JP2007238796A - Method for increasing viscosity of episulfide compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-viscosity body of an episulfide compound. <P>SOLUTION: The viscosity of the episulfide compound is gradually increased as follows. (A) 85-98 wt.% of the episulfide compound is mixed and reacted with (B) 2-15 wt.% of sulfur. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for thickening an episulfide compound that is a monomer of a high refractive index resin that can be used in plastic lenses, prisms, optical films, optical fibers, information recording substrates, LED sealing materials, coating materials, optical adhesives, and the like. .

In recent years, plastic materials are widely used in various optical materials because they are light and tough and easy to dye. One of the performances required for many optical materials is a high refractive index. As for optical materials having a high refractive index, a large number of episulfide compounds that enable optical materials having a refractive index of 1.7 or more have been found (see Patent Document 1, Patent Document 2, and Patent Document 3). Among these, the episulfide compound represented by the general formula (1) is particularly useful because it exhibits a higher refractive index.
However, since the episulfide compound represented by the general formula (1) has a low viscosity of about 10 to 30 mPa · s at room temperature, there is a problem that it is difficult to use depending on the application. Specifically, when a thin film is formed on a film or a substrate, there are problems that repellence is likely to occur and liquid dripping easily. When it is hard to cure, there is a problem that it is difficult to raise. Under such circumstances, it has been strongly desired to increase the viscosity of the episulfide compound.

The episulfide compound can be cured with the base catalyst described in the above patent. Therefore, in principle, thickening using these base catalysts is possible, but when these catalysts are used, the viscosity rises at a stretch and reaches curing, so that the thickening can be stopped at the desired viscosity. There was a problem that it was difficult. Further, when trouble or the like occurs and the thickening stop is delayed, there is a problem that curing occurs in the reaction kettle and it is difficult to take out the cured product. Accordingly, there has been a demand for the development of a thickening method in which the thickening progresses mildly and does not eventually reach curing.

  The combination of the episulfide compound and sulfur is described in Patent Literature 4, Patent Literature 5, Patent Literature 6, Patent Literature 7, Patent Literature 8, Patent Literature 9, Patent Literature 10, and the like. In these patents, sulfur is added for the purpose of improving the refractive index. Furthermore, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and Patent Document 8 only disclose a method of mixing an episulfide compound and sulfur and directly curing in a mold. Not disclosed. In addition, Patent Document 7 and Patent Document 8 have a description of the reaction between an episulfide compound and sulfur. In the detailed description thereof, “the set temperature, the time required for this, etc. It is sufficient that the components are sufficiently mixed. However, excessive temperature and time are suitable, for example, an undesirable reaction between the raw materials and additives occurs, and the viscosity increases and makes the casting operation difficult. As is clear from the description, it is disclosed a reaction method in which thickening does not easily occur.

JP-A-9-71580 Japanese Patent Laid-Open No. 9-110979 Japanese Patent Laid-Open No. 9-255781 Japanese Patent Laid-Open No. 2001-2783 JP 2001-2933 A JP 2002-122701 A JP 2004-43526 A Japanese Patent Application Laid-Open No. 2004-237481 JP 2004-269673 A JP 2004-339329 A

  An object of the present invention is to provide a high viscosity product of an episulfide compound.

（ここで、ｍは０〜４の整数、ｎは０〜１の整数を表す。）
更に、（Ａ）一般式（１）で表されるエピスルフィド化合物４５〜９７ｗｔ％と（Ｂ）硫黄２〜１５ｗｔ％および（Ｃ）ＳＨ基を１分子中に１個以上有する化合物１〜４０ｗｔ％を混合し反応させることによっても、同様にエピスルフィド化合物が穏やかに増粘することを見出し本発明に至った。 As a result of studies to solve the above problems, the present inventors have mixed (A) 85 to 98 wt% of the episulfide compound represented by the general formula (1) and (B) 2 to 15 wt% of sulfur and reacting them. As a result, it was found that the episulfide compound increases in viscosity gently.

