JPH0341110A - High-refractive index optical resin - Google Patents

Abstract

PURPOSE:To provide a high-refractive index optical resin excellent in optical transparency, heat resistance, solvent resistance, impact resistance, etc., by copolymerizing a specified N-substituted benzothiazoline-2-thione monomer with a vinyl monomer. CONSTITUTION:An N-substituted benzothiazoline-2-thione monomer of formula I (wherein R is formula II, III, IV, V or VI), e.g. N-vinylbenzothiazoline-2-thione, is copolymerized with another vinyl monomer (e.g. styrene or methyl methacrylate). In this way, a high-refractive index optical resin having a refractive index >=1.6 and a low specific gravity and suited for spectacle lenses, camera lenses, etc., can be produced. The compound of formula I can be synthesized by, e.g. a rearrangement reaction of, e.g. 2-alkylthiobenzothiazole.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention uses a specific N-substituted penzothiazoline-2-thione monomer as a raw material monomer to produce a plastic having excellent transparency and a high refractive index. The present invention relates to a high refractive index optical resin useful as a resin material for lenses and other optical applications.

<Prior Art> In recent years, synthetic resin materials that are lightweight, easy to mold, have excellent impact resistance, dyeability, etc. have been used as plastic lens materials in place of inorganic glass. As the synthetic resin material, for example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate are known. However, polymethyl methacrylate and polydiethylene glycol bisallyl carbonate are lightweight and aluminum resistant! Although it has excellent properties, it has a low refractive index of about 1.49, so when used as a lens, it requires a thicker lens than inorganic glass, and has the disadvantage that it is not suitable for increasing magnification or reducing weight.

In addition, although the refractive index of polystyrene and polycarbonate is high at about 1.58 to 1.59, since these resins are thermoplastic, there is a problem that optical distortion due to birefringence is likely to occur during injection molding. has drawbacks such as poor solvent resistance and scratch resistance.

Therefore, in recent years, several technical proposals have been made to improve these conventional drawbacks with a high refractive index. An example of a copolymer with phthalate is given in JP-A-59-81318, and an example of a copolymer of diallyl phthalate and unsaturated fatty acid alcohol benzoate is given in JP-A-59-19.
No. 1708 discloses examples of di(meth)acrylates containing bisphenol A, copolymers of diallyl isophthalate, diethylene glycol bisallyl carbonate, and the like.

However, in the above example, the refractive index is 1.52 to 1.56.
In addition, there is a problem that unreacted allyl monomer tends to remain.

Further, JP-A-57-28115 discloses a copolymer of a styrene vinyl monomer and an unsaturated carboxylic acid heavy metal salt, and JP-A-60-55007 discloses a copolymer of a styrene-based vinyl monomer and a heavy metal salt of an unsaturated carboxylic acid, and JP-A-60-55007 discloses a copolymer of a styrene-based vinyl monomer and a heavy metal salt of an unsaturated carboxylic acid, and a copolymer of a halogen-substituted diallyl phthalate and a halogen-substituted Copolymers with allyl benzoate are mentioned, but these have a refractive index of 1.
Although it has a high value of about 58 to 1.60, because it uses metal salts and allyl threads containing halogen-substituted aromatic rings, the specific gravity of the polymer is high, making the resulting lenses heavy and impeding weight reduction. It has its drawbacks.

Furthermore, in JP-A-55-13747, the halogen-substituted styrene, di(meth) containing bisphenol A,
A copolymer of acrylate, a benzyl methacrylate monomer, and a phenol methacrylate monomer is described in JP-A-59-133211 as a copolymer of hydroxyl (meