Polythiol composition, composition for optical material and preparation method of polythiol composition

Abstract

The invention discloses a polythiol composition, a composition for an optical material and a preparation method of the polythiol composition, the polythiol composition comprises a thiol compound shown in the formula 1, and the mass ratio of the thiol compound shown in the formula 1 in the polythiol composition is 0.01%-15%. The invention can effectively improve the problem of poor demoulding property of the resin lens, and can increase the softening temperature of the resin, thereby enhancing the heat resistance of the resin lens, enhancing the yield of the resin lens and lowering the production cost.

Description

Technical Field

[0001] This invention relates to the field of optical resin technology, specifically to a polythiol composition, a composition for optical materials, and a method for preparing the same. Background Technology

[0002] Polyurethane resin materials, prepared from polythiol compounds and isocyanates, are widely used as optical materials in eyeglass lenses, camera lenses, and other applications due to their excellent properties such as light weight, high toughness, ease of dyeing, strong impact resistance, high refractive index, and high Abbe number. The high refractive index of optical materials allows for thinner lens walls, and the high Abbe number reduces chromatic aberration. Therefore, the performance indicators of optical resin lenses significantly restrict and influence their development trend and downstream applications.

[0003] Current optical resin materials typically use polysulfide urethane resin materials prepared from polythiol compounds (e.g., 2,3-dithio(2-mercapto)-1-propanethiol) and isocyanates. The preparation method is as follows: two glass molds are bonded together with tape, with a center distance of about 2 mm between the two molds. The polythiol, isocyanate and additives are mixed and degassed to obtain a prepolymer. The prepolymer is poured into the mold and the tape is then sealed. After curing and demolding, the resin material is obtained.

[0004] However, during the preparation process, for the currently disclosed polyurethane resin materials, some cured optical resin materials are difficult to demold and are easily damaged during demolding, resulting in obvious cracks. In addition, the softening temperature of some resins is too low, which affects the further dyeing and processing of the optical resin, leading to a lower yield of resin lenses and higher production costs. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that existing polysulfide urethane resin materials are difficult to demold during the preparation process and have a low softening temperature, resulting in a low yield. The present invention provides a polythiol composition, an optical material composition and a preparation method thereof to solve the above problems.

[0006] A polythiol composition comprising a thiol compound represented by Formula 1,

[0007] Formula 1:

[0008] The thiol compound represented by Formula 1 accounts for 0.01%-15% of the mass of the polythiol composition. For example, the mass percentage of the thiol compound in the polythiol composition is 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0009] The polythiol composition of the present invention further includes polythiol compound A; said polythiol compound A is prepared from mercaptoethanol, epihalohydrin compound and sulfur source as raw materials; wherein the epihalohydrin compound may be epichlorohydrin, and the sulfur source may be hydrogen sulfide, thiourea, sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate, calcium thiocyanate, etc.; preferably, said polythiol compound A is prepared from 2-mercaptoethanol, epichlorohydrin and thiourea as raw materials.

[0010] When reacting 2-mercaptoethanol with epichlorohydrin, a catalyst comprising at least one selected from the group consisting of metal hydroxides and metal carbonates is used for catalysis. Metal hydroxides include, but are not limited to, sodium hydroxide and potassium hydroxide, and metal carbonates include, but are not limited to, sodium carbonate and potassium carbonate.

[0011] Further, the polythiol compound A includes at least one selected from 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 1,2,6-trimercapto-4-thiahexane, 1,5-dimercapto-2-mercaptomethyl-3-thiapentane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane.

[0012] The structure of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane is shown in formula a1 below:

[0013] Formula a1:

[0014] The structure of 1,2,6-trimercapto-4-thionehexane is shown in formula a2 below:

[0015] Formula a2:

[0016] The structure of 1,5-dimercapto-2-mercaptomethyl-3-thiapentane is shown in formula a3 below:

[0017] Formula a3:

[0018] The structure of 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane is shown in formula a4 below:

[0019] Formula a4:

[0020] The structure of 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane is shown in formula a5 below:

[0021] Formula a5:

[0022] The structure of 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane is shown in formula a6 below:

[0023] Formula a6:

[0024] The method for manufacturing the polythiol composition is as follows:

[0025] Step 1: Reaction of mercaptoethanol and epichlorohydrin under the action of a catalyst yields a polyol intermediate compound.