(Here, m represents an integer of 0 to 4, and n represents an integer of 0 to 1.)
Further, (A) 45 to 97 wt% of an episulfide compound represented by the general formula (1), (B) 2 to 15 wt% of sulfur, and (C) 1 to 40 wt% of a compound having one or more SH groups in one molecule. Similarly, the present inventors found that the episulfide compound can be gently thickened by mixing and reacting.

  According to the present invention, it is possible to provide a high-viscosity product of an episulfide compound that is a monomer for a high refractive index resin.

As the viscosity of the high-viscosity material increases, the crosslinking reaction proceeds, and thus problems such as poor operability and difficulty in washing with a solvent occur. The industrially easy-to-handle viscosity is 200 mPa · s to 100,000 mPa · s, the easy-to-handle viscosity is 200 mPa · s to 10,000 mPa · s, and the most easy-to-handle viscosity is 200 mPa · s to 1,000 mPa · s. .
In consideration of the refractive index, the episulfide compound represented by the general formula (1) is bis (β-epithiopropyl) sulfide (n = 0) or bis (β-epithiopropyl) disulfide (n = 1, m = 0). ) Is preferable. The purity of the episulfide compound is preferably 96% or more considering the refractive index and other performance.
The amount of sulfur added is preferably 2 to 15 wt%, more preferably 5 to 12 wt%, and most preferably 7 to 10 wt% in the thickening composition. When the amount of sulfur added is less than 2 wt%, the speed of thickening becomes extremely slow. On the other hand, when the amount is more than 10 wt%, there are problems that the speed of thickening becomes too fast and control becomes difficult, and the cured product is likely to be colored.
The reaction temperature of the episulfide compound and sulfur is preferably 0 ° C to 100 ° C, more preferably 10 ° C to 70 ° C, and most preferably 20 ° C to 50 ° C. If the reaction temperature is too low, the thickening rate becomes extremely slow, and if the reaction temperature is too high, the thickening rate becomes too fast and control becomes difficult.
The reaction time varies depending on the desired viscosity and reaction conditions, but considering the ease of control of thickening, it is preferably 0.5 to 30 days, more preferably 2 to 20 days, most preferably 4 to 10 days. preferable.

As the thickening terminator, an acid substance or a halide of silicon, germanium, tin, or antimony can be used.
The acid substance can be used as long as it is an acid, but in view of operability and solubility in a high-viscosity material, phosphoric acid esters and phosphites that are colorless and transparent liquids at room temperature are preferred. Specific examples include the following compounds. Methyl phosphoric acid, butyl phosphoric acid, isodecyl phosphoric acid, 2-ethylhexyl phosphoric acid, dimethyl phosphite, diethyl phosphite, dibutyl phosphite, diisopropyl phosphite, diphenyl phosphite. Of these, diphenyl phosphite is most preferred. These may be used alone or in combination of two or more.
Among the halides of silicon, germanium, tin and antimony, preferred are chlorides, more preferred are trichloro or dichloro compounds, and further preferred are germanium, tin and antimony trichloro or dichloro compounds having an alkyl group. is there. Specific examples of the most preferred are dibutyltin dichloride, butyltin trichloride, dioctyltin dichloride, octyltin trichloride, dibutyldichlorogermanium, butyltrichlorogermanium, diphenyldichlorogermanium, phenyltrichlorogermanium, triphenylantimony dichloride. These may be used alone or in combination of two or more.
About the addition amount of a terminator, 0.001 to 5 weight part is preferable with respect to 100 weight part of high viscosity bodies obtained, Preferably it is 0.01 to 1 weight part. If the amount of the terminator is too small, it is difficult to sufficiently suppress the thickening, and if the amount of the terminator is too large, subsequent curing will not proceed sufficiently.
The storage condition of the compound whose viscosity has been stopped is preferably in the range of −10 ° C. to 50 ° C., more preferably in the range of 0 ° C. to 30 ° C., and most preferably in the range of 5 ° C. to 25 ° C. When the storage temperature exceeds 50 ° C., it is difficult to sufficiently suppress thickening, and when the storage temperature is too low, solid precipitation occurs.

