Composition for optical material and optical material

Abstract

The present application belongs to the technical field of optical resin, and particularly relates to a composition for optical material and an optical material, wherein the composition for optical material comprises a cyclic sulfur compound, and the solvent content is below 1500 ppm; the composition can improve the heat resistance of the optical material when producing high-refractive optical material, ensure the feasibility of the lens in the later processing and the safety in the use process, and can make the haze of the produced optical material lower, and ensure the light transmittance of the lens.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of new organic materials and optical materials, and particularly relates to a composition for optical materials and optical materials, which are suitable for optical materials such as plastic lenses, prisms, optical fibers, information storage substrates, filters, etc. BACKGROUND

[0002] The refractive index of mainstream eyeglass lenses on the market is about 1.6 at present, so if a high-power lens is to be made, the thickness of the eyeglass lens must be increased, which also increases the weight of the eyeglass. Compared with optical glass, resin optical materials have emerged, which have the advantages of high refractive index, light weight, impact resistance and easy processing, and can be better applied to eyeglass lenses and other products. However, in the later processing and use of eyeglass lenses, the lenses are required to have both high heat-induced deformation resistance and high heat resistance, and the former is particularly important.

[0003] At present, in order to improve the heat resistance, special isocyanates with high cost, high rigid structure and high refractive index are added as a representative solution. From the cost point of view, isocyanates with low cost, excellent anti-yellowing performance and high refractive index, such as 1,4-cyclohexane diisocyanate, m-xylylene diisocyanate, isophorone diisocyanate, 1,6-diisocyanatohexane, diisocyanatopolyethylene glycol, dicyclohexylmethane 4,4-diisocyanate, etc., are used to replace special isocyanates to become the mainstream of developing low-cost polyurethane resin lenses at present, but the polyurethane resin lenses inevitably have the problem of low heat resistance temperature, which greatly increases the quality risks of low-cost polyurethane resin lenses in the later processing and long-term use. Moreover, the haze of the resin lenses on the market is basically about 1%, but if they are to have high light transmittance, the haze should be below 0.5, and the resin lenses on the market cannot meet the higher light transmittance requirement of resin lenses. SUMMARY

[0004] In view of the many deficiencies of the prior art, the present application provides a composition for optical materials and optical materials, which can improve the heat resistance of the optical materials when producing high-refractive-index optical materials by controlling the solvent content in the cyclic sulfur compound to be below 1500 ppm, ensure the feasibility of the lenses in the later processing and the safety in the use process, and make the haze of the produced optical materials lower to ensure the light transmittance of the lenses.

[0005] The inventors have found that the solvent content of the cyclic sulfur compound has a decisive influence on the heat resistance and haze of the optical material. When the solvent content of the cyclic sulfur compound is too high, the cross-linking degree during the curing process is reduced, resulting in poor heat resistance and a higher probability of deformation. However, a certain amount of solvent is required because the presence of a certain amount of solvent can improve the compatibility of the UV powder and the main resin, avoid separation and precipitation during the resin warming and curing process, and thus cause the haze value of the lens to become larger, making the lens appear foggy. When the solvent residue exceeds a certain value, the compatibility of the UV powder in the composition is low, and light scattering easily occurs inside or on the surface of the lens during the lens production process, causing a cloudy state. Through research, it has been found that only when the solvent content of the cyclic sulfur compound is below 1500 ppm, the heat resistance of the optical material is effectively improved, and the haze of the optical material is low, meeting the requirements of high-heat-resistance, high-transmittance, and high-refractive-index resin lenses on the market.

[0006] Under the guidance of the above concept, the technical solutions of the present application are as follows:

[0007] An optical material composition includes a cyclic sulfur compound, which has the following structural formula:

[0008]

[0009] wherein m is 1 or 2, and the solvent content is below 1500 ppm.

[0010] Preferably, the solvent content of the cyclic sulfur compound is 500-1500 ppm.

[0011] Preferably, the cyclic sulfur compound accounts for 60-95% of the total weight of the optical material composition. Further preferably, the cyclic sulfur compound accounts for 70-90% of the total weight of the optical material composition.

[0012] Preferably, the optical material composition further includes a thiol compound and an isocyanate compound. Further preferably, the thiol compound accounts for 1-20% of the total weight of the optical material composition, more preferably 3-10%, and the isocyanate compound accounts for 1-20% of the total weight of the optical material composition, more preferably 3-10%.

