COMPOSITION FOR OPTICAL MATERIAL AND OPTICAL MATERIAL

Abstract

The present invention provides a composition for an optical material containing a compound (a) and/or a compound (b) and a compound (c) which are described below. In a preferable embodiment, the proportion of the compound (a) and/or the compound (b) is 0.001-30.0% by mass. The compound (a) is a compound represented by formula (1). The compound (b) is a compound represented by formula (2). The compound (c) is an episulfide compound.

##STR00001##

Claims

1. A composition for optical materials comprising a compound (a) and/or a compound (b) and a compound (c), wherein: the compound (a) is a compound represented by formula (1): ##STR00012## the compound (b) is a compound represented by formula (2): ##STR00013## and the compound (c) is an episulfide compound.

2. The composition for optical materials according to claim 1, wherein the ratio of the compound (a) and/or the compound (b) is 0.001 to 30.0% by mass.

3. A method for producing an optical material, which comprises: adding a polymerization catalyst to the composition for optical materials according to claim 1 in an amount of 0.0001 to 10 parts by mass relative to 100 parts by mass of the composition for optical materials, and polymerizing and curing the resultant materials.

4. An optical material obtained by the method according to claim 3.

5. An optical lens made of the optical material according to claim 4.

6. A method for producing an optical material, which comprises: adding a polymerization catalyst to the composition for optical materials according to claim 2 in an amount of 0.0001 to 10 parts by mass relative to 100 parts by mass of the composition for optical materials, and polymerizing and curing the resultant materials.

Description

EXAMPLES

[0056] Hereinafter, the present invention will be specifically described by way of illustrative examples, but the present invention is not limited thereto. Note that evaluation was carried out in manners described below.

[Mold Release Characteristics]

[0057] 10 lenses of −4D having a diameter of 70 mm and a central thicknesses of 1.0 mm were prepared, and mold release characteristics thereof were evaluated. The case where 10 lenses were successfully removed from the mold was rated as A. The case where 9 lenses were successfully removed from the mold was rated as B. The case where 8 lenses were successfully removed from the mold was rated as C. The case where 7 lenses or less were successfully removed from the mold was rated as D. A and B are regarded as acceptable.

[Measurement of Heat Resistance (Tg) of Optical Material]

[0058] A sample was cut to have a thickness of 3 mm, and the TMA measurement (Seiko Instruments Inc., TMA/SS6100) was carried out by adding 10 g of weight to a pin ((p: 0.5 mm) and elevating the temperature from 30° C. at a rate of 10° C./min to measure the softening point. The case where the softening point was 70° C. or higher was rated as A. The case where the softening point was 50° C. or higher and lower than 70° C. was rated as B. The case where the softening point was lower than 50° C. was rated as C. A and B are regarded as acceptable.

Synthesis Example 1

[0059] The compound (a) was obtained according to the technique described in Japanese Laid-Open Patent Publication No. H05-279321. Next, 15 g of the compound (a) was dissolved in a mixed solvent consisting of 100 ml of toluene and 150 ml of methanol. Subsequently, 2.8 g of sodium borohydride was added thereto while stirring at 5° C. After stirring for 1 hour, 150 ml of water was added thereto and a toluene layer was extracted. After that, washing with water was carried out, toluene was distilled away, and then purification was carried out using a silica gel column, thereby obtaining 4.5 g of the compound (b).

Example 1

[0060] To 99.999 parts by mass of tetrakis(β-epithiopropylthiomethyl)methane (compound represented by formula (4)) as the compound (c), 0.001 part by mass of the compound (a) synthesized in Synthesis Example 1 and 0.05 part by mass of tetra-n-butylphosphonium bromide as a polymerization catalyst were added, and then the mixture was well mixed homogeneously. Next, the obtained mixture was subjected to the deaeration treatment at a vacuum degree of 1.3 kPa and then injected into a mold. It was heated at 30° C. for 10 hours, then the temperature was elevated to 100° C. over 10 hours at a constant rate, and finally, it was heated at 100° C. for 1 hour to be polymerized and cured. After cooling, the obtained product was released from the mold and annealed at 120° C. for 30 minutes, thereby obtaining a molded plate. The evaluation results regarding mold release characteristics and heat resistance are shown in Table 1.

Examples 2-8 and Comparative Examples 1-2

[0061] The process was carried out in a manner similar to that in Example 1, except that the composition was as shown in Table 1. The evaluation results are shown in Table 1.

TABLE-US-00001 TABLE 1 Compound (parts by mass) Mold release Heat Examples (a) (b) (c) Lenthionine characteristics resistance Example 1 0.001 0 99.999 Not used B B Example 2 0.008 0.002 99.99 Not used B A Example 3 0.08 0.02 99.9 Not used A A Example 4 0.7 0.2 99.1 Not used A A Example 5 2.7 0.2 97.1 Not used A A Example 6 4.5 4.5 91.0 Not used B A Example 7 15.0 10.0 75.0 Not used B B Example 8 0 0.001 99.999 Not used B B Comparative 0 0 99.999 0.001 C A Example 1 Comparative 0 0 90.0 10.0 C C Example 2

Example 9

[0062] To 99.999 parts by mass of bis(β-epithiopropyl)sulfide (compound represented by formula (3), wherein n=0) as the compound (c), 0.001 part by mass of the compound (a) synthesized in Synthesis Example 1 and 0.05 part by mass of tetra-n-butylphosphonium bromide as a polymerization catalyst were added, and then the mixture was well mixed homogeneously. Next, the obtained mixture was subjected to the deaeration treatment at a vacuum degree of 1.3 kPa and then injected into a mold. It was heated at 30° C. for 10 hours, then the temperature was elevated to 100° C. over 10 hours at a constant rate, and finally, it was heated at 100° C. for 1 hour to be polymerized and cured. After cooling, the obtained product was released from the mold and annealed at 120° C. for 30 minutes, thereby obtaining a molded plate. The evaluation results regarding mold release characteristics and heat resistance are shown in Table 2.

Examples 10-16 and Comparative Examples 3-4

[0063] The process was carried out in a manner similar to that in Example 9, except that the composition was as shown in Table 2. The evaluation results are shown in Table 2.

TABLE-US-00002 TABLE 2 Compound (parts by mass) Mold release Heat Examples (a) (b) (c) Lenthionine characteristics resistance Example 9 0.001 0 99.999 Not used B B Example 10 0.008 0.002 99.99 Not used B A Example 11 0.07 0.03 99.9 Not used A A Example 12 0.8 0.1 99.1 Not used A A Example 13 2.6 0.3 97.1 Not used A A Example 14 4.8 4.2 91.0 Not used B A Example 15 15.0 10.0 75.0 Not used B B Example 16 0 0.001 99.999 Not used B B Comparative 0 0 99.999 0.001 C A Example 3 Comparative 0 0 90.0 10.0 C C Example 4