C2-C3)alkylene polyols, polytetramethylene ether glycols, and polytrimethylene ether glycols. Examples of the polyoxy(C2-C3)alkylene polyol include addition polymers of C2-3 alkylene oxides such as ethylene oxide and propylene oxide (including random and / or block copolymers of two or more alkylene oxides) using the above-mentioned low molecular weight polyol as an initiator. In addition, specific examples of the polyoxy(C2-3)alkylene include polyethylene glycol, polypropylene glycol, and polyethylene-propylene copolymers.

[0126] Examples of the polytetramethylene ether glycol include ring-opening polymers (polytetramethylene ether glycols) obtained by cationic polymerization of tetrahydrofuran, and amorphous polytetramethylene ether glycols obtained by copolymerizing polymerization units of tetrahydrofuran with the above-mentioned diols.

[0127] In addition, plant-derived polytetramethylene ether glycols starting from plant-derived tetrahydrofuran based on raw materials such as furfural can also be mentioned.

[0128] Examples of the polytrimethylene ether glycol include polyols produced by polycondensation of plant-derived 1,3-propanediol.

[0129] Examples of the polyester polyol include condensates obtained by reacting the above-mentioned low molecular weight polyol (preferably a diol) with a polybasic acid (preferably a dibasic acid) under known conditions.

[0130] As the polybasic acid, examples thereof include saturated aliphatic dicarboxylic acids (C11-C13) such as oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, sebacic acid, etc., unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, etc., aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, naphthalene dicarboxylic acid, etc., alicyclic dicarboxylic acids such as hexahydrophthalic acid, etc., other carboxylic acids such as dimer acid, hydrogenated dimer acid, HET acid, etc., and acid anhydrides derived from these carboxylic acids such as oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C12-C18) succinic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, and acyl halides derived from these carboxylic acids such as oxalyl dichloride, adipoyl dichloride, sebacoyl dichloride, etc.

[0131] In addition, as the polyester polyol, examples thereof include vegetable oil-based polyester polyols obtained by subjecting the above-mentioned low-molecular-weight polyols and hydroxycarboxylic acids such as vegetable oil fatty acids containing hydroxyl groups (for example, castor oil fatty acid containing ricinoleic acid, hydrogenated castor oil fatty acid containing 12-hydroxy stearic acid, etc.) to a condensation reaction under known conditions.

[0132] In addition, as the polyester polyol, examples thereof include polycaprolactone polyols, polypentanolide polyols, and lactone-based polyester polyols obtained by copolymerizing them with the above-mentioned diols, which are obtained by subjecting the above-mentioned low-molecular-weight polyols (preferably diols) as initiators to ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone.

[0133] As the polycarbonate polyol, examples thereof include ring-opening polymers of ethylene carbonate using the above-mentioned low-molecular-weight polyols (preferably diols) as initiators, and amorphous polycarbonate polyols obtained by copolymerizing the above-mentioned diols with the ring-opening polymers.

[0134] In addition, regarding the polyurethane polyol, examples thereof include polyester polyurethane polyols, polyether polyurethane polyols, polycarbonate polyurethane polyols, or polyester polyether polyurethane polyols obtained by reacting the polyester polyol, polyether polyol, and / or polycarbonate polyol obtained in the above manner with the above-mentioned polyisocyanate (including XDI. The same applies hereinafter) at a ratio where the equivalent ratio of hydroxyl group to isocyanate group (OH / NCO) is greater than 1.

[0135] As the epoxy polyol, examples thereof include epoxy polyols obtained by reacting the above-mentioned low-molecular-weight polyols with polyfunctional haloalcohols such as epichlorohydrin and β-methylepichlorohydrin.

[0136] Examples of vegetable oil polyols include vegetable oils containing hydroxyl groups such as castor oil and coconut oil. Examples include castor oil polyol, or ester-modified castor oil polyol obtained by reacting castor oil polyol with polypropylene polyol, etc.

[0137] Examples of polyolefin polyols include polybutadiene polyol, partially saponified ethylene-vinyl acetate copolymer, etc.

[0138] Examples of acrylic polyols include copolymers obtained by copolymerizing an acrylic ester containing a hydroxyl group and a copolymerizable vinyl monomer copolymerizable with the acrylic ester containing a hydroxyl group.

[0139] Examples of acrylic esters containing a hydroxyl group include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2,2-dihydroxymethylbutyl (meth)acrylate, polyhydroxyalkyl maleate, polyhydroxyalkyl fumarate, etc. Preferred examples include 2-hydroxyethyl (meth)acrylate, etc.

[0140] Examples of copolymerizable vinyl monomers include (meth)acrylic acid alkyl esters (carbon number 1-12) such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl acrylate, isobornyl (meth)acrylate, etc., and styrene, vinyltoluene, α-methylstyrene, etc.

[0141] Aromatic vinyl monomers, vinyl cyanides such as (meth)acrylonitrile, vinyl monomers containing a carboxyl group such as (meth)acrylic acid, fumaric acid, maleic acid, itaconic acid, or their alkyl esters, alkane polyol poly(meth)acrylates such as ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, oligoethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc., vinyl monomers containing an isocyanate group such as 3-(2-isocyanato-2-propyl)-α-methylstyrene, etc.