It is known that an episulfide compound is improved in oxidation resistance (yellowing resistance) by polymerization and curing together with a compound having an SH group (Japanese Patent Laid-Open No. 10-298287). In the present invention, it is possible to obtain a high-viscosity material even in the presence of a compound having an SH group in addition to an episulfide compound and sulfur. As the compound having an SH group, one disclosed in JP-A-10-298287 can be used as it is, but a compound having two or more SH groups in one molecule is preferable. Specific examples include methanedithiol, methanetrithiol, 1,2-dimercaptoethane, bis (2-mercaptoethyl) sulfide, bis (2-mercaptoethyl) ether, bis (2,3-dimercaptopropyl) sulfide, 1,2,3-trimercaptopropane, 2-mercaptomethyl-1,3-dimercaptopropane, 2-mercaptomethyl-1,5-dimercapto-3-thiapentane, 4-mercaptomethyl-1,8-dimercapto-3 , 6-dithiaoctane, 2,4-bis (mercaptomethyl) -1,5-dimercapto-3-thiapentane, 4,8-bis (mercaptomethyl) -1,11-dimercapto-3,6,9-trithiaundecane 4,7-bis (mercaptomethyl) -1,11-dimercapto-3,6,9-tritium Undecane, 5,7-bis (mercaptomethyl) -1,11-dimercapto-3,6,9-trithiaundecane, 3,5-bis (mercaptomethylthio) -1,7-dimercapto-2,6-dithiaheptane, 1,2,7-trimercapto-4,6-dithiaheptane, 1,2,9-trimercapto-4,6,8-trithianonane, 1,2,6,7-tetramercapto-4-thiaheptane, 1,2 , 8,9-tetramercapto-4,6-dithianonane, 1,2,10,11-tetramercapto-4,6,8-trithiaundecane, 1,2,12,13-tetramercapto-4,6 8,10-tetrathiatridecane, ethylene glycol bis (thioglycolate), trimethylolpropane tris (thioglycolate), pentaerythritol Trakis (thioglycolate), ethylene glycol bis (3-mercaptopropionate), trimethylolpropane tri (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), tetrakis (mercaptomethyl) methane Tetrakis (4-mercapto-2-thiabutyl) methane, tetrakis (7-mercapto-2,5-dithiaheptyl) methane, trimethylolpropane tris (2-mercaptoacetate), trimethylolpropane tris (3-mercaptopropionate) Pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate), 2,5-bis (mercaptomethyl) -1,4-dithiane, bis (4 Mercaptophenyl) sulfide, bis (4-mercaptomethylphenyl) methane, 2,2-bis (4-mercaptomethylphenyl) propane, bis (4-mercaptomethylphenyl) ether, bis (4-mercaptomethylphenyl) sulfide, etc. Can be mentioned. More preferably, ethylene glycol bis (thioglycolate), trimethylolpropane tris (thioglycolate), pentaerythritol tetrakis (thioglycolate), ethylene glycol bis (3-mercaptopropionate), trimethylolpropane tri (3- Mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), bis (2-mercaptoethyl) sulfide, bis (2-mercaptoethyl ether), 1,2,6,7-tetramercapto-4-thiaheptane Alternatively, 2-mercaptomethyl-1,5-dimercapto-3-thiapentane and the like can be mentioned. These may be used alone or in combination of two or more.
The addition amount of the compound having an SH group is preferably 1 to 40 wt%, more preferably 3 to 30 wt%, and most preferably 5 to 20 wt% in the composition for thickening. Addition of 1 wt% or less is insufficient in oxidation resistance, and yellowing due to heat tends to occur. On the other hand, when the amount is 40 wt% or more, the oxidation resistance itself is saturated, and no improvement effect is recognized.

