JP2001031675A - New polythiol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a specific new polythiol useful as a raw material for plastic lens of high refractive index and high Abbe's number with high heat resistance. SOLUTION: This new compound is a compound of the formula, e.g. 2- mrcaptomethyl-6-mercapto-1,4-dithiacycloheptane. The compound of the formula is obtained by the following process: hydrogen sulfide is reacted with an epihalohydrin to synthesize a bis(3-halogeno-2-hydroxypropyl sulfide, which, in turn, is reacted with thiourea in the presence of a hydrohalogenic acid such as hydrochloric acid or hydrobromic acid to form an isothiuronium salt, which is then hydrolyzed with a base such as ammonia water or an aqueous sodium carbonate solution. Furthermore, the compound of the formula and a polyisocyanate are homogeneously mixed together with an additive or the like followed by defoaming the mixture e.g. under agitation at reduced pressures, and the resultant defoamed liquid is injected into a mold and cure by heating to obtain a urethane-based plastic lens; wherein the above heating is carried out at 0-200 deg.C and the curing is finished in 1-100 h.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polythiol useful as a raw material for polyurethane resin, a raw material for coating material, an epoxy curing agent, a vulcanizing agent for synthetic resin, and as an additive, and particularly to a monomer for urethane plastic lens. And a urethane-based plastic lens obtained using the polythiol as a raw material.

[0002]

2. Description of the Related Art Urethane-based plastic lenses are now widely used for plastic lenses for spectacles due to their tough properties and excellent optical properties. Among them,
Urethane-based plastic lenses using 2,5-bis (mercaptomethyl) -1,4-dithiane (JP-B-7-5)
No. 585, Japanese Patent Publication No. 6-5323) have a preferable feature that the Abbe number is slightly higher than that of a urethane-based plastic lens using other polythiols.

[0003]

However, even with the use of 2,5-bis (mercaptomethyl) -1,4-dithiane, the heat resistance as represented by, for example, xylylene diisocyanate does not become very high. When polymerized with such a polyisocyanate, the heat resistance was still insufficient.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of intensive study, the following equation (1)

Embedded image It has been found that the use of the novel polythiol represented by the formula (1) further improves the heat resistance as compared with the case of using 2,5-bis (mercaptomethyl) -1,4-dithiane, and reached the present invention.

That is, the present invention provides the following formula (1)

Embedded image And a urethane-based plastic lens obtained by polymerizing a polythiol of the formula (1) with a polyisocyanate.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The polythiol of the formula (1) according to the present invention is an organic compound in which a mercaptomethyl group and a mercapto group are bonded to a dithiacycloheptane skeleton.

The polythiol of the formula (1) according to the present invention is synthesized, for example, by the following method.

Bis (3-halogeno-2-hydroxypropyl) sulfide is synthesized by reacting epihalohydrin with hydrogen sulfide, and then reacted with thiourea in the presence of a hydrohalic acid such as hydrochloric acid or hydrobromic acid. Generates isothiuronium salt, aqueous ammonia, aqueous sodium carbonate,
The polythiol represented by the formula (1) of the present invention is synthesized by hydrolysis with a base such as aqueous sodium hydroxide, aqueous potassium hydroxide, or aqueous hydrazine.

The thus obtained 2-mercaptomethyl-6-mercapto-1,4-formula (1) of the present invention is obtained.
Dithiacycloheptane is used not only as a monomer for urethane plastic lenses, but also for a wide variety of applications such as raw materials for polyurethane resins, coating materials, epoxy curing agents, synthetic resin vulcanizing agents, and various other additives. It can be suitably used.

Next, the production of the urethane-based plastic lens of the present invention will be described. The 2-mercaptomethyl-6-mercapto-1,4-dithiacycloheptane represented by the formula (1) of the present invention may be added as needed for the purpose of polyisocyanate, three-dimensional cross-linking agent and the like. Certain other monomers and additives are mixed and homogenized, and after defoaming by stirring under reduced pressure or the like, the defoaming liquid is poured into a molding mold and cured mainly by heat, so that the urethane-based plastic lens of the present invention is obtained. can get.

The heating condition is such that the temperature is gradually raised from a low temperature to a high temperature in a temperature range of about 0 to 200 ° C., and the heating is completed in about 1 to 100 hours.

When a radiation polymerizable monomer is used as the other monomer, radiation irradiation may be used in combination. When irradiating radiation, ultraviolet rays of 400 nm or less are mainly used. Irradiation conditions of ultraviolet rays are approximately 1 to 1000 mJ.
In many cases, irradiation is performed for 1 to 7200 sec at an intensity of / see, and sometimes cooling or irradiation is performed several times before irradiation for the purpose of removing heat or obtaining an optically uniform molded product. There is also.