[0142] Furthermore, acrylic polyols can be obtained by copolymerizing these acrylic esters containing a hydroxyl group and copolymerizable vinyl monomers in the presence of an appropriate solvent and polymerization initiator.

[0143] In addition, acrylic polyols include, for example, polysiloxane polyols and fluoropolyols.

[0144] As the polysiloxane polyol, for example, an acrylic polyol obtained by copolymerizing the above-mentioned acrylic polyol and incorporating a vinyl group-containing polysiloxane compound such as γ-methacryloxypropyltrimethoxysilane as a copolymerizable vinyl monomer can be cited.

[0145] As the fluoropolyol, for example, an acrylic polyol obtained by copolymerizing the above-mentioned acrylic polyol and incorporating a vinyl group-containing fluorine compound such as tetrafluoroethylene or chlorotrifluoroethylene as a copolymerizable vinyl monomer can be cited.

[0146] The vinyl monomer-modified polyol can be obtained by reacting the above-mentioned high molecular weight polyol with a vinyl monomer such as the above-mentioned (meth)acrylic acid alkyl ester.

[0147] The above polyol components can be used alone or in combination of two or more.

[0148] In addition, in the reaction between the polyisocyanate component and the component containing an active hydrogen group, when the equivalent ratio of the active hydrogen group to the isocyanate group is less than 1, an isocyanate group-terminated polymer having an isocyanate group at the molecular end is formed, and when the equivalent ratio of the active hydrogen group to the isocyanate group is greater than 1, an active hydrogen group-terminated polymer having an active hydrogen group at the molecular end is formed. Both the isocyanate group-terminated polymer and the active hydrogen group-terminated polymer are included in the resin (polyurethane resin). The isocyanate group-terminated polymer is a one-component curable resin.

[0149] As the uses of the polyurethane resin, specifically, it can be suitably applied to inks, transfer foils, adhesives, binders, gels, elastomers, foams, adhesives, liquid-curing sealants, RIM molded products, microcellular polyurethanes, various microcapsules, optical materials, aqueous resins, thermosetting resins, active energy ray (e.g., electron beam, ultraviolet ray, etc.) curable resins, artificial and synthetic leathers, solidifying powders, robot components, moving components, healthcare materials, base resins for carbon fiber reinforced plastics (CFRP), transparent rubbers, transparent rigid resins, waterproof materials, films, sheets, tubes, plates, speakers, sensors, organic electroluminescent components, solar power generation components, robot components, wearable components, sports goods, leisure goods, medical supplies, nursing supplies, residential components, audio components, lighting components, chandeliers, outdoor electric lights, packaging, anti-vibration / anti-seismic / damping components, soundproof components, daily necessities, sundries, buffers, bedding, stress absorption materials, stress relaxation materials, interior and exterior decorative parts of automobiles, conveying mechanism components, components for office automation equipment, surface protection components for sundries, self-healing materials, health appliances, etc.

[0150] Sixth aspect, the present invention provides an optical material, which is polymerized from a benzene dimethylene diisocyanate composition provided by the first aspect, or a benzene dimethylene diisocyanate composition prepared by the preparation method provided by the second aspect, or a modified composition of the benzene dimethylene diisocyanate composition provided by the third aspect and a polythiol compound.

[0151] Preferably, the optical material includes a plastic lens material, an automobile headlamp cover material or a transparent roof material.

[0152] Among them, the plastic lens material can be used as an eye lens material, a lens material for a smart phone or a tablet.

[0153] Preferably, the polythiol compound is selected from aliphatic polythiol compounds such as methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol, 1,6-hexanedithiol, 1,2,3-propanetrithiol, 1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2-dithiol, 2-methylcyclohexane-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, bis(2-mercaptoethyl) thiodipropionate, 2,3-dimercapto-1-propanol (2-mercaptoacetate), 2,3-dimercapto-1-propanol (3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate), diethylene glycol bis(3-mercaptopropionate), 1,2-dimercaptopropyl methyl ether, 2,3-dimercaptopropyl methyl ether, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, bis(2-mercaptoethyl) ether, ethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), trimethylolpropane bis(2-mercaptoacetate), trimethylolpropane bis(3-mercaptopropionate), pentaerythritol tetra(2-mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), tetra(mercaptomethyl)methane, 2,3-dithio(2-mercapto)-1-propanethiol, etc.;

[0154] Aromatic polythiol compounds such as 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,2-bis(mercaptomethyl)benzene, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 1,2-bis(mercaptoethyl)benzene, 1,3-bis(mercaptoethyl)benzene, 1,4-bis(mercaptoethyl)benzene, 1,2,3-benzenetrithiol, 1,2,4-benzenetrithiol, 1,3,5-benzenetrithiol, 1,2,3-tris(mercaptomethyl)benzene, 1,2,4-tris(mercaptomethyl)benzene, 1,3,5-tris(mercaptomethyl)benzene, 1,2,3-tris(mercaptoethyl)benzene, 1,2,4-tris(mercaptoethyl)benzene, 1,3,5-tris(mercaptoethyl)benzene, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,3-bis(p-methoxyphenyl)propane-2,2-dithiol, 1,3-diphenylpropane-2,2-dithiol, phenylmethane-1,1-dithiol, 2,4-bis(p-mercaptophenyl)pentane;