[0026] Step 2: React the polyol intermediate obtained in Step 1 with thiourea and hydrogen chloride to obtain isothiourea salt.

[0027] Step 3: Add ammonia water dropwise to the isothiourea salt obtained in Step 2 at 10-60℃, and hydrolyze the isothiourea salt at 10-60℃ to obtain a polythiol composition.

[0028] Step 4: Purify the polythiol obtained in Step 3.

[0029] It is worth noting that the polythiol composition can also be prepared by other methods, as long as the content of the thiol compound shown in Formula 1 is within the specified range. For example, by mixing thiol compounds having the structure shown in Formula 1 with polythiol compound A in different proportions, polythiol compositions with different contents of the thiol compound shown in Formula 1 can be obtained.

[0030] An optical material composition comprising the above-described polythiol composition and a polyisocyanate.

[0031] The polyisocyanate is selected from one or more of the following: tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, 4,4'-diisocyanate dicyclohexylmethane, isophorone diisocyanate, norbornene diisocyanate, phenylenediamine diisocyanate, hydrogenated phenylenediamine diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and triphenylmethane triisocyanate.

[0032] The optical material composition further includes a polythiol compound B, which is selected from 1,2-dimercaptoethane, 1,2-dimercaptopropane, 1,3-dimercaptopropane, 1,4-dimercaptobutane, 1,6-dimercaptohexane, 1,2,3-propanetrithiol, tetra(mercaptomethyl)methane, ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(2-mercaptoacetate), 1,4-butanediol bis(2-mercaptoacetate), trimethylolpropane tri(2-mercaptoacetate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(2-mercaptoacet ... Tetraol tetra(3-mercaptopropionate), 1,2,3-tris(mercaptomethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, 1,2,3-tris(3-mercaptopropylthio)propane, tetra(mercaptomethylthiomethyl)methane, tetra(2-mercaptoethylthiomethyl)methane, tetra(3-mercaptopropylthiomethyl)methane, bis(2,3-dimercaptopropyl)sulfide, 1,1,3,3-tetra(mercaptomethylthio)propane, 1,1,2,2-tetra(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithionecyclohexane, tri(mercaptomethylthio)methane, tri(mercaptoethylthio)methane.

[0033] The mass ratio of the polythiol composition to the polyisocyanate is 1:0.7-2.0. For example, the mass ratio of the polythiol composition to the polyisocyanate is 1:0.7, 1:0.9, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, etc.

[0034] The mass percentage of the polythiol composition in the optical material is 25% or more, preferably 30% or more; for example, the mass percentage of the polythiol composition in the optical material can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, etc.

[0035] The mass percentage of polythiol compound B in optical materials is ≤50%; for example, the mass percentage of polythiol compound B in optical materials can be 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 1%, etc.

[0036] The preparation method of the above-mentioned optical material includes: adding a catalyst of 0.01%-2% based on the total mass of the optical material composition to the optical material composition for polymerization and curing.

[0037] The catalyst is selected from one or more of dibutyltin dichloride, dimethyltin dichloride, dimethyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate, dibutyltin dibutoxide, dioctyltin dibutoxide, di(2-ethylhexyl)tin oxide, dioctyltin oxide, dibutyltin sulfide, and stannous octoate.

[0038] The raw materials of the optical material also contain additives, including but not limited to release agents and ultraviolet absorbers.

[0039] The ultraviolet absorber can be a benzophenone compound or a benzotriazole compound, such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-4-octylphenyl)-2H-benzotriazole, 2-(2-hydroxy-4-methoxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-4-octylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, or 2-(3,5-di-tert-pentyl-2-hydroxyphenyl)-2H-benzotriazole.

[0040] Based on 100 parts by weight of the raw materials of the optical material, the amount of ultraviolet absorber added is 0.01-1 parts by weight.

[0041] The release agent may be an acidic phosphate ester. Examples of acidic phosphate esters include monophosphate esters, diesters, and polyphosphate esters, which may be used individually or in combination of two or more.

[0042] Based on 100 parts by weight of the raw material of the optical material, the amount of the release agent added is 0.01-1 parts by weight.

[0043] The polymerization and curing process involves maintaining or slowly increasing the temperature within a range of 10-150℃ for 1-60 hours. After curing, the optical material needs to be annealed to remove strain. Preferably, the annealing process involves treating the obtained optical material at a temperature of 50-150℃ for approximately 10 minutes to 5 hours.

