JPH0841049A - 1,4-dithiane ring-containing vinyl compound and isomer mixture thereof - Google Patents

Abstract

PURPOSE:To obtain a 1,4-dithiane ring-containing vinyl compound which is represented by the formula and gives a resin material useful in the production of optical parts such as lenses because the material has a low specific gravity, high refractive index, low dispersion as well as high resistance to weather and heat. CONSTITUTION:This compound is represented by formula I (R is H, methyl) and is obtained, for example, by carrying out the reaction of a 2,5bis(mercaptomethyl)-1,4-dithiane of formula II with chloromethyl-styrene using a base such as sodium hydroxide in the presence of a phase transfer catalyst such as hexadecyltributylphosphonium bromide at 0-50 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel vinyl compound and a mixture of isomers thereof used in a composition for polymerization which is cured by the action of heat and / or active energy rays. More specifically, lenses, prisms, mirrors,
The present invention relates to a novel vinyl compound and a mixture of isomers thereof, which is used in a composition for casting polymerization suitable for producing optical parts such as optical discs.

[0002]

2. Description of the Related Art Heretofore, various resins for plastic lenses have been studied as a substance replacing inorganic glass. For example, a cured product obtained by polymerizing methyl methacrylate or a monomer whose main component is diethylene glycol bisallyl carbonate is used as an optical component such as a lens.
However, these have many problems and are not of a sufficiently satisfactory property. For example, some of these resin materials have a refractive index of 1.50, which is lower than that of glass,
In order to obtain the desired refractive index, the lens must be made thick, and weight saving is not sufficient. Further, particularly in the case of a concave lens, the thickness around the lens becomes thick and chromatic aberration occurs, which is not preferable. Various resins such as polystyrene and polycarbonate are also used, but since these are thermoplastic resins, there are problems that optical distortion easily occurs due to birefringence during injection molding and that they are easily colored.

Therefore, there is a demand for a material which realizes a high refractive index and a low dispersion while making the best use of the characteristic of plastic having a low specific gravity. As a material therefor, tetrachlorometa-xylylenedithiol, a polymer of 1,3,5-trimercaptobenzene and diisocyanate (JP-A-63-46213), pentaerythritol tetrakisthiopropionate and diisocyanate. And a polymer of pentaerythritol tetrakisthiopropionate and a vinyl compound (JP-A-63-309509) and the like are known.

However, even though these proposals have made some contributions, they are not necessarily satisfactory to the knowledge of the present inventors. For example, the thiol compound described in JP-A-63-46213 has problems that the polymer obtained from the thiol compound has a high refractive index, but has a low Abbe number and poor weather resistance. Further, JP-A 64-26622 and JP-A 63-30
The thiol compound described in Japanese Patent Publication No. 9509 has a low refractive index although the polymer obtained from the thiol compound has a large Abbe number,
There is also a problem that the heat resistance is poor.

[0005]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned problems and can obtain a resin material having low specific gravity, high refractive index, low dispersion, and excellent weather resistance and heat resistance. It is intended to provide vinyl compounds and isomer mixtures thereof.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a 1,4-dithiane ring-containing vinyl compound represented by the following general formula (I) and its isomer mixture.

[0007]

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The resin material obtained from the 1,4-dithiane ring-containing vinyl compound in the present invention has a low specific gravity, a high refractive index and a low dispersion, and is excellent in weather resistance and heat resistance. This is a solution to the problems found in plastics for plastic lenses.

(New vinyl compound) In the general formula (I), the vinyl group is preferably in the m-position or the p-position depending on the mechanical properties of the resin obtained by polymerizing and curing the vinyl compound.

According to the present invention represented by the general formula (I),
The following compounds may be mentioned as specific examples of the 4-dithiane ring-containing vinyl compound.

[0011]

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In the above compound, when an isomer mixture is used as an available raw material described later, the substitution position of the vinyl group is not always the same on the left and right with respect to the 1,4 dithiane ring. However, also in this case, the substitution position of the vinyl group is preferably a combination of m-position and p-position.

The compound represented by the general formula (I) is represented by the following (i)
Alternatively, it can be synthesized by any purposeful method such as (ii). (I) Reaction of 1,4-dithiane ring-containing thiol with chloromethylstyrene It can be obtained from 1,4-dithiane ring-containing thiol represented by the following general formula (II) and chloromethylstyrene by dehydrochlorination reaction.

[0014]

[Chemical 4]

The 2,5-bis (mercaptomethyl) -1,4-dithianes represented by the above formula (II) are prepared by reacting diallyl disulfide or dimethallyl disulfide with a halogenating agent such as bromine or sulfuryl chloride. After halogenation and cyclization, the following general formula (III)

[0016]

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2,5-bis (halomethyl) -represented by
1,4-dithianes were obtained (J. Org. Chem., 34 , 3389).
(1969)), and further obtained by reacting this dithiane with thiourea to form an isothiuronium salt, followed by alkaline hydrolysis and acidification (Proceedings of the 59th Annual Meeting of the Chemical Society of Japan, Ith Conference). Pp. 539, JP-A-3
No. 236386).

