MXPA02002310A - Thioglycerol derivatives and their use in polysulfide compositions for optical material - Google Patents

Abstract

Novel thioglycerol derivatives, processes for their manufacture, and optical materials made from such compounds. The thioglycerol derivatives have high concentrations of sulfur relative to compounds conventionally used for optical materials, and thus exhibit high refractive indices without sacrificing processability.

Description

DERIVATIVES OF TIOGLICEROL AND ITS USE IN COMPOSITIONS OF POLYSULPHIDE FOR OPTICAL MATERIAL Field of the Invention The present invention relates to thioglycerol derivatives and their preparation, the derivatives having utility in optical materials such as lenses. Plastic lenses for use in glasses and cameras have increasingly spread in view of their light weight, durability, drying ability and work compared to conventional glass lenses. Resin compositions suitable for the manufacture of optical lenses must possess certain characteristics, including a high refractive index, high surface accuracy, low dispersion properties and good heat resistance, impact resistance and tear resistance. Dethylene glycol bis (allylcarbonate (LAC) and polycarbonate have been conventionally used for plastic lenses). However, lenses made of LAC have lower refractive indices than lenses made of glass of a corresponding general thickness, and therefore do not work as well in this regard. U.S. Patent Nos. 4,775,733 and 3, 191, 055 disclose polyurethane lenses made of a polymer between a xylylene diisocyanate compound and a polythiol compound having a higher refractive index than lenses made of DAC. However, such lenses generally suffer from a resistance to Poor heat, hindering the ability to use high temperatures during the heat treatment processing steps. It would therefore be desirable to develop compositions for use in making optical materials that do not suffer from the various disadvantages mentioned above, and which have a good commercialization and process capability. PCT publication WO-A-99 2741 6 provides disulfide compositions formed by the oxidation of thiog licerol esters of thioglycolic acid. In particular, publication 2741 6 specifically explains the use of simple disulphides. The meaning of a number of links is not included or explained in the reference 2741 6. Examples from 1 to 2741 refer only to the use of simple disulfide compounds. Although they are useful as optical materials, they are limited in the scope of their usefulness by a narrow range of refractive indices provided by simple dissufficient bonds. As a practical matter, the more disulfide bonds, the higher the refractive index. Therefore, it is desirable to provide a composition having a higher refractive index than those shown in reference 2741. 6. The DATABASE CH EMABS [On line] CH EM ICAL ABSTRACTS SERVICE, COLUMBUS, OH ION, USA; STN, CAPLUS access number 1 989: 575328, XP0021 50492 and J P 01 0901 70 A (Mitsui Toatsu Chemicals I nc.) April 6, 1989 (1989-19-06) provides novel compositions of polythiol which are derivatives of 2,3-d imercapto-1-propanol.

Optical materials such as lenses can be prepared from the derivatives of the present invention by conventional means. Suitable additives such as surface active agents can be used. The resulting lenses can be subjected as necessary to various physical and chemical treatments such as surface polishing, anti-static treatment, hard coating treatment, non-reflective coating treatment, dyes, photochromatography treatment, etc. , all well known to those skilled in the art. The present invention is further illustrated by means of the following non-limiting examples. EXAMPLE 1 Thioglycerol (1 994.60 g) was placed in a 5-liter, 3-necked round bottom flask, equipped with a magnetic stirrer, a thermocouple, and a distillation head with a vacuum outlet., 7.78 moles) and thioglycolic acid (2332.96g, 24.82 moles). Methane sulphonic acid (14.1 6g, 0.1 mole) was added, vacuum was applied (5 to 10 mm Hg) and the reaction was heated to a temperature of 70 ° C. When the reaction temperature reached about 40 ° C, the water was distilled. The reaction was heated to a temperature of 70 ° C for a period of 4 to 5 hours and cooled to room temperature. Subsequently the reaction was transferred to a 6 liter Erlenmeyer flask which was equipped with an overhead stirrer.

Aqueous ammonia (4218. OOg, 5%, 12.41 moles) was added and the reaction was stirred for a period of 30 to 45 minutes. At a temperature of approximately 35 to 40 ° C, the exotherm occurs at the time of the ammonia addition. This can be controlled by cooling the reaction at a temperature of 10 to 15 ° C before the addition of the ammonia. The top layer of ammonia was then removed and the reaction washed with 3 x 2 liters of water. After the washing was completed, the reaction was separated free of water, either by vacuum distillation or rotary evaporator to produce 1994.6g, 69%, of TGBMA in the form of a light yellow oil. The refractive index was 1.5825 EJ MPLO 2 In a 250 ml three neck flask equipped with a condenser, thermometer, magnetic stirrer and a constant addition funnel was added thioglycerol (42.OOg, 0.39 moles), water (32.40). g, 1. 80 moles), and ferrous sulfate (002g, 0.3 moles). Hydrogen peroxide (42.OOg, 0.30 mol) was slowly added, maintaining a temperature below 50 ° C. Care was taken not to add hydrogen peroxide too quickly, thus avoiding the accumulation of excess peroxide. The reaction mixture was! Extracted with methyl isobutyl ketone to remove thioglycerol that had not reacted. The aqueous portion was concentrated until dried, after testing the unreacted peroxide, resulting in 41.90g of disulphide product (yield greater than 99%). The index of refraction was 1.5670.

EJ, EMPLO 3 Dithioglycerol tetramercaptoacetate was prepared using the procedure described in Example 1, after adjusting the stoichiometry. EXAMPLE 4 1,3-Dimercapto-2-propanol (12.8 g, 0.1 mol), thioglycolic acid (9.5 g, 0.1 mol) and methane sulfonic acid (0.13 g, 1.30 mol) were combined and heated to a temperature of 70 ° C under approximately 4mm vacuum. The reaction mixture maintained at this temperature and the pressure for a period of 2 to 3 hours until the water of the reaction had been distilled. The completion of the reaction can be monitored by means of the titration of the acid number. The reaction was washed with 3.7% aqueous ammonia followed by one or two washings of water to remove excess thioglycolic acid. The final product was separated until dried resulting in a yield of 79%. The refractive index was 1.6200. EXAMPLE 5 Thioglycerol (1000.OOg, 9.26 moles), thioglycolic acid (1874.07) was placed in a 5-liter 3-necked round bottom flask equipped with a magnetic stirrer, thermocouple and a distillation head as a vacuum outlet. g, 20.37 mo) and methane sulfonic acid (11 52 g, 0. 12 moles). Vacuum (from 5 to 10mm Hg) was applied and the reaction was heated to a temperature of 70 ° C. The reaction was heated to a temperature of 70 ° C for a period of 3 to 4 hours at which time the crude refractive index was 1.5500. After a warm-up For a period of 2 to 3 hours, which raises the crude refractive index to 1.5610, the reaction was cooled and transferred to a 6-liter Erlenmeyer flask equipped with an overhead stirrer. Aqueous ammonia (2361.3g, 5%, 6.95 moles) was added to the Erlenmeyer flask, and the reaction was stirred for a period of 30 to 60 minutes. The exotherm occurs at a temperature of approximately 35 to 40 ° C at the time of the ammonia addition. The cooling of the reaction at a temperature of 10 to 15 ° C before the addition of the ammonia can control the exotherm. The top layer of ammonia was then removed and the reaction washed with 3 X 2 liters of water. After the washing was finished, the reaction was separated free of water, either by vacuum distillation or a rotary evaporator to produce 1777.9g, 75% TGBMA in the form of a light yellow oil, Now the refractive index h had increased to 1.5825 from the crude refractive index of 1.5610.