[0044] The technical solution of this invention has the following advantages:

[0045] The present invention provides a polythiol composition comprising a thiol compound with a specific structure, namely the thiol compound shown in Formula 1. By combining the thiol compound shown in Formula 1 with other types of conventional thiol compounds and controlling the content ratio of the thiol compound shown in Formula 1, when it is used as a raw material in polysulfide urethane resin material to prepare lenses, the problem of poor release properties of resin lenses can be effectively improved, and the softening temperature of the resin can be increased, thereby improving the heat resistance of the resin lens, increasing the yield of resin lenses, and reducing production costs. Detailed Implementation

[0046] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0047] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0048] Example 1

[0049] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.01% by mass in the polythiol composition.

[0050] Among them, polythiol compound A is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (CAS: 131538-00-6);

[0051] Formula 1: The preparation process of the thiol compound shown in Formula 1 is as follows:

[0052] 80.0 parts by weight of 2-mercaptoethanol, 40.0 parts by weight of degassed water, and 0.20 g of 32% sodium hydroxide solution were added to a reactor and stirred for 10 min at 10-20℃. 100 g of epichlorohydrin was added dropwise over 2 h at 10-20℃ to generate a chlorodiol intermediate. Then, 135 g of 32% sodium hydroxide solution was added dropwise over 60 min at 10-20℃, and the mixture was allowed to mature for 60 min after the addition was complete. After maturation, 500 g of 31% concentrated hydrochloric acid and 280 g of thiourea were added to the system, and the mixture was refluxed at 110℃ for 5 h to obtain isothiourea salt. The reaction was then cooled to room temperature. 500 g of 26% ammonia solution was added dropwise over 50 min at room temperature, and the mixture was allowed to mature at 40℃ for 6 h after the addition was complete. After maturation, the mixture was allowed to stand and the organic phase was collected. 100 g of 31% concentrated hydrochloric acid was added to the organic phase, and the mixture was stirred and washed at room temperature for 30 min. The mixture was then allowed to stand for phase separation, and the organic phase was collected. This process was repeated twice. 80 g of 0.1% sodium carbonate solution was added, and the mixture was stirred and washed at room temperature for 30 min. The mixture was then allowed to stand for phase separation, and the organic phase was collected. The organic phase was washed three times with pure water, then dehydrated by nitrogen stripping at room temperature. After filtration through a 0.45 μm filter, 152.2 g of a polythiol mixture, mainly composed of the thiol compound of formula 1, was obtained.

[0053] The thiol compound shown in Formula 1 was obtained by separation from a mixture of polythiols, with the thiol compound as the main component, using high performance liquid chromatography.

[0054] The target product was subjected to nuclear magnetic resonance (NMR) testing, and the results are as follows: 1H NMR (DMSO-d6, 400MHz) δppm: 3.80 (s, 1H), 2.95 (m, 2H), 2.90 (m, 2H), 2.76 (t, 2H), 2.58 (m, 1H), 2.36 (m, 2H).

[0055] The above test results show that the above method can obtain thiol compounds with the structure shown in Formula 1.

[0056] A method for preparing an optical material, comprising:

[0057] 56 parts by weight of phenylenediamine diisocyanate (CAS: 3634-83-1), 0.10 parts by weight of catalyst, 0.10 parts by weight of release agent, and 0.10 parts by weight of ultraviolet absorber were dissolved by stirring at room temperature; 44 parts by weight of polythiol composition were added and stirred evenly; wherein the catalyst was dibutyltin dichloride (CAS: 683-18-1), the release agent was acidic phosphate ester (Zelec UN), and the ultraviolet absorber was 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole (CAS: 2440-22-4). A mixed solution was prepared by degassing under an absolute pressure of 500 Pa for 1.0 h. The solution was then filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of about 2 mm). The mold was then placed in an oven for programmed temperature curing, starting at 25 °C and increasing to 150 °C at a rate of 10 °C / h. After holding at this temperature for 1 h, the mold was demolded to obtain the optical material.

[0058] Example 2

[0059] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.05%, while the rest is exactly the same as in Example 1.

[0060] Example 3

[0061] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.1%, while the rest is exactly the same as in Example 1.

[0062] Example 4

[0063] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.5%, while the rest is exactly the same as in Example 1.

[0064] Example 5

[0065] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 1.0%, while the rest is exactly the same as in Example 1.

[0066] Example 6

[0067] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 3.0%, while the rest is exactly the same as in Example 1.