The polyisocyanate used as the monomer for the urethane-based plastic lens of the present invention is an organic compound having two or more isocyanate groups in a molecule, and examples thereof include the following compounds.

Typical polyisocyanates include, for example, m-xylylene diisocyanate, α, α,
α ', α'-tetramethyl-m-xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, hexamethylene diisocyanate, trimethyl Hexamethylene diisocyanate, bis (isocyanatomethyl) norbornane, bis (isocyanatomethylthio) methane and the like can be mentioned.
In addition, this invention is not limited only to these listed compounds.

As other monomers added as required, for example, polythiols other than the formula (1), (meth) acrylic compounds, allyl or vinyl compounds, (thio) epoxy compounds and the like can be mentioned. When these other monomers are added as a three-dimensional cross-linking agent, a preferable result may be obtained when a polythiol having three or more functions is selected.

As typical polythiols other than the formula (1), trithiol or higher polythiols are relatively preferable.
For example, the following compounds may be mentioned.

For example, pentaerythritol poly (thioglycolate), pentaerythritol poly (3-mercaptopropionate), 4- (mercaptomethyl)-
3,6-dithiaoctane-1,8-dithiol, 4,8
-Bis (mercaptomethyl) -3,6,9-trithiaundecane-1,11-dithiol, trithioglycerin, 1,1,3,3-tetrakis (mercaptomethyl)
-2-thiapropane and the like. In addition, this invention is not limited only to these listed compounds.

As the (meth) acrylic compound, for example, ethylene glycol di [(meth) acrylate],
Diethylene glycol di [(meth) acrylate], butanediol di [(meth) acrylate], neopentyl glycol di [(meth) acrylate], trimethylolpropane tris [(meth) acrylate], pentaerythritol tris [(meth) acrylate] Pentaerythritol tetrakis [(meth) acrylate], dipentaerythritol hexa [(meth) acrylate], 2,2-bis [(meth) acryloylethoxyethoxyphenyl] propane, 2,2-bis [(meth) acryloylethoxyphenyl ] Propane, bis [(meth) acryloylethoxyethoxyphenyl] methane, bis [(meth) acryloylethoxyphenyl]
Methane, bis [(meth) acryloylmethyl] tricyclodecane, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, ethanedithioldi [(meth) acrylate ], 3-thiaheptane-1,5-dithioldi [(meth) acrylate], 2,5-bis [(meth) acryloylthiomethyl] -1,4-dithiane, and the like. In addition, this invention is not limited only to these listed compounds.

Examples of the allyl or vinyl compound include, for example, diethylene glycol bis (allyl carbonate), diallyl sulfide, styrene, isopropenylbenzene, divinylbenzene, vinylcyclohexene oxide, diisopropenylbenzene, 3-isopropenyl-α, α-dimethyl Benzyl isocyanate and the like. In addition, this invention is not limited only to these listed compounds.

Examples of (thio) epoxy compounds include bisphenol A diglindyl ether, bisphenol A bis [3-glycidyloxy-2-hydroxy-1-propyl ether], 3,4-epoxycyclohexylcarboxylic acid 3,4- Epoxycyclohexylmethyl ester, 1,4-butanedicarboxylic acid di3,4-epoxycyclohexylmethyl ester, vinylcyclohexene dioxide, diglycidyl sulfide, bis (epithiopropyl) sulfide, bis (epithiopropyl) disulfide and the like. Can be In addition, this invention is not limited only to these listed compounds.

In the production of the urethane-based plastic lens of the present invention, a heat catalyst, a photocatalyst, an ultraviolet absorber, an internal mold release agent, an antioxidant, a polymerization inhibitor, an oil-soluble dye, a filler, Known additives such as a plasticizer may be added.

Further, the obtained urethane-based plastic lens or its resin of the present invention can obtain molded articles of various forms by changing a molding mold at the time of casting polymerization, and can be used for spectacle lenses, camera lenses, It can be used for various applications as an optical material such as a light emitting diode (LED) and a transparent resin. Among them, it is particularly useful for eyeglass lenses.

Further, the urethane-based plastic lens of the present invention is provided with anti-reflection, high hardness, high abrasion resistance, high chemical resistance, high anti-fogging property, and high fashionability, if necessary. Surface polishing, antistatic treatment,
A physical or chemical treatment such as a hard coat treatment, a non-reflection coat treatment, or a light control treatment can be performed.

[0024]

The present invention will be described below in more detail with reference to examples and comparative examples. In addition, the refractive index, Abbe number, and heat resistance of the obtained urethane-based plastic lens were measured by the following methods. Refractive index, Abbe number: 20 ° C. using a Pulfrich refractometer
Was measured. Heat resistance; measured by TMA.