[0155] Aromatic polythiol compounds containing sulfur atoms other than mercapto groups such as 1,2-bis(mercaptoethylthio)benzene, 1,3-bis(mercaptoethylthio)benzene, 1,4-bis(mercaptoethylthio)benzene, 1,2,3-tris(mercaptomethylthio)benzene, 1,2,4-tris(mercaptomethylthio)benzene, 1,3,5-tris(mercaptomethylthio)benzene, 1,2,3-tris(mercaptoethylthio)benzene, 1,2,4-tris(mercaptoethylthio)benzene, 1,3,5-tris(mercaptoethylthio)benzene, and their alkylated products;

[0156] Bis(mercaptomethyl)sulfide, bis(mercaptomethyl)disulfide, bis(mercaptoethyl)sulfide, bis(mercaptoethyl)disulfide, bis(mercaptopropyl)sulfide, bis(mercaptomethylthio)methane, bis(2-mercaptoethylthio)methane, bis(3-mercaptopropylthio)methane, 1,2-bis(mercaptomethylthio)ethane, 1,2-bis(2-mercaptoethylthio)ethane, 1,2-bis(3-mercaptopropylthio)ethane, 1,3-bis(mercaptomethylthio)propane, 1,3-bis(2-mercaptoethylthio)propane, 1,3-bis(3-mercaptopropylthio)propane, 1,2,3-tris(mercaptomethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, 1,2,3-tris(3-mercaptopropylthio)propane, 1,2-bis[(2-mercaptoethyl)thio]-3-mercaptopropane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, bis(mercaptomethyl)-3,6,9-trithia-1,11-undecanedithiol, tetrakis(mercaptomethylthiomethyl)methane, tetrakis(2-mercaptoethylthiomethyl)methane, tetrakis(3-mercaptopropylthiomethyl)methane, bis(2,3-dimercaptopropyl)sulfide, bis(1,3-dimercaptopropyl)sulfide, 2,5-dimercapto-1,4-dithiane, 2,5-dimercaptomethyl-1,4-dithiane, 2,5-dimercaptomethyl-2,5-dimethyl-1,4-dithiane, bis(mercaptomethyl)disulfide, bis(mercaptoethyl)disulfide, bis(mercaptopropyl)disulfide and other aliphatic polythiol compounds containing sulfur atoms other than mercapto groups, and esters of these with mercaptoacetic acid and mercaptopropionic acid;

[0157] Aliphatic polythiol compounds containing sulfur atoms and ester bonds other than mercapto groups, such as hydroxymethyl thioether bis(2-mercaptoacetate), hydroxymethyl thioether bis(3-mercaptopropionate), hydroxyethyl thioether bis(2-mercaptoacetate), hydroxyethyl thioether bis(3-mercaptopropionate), hydroxypropyl thioether bis(2-mercaptoacetate), hydroxypropyl thioether bis(3-mercaptopropionate), hydroxymethyl disulfide bis(2-mercaptoacetate), hydroxymethyl disulfide bis(3-mercaptopropionate), hydroxyethyl disulfide bis(2-mercaptoacetate), hydroxyethyl disulfide bis(3-mercaptopropionate), hydroxypropyl disulfide bis(2-mercaptoacetate), hydroxypropyl disulfide bis(3-mercaptopropionate), 2-mercaptoethyl ether bis(2-mercaptoacetate), 2-mercaptoethyl ether bis(3-mercaptopropionate), 1,4-dithiane-2,5-diol bis(2-mercaptoacetate), 1,4-dithiane-2,5-diol bis(3-mercaptopropionate), sulfinyl diacetic acid bis(2-mercaptoethyl ester), thiodipropionic acid bis(2-mercaptoethyl ester), 4,4'-thiodibutyric acid bis(2-mercaptoethyl ester), disulfinyl diacetic acid bis(2-mercaptoethyl ester), dithiodipropionic acid bis(2-mercaptoethyl ester), 4,4'-dithiodibutyric acid bis(2-mercaptoethyl ester), sulfinyl diacetic acid bis(2,3-dimercaptopropyl ester), thiodipropionic acid bis(2,3-dimercaptopropyl ester), disulfinyl diacetic acid bis(2,3-dimercaptopropyl ester), dithiodipropionic acid bis(2,3-dimercaptopropyl ester), etc.;

[0158] Heterocyclic compounds containing sulfur atoms other than mercapto groups, such as 3,4-thiophenedithiol, 2,5-dimercapto-1,3,4-thiadiazole;

[0159] Compounds containing hydroxyl groups other than mercapto groups, such as 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerol bis(mercaptoacetate), 1-hydroxy-4-mercaptocyclohexane, 2,4-dimercaptophenol, 2-mercaptohydroquinone, 4-mercaptophenol, 3,4-dimercapto-2-propanol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3-butanediol, pentaerythritol tris(3-mercaptopropionate), pentaerythritol mono(3-mercaptopropionate), pentaerythritol bis(3-mercaptopropionate), pentaerythritol tris(mercaptoacetate), dipentaerythritol penta(3-mercaptopropionate), hydroxymethyl-tris(mercaptoethylthiomethyl)methane, 1-hydroxyethylthio-3-mercaptoethylthio benzene;