[0068] Example 7

[0069] The difference from Example 1 is that the thiol compound represented by Formula 1 accounts for 6.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 1.

[0070] Example 8

[0071] The difference from Example 1 is that the thiol compound represented by Formula 1 accounts for 9.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 1.

[0072] Example 9

[0073] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 12.0%, while the rest is exactly the same as in Example 1.

[0074] Example 10

[0075] The difference from Example 1 is that the thiol compound represented by Formula 1 accounts for 15.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 1.

[0076] Comparative Example 1

[0077] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 17.0%, while the rest is exactly the same as in Example 1.

[0078] Comparative Example 2

[0079] The difference from Example 1 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.005%, while the rest is exactly the same as in Example 1.

[0080] Comparative Example 3

[0081] The difference from Example 1 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, CAS: 131538-00-6) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 1.

[0082] Example 11

[0083] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.01% by mass in the polythiol composition.

[0084] Among them, polythiol compound A is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane;

[0085] Formula 1: The preparation process of the thiol compound shown in Formula 1 is the same as that in Example 1.

[0086] A method for preparing an optical material, comprising:

[0087] 52 parts by weight of hydrogenated dimethyl phthalate (CAS: 38661-72-2), 0.10 parts by weight of catalyst, 0.10 parts by weight of release agent, and 0.10 parts by weight of ultraviolet absorber were dissolved by stirring at room temperature; 28 parts by weight of polythiol composition and 20 parts by weight of pentaerythritol tetramercaptopropionate (CAS: 7575-23-7) were added and stirred evenly; wherein, the catalyst is dibutyltin dichloride, the release agent is acidic phosphate (Zelec UN), and the ultraviolet absorber is 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole. A mixed solution was prepared by degassing under an absolute pressure of 500 Pa for 1.0 h. The solution was then filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of about 2 mm). The mold was then placed in an oven for programmed temperature curing, starting at 25 °C and increasing to 150 °C at a rate of 10 °C / h. After holding at this temperature for 1 h, the mold was demolded to obtain the optical material.

[0088] Example 12

[0089] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.05%, while the rest is exactly the same as in Example 11.

[0090] Example 13

[0091] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.1%, while the rest is exactly the same as in Example 11.

[0092] Example 14

[0093] The difference from Example 11 is that the thiol compound represented by Formula 1 accounts for 0.5% of the mass of the polythiol composition, while the rest is exactly the same as in Example 11.

[0094] Example 15

[0095] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 1.0%, while the rest is exactly the same as in Example 11.

[0096] Example 16

[0097] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 3.0%, while the rest is exactly the same as in Example 11.

[0098] Example 17

[0099] The difference from Example 11 is that the thiol compound represented by Formula 1 accounts for 6.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 11.

[0100] Example 18

[0101] The difference from Example 11 is that the thiol compound represented by Formula 1 accounts for 9.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 11.

[0102] Example 19

[0103] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 12.0%, while the rest is exactly the same as in Example 11.

[0104] Example 20

[0105] The difference from Example 1 is that the thiol compound represented by Formula 1 accounts for 15.0% of the mass of the polythiol composition, while the rest is exactly the same as in Example 1.

[0106] Comparative Example 4

[0107] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 17.0%, while the rest is exactly the same as in Example 11.

[0108] Comparative Example 5

[0109] The difference from Example 11 is that the mass percentage of the thiol compound represented by Formula 1 in the polythiol composition is 0.005%, while the rest is exactly the same as in Example 11.

[0110] Comparative Example 6

[0111] The difference from Example 11 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 11.

[0112] Example 21

[0113] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.05% by mass in the polythiol composition.

[0114] Among them, polythiol compound A is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane;

[0115] Formula 1: The preparation process of the thiol compound shown in Formula 1 is the same as that in Example 1.

[0116] A method for preparing an optical material, comprising:

[0117] 40 parts by weight of phthalimide diisocyanate (CAS: 3634-83-1), 8 parts by weight of hexamethylene diisocyanate (CAS: 822-06-0), 10 parts by weight of isophorone diisocyanate (CAS: 4098-71-9), 0.10 parts by weight of catalyst, 0.10 parts by weight of release agent, and 0.10 parts by weight of ultraviolet absorber were stirred and dissolved at room temperature; 42 parts by weight of polythiol composition were added and stirred evenly; wherein the catalyst was dibutyltin dilaurate (CAS: 77-58-7), the release agent was acidic phosphate (Zelec UN), and the ultraviolet absorber was 2-(3,5-di-tert-pentyl-2-hydroxyphenyl)benzotriazole (CAS: 25973-55-1). A mixed solution was prepared by degassing under an absolute pressure of 500 Pa for 1.0 h. The solution was then filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of about 2 mm). The mold was then placed in an oven for programmed temperature curing, starting at 25 °C and increasing to 150 °C at a rate of 10 °C / h. After holding at this temperature for 1 h, the mold was demolded to obtain the optical material.

[0118] Comparative Example 7

[0119] The difference from Example 21 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 21.

[0120] Example 22

[0121] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.1% by mass in the polythiol composition.

[0122] Among them, polythiol compound A is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane and 1,2,6-trimercapto-4-thiahexane in a mass ratio of 1:1;

[0123] The preparation process of the polythiol compound 1,2,6-trimercapto-4-thionehexane (a2) is as follows:

[0124] Add 86.0 parts by weight of 2-mercaptoethanol, 45.0 parts by weight of degassed water, and 0.60 g of 32% sodium hydroxide solution to the reactor, and stir and mix at 10℃-20℃ for 20 min. Then add 92.5 g of epichlorohydrin dropwise at 10-20℃ for 4 h, and react at 10-20℃ for 3 h.

[0125] After the reaction was complete, 520 g of 31% concentrated hydrochloric acid and 266 g of thiourea were added to the system, and the mixture was refluxed at 110 °C for 4 h to obtain isothiourea salt. After the reaction was complete, the mixture was cooled to room temperature. 560 g of 26% ammonia solution was added dropwise to the system at room temperature for 1 h. After the addition was complete, the temperature was raised to 40-50 °C and allowed to mature for 3 h. After maturation, the mixture was allowed to stand and the organic phase was collected. 150 g of 31% concentrated hydrochloric acid was added to the organic phase, and the mixture was stirred and washed at 25-35 °C for 1 h, then allowed to stand and the organic phase was collected. This process was repeated once. 150 g of pure water was added to the organic phase, and the mixture was stirred and washed at 25-35 °C for 30 min, then allowed to stand and the organic phase was collected. 150 g of 0.1% ammonia solution was added to the organic phase, and the mixture was stirred and washed at 25-35 °C for 30 min, then allowed to stand and the organic phase was collected. After the organic phase was washed three times with pure water, it was dehydrated by nitrogen stripping at room temperature and filtered through a 0.45 μm filter to obtain 158 g of a polythiol mixture mainly composed of 1,2,6-trimercapto-4-thiahexane (a2) and 1,5-dimercapto-2-mercaptomethyl-3-thiapentane (a3).

[0126] The polythiols, mainly composed of a2 and a3, were separated by high performance liquid chromatography to obtain a2 and a3 polythiols respectively. This separation method is a conventional technique for those skilled in the art and will not be described in detail here.

[0127] The target product underwent nuclear magnetic resonance (NMR) testing, and the results are as follows:

[0128] 1,2,6-Trimercapto-4-thiohexane (a2) 1H NMR (DMSO-d6, 400MHz) δppm: 3.82 (s, 3H), 3.23 (m, 1H), 2.94 (m, 2H), 2.81 (m, 2H), 2.70 (m, 2H), 2.65 (m, 2H).

[0129] 1,5-Dimercapto-2-mercaptomethyl-3-thiapentane (a3) ​​1H NMR (DMSO-d6, 400MHz) δppm: 3.69 (s, 3H), 3.12 (m, 1H), 2.83 (m, 4H), 2.73 (m, 2H), 2.68 (m, 2H).

[0130] Formula 1: The preparation process of the thiol compound shown in Formula 1 is the same as that in Example 1.

[0131] A method for preparing an optical material, comprising:

[0132] 20 parts by weight of hydrogenated dimethyl diisocyanate (CAS: 38661-72-2), 20 parts by weight of hexamethylene diisocyanate (CAS: 822-06-0), 20 parts by weight of isophorone diisocyanate (CAS: 4098-71-9), 0.10 parts by weight of catalyst, 0.10 parts by weight of release agent, and 0.10 parts by weight of ultraviolet absorber were stirred and dissolved at room temperature; 40 parts by weight of polythiol composition were added and stirred evenly; wherein the catalyst was dimethyl tin dichloride (CAS: 753-73-1), the release agent was acidic phosphate ester (Zelec UN), and the ultraviolet absorber was 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole (CAS: 3147-75-9). A mixed solution was prepared by degassing under an absolute pressure of 500 Pa for 1.0 h. The solution was then filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of about 2 mm). The mold was then placed in an oven for programmed temperature curing, starting at 25 °C and increasing to 150 °C at a rate of 10 °C / h. After holding at this temperature for 1 h, the mold was demolded to obtain the optical material.