The obtained 2,5-bis (mercaptomethyl) -1,4-dithianes and easily available chloromethylstyrene (for example, CMS-produced by Seimi Chemical Co., Ltd.)
14 (p isomer, purity 95%), CMS-P (m isomer 60%,
(p-form 40%, purity 95%) with the addition of a base such as sodium hydroxide, potassium hydroxide or potassium carbonate in the presence or absence of a phase transfer catalyst such as hexadecyltributylphosphonium bromide. By doing so, the intended 1,4-dithiane ring-containing vinyl compound can be obtained.

When a mixture of isomers is used for chloromethylstyrene, the isomer ratio of the resulting 1,4-dithiane ring-containing vinyl compound is the same as that of the raw material chloromethylstyrene. This reaction is preferably carried out in a solvent, and it is particularly preferable to use a solvent such as water, alcohol, a water-alcohol mixed system, or a ketone.

The reaction temperature may be -10 ° C to 100 ° C and may be any temperature, but it is preferably 0 ° C to 50 ° C. If the temperature is too low, the reaction is difficult to proceed, and if it is too high, the product may be colored. The amount of chloromethylstyrene used is 0.8 to 2.0 equivalents, preferably 1.0 to 1.5 equivalents, based on the corresponding mercapto group. The amount of the base used is 0.8 to 2.0 equivalents, preferably 1.0 to 1.5 equivalents, relative to the corresponding mercapto group. If the amount of the base used is small, problems such as 2,5-bis (mercaptomethyl) -1,4-dithianes remaining or chloromethylstyrene remaining may occur. Coloring may occur if the amount of the base is excessive. The amount of the phase transfer catalyst used is preferably 0.1 mol% or less based on the corresponding mercapto group.

(Ii) Reaction of halide of 1,4-dithiane ring with mercaptomethylstyrene 2,5-bis (halomethyl) -1,4-dithiane represented by the general formula (III) and mercaptomethylstyrene Can also be obtained by a dehydrohalogenation reaction.

The mercaptomethylstyrene can be obtained by reacting the above-mentioned chloromethylstyrene with thiourea in the presence of a solvent, hydrolyzing with alkali, and acidifying (using a mixture of isomers to chloromethylstyrene). If so, the isomer ratio will be the same isomer ratio as the raw material chloromethylstyrene).

The reaction of 2,5-bis (halomethyl) -1,4-dithianes with mercaptomethylstyrene is 1,4-
It can be carried out under the same reaction conditions as the reaction between the dithian ring-containing dithiol and chloromethylstyrene. The amount of mercaptomethylstyrene used is 0.8 to 2.0 equivalents, preferably 1.0 to 1.5 equivalents, relative to the corresponding halide of the 1,4-dithiane ring. The amount of the base used is 0.8 to 0.8 with respect to the corresponding mercaptomethylstyrene.
Use 2.0 equivalents, preferably 1.0 to 1.5 equivalents. When the amount of the base used is small, there arises a problem that the halide of the 1,4-dithiane ring remains or the mercaptomethylstyrene remains. Coloring may occur if the amount of the base is excessive. The amount of phase transfer catalyst used is 1,4
It is preferably 0.1 mol% or less with respect to the halide of the dithian ring.

When a mixture of isomers is used as the raw material chloromethylstyrene, the isomer ratio of the resulting 1,4-dithiane ring-containing vinyl compound is the same as that of chloromethylstyrene.

(Resin Material) In the novel vinyl compound according to the present invention, a vinyl compound in the m-position or p-position to the vinyl group is preferably used upon polymerization and curing. Further, the raw material availability, the mechanical properties of the obtained resin From the viewpoint of, it is preferable to use a mixture of isomers at the m-position and the p-position. When mixing, the mixing ratio of the m-position and p-position compounds is 1: 9-
It is 9: 1, preferably 3: 7 to 7: 3.

The novel vinyl compound according to the present invention can be polymerized and cured by mixing it with a homofunctional or radically copolymerizable polyfunctional unsaturated monomer or a monofunctional unsaturated monomer. The composition ratio of the monomers is preferably such that the novel vinyl compound according to the present invention accounts for 10 to 100% by weight, particularly 40 to 100% by weight, based on the total monomers.