[0160] 1,1,3,3 - Tetrakis(mercaptomethylthio)propane, 1,1,2,2 - tetrakis(mercaptomethylthio)ethane, 4,6 - bis(mercaptomethylthio)-1,3 - dithiane, 1,1,5,5 - tetrakis(mercaptomethylthio)-3 - thiapentane, 1,1,6,6 - tetrakis(mercaptomethylthio)-3,4 - dithiahexane, 2,2 - bis(mercaptomethylthio)ethanethiol, 2-(4,5 - dimercapto - 2 - thiapentyl)-1,3 - dithiacyclopentane, 2,2 - bis(mercaptomethyl)-1,3 - dithiacyclopentane, 2,5 - bis(4,4 - bis(mercaptomethylthio)-2 - thiabutyl)-1,4 - dithiane, 2,2 - bis(mercaptomethylthio)-1,3 - propanedithiol, 3 - mercaptomethylthio - 1,7 - dimercapto - 2,6 - dithiaheptane, 3,6 - bis(mercaptomethylthio)-1,9 - dimercapto - 2,5,8 - trithianonane, 4,6 - bis(mercaptomethylthio)-1,9 - dimercapto - 2,5,8 - trithianonane, 3 - mercaptomethylthio - 1,6 - dimercapto - 2,5 - dithiahexane, 2-(2,2 - bis(mercaptomethylthio)ethyl)-1,3 - dithiacyclobutane, 1,1,9,9 - tetrakis(mercaptomethylthio)-5-(3,3 - bis(mercaptomethylthio)-1 - thiapropyl)3,7 - dithianonane, tris(2,2 - bis(mercaptomethylthio)ethyl)methane, tris(4,4 - bis(mercaptomethylthio)-2 - thiabutyl)methane, tetrakis(2,2 - bis(mercaptomethylthio)ethyl)methane, tetrakis(4,4 - bis(mercaptomethylthio)-2 - thiabutyl)methane, 3,5,9,11 - tetrakis(mercaptomethylthio)-1,13 - dimercapto - 2,6,8,12 - tetrathiatridecane, 3,5,9,11,15,17 - hexakis(mercaptomethylthio)-1,19 - dimercapto - 2,6,8,12,14,18 - hexathianonadecane, 9-(2,2 - bis(mercaptomethylthio)ethyl)-3,5,13,15 - tetrakis(mercaptomethylthio)-1,17 - dimercapto - 2,6,8,10,12,16 - hexathiaheptadecane, 3,4,8,9 - tetrakis(mercaptomethylthio)-1,11 - dimercapto - 2,5,7,10 - tetrathiaundecane, 3,4,8,9,13,14 - hexakis(mercaptomethylthio)-1,16 - dimercapto - 2,5,7,10,12,15 - hexathiahexadecane, 8 - {bis(mercaptomethylthio)methyl}-3,4,12,13 - tetrakis(mercaptomethylthio)-1,15 - dimercapto - 2,5,7,9,11,14 - hexathiapentadecane, 4,6 - bis{3,5 - bis(mercaptomethylthio)-7 - mercapto - 2,6 - dithiaheptylthio}-1,3 - dithiane, 4 - {3,5 - bis(mercaptomethylthio)-7 - mercapto - 2,6 - dithiaheptylthio}-6 - mercaptomethylthio - 1,3 - dithiane, 1,1 - bis{4-(6 - mercaptomethylthio)-1,3 - dithianylthio}-3,3 - bis(mercaptomethylthio)propane, 1,3 - Bis{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-1,3 - bis(mercaptomethylthio)propane, 1-{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-3-{2,2 - bis(mercaptomethylthio)ethyl}-7,9 - bis(mercaptomethylthio)-2,4,6,10 - tetrathiaundecane, 1-{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-3-{2-(1,3 - dithiacyclobutyl)}methyl - 7,9 - bis(mercaptomethylthio)-2,4,6,10 - tetrathiaundecane, 1,5 - bis{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-3-{2-(1,3 - dithiacyclobutyl)}methyl - 2,4 - dithiapentane, 4,6 - Bis[3-{2-(1,3 - dithiacyclobutyl)}methyl - 5 - mercapto - 2,4 - dithiapentylthio]-1,3 - dithiane, 4,6 - Bis{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-1,3 - dithiane, 4-{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-6-{4-(6 - Mercaptomethylthio)-1,3 - dithianylthio}-1,3 - dithiane, 3-{2-(1,3 - dithiacyclobutyl)}methyl - 7,9 - bis(mercaptomethylthio)-1,11 - dimercapto - 2,4,6,10 - tetrathiaundecane, 9-{2-(1,3 - dithiacyclobutyl)}methyl - 3,5,13,15 - tetra(mercaptomethylthio)-1,17 - dimercapto - 2,6,8,10,12,16 - hexathiaheptadecane, 3-{2-(1,3 - dithiacyclobutyl)}methyl - 7,9,13,15 - tetra(mercaptomethylthio)-1,17 - dimercapto - 2,4,6,10,12,16 - hexathiaheptadecane, 3,7 - Bis{2-(1,3 - dithiacyclobutyl)}methyl - 1,9 - dimercapto - 2,4,6,8 - tetrathianonane, 4-{3,4,8,9 - tetra(mercaptomethylthio)-11 - mercapto - 2,5,7,10 - tetrathiaundecyl}-5 - mercaptomethylthio - 1,3 - dithiacyclopentane, 4,5 - Bis{3,4 - bis(mercaptomethylthio)-6 - mercapto - 2,5 - dithiahexylthio}-1,3 - dithiacyclopentane, 4-{3,4 - bis(mercaptomethylthio)-6 - mercapto - 2,5 - dithiahexylthio}-5 - mercaptomethylthio - 1,3 - dithiacyclopentane, 4-{3 - bis(mercaptomethylthio)methyl - 5,6 - bis(mercaptomethylthio)-8 - mercapto - 2,4,7 - trithiaoctyl}-5 - mercaptomethylthio - 1,3 - dithiacyclopentane, 2 - [Bis{3,4 - bis(mercaptomethylthio)-6 - mercapto - 2,5 - dithiahexylthio}methyl]-1,3 - dithiacyclobutane, 2-{3,4 - bis(mercaptomethylthio)-6 - mercapto - 2,5 - dithiahexylthio}mercaptomethylthio methyl - 1,3 - dithiacyclobutane, 2-{3,4,8,9-Tetrakis(mercaptomethylthio)-11-mercapto-2,5,7,10-tetrathiaundecylthio}mercaptomethyl-1,3-dithiolane, 2-{3-Bis(mercaptomethylthio)methyl-5,6-bis(mercaptomethylthio)-8-mercapto-2,4,7-trithiaoctyl}mercaptomethyl-1,3-dithiolane, 4,5-Bis[1-{2-(1,3-dithiolanyl)}-3-mercapto-2-thiapropylthio]-1,3-dithiolane, 4-[1-{2-(1,3-dithiolanyl)}-3-mercapto-2-thiapropylthio]-5-{1,2-bis(mercaptomethylthio)-4-mercapto-3-thiabutylthio}-1,3-dithiolane, 2-[Bis{4-(5-mercaptomethylthio-1,3-dithiolanyl)thio}]methyl-1,3-dithiolane, 4-{4-(5-mercaptomethylthio-1,3-dithiolanyl)thio}-5-[1-{2-(1,3-dithiolanyl)}-3-mercapto-2-thiapropylthio]-1,3-dithiolane, and compounds having a dithioacetal or dithioketal skeleton such as their oligomers;