[0133] Comparative Example 8

[0134] The difference from Example 22 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 22.

[0135] Example 23

[0136] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.1% by mass in the polythiol composition.

[0137] Among them, polythiol compound A contains 1,5-dimercapto-2-mercaptomethyl-3-thiapentane and 1,2,6-trimercapto-4-thiahexane; the preparation process of the 1,5-dimercapto-2-mercaptomethyl-3-thiapentane is as shown in Example 22 above.

[0138] Formula 1: The preparation process of the thiol compound shown in Formula 1 is the same as that in Example 1.

[0139] A method for preparing an optical material, comprising:

[0140] 50 parts by weight of dimethyl phthalate, 2 parts by weight of catalyst, 0.01 parts by weight of release agent, and 0.01 parts by weight of ultraviolet absorber were dissolved by stirring at room temperature. 50 parts by weight of a polythiol composition were added and stirred until homogeneous. The catalyst was dibutyltin dichloride, the release agent was acidic phosphate (Zelec UN), and the ultraviolet absorber was 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole. A mixed solution was prepared by degassing at an absolute pressure of 500 Pa for 1.0 h. The solution was filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of approximately 2 mm). The mold was then placed in an oven for programmed temperature curing, starting at 10 °C and increasing to 120 °C at a rate of 5 °C / h. After holding at this temperature for 10 h, the mold was further annealed at 100 °C for 3 h. After cooling, the mold was demolded to obtain the optical material.

[0141] Comparative Example 9

[0142] The difference from Example 23 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 23.

[0143] Example 24

[0144] A polythiol composition comprising a thiol compound of Formula 1 and polythiol compound A; wherein the thiol compound of Formula 1 accounts for 0.1% by mass in the polythiol composition.

[0145] Among them, polythiol compound A contains 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (CAS:170016-27-0), 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (CAS:170016-26-9), and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (CAS:170016-25-8);

[0146] Formula 1: The preparation process of the thiol compound shown in Formula 1 is the same as that in Example 1.

[0147] A method for preparing an optical material, comprising:

[0148] 42 parts by weight of dimethyl phthalate, 0.1 parts by weight of catalyst, 1 part by weight of release agent, and 1 part by weight of ultraviolet absorber were dissolved by stirring at room temperature. 58 parts by weight of a polythiol composition were added and stirred until homogeneous. The catalyst was dibutyltin dichloride, the release agent was acidic phosphate (Zelec UN), and the ultraviolet absorber was 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole. A mixed solution was prepared by degassing at an absolute pressure of 500 Pa for 1.0 h. The solution was filtered through a 1 μm filter and poured into a designated mold (two glass molds were bonded together with tape, with a center-to-center distance of approximately 2 mm). The mold was then placed in an oven for curing and annealing. Starting at 10 °C, the temperature was increased to 130 °C at a rate of 5 °C / h, held at this temperature for 15 h, and then further annealed at 110 °C for 4 h. After cooling, the material was demolded to obtain the optical material.

[0149] Comparative Example 10

[0150] The difference from Example 24 is that the polythiol composition uses polythiol compound A (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) of formula a1 instead of the thiol compound of formula 1, otherwise it is exactly the same as Example 24.

[0151] Experimental Example

[0152] The optical materials prepared using the above-described embodiments and comparative examples were tested for mold release properties and thermal resistance (Tg).

[0153] Demolding performance: Fabricate 10 lenses with a diameter of 80mm and a thickness of 2.0mm, and evaluate their demolding performance. Record the following: A) all 10 lenses can be demolded; B) 9 lenses can be demolded; C) 8 lenses can be demolded; D) 7 or fewer lenses can be demolded. A score of B or higher indicates that the lens demolding performance is acceptable.

[0154] Heat resistance (Tg): The glass transition temperature (Tg) was measured using a DSC-3 differential scanning calorimeter at a heating rate of 10℃ / min. The higher the Tg, the better the heat resistance.

[0155] The test results are shown in Tables 1-3 below.