[0013] Further preferably, the thiol compound has at least two thiol groups, and the thiol compound is selected from one or more of 2-mercaptoethanol, 3-mercaptopropanol, 2-hydroxypropyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, bis(2-mercaptoethyl) sulfide, 2,5-dimercaptomethyl-1,4-dithiane, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 4- mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 4,8-dimercaptomethyl-1,1 1 -dimercapto- 3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,1 1 -dimercapto-3,6,9-trithiaundecane, 5,7- dimercaptomethyl-1,1 1 -dimercapto-3,6,9-trithiaundecane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetrathiodiglycol ester, trimethylolpropane trithiodiglycol ester, trimethylolpropane trimercaptoacetate, and one or more of 2-mercaptoethanol, 3-mercaptopropanol, 2-hydroxypropyl mercaptan, bis(2- mercaptoethyl) sulfide, and 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane.

[0014] Further preferably, the isocyanate compound has at least two isocyanate groups, and the isocyanate compound is selected from one or more of diethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 2,6-bis(isocyanatomethyl)decahydronaphthalene, tolylene diisocyanate, o-tolidene diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, 2,2'-bis(4-isocyanatophenyl)propane, triphenylmethane triisocyanate, bis(diisocyanatotolyl)phenylmethane, 1,3-m-xylylene diisocyanate, 1,4-p-xylylene diisocyanate, 4,4'-diisocyanatodiphenyl, dicyclohexylmethane-4,4'-diisocyanate, 1,1 '-methylenebis(4-isocyanatophenyl), m-xylylene diisocyanate, p-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-tetramethylxylylene diisocyanate, bis(isocyanatomethyl)norbornane, bis(isocyanatomethyl)adamantane, thiodiethyl diisocyanate, thiodipropyl diisocyanate, thiodihexyl diisocyanate. More preferably, the isocyanate compound is one of isophorone diisocyanate, m-xylylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane.

[0015] Preferably, the optical material composition further comprises a polymerization catalyst of imidazole or phosphine, and the polymerization catalyst is 0.01-1% of the total weight of the optical material composition. The amount of the polymerization catalyst varies according to the composition, mixing ratio and curing method of the composition, and the polymerization catalyst is 0.03-0.5% of the total weight of the optical material composition.

[0016] Preferably, in the manufacture of the corresponding optical material, the additives are added to the above-mentioned polymerization-curable composition, which can further improve the practicability of the obtained optical material. The optical material composition can further comprise additives such as ultraviolet absorbers, release agents, blue agents and red agents; wherein the ultraviolet absorber is selected from one or more of UV-P, UV-9, UV-531, UV-324, UV-326, UV-329, UV-1157, and the addition amount is 0.001%-1%, further preferably 0.01%-0.5%; the blue agent and the red agent are added according to the actual needs of the optical material; the release agent is selected from one or more of di-n-butyl phosphate, El310, nonylphenol polyoxyethylene ether phosphate, and Zelec UN™, and the addition amount is 0.001%-1%, further preferably 0.01%-0.5%.

[0017] An optical material is obtained by curing the above-mentioned optical material composition, and the specific steps are as follows:

[0018] a) uniformly mixing the optical material composition to obtain a mixed reactant;

[0019] b) injecting the reaction mixture obtained in step a) through a filter membrane into a mold for the first curing, and after demolding, the second curing is carried out to obtain an optical resin material.

[0020] In step b), the temperature rising procedure of the first curing is as follows: the initial temperature is 15-25℃, and the temperature is kept for 2.0-3.5h, then the temperature is raised to 45-60℃ for 10-15h, the temperature is raised to 75-90℃ for 2.0-4.0h, and finally the temperature is lowered to 60-75℃ for 1.5-2.5h; the temperature of the second curing in step b) is 80-110℃, and the time is 2-4h.

[0021] The optical material obtained by the technical solution of the present application can be used for optical lenses, and the optical material prepared has a refractive index of 1.7056 or more, a softening temperature of 92℃ or more, and a haze of 0.55 or less.