Upon polymerization and curing, any of heat polymerization, active energy ray polymerization and a combination of these methods can be employed. In the case of thermal polymerization, a thermal polymerization initiator, for example, preferably benzoyl peroxide,
Diisopropyl peroxycarbonate, lauroyl peroxide, t-butyl peroxy (2-ethylhexanoate), azoisobutyronitrile, etc. are added and the heating temperature is 20 ° C to 150 ° C, preferably 30 ° C to 130 ° C.
It is preferable to polymerize and cure in the range of 1 to 30 hours, preferably 10 to 20 hours.

At the time of ultraviolet curing, a photopolymerization initiator such as benzophenone, benzoin methyl ether, diethoxyacetophenone or 2,4,6-trimethylbenzoyldiphenylphosphine oxide is preferably added to 0.01 to 300 J /. cm ² , especially 20-100
It is preferable to irradiate with a light amount of J / cm ² .

[0029]

The present invention will be described in more detail with reference to the following experimental examples. Synthesis Example 1 Synthesis of 2,5-bis (bromomethyl) -1,4-dithiane 29.2 g (0.2 mol) of diallyl disulfide was added to 1
After dissolving in 000 ml of dichloromethane, 32 g (0.2 mol) of bromine was added dropwise at -78 ° C over 1 hour. After that, the temperature was raised to −20 ° C., and after stirring at that temperature for 8 hours, the temperature was raised to room temperature and dichloromethane was distilled off under reduced pressure to obtain 2,5-bis (bromomethyl) -1,4-dithiane. Obtained. (80% yield from diallyl disulfide)

Synthesis Example 2 2,5-bis (mercaptomethyl) -1,4-dithiane
Synthesis of 2,5-bis (bromomethane) obtained by the reaction of Synthesis Example 1
Chill) -1,4-dithiane 61.2 g (0.2 mol)
And 150 ml of ethanol and 30.4 g of thiourea
(0.4 mol) was added and the mixture was refluxed for 1.5 hours. Generated
The precipitate was filtered off, washed with ethanol and dried. Water 100
Disperse this precipitate in ml and add 15% aqueous sodium hydroxide.
The liquid (85.3 g) was added dropwise over 1 hour and refluxed for 1 hour. Anti
The reaction mixture was acidified with hydrochloric acid and extracted with dichloromethane.
2 x 10 after distilling off dichloromethane ^-2Distillation at mmHg
Then, a fraction of 121 ° C. was obtained. (Is diallyl disulfide?
Yield 60%)

Example 1 2,5-bis (mercaptomethyl) obtained in Synthesis Example 2
0.1 mol of -1,4-dithiane, 0.2 mol of chloromethylstyrene (a mixture of m-form: p-form = about 7: 3), 0.2 mol of sodium hydroxide as a solvent, and methanol 2
It was made to react at room temperature using 00 ml. The reaction product obtained by washing with water after the reaction (yield 40.0 g, 90% yield) was a liquid at room temperature, and was ¹ H-NMR (FIG. 1) and IR (FIG. 2).
The following structural formula

[0032]

[Chemical 6]

It was confirmed that the mixture was a mixture of m and p bodies of about 7: 3.

Example 2 2,5-bis (bromomethyl) -obtained in Synthesis Example 1
1,4-dithiane 0.1 mol, mercaptomethylstyrene (m-body: p-body = mixture of about 7: 3) 0.2 mol,
The same reaction as in Example 1 was carried out using 0.2 mol of sodium hydroxide. The obtained reaction product (yield 40.0 g, yield 90%) was a liquid at room temperature, and it was confirmed from liquid chromatography, ¹ H-NMR, and IR that it was the same compound as in Example 1.

Reference Example 100 parts by weight of the vinyl compound obtained in Example 1 and t-butylperoxy-2-ethylhexanoate 0.1.
The mixture containing 5 parts by weight was cast into a 2 mm mold composed of a glass plate and silicon rubber. Then 3
The temperature was raised from 0 ° C. to 100 ° C. over 15 hours to be cured. The obtained cured product had a refractive index n _D = 1.65 and an Abbe number ν _D = 35.

[Brief description of drawings]

FIG. 1 ¹ H-NM of the compound obtained in Example 1.
R spectrum chart

FIG. 2 is an IR spectrum chart of the compound obtained in Example 1.

Claims (6)

[Claims] 1. A 1,4-dithiane ring-containing vinyl compound represented by the following general formula (I): 2. An isomer mixture composed of a 1,4-dithiane ring-containing vinyl compound represented by the general formula (I). 3. A mixture of isomers according to claim 2, which is composed of m and p isomers. 4. The 1,4-dithiane ring-containing vinyl compound according to claim 1, wherein R = H in the general formula (I). 5. An isomer mixture consisting of a 1,4-dithiane ring-containing vinyl compound according to claim 1, wherein R = H in the general formula (I). 6. The isomer mixture according to claim 5, which is composed of m and p isomers.