[0156] Table 1

[0157] Demolding properties Heat resistance (Tg) / ℃ Example 1 A 84.5 Example 2 B 85.1 Example 3 A 83.4 Example 4 A 84.2 Example 5 A 85.5 Example 6 A 86.0 Example 7 A 83.0 Example 8 A 84.2 Example 9 A 85.2 Example 10 B 86.5 Comparative Example 1 C 79.8 Comparative Example 2 C 80.1 Comparative Example 3 C 78.9

[0158] Table 2

[0159]

[0160]

[0161] Table 3

[0162] Demolding properties Heat resistance (Tg) / ℃ Example 21 A 84.9 Comparative Example 7 C 80.2 Example 22 A 83.5 Comparative Example 8 C 80.1 Example 23 A 93.3 Comparative Example 9 C 85.0 Example 24 A 104.1 Comparative Example 10 C 98.2

[0163] As shown in Tables 1-3 above, by combining the thiol compound shown in Formula 1 with other types of conventional thiol compounds and controlling the content ratio of the thiol compound shown in Formula 1, and using it as a raw material in polyurethane resin to prepare optical materials, the problem of poor mold release of optical materials can be effectively improved, and the heat resistance of resin lenses can be improved, the yield of resin lenses can be increased, and the production cost can be reduced.

[0164] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A polythiol composition, characterized in that, Including the thiol compounds shown in Formula 1, Formula 1: The thiol compound represented by Formula 1 accounts for 0.01%-15% of the mass of the polythiol composition.

2. The polythiol composition according to claim 1, characterized in that, It also includes polythiol compound A; said polythiol compound A is prepared from mercaptoethanol, epihalool compound and sulfur source.

3. The polythiol composition according to claim 2, characterized in that, The polythiol compound A includes at least one selected from the following: 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 1,2,6-trimercapto-4-thiahexane, 1,5-dimercapto-2-mercaptomethyl-3-thiapentane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane.

4. A composition for use in optical materials, characterized in that, It comprises the polythiol composition according to any one of claims 1-3 and the polyisocyanate.

5. The composition for optical materials according to claim 4, characterized in that, The polyisocyanate is selected from one or more of the following: tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, 4,4'-diisocyanate dicyclohexylmethane, isophorone diisocyanate, norbornene diisocyanate, phenylenediamine diisocyanate, hydrogenated phenylenediamine diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and triphenylmethane triisocyanate.

6. The composition for optical materials according to any one of claims 4-5, characterized in that, The optical material composition further includes a polythiol compound B, which is selected from 1,2-dimercaptoethane, 1,2-dimercaptopropane, 1,3-dimercaptopropane, 1,4-dimercaptobutane, 1,6-dimercaptohexane, 1,2,3-propanetrithiol, tetra(mercaptomethyl)methane, ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(2-mercaptoacetate), 1,4-butanediol bis(2-mercaptoacetate), trimethylolpropane tri(2-mercaptoacetate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(2-mercaptoacet ... Tetraol tetra(3-mercaptopropionate), 1,2,3-tris(mercaptomethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, 1,2,3-tris(3-mercaptopropylthio)propane, tetra(mercaptomethylthiomethyl)methane, tetra(2-mercaptoethylthiomethyl)methane, tetra(3-mercaptopropylthiomethyl)methane, bis(2,3-dimercaptopropyl)sulfide, 1,1,3,3-tetra(mercaptomethylthio)propane, 1,1,2,2-tetra(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithionecyclohexane, tri(mercaptomethylthio)methane, tri(mercaptoethylthio)methane.

7. The composition for optical materials according to any one of claims 4-6, characterized in that, The mass ratio of the polythiol composition to the polyisocyanate is 1:0.7-2.

0.

8. A method for preparing an optical material, characterized in that, Add 0.01%-2% of a catalyst based on the total mass of the optical material composition to the composition according to any one of claims 4-7 and perform polymerization and curing.

9. The preparation method according to claim 8, characterized in that, The catalyst is selected from one or more of dibutyltin dichloride, dimethyltin dichloride, dimethyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate, dibutyltin dibutoxide, dioctyltin dibutoxide, di(2-ethylhexyl)tin oxide, dioctyltin oxide, dibutyltin sulfide, and stannous octoate.

10. The preparation method according to claim 8 or 9, characterized in that, The polymerization and curing temperature is 10-150℃, and the polymerization and curing time is 1-60h.

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