The high-viscosity material obtained in the present invention can be cured with heat and light. Conventionally known catalysts can be used in thermosetting, and preferred specific examples include triethylamine, N, N-dimethylcyclohexylamine, N, N-diethylethanolamine, N, N-dimethylaniline, pyridine, and N-methylpiperidine. Amines such as piperazine triethylenediamine and imidazole, phosphines such as tri-n-butylphosphine and triphenylphosphine, tetra-n-butylphosphonium bromide, tetra-n-butylammonium bromide, triethylbenzylammonium chloride, cetyldimethyl Examples include quaternary ammonium salts such as benzylammonium chloride and 1-n-dodecylpyridinium chloride, and quaternary phosphonium salts such as tetraphenylphosphonium bromide. In the case of thermosetting, the high-viscosity material is cured by heating in the temperature range of 20 ° C. to 200 ° C. for several minutes to several days. Examples of the heat source that can be used for curing include an electric oven, a thermostatic bath, and a dryer.
In the case of photocuring, catalysts described in Japanese Patent Application Nos. 2003-288288 and 2004-029979 can be suitably used. In the case of photocuring, curing is performed by irradiating a high-viscosity material with ultraviolet rays, but the ultraviolet ray source used is not particularly limited as long as it is an apparatus that generates ultraviolet rays. Specific examples include a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, and a high power metal halide lamp.
As described above, only a part of the curing catalyst of high viscosity is exemplified, but it is not limited to these listed compounds as long as the polymerization promoting effect is exhibited. These catalysts may be used alone or in combination of two or more. The addition amount of the catalyst is 0.0001 to 10.0 parts by weight, preferably 0.0005 to 5.0 parts by weight, with respect to 100 parts by weight of the high-viscosity material.

When the reaction between episulfide and sulfur is slow and it is difficult to increase the viscosity, a reaction accelerator disclosed in JP-A No. 2004-269673 can be used. Among these, preferred compounds are 2-mercapto-1-methylimidazole, triphenylphosphine, 3,5-dimethylpyrazole, N-cyclohexyl-2-benzothiazolylsulfenamide, dipentamethylenethiuram tetrasulfide, tetrabutylthiuram. Disulfide, tetraethylthiuram disulfide, 1,2,3-triphenylguanidine, 1,3-diphenylguanidine, 1,1,3,3-tetramethyleneguanidine, aminoguanidine sulfate, trimethylthiourea, tetraethylthiourea, dimethylethyl Thiourea, zinc dibutyldithiocarbamate, zinc dibenzyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, pipecoryldithiocarbamate Corium, is a thio urethanes. The reaction accelerator is used in an amount of 0.001 to 5 parts by weight, preferably 0.1 to 0.1 parts by weight, based on 100 parts by weight of the thickening composition. 005 to 2 parts by weight, more preferably 0.01 to 1 part by weight.

Furthermore, in order to adjust the performance of the high-viscosity body as desired, it is possible to add a compound capable of reacting with some or all of the composition components as necessary. Compounds that can react with a part or all of the composition components include epoxy compounds, iso (thio) cyanates, carboxylic acids, carboxylic anhydrides, phenols, amines, vinyl compounds, allyl compounds, Examples include acrylic compounds and methacrylic compounds. The addition amount in the case of using the compound which can react with a part or all of a composition component is 1-200 weight part with respect to 100 weight part of high viscosity bodies.
In addition, the high-viscosity material of the present invention contains various performance improving additives such as antioxidants, bluing agents, ultraviolet absorbers, adhesion improvers, wettability improvers, releasability improvers, and antistatic agents. In addition, it is of course possible to further improve the practicality of the obtained optical element.

It is preferable to handle high-viscosity materials in a clean room to avoid contamination such as dust and foreign substances, and curing can be performed by covering the atmosphere with an appropriate film in an inert gas stream such as nitrogen or helium. I do not care.
It is preferable to perform a deaeration process and a filtration process before polymerizing and curing the high-viscosity material from the viewpoint of achieving high transparency of the optical element. The deaeration treatment is usually performed at 0 to 100 ° C. under a reduced pressure of 0.001 to 50 torr for 1 minute to 24 hours. The filtration treatment is performed by passing through a filter such as PTFE or PET having a pore size of about 0.05 to 10 μm.