Example 1 (Synthesis of polythiol of formula (1)) Bis (3-
Chloro-2-hydroxypropyl) sulfide100.
0 g (0.41 mol), 190.0 g of 35% hydrochloric acid (1.
82 mol), 10.0 g of 95% sulfuric acid and thiourea.
0 g (2.73 mol) of the mixture was heated and stirred under reflux (11
(0 ° C.) for 3 hours.

After cooling the reaction solution to room temperature, toluene
0 ml, and 250.0% ammonia water 180.0 g (2.
64 mol) was carefully added while observing the situation, and the mixture was hydrolyzed at 60 ° C. for 3 hours. After the completion of the hydrolysis reaction, the stirring was stopped, and the separated lower aqueous layer was separated and discarded. The obtained organic layer was washed with 200 ml of 35% hydrochloric acid and then washed with 200 ml of water.
Washed three times with water. The organic layer washed with water is desolvated under reduced pressure to obtain 47.1 g of a residue containing 2-mercaptomethyl-6-mercapto-1,4-dithiacycloheptane represented by the formula (1) of the present invention. Was.

Acetonitrile is added to the residue to separate and discard the insoluble matter, and the solvent is removed again under reduced pressure to contain the 2-mercaptomethyl-6-mercapto-1,4-dithiacycloheptane of the present invention. 28.5 g of a residue were obtained.

5.8 g of the residue was purified by reverse phase (ODS) column chromatography, chloroform and NaCl were added to the obtained separation liquid, and the mixture was extracted with chloroform. To give 1.0 g of 2-mercaptomethyl-6-mercapto-1,4-dithiacycloheptane (oil) represented by the formula (1) of the present invention.
I got

When the obtained compound was identified by the following identification method, it was confirmed that it was the desired 2-mercaptomethyl-6-mercapto-1,4-dithiacycloheptane. · IR spectrum (FIG. 1), mass spectrum (FIG. 2), ¹ H-NMR (Fig. 3), ^{1 3} C-NMR (Fig. 4).

Example 2 2-mercaptomethyl-synthesized according to Example 1
6-mercapto-1,4-dithiacycloheptane
3 g (0.053 mol), 4- (mercaptomethyl)-
3,6-dithiaoctane-1,8-dithiol 13.8
g (0.053 mol), m-xylylene diisocyanate 24.9 g (0.132 mol), dibutyltin dichloride 10.0 mg (200 ppm), 2- (2-hydroxy-5-t-octylphenyl) benzotriazole 25 mg (500 ppm), 75 mg of di (1,4,7-trimethyl-3,6,9-trioxatridecyl) phosphoric acid
(1500 ppm) was mixed and defoamed while uniformly mixing and dissolving under reduced pressure. After the defoaming is completed, the defoaming liquid is poured into a molding mold prepared in advance, and the temperature is reduced from room temperature to 120 ° C.
The composition was cured by heating to 20 ° C. over 20 hours.

The obtained urethane-based plastic lens was transparent, had a refractive index of 1.661, an Abbe number of 33, and a heat resistance of 104 ° C. (TMA). The results are shown in Table 1.

Comparative Examples 1 and 2 The 2-mercaptomethyl-6 of the present invention used in Example 2
Example 2 using another polythiol shown in Table 1 in place of mercapto-1,4-dithiacycloheptane
In the same manner as described above, a urethane-based plastic lens was manufactured. The results are shown in Table 1.

[0033]

[Table 1]

[0034]

By using the novel polythiol of the present invention, a plastic lens having a high refractive index, a high Abbe number and excellent heat resistance can be provided.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the compound obtained in Example 1.

FIG. 2 is a mass spectrum of the compound obtained in Example 1.

FIG. 3 is a ¹ H-NMR spectrum of the compound obtained in Example 1.

FIG. 4 is a ¹³ C-NMR spectrum of the compound obtained in Example 1.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshinobu Kanamura 30 Asamuta-cho, Omuta-shi, Fukuoka Mitsui Chemicals, Inc.F-term (reference) 4J034 BA02 CA32 CB03 CB07 CC15 CC23 CC29 CC39 CC46 CC52 CC61 CC62 CC65 CD08 HA01 HA07 HA11 HB03 HC03 HC12 HC17 HC22 HC46 HC52 HC54 HC61 HC64 HC67 HC71 HC73 QB08 QD03 RA13

Claims (2)

[Claims] [Claim 1] The following formula (1) Polythiol represented by 2. A urethane-based plastic lens obtained by reacting the polythiol according to claim 1 with a polyisocyanate.