[0161] Tris(mercaptomethylthio)methane, tris(mercaptoethylthio)methane, 1,1,5,5 - tetrakis(mercaptomethylthio)-2,4 - dithiapentane, bis(4,4 - bis(mercaptomethylthio)-1,3 - dithia - butyl)(mercaptomethylthio)methane, tris(4,4 - bis(mercaptomethylthio)-1,3 - dithia - butyl)methane, 2,4,6 - tris(mercaptomethylthio)-1,3,5 - trithiane, 2,4 - bis(mercaptomethylthio)-1,3,5 - trithiane, 1,1,3,3 - tetrakis(mercaptomethylthio)-2 - thiapropane, bis(mercaptomethyl)methylthio - 1,3,5 - trithiane, tris(((4 - mercaptomethyl - 2,5 - dithia - cyclohexyl - 1 - yl)methylthio)methane, 2,4 - bis(mercaptomethylthio)-1,3 - dithiolane, 2 - mercaptoethylthio - 4 - mercaptomethyl - 1,3 - dithiolane, 2-(2,3 - dimercaptopropylthio)-1,3 - dithiolane, 4 - mercaptomethyl - 2-(2,3 - dimercaptopropylthio)-1,3 - dithiolane, 4 - mercaptomethyl - 2-(1,3 - dimercapto - 2 - propylthio)-1,3 - dithiolane, tris(2,2 - bis(mercaptomethylthio)-1 - thiaethyl)methane, tris(3,3 - bis(mercaptomethylthio)-2 - thiapropyl)methane, tris(4,4 - bis(mercaptomethylthio)-3 - thiabutyl)methane, 2,4,6 - tris(3,3 - bis(mercaptomethylthio)-2 - thiapropyl)-1,3,5 - trithiane, tetrakis(3,3 - bis(mercaptomethylthio)-2 - thiapropyl)methane, etc., and their oligomers and other compounds having a trithiocarbonate skeleton;

[0162] 3,3’ - bis(mercaptomethylthio)-1,5 - dimercapto - 2,4 - dithiapentane, 2,2’ - bis(mercaptomethylthio)-1,3 - dithiolane, 2,7 - bis(mercaptomethyl)-1,4,5,9 - tetrathiaspiro[4,4]nonane, 3,9 - dimercapto - 1,5,7,11 - tetrathiaspiro[5,5]undecane, and their oligomers and other compounds having a tetrathiocarbonate skeleton, etc.

[0163] However, the polythiol compounds are not limited to the compounds listed above. In addition, the compounds listed above can be used alone or in combination of two or more.

[0164] Among the compounds listed above, it is particularly preferable to use at least one polythiol compound selected from the group consisting of 2,3 - dithio(2 - mercapto)-1 - propanethiol, 1,2 - bis[(2 - mercaptoethyl)thio]-3 - mercaptopropane, bis(mercaptomethyl)-3,6,9 - trithia - 1,11 - undecanedithiol, pentaerythritol tetra(3 - mercaptopropionate), 1,1,3,3 - tetrakis(mercaptomethylthio)propane, and 2 - mercaptoethanol.

[0165] Preferably, the preparation method of the optical material is carried out in the presence of a polymerization catalyst, and the polymerization catalyst is preferably an organotin compound, such as dialkyltin halides such as dibutyltin dichloride and dimethyltin dichloride; dialkyltin dicarboxylates such as dimethyltin diacetate, dibutyltin dioctanoate, and dibutyltin dilaurate.

[0166] In addition, according to the purpose, various additives such as chain extenders, crosslinking agents, light stabilizers, ultraviolet absorbers, antioxidants, oil-soluble dyes, fillers, and mold release agents are optionally added in the preparation method of the optical material.

[0167] The optical material formed of a polyurethane resin is usually manufactured by injection polymerization. Specifically, a polythiol compound and an isocyanate compound are mixed, and appropriate additives are optionally added. When necessary, the mixture (polymerizable composition) is degassed by an appropriate method and then injected into an injection mold for an optical material. Usually, it is slowly heated from a low temperature to a high temperature to polymerize it. Then, the optical material is obtained by demolding.

[0168] If the content ratio of XIT in the XDI composition or XDI-modified composition for an optical material is 1-1000 ppm, the optical material can be stably manufactured from the XDI composition or XDI-modified composition for an optical material. If the content ratio of XIT in the XDI composition or XDI-modified composition for an optical material is below the above upper limit, the discoloration of the optical material can be suppressed.

[0169] The stripe incidence rate of the optical material provided by the present invention can be controlled to be less than 1%, and can be as low as 0%.

[0170] The measurement methods for the relevant tests in the present invention are as follows:

[0171] 1. Content ratio of compound 1,3-XIT

[0172] The content is analyzed by liquid chromatography-mass spectrometry under the following conditions.

[0173] Preparation of standard solution: m-Xylylene diisocyanate trimer is prepared according to the method of Patent CN113234034A (Example 1) as the 1,3-XIT standard, and its structural formula is Nuclear magnetic resonance is tested using Bruker 400MHz, and the nuclear magnetic resonance data 1 HNMR(400MHz DMSO)δ7.45-7.42(m,2H)7.17-7.04(m,9H)5.20-5.16(m,6H)4.65-4.61(m,6H); 1CNMR (400 MHz, DMSO) δ 151.0, 138.7, 138.3, 128.8, 128.4, 125.9, 125.0, 123.9, 54.9, 46.8. The XIT reference standard was dissolved in acetonitrile to obtain a reference standard solution with a concentration of 1 wt%.

[0174] Preparation of the test solution: 0.1 g of the sample to be tested was taken, 0.5 g of di-n-butylamine was added, and it was dissolved in 2 ml of acetonitrile to prepare the test solution. The reference standard solution and the test solution were injected into the liquid chromatography-mass spectrometry instrument for testing according to the following chromatographic conditions and mass spectrometry conditions, and the external standard method was used to calculate the mass content of XIT in the sample to be tested.

[0175] Chromatographic conditions: Instrument: Agilent 1290; Chromatographic column: Agilent Extend C18 RRHD (2.1×100 mm, 1.8 μm); Column temperature: 40 °C; Flow rate: 0.2 ml / min; Mobile phase: A: acetonitrile, B: pure water; Gradient elution was carried out according to Table 1, Injection volume: 20 μL; Mass spectrometry conditions: Ionization mode: positive ion mode; Nebulizer gas temperature: 300 °C; Dry gas flow rate: 8 L / min; Capillary voltage: 3.5 kV; Scanning mode: SIM, Detection ions: m / z 952, 564.

[0176] Table 1 Gradient elution table

[0177] Time (min) Mobile Phase A (volume percentage) Mobile Phase B (volume percentage) 0-5 70％ 30％ 5 - 6 min 70％→80％ 30％→20％ 6 - 11 min 80％ 20％ 11 - 12 min 80％→90％ 20％→10％ 12 - 17 min 90％ 10％ 17 - 18 min 90％→100％ 10％→0％ 18 - 23 min 100％ 0％

[0178] 2. Mass content of benzylidene diisocyanate

[0179] Analysis was carried out by gas chromatography under the following conditions to test the normalized content.

[0180] Instrument: Agilent 7890

[0181] (1) Chromatographic column: DB-5 (30 m × 0.25 mm × 0.25 μm); (2) Injection volume: 0.5 μL; (3) Split ratio: 1 / 30; (4) Injection port temperature: 260 °C; (5) Column flow rate: 1.5 mL / min; (6) Programmed temperature rise: Hold at 100 °C for 1 min, rise to 280 °C at 10 °C / min, hold for 20 min; (7) FID detector temperature: 280 °C; (8) Hydrogen flow rate: 40 mL / min, Air flow rate: 400 mL / min.

[0182] 3. XDA color number: The XDA color number was measured using a HACH LICO 690 bench-top liquid platinum-cobalt colorimeter.

[0183] 4. Refractive index: Measured at 20 °C using an Abbe refractometer (NAR4T, ATAGO).

[0184] 5. Stripe incidence: Stripes refer to the phenomenon that the refractive index of a part is different from that of the surrounding part due to different resin composition. Visually observe 200 lenses under a high-pressure mercury lamp, identify lenses with stripes, and calculate the stripe incidence.

[0185] 6. Transmittance consistency: Hunterlab USVIS1839 colorimeter, the test light source is a xenon lamp that is filtered to simulate the standard D65 light source, and the test mode is total transmission. The average value in the range of 500nm-780nm is selected as the lens transmittance in the visible spectrum region, and 200 lenses are tested to confirm the lenses with consistent transmittance. The transmittance consistency is calculated according to the following formula. Transmittance consistency = lenses with consistent transmittance / 200*100%. The method for determining whether a lens is a lens with consistent transmittance is as follows:

[0186] Calculate the average transmittance of 200 lenses in the visible spectrum region, and calculate the RSD value of the average value and the transmittance of a certain lens in the visible spectrum region. If the RSD value is ≤2%, the lens is recorded as a lens with consistent transmittance, otherwise it is a lens with inconsistent transmittance.

[0187] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0188] It should be noted that, unless otherwise specified, "parts" and "%" are based on mass.

[0189] Example 1

[0190] This embodiment provides a method for preparing an XDI composition, comprising the following steps: adding 1000 parts by mass of chlorobenzene into Figure 1 In the salt-forming kettle 1 shown. Next, the salt-forming temperature in the salt-forming kettle was adjusted to 25°C, and the salt-forming pressure (gauge pressure) in the salt-forming kettle was adjusted to 0.04 MPaG.

[0191] Next, HCl gas was continuously blown into the salt-forming reactor 1 from the hydrogen chloride supply line at a supply rate of 64 parts by mass / hr, and a 1,3-XDA solution (the solvent of the 1,3-XDA solution was chlorobenzen, and the color number of the raw material 1,3-XDA used to prepare the 1,3-XDA solution was 5 Hazen) with a content of 7.5 wt.% was continuously charged into the salt-forming reactor 1 from the amine supply line at a supply rate of 1000 parts by mass / hr, with an average residence time of 4 hours. At the same time, a slurry containing 1,3-XDA hydrochloride was transported to the photochemical reactor 1 through the hydrochloride transport line.

[0192] Next, phosgene corresponding to 5 times, 4 times, and 1 times the molar amount of 1,3-XDA was continuously introduced into photochemical kettle 2, photochemical kettle 3, and photochemical kettle 4, respectively. The reaction temperature of the three reaction kettles was 150 °C, the reaction pressure was 200 kpaG, and the residence time was 2 h.

[0193] Thereby, 1,3-XDA hydrochloride reacts with phosgene to generate 1,3-XDI, and a reaction substance containing 1,3-XDI is prepared. In addition, a part of the unreacted phosgene is condensed by a condenser and condensed into the photochemical kettle.

[0194] Next, the photochemical reaction liquid was continuously transported to the degassing tower 5. Then, the reaction substance was degassed in the degassing tower 5. Next, through the degassed substance transport line, the degassed substance was discharged from the degassing tower and continuously transported to the desolventizing tower 6. After desolventizing treatment, 110 parts by mass of a crude product with a 1,3-XDI content of 94 wt.% was prepared.

[0195] Next, the crude product was discharged from the desolventizing tower 6 through the crude product transport line, and the material after desolventizing was continuously transported to the de-tarring device 7. Then, the crude product was de-tarred in the de-tarring device 7 to prepare an intermediate substance. Next, the intermediate substance was continuously transported to the rectifying tower 8 at a supply rate of 100 parts by mass / hr. For the rectifying tower, fillers equivalent to 25 theoretical plates were filled. Then, in the rectifying tower, light components were removed from the top of the tower, and a 1,3-XDI composition product was taken from the middle of the tower, as shown in Table 2 specifically.

[0196] The rectifying conditions in the rectifying tower are as follows:

[0197] Bottom temperature: 149 °C;

[0198] Top temperature: 120 °C;

[0199] Top pressure: 150 Pa;

[0200] Residence time: 4 h;

[0201] Top reflux ratio: 5:1.

[0202] Example 2-5

[0203] Examples 2-5 respectively provide a preparation method of an XDI composition. The difference is only that 1,3-XDI compositions with different component contents are obtained by using 1,3-XDA with different color numbers as raw materials, as shown in Table 2 specifically.

[0204] Example 6

[0205] This example provides a method for preparing an XDI composition. The difference lies only in the preparation method. The preparation method of this example is as follows: The XDI composition is prepared by the method of Example 1 of this patent. The above-prepared 1,3-XIT standard is added to the XDI composition obtained in Example 1 to obtain the XDI composition. The concentration of the 1,3-XIT standard in the XDI composition prepared in this example is 650 ppm.

[0206] Comparative Example 1

[0207] This comparative example provides an XDI composition and a method for its preparation. The difference lies only in that XDI with different component contents is obtained by using 1,3-XDA with different color numbers as raw materials, as shown in Table 2 specifically.

[0208] Comparative Example 2

[0209] The XDI is prepared by the method of Example 1 of Patent Application US5196572A.

[0210] Application Performance Test

[0211] The XDI compositions prepared in Examples 1 - 6 and Comparative Example 1 above or the XDI prepared in Comparative Example 2 are respectively used to prepare optical materials (plastic lens materials), and performance evaluation is carried out as follows:

[0212] (1) Preparation method:

[0213] 0.001 part by mass of dibutyltin dichloride, 0.07 part by mass of an internal mold release agent (manufactured by Stepan Company, ZELEC UN, acidic phosphate ester), and 0.05 part by mass of an ultraviolet absorber (manufactured by Sakai Chemical Industry Co., Ltd., Biosorb 583) are charged into a flask. 36.4 parts by mass of the XDI composition prepared in Examples 1 - 6 or Comparative Example 1 or the XDI prepared in Comparative Example 2 are respectively charged. Then, they are stirred at 25°C for 1 hour to dissolve them to prepare a polyisocyanate component.