The thickening method by the reaction of the episulfide compound of the present invention with sulfur will be described in the order of operation.
Add sulfur to the episulfide compound, and if necessary, a compound having one or more SH groups in one molecule, and add sulfur with stirring or non-stirring at 0 ° C. to 100 ° C. for 1 minute to 2 hours. Dissolve completely. The temperature at this time may be a temperature at which sulfur can be completely dissolved, but is preferably 0 ° C to 100 ° C, more preferably 10 ° C to 80 ° C, and most preferably 20 ° C to 60 ° C. The sulfur dissolution time is 1 minute to 2 hours, preferably 5 minutes to 1.5 hours, and most preferably 10 minutes to 1 hour. Moreover, when dissolving sulfur, a reaction accelerator may be added.
Thickening due to the reaction between the episulfide compound and sulfur is carried out at 0 ° C. to 100 ° C. for 0.5 to 30 days with or without stirring. Thereafter, an acid substance or a halide of silicon, germanium, tin, or antimony is added to stop the thickening. The obtained high viscosity body is stored at -10 ° C to 50 ° C.
All of the above operations may be performed in the air, but it is desirable to perform in an inert gas atmosphere.
The high-viscosity material is cured by heat or light after adding a polymerization catalyst and various performance improvers to the high-viscosity material.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. The viscosity and refractive index were measured by the following method.
Viscosity measurement: The viscosity at 25 ° C. was measured using a corn plate viscometer model DV-II manufactured by Brookfield.
Refractive index (nd): measured at 25 ° C. using an Abbe refractometer.

Example 1
A thickening flask by addition of sulfur was charged with 93 g of bis (β-epithiopropyl) sulfide and 7 g of sulfur, and the atmosphere in the flask was replaced with nitrogen. The solution was heated to 50 ° C. with stirring to completely dissolve sulfur. Thereafter, the solution was returned to room temperature, about 1 g of the solution was sampled, and the viscosity was measured. The viscosity at this time was 12 mPa · s.
The flask was again purged with nitrogen and then allowed to stand in a storage kept at 25 ° C. Sampling was performed after a predetermined number of elapsed days, and the viscosity was measured in the same manner as described above. The results are shown in FIG. As shown in FIG. 1, the viscosity increased slowly.
Furthermore, when the solution was observed after 30 days, the solution was in a gel form.

Comparative Example 1
The flask was charged with 100 g of bis (β-epithiopropyl) sulfide and 0.02 g of tetra (n-butyl) phosphonium bromide, which is a general curing catalyst for episulfide compounds, and the inside of the flask was purged with nitrogen and stirred to completely dissolve the catalyst. I let you. About 1 g of this solution was sampled and the viscosity was measured. The viscosity at this time was 11 mPa · s.
The flask was again purged with nitrogen and then allowed to stand in a storage kept at 25 ° C. Sampling was performed after a predetermined number of elapsed days, and the viscosity was measured in the same manner as described above. The results are shown in FIG. Despite the use of a small amount of the curing catalyst, the viscosity increased at a stretch, and it was found that it was difficult to control the viscosity with the conventional curing catalyst. Furthermore, when the solution was observed after 4 days, the solution was solidified.

Example 2
87 g of bis (β-epithiopropyl) sulfide, 5 g of dimercaptoethyl sulfide and 8 g of sulfur were charged into a thickening flask by addition of sulfur in the presence of an SH compound , and the atmosphere in the flask was replaced with nitrogen. The solution was heated to 50 ° C. with stirring to completely dissolve sulfur. Thereafter, the solution was returned to room temperature and allowed to stand in a storage kept at 25 ° C. After 7 days, sampling was performed to measure the viscosity. The viscosity at this time was 770 mPa · s.