[0022] In conclusion, the present application provides a kind of optical material composition and optical material, when obtaining high refractive index optical material, the heat resistance of optical material can be improved and the haze of optical material is reduced, while improving the thermal stability of optical material, the light transmittance is improved, the material with excellent performance of the present application can be applied to optical materials such as plastic lens, prism, optical fiber, information storage substrate, filter, etc., with high popularization value and commercial value. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Gas chromatogram of bis (beta-epithiopropyl) sulfide in Example 1. DETAILED DESCRIPTION

[0024] The above content of the present application is further described in detail through the specific embodiments in the form of examples, but this should not be understood as the scope of the above subject matter of the present application is limited to the following examples. Any technology realized based on the above content of the present application belongs to the scope of the present application, and the raw materials used in the following examples and comparative examples are all commercially available products, which are purchased on the market or prepared through other literature. If the solvent content of the episulfide compound can reach the limited content of the episulfide compound defined in the present application, it can be directly used; if the solvent content of the episulfide compound is higher than the limited residual solvent content of the episulfide compound defined in the present application, the existing solvent removal method in the prior art can be used for treatment, so that the specific solvent content is reached, and then used, such as using a centrifugal molecular still to remove the solvent, so that the solvent content of the episulfide compound is reduced to a specific value; if the solvent content of the episulfide compound is lower than the limited content of the episulfide compound defined in the present application, the existing solvent of the episulfide compound or the common solvent of the episulfide compound can be added to the episulfide compound, so that the specific solvent content is reached, and then used.

[0025] In order to further illustrate the present application, the following contents are described in detail.

[0026] 1. Measurement of solvent content

[0027] The solvent content in the episulfide compound is measured by using a gilent 6890N gas chromatograph, an Agilent G 1888 headspace sampler and a headspace sampling-capillary gas chromatography.

[0028] 2. Solvent removal method

[0029] A centrifugal molecular still is used to control the heating temperature at 20-40℃ and the vacuum degree at 10pa-1000pa to reach the required residual solvent value of the episulfide compound. The specific process is as follows:

[0030] bis(β-epithiopropyl) sulfide with a solvent content of 2500 ppm: heating temperature of 30°C, vacuum degree of 500 pa, until the solvent residue is 1500 ppm; bis(β-epithiopropyl) sulfide with a solvent content of 2500 ppm: heating temperature of 35°C, vacuum degree of 100 pa, until the solvent residue is 500 ppm. In the actual operation process, according to the required final solvent content, the appropriate heating temperature and vacuum degree are selected.

[0031] 3. Heat resistance determination

[0032] Glass transition temperature (Tg): the glass transition temperature of the optical material is tested by a differential scanning calorimeter (DSC);

[0033] 4. Haze determination

[0034] HunterLab UltraScan PRO spectrophotometer, the haze value of the optical material is respectively: haze value ≥ 1% quality is poor; 0.5% ≤ haze value < 1% quality is good; haze value < 0.5 quality is excellent.

[0035]

[0036] wherein m is 1 or 2, when m is 1, the bis(β-epithiopropyl) sulfide, when m is 2, the cyclic sulfur compound is bis(β-epithiopropyl) disulfide.

[0037] An optical material is obtained by curing an optical material composition, and the specific steps are as follows:

[0038] a) uniformly mixing the optical material with the composition to obtain a mixed reactant;

[0039] b) injecting the reaction mixture obtained in step a) into a mold through a filter membrane to perform the first curing, and after demolding, the second curing is performed to obtain the optical resin material.

[0040] wherein, the temperature rising procedure of the first curing in step b) is: the initial temperature is 15-25°C, the temperature is kept for 2.0-3.5h, then the temperature is raised to 45-60°C for 10-15h, the temperature is raised to 75-90°C for 2.0-4.0h, and finally the temperature is lowered to 60-75°C for 1.5-2.5h; the temperature of the second curing in step b) is 80-110°C, and the time is 2-4h.

[0041] Example 1

[0042] A preparation method of an optical material is as follows:

[0043] An optical material composition comprises: bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content is 1500 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst-tetrabutylphosphonium bromide 0.5 parts by mass, release agent-di-n-butyl phosphate 0.1 parts by mass, UV326 ultraviolet absorber 0.1 parts by mass;

[0044] Specific preparation steps: the optical material composition is degassed at room temperature, filtered through a 0.5 μm PTFE filter after degassing is completed, injected into a mold, and the programmed curing is started. The temperature program of the first curing is: the initial temperature is 25°C, the temperature is kept for 3.5 h, then the temperature is increased to 60°C for 10 h, the temperature is increased to 85°C for 3.0 h, and finally the temperature is decreased to 60°C for 2.5 h. The temperature of the second curing in step b) is 110°C, and the time is 4 h, thereby obtaining an optical lens material

[0045] Example 2

[0046] A preparation method of an optical material is as follows:

[0047] An optical material composition comprises: bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content is 1300 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst-tetrabutylphosphonium bromide 0.5 parts by mass, release agent-di-n-butyl phosphate 0.1 parts by mass, UV326 ultraviolet absorber 0.1 parts by mass;

[0048] The specific preparation steps are the same as those in Example 1.

[0049] Example 3

[0050] A preparation method of an optical material is as follows:

[0051] An optical material composition comprises: bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content is 1100 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst-tetrabutylphosphonium bromide 0.5 parts by mass, release agent-di-n-butyl phosphate 0.1 parts by mass, UV326 ultraviolet absorber 0.1 parts by mass;

[0052] The specific preparation steps are the same as those in Example 1.

[0053] Example 4

[0054] A preparation method of an optical material is as follows:

[0055] An optical material composition consisting of bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content 900 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst - tetrabutylphosphonium bromide 0.5 parts by mass, release agent - di-n-butyl phosphate 0.1 parts by mass, UV 326 ultraviolet absorber 0.1 parts by mass;

[0056] The specific preparation steps are the same as in Example 1.

[0057] Example 5

[0058] An optical material is prepared as follows:

[0059] An optical material composition consisting of bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content 700 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst - tetrabutylphosphonium bromide 0.5 parts by mass, release agent - di-n-butyl phosphate 0.1 parts by mass, UV 326 ultraviolet absorber 0.1 parts by mass;

[0060] The specific preparation steps are the same as in Example 1.

[0061] Example 6

[0062] An optical material is prepared as follows:

[0063] An optical material composition consisting of bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content 500 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst - tetrabutylphosphonium bromide 0.5 parts by mass, release agent - di-n-butyl phosphate 0.1 parts by mass, UV 326 ultraviolet absorber 0.1 parts by mass;

[0064] The specific preparation steps are the same as in Example 1.

[0065] Example 7

[0066] An optical material is prepared as follows:

[0067] An optical material composition consisting of bis(β-epithiopropyl) sulfide 90 parts by mass (solvent content 300 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst - tetrabutylphosphonium bromide 0.5 parts by mass, release agent - di-n-butyl phosphate 0.1 parts by mass, UV 326 ultraviolet absorber 0.1 parts by mass;

[0068] The specific preparation steps are the same as in Example 1.

[0069] Example 8

[0070] A method for preparing an optical material is as follows:

[0071] The optical material composition consists of bis(β-epithiopropyl) disulfide 90 parts by mass (solvent content 100 ppm), bis(2-mercaptoethyl) sulfide 6.2 parts by mass, isophorone diisocyanate 3.1 parts by mass, catalyst-tetrabutylphosphonium bromide 0.5 parts by mass, release agent-di-n-butyl phosphate 0.1 parts by mass, UV 326 ultraviolet absorber 0.1 parts by mass;

[0072] The specific preparation steps are the same as in Example 1.

[0073] Comparative Example 1

[0074] Except that bis(β-epithiopropyl) sulfide having a solvent content of 1700 ppm was used, the other conditions were the same as in Example 1.

[0075] Comparative Example 2

[0076] Except that bis(β-epithiopropyl) sulfide having a solvent content of 1900 ppm was used, the other conditions were the same as in Example 1.

[0077] Comparative Example 3

[0078] Except that bis(β-epithiopropyl) disulfide having a solvent content of 2100 ppm was used, the other conditions were the same as in Example 5.

[0079] Comparative Example 4

[0080] Except that bis(β-epithiopropyl) disulfide having a solvent content of 2300 ppm was used, the other conditions were the same as in Example 5.

[0081] Comparative Example 5

[0082] Except that bis(β-epithiopropyl) sulfide having a solvent content of 2500 ppm was used, the other conditions were the same as in Example 7.

[0083] Comparative Example 6

[0084] Except that bis(β-epithiopropyl) sulfide having a solvent content of 2700 ppm was used, the other conditions were the same as in Example 7.