[0214] Then, 33.6 parts by mass of 2,3-dithio(2-mercapto)-1-propanethiol (CAS No.: 131538-00-6, polythiol component) is charged into the polyisocyanate component and mixed to prepare a resin composition.

[0215] The resin composition was degassed at 600 Pa for 1 hour and then filtered through a 1-μm PTFE filter. Then, it was injected into an injection mold for a lens composed of a 75-mm-diameter, -4D glass mold and tape. This injection mold was placed in an oven and maintained at 40 °C for 2 hours, heated to 50 °C over 4 hours and maintained at 50 °C for 2 hours, heated to 60 °C over 3 hours and maintained at 60 °C for 2 hours. It was further heated to 70 °C over 3 hours and maintained at 70 °C for 2 hours, heated to 100 °C over 3 hours, and then heated to 130 °C over 1 hour and maintained at 130 °C for 2 hours. As described above, polymerization was carried out for a total of 24 hours in the temperature range of 40 °C to 130 °C. After the polymerization was completed, the injection mold was taken out of the oven, demolded, and a lens was obtained. The obtained lens was then annealed at 120 °C for 3 hours. As described above, 200 lenses were fabricated.

[0216] (2) Performance evaluation:

[0217] The refractive index and stripe occurrence rate of the obtained plastic lens were measured. The results are shown in Table 2.

[0218] Table 2 Test results

[0219]

[0220]

[0221] “—” indicates non-existence.

[0222] From the results, it can be seen that gels appeared during the polymerization of the XDI composition of Comparative Example 2, and lens specimens could not be prepared. Compared with Comparative Examples 1-2, the homogeneity of the polyurethane resin prepared from the XDI compositions provided in each example of the present invention was significantly improved, thereby improving the homogeneity of the lens and significantly reducing the stripe occurrence rate of the lens.

[0223] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A benzene diisocyanate methylene composition, characterized in that, The benzylidene diisocyanate composition comprises benzylidene diisocyanate and 1 - 1000 ppm of a compound represented by the following formula (I); wherein, R1, R2 or R3 are independently selected from or 2. The benzylidene diisocyanate composition according to claim 1, wherein The content of benzylidene diisocyanate in the benzylidene diisocyanate composition is greater than 98 wt%.

3. The benzene diisocyanate methylene composition according to claim 1 or 2, characterized in that The compounds represented by the formula (I) are selected from or 4. The benzene diisocyanate methylene composition according to any one of claims 1-3, characterized in that, The benzylidene diisocyanate includes any one or at least two combinations of 1,2-benzylidene diisocyanate, 1,3-benzylidene diisocyanate or 1,4-benzylidene diisocyanate, preferably 1,3-benzylidene diisocyanate and / or 1,4-benzylidene diisocyanate, more preferably 1,3-benzylidene diisocyanate.

5. A method for preparing the benzene diisocyanate methylene composition according to any one of claims 1-4, characterized in that, The preparation method comprises the following steps: (1) Isocyanation process: subjecting xylylenediamine or xylylenediamine hydrochloride to an isocyanation reaction with phosgene in the presence of a reaction solvent; (2) Separation process: separating and purifying the reaction product obtained in step (1) to obtain the benzylidene diisocyanate composition; wherein, the color number of xylylenediamine is less than or equal to 15 Hazen; or, The preparation method includes mixing benzylidene diisocyanate and the compound represented by formula (I) to obtain.

6. A modified composition of a benzene diisocyanate methylene composition, characterized in that, The modified composition is a modified composition obtained by modifying the benzylidene diisocyanate composition according to any one of claims 1 - 4 or the benzylidene diisocyanate composition prepared by the preparation method according to claim 5, and the modified composition contains any one or at least two combinations of the following groups (a) - (i): (a) isocyanurate group, (b) uretdione group, (c) biuret group, (d) carbamate group, (e) urea group, (f) iminooxadiazinedione group, (g) urethane group, (h) uretonimine group or (i) carbodiimide group.

7. A resin composition, characterized in that, The resin composition includes the benzylidene diisocyanate composition according to any one of claims 1 - 4 or the benzylidene diisocyanate composition prepared by the preparation method according to claim 5 or the modified composition of the benzylidene diisocyanate composition according to claim 6 and a substance containing an active hydrogen group.

8. A polyurethane resin, characterized in that, The polyurethane resin is prepared by reacting the benzylidene diisocyanate composition according to any one of claims 1 - 4 or the benzylidene diisocyanate composition prepared by the preparation method according to claim 5 or the modified composition of the benzylidene diisocyanate composition according to claim 6 with a substance containing an active hydrogen group.

9. An optical material, characterized in that, The optical material is polymerized from the benzylidene diisocyanate composition according to any one of claims 1 - 4 or the benzylidene diisocyanate composition prepared by the preparation method according to claim 5 or the modified composition of the benzylidene diisocyanate composition according to claim 6 and a polythiol compound.

10. The optical material according to claim 9, characterized in that, The optical material includes plastic lens material, automotive headlamp housing material or transparent roof material.

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