Example 3
Stopping thickening with acid, storage and preparation of cured product (β-epithiopropyl) sulfide was thickened in exactly the same manner as in Example 1. When the solution viscosity reached approximately 500 mPa · s, 0.1 part by weight of diphenyl phosphite as a thickening stop agent was added to 100 parts by weight of the high-viscosity material, and the mixture was sufficiently stirred and dissolved. The viscosity at this time was 510 mPa · s. After replacing the flask with nitrogen, the flask was left in a storage cabinet maintained at a temperature of 10 ° C. After 23 days, when the viscosity was measured again, it was 520 mPa · s, and almost no change in viscosity was observed.
To 100 parts by weight of the high-viscosity material after storage, 0.4 parts by weight of the curing catalyst tetra (n-butyl) phosphonium bromide was added and sufficiently stirred to dissolve. This solution was poured into a glass mold and cured with the following temperature pattern. After the cured product was annealed at 110 ° C. for 1 hour, the refractive index was measured to be 1.72 (d line).
Curing temperature pattern: 10 hours at 30 ° C, 10 hours from 30 ° C to 100 ° C, 1 hour at 100 ° C

Example 4
Stopping thickening with chlorine compound, storage and preparation of cured product (β-epithiopropyl) sulfide was thickened in exactly the same manner as in Example 1. When the solution viscosity reached approximately 1000 mPa · s, 0.1 part by weight of dibutyltin dichloride was added as a thickening stop agent to 100 parts by weight of the high-viscosity material, and the mixture was sufficiently stirred and dissolved. The viscosity at this time was 1200 mPa · s. After replacing the flask with nitrogen, the flask was left in a storage cabinet maintained at a temperature of 10 ° C. After 21 days, when the viscosity was measured again, it was 1340 mPa · s, and the viscosity only increased slightly.
To 100 parts by weight of the high-viscosity material after storage, 0.4 parts by weight of the curing catalyst tetra (n-butyl) phosphonium bromide was added and sufficiently stirred to dissolve. This solution was poured into a glass mold and cured with the same temperature pattern as in Example 3. After the cured product was annealed at 110 ° C. for 1 hour, the refractive index of the cured product was measured and found to be 1.72 (d line).

Comparative Example 2
The flask was charged with 93 g of bis (β-epithiopropyl) sulfide and 7 g of sulfur, and the atmosphere in the flask was replaced with nitrogen. The solution was heated to 50 ° C. with stirring to completely dissolve sulfur. Thereafter, the solution was returned to room temperature, and 0.1 g of a curing catalyst tetra (n-butyl) phosphonium bromide was added to this solution and sufficiently stirred and dissolved. This solution was poured into a glass mold and cured with the same temperature pattern as in Example 3. After the cured product was annealed at 110 ° C. for 1 hour, the refractive index of the cured product was measured and found to be 1.72 (d line).
From this result, it was confirmed that the cured product obtained in this Comparative Example and the cured products obtained in Examples 2 and 3 were physically equivalent.

Claims (7)

(A) A method for thickening an episulfide compound, comprising mixing and reacting 85 to 98 wt% of an episulfide compound represented by the following general formula (1) and 2 to 15 wt% of sulfur (B).

(Here, m represents an integer of 0 to 4, and n represents an integer of 0 to 1.) (A) 45 to 97 wt% of an episulfide compound represented by the following general formula (1), (B) 2 to 15 wt% of sulfur, and (C) 1 to 40 wt% of a compound having one or more SH groups in one molecule are mixed. And a method for increasing the viscosity of the episulfide compound.

(Here, m represents an integer of 0 to 4, and n represents an integer of 0 to 1.) 3. A method for stopping thickening, comprising adding an acid substance or a halide of silicon, germanium, tin or antimony to the composition according to claim 1 or 2. A high-viscosity body obtained by the method according to claim 3. The storage method which stores the high-viscosity body of Claim 4 in -10 degreeC-50 degreeC. A resin obtained by polymerizing and curing the high-viscosity material according to claim 4. An optical material obtained from the resin according to claim 6.