[0085] Comparative Example 7

[0086] Except that bis(β-epithiopropyl) sulfide having a solvent content of 2900 ppm was used, the other conditions were the same as in Example 7.

[0087] Comparative Example 8

[0088] Except that bis(β-epithiopropyl) sulfide having a solvent content of 3100 ppm was used, the other conditions were the same as in Example 7.

[0089] The final product performance of each embodiment and comparative example is shown in Table 1 below:

[0090]

[0091] As can be seen from the results in the above table, when the solvent content in the episulfide compound in Examples 1-8 is 1500 ppm or less, the Tg of the optical lens material obtained by curing is relatively high and the haze is relatively low, and the comprehensive performance of the products prepared in Examples 1-6 is higher than that in Examples 7-8, further proving that the episulfide compound controls the solvent content to be 500-1500 ppm, so that the optical lens material has the excellent performance of having a relatively high Tg and a relatively low haze; the solvent content in the episulfide compound in Comparative Examples 1-8 is greater than 1500 ppm, the Tg of the optical lens material obtained by curing is relatively low, the haze is relatively high, and as the solvent content increases, the softening temperature continuously decreases and the haze gradually increases. The optical material obtained by the technical scheme of the present application can be used for optical lenses, and the optical material prepared has a refractive index of 1.7056 or more, a softening temperature of 92℃ or more, and a haze of 0.55 or less, and has high promotional value.

[0092] In summary, the optical material composition and optical material provided by the present application can improve the heat resistance of the optical material and reduce the haze of the optical material when obtaining high refractive index optical material, improve the light transmittance while improving the thermal stability of the optical material.

[0093] The above examples enable one of ordinary skill in the art to make and use the present application. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composition for use in optical materials, comprising a cyclic sulfide compound having the following structural formula: （1）； Where m is 1 or 2, and the characteristic is: Its solvent content is between 500-1100 ppm; The cyclic sulfide compound accounts for 60-95% of the total weight of the composition for optical materials; The optical material composition further includes thiols and isocyanates; The isocyanate compound contains at least two isocyanate groups.

2. The composition for optical materials according to claim 1, characterized in that: The cyclic sulfide compound accounts for 70-90% of the total weight of the composition for optical materials.

3. The composition for optical materials according to claim 1, characterized in that: The thiol compound accounts for 1-20% of the total weight of the optical material composition, and the isocyanate compound accounts for 1-20% of the total weight of the optical material composition.

4. The composition for optical materials according to claim 3, characterized in that: The thiol compound is selected from 2-mercaptoethanol, 3-mercaptopropanol, 2-hydroxypropylthiol, n-hexylthiol, n-octylthiol, bis(2-mercaptoethyl) sulfide, 2,5-dimercaptomethyl-1,4-dithiane, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trisulfide. One or more of the following: undecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 1,1,3,3-tetra(mercaptomethylthio)propane, pentaerythritol tetra(3-mercaptopropionic acid) ester, pentaerythritol tetrathioethylene glycol ester, trimethylolpropane trithioethylene glycol ester, and trimethylolpropane trimercaptopropionate.

5. The composition for optical materials according to claim 1, characterized in that: The isocyanate compounds are selected from diethylidene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, isophorone diisocyanate, 2,6-bis(isocyanate methyl)decahydronaphthalene, toluene diisocyanate, o-toluidine diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, 2,2'-bis(4-isocyanate phenyl)propane, triphenylmethane triisocyanate, and bis(diisocyanate toluene). One or more of the following: 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diisocyanate-biphenyl, dicyclohexylmethane-4,4'-diisocyanate, 1,1'-methylenebis(4-isocyanate-benzene), m-xylyl diisocyanate, p-xylyl diisocyanate, m-tetramethylxylyl diisocyanate, p-tetramethylxylyl diisocyanate, bis(isocyanate-methyl)norbornene, bis(isocyanate-methyl)adamantane, thiodiethyl diisocyanate, thiodipropyl diisocyanate, and thiodihexyl diisocyanate.

6. The composition for optical materials according to claim 1, characterized in that: The optical material composition also includes an imidazole or phosphine polymerization catalyst, which accounts for 0.01-1% of the total weight of the optical material composition.

7. An optical material, characterized in that: Obtained by curing the optical material composition according to any one of claims 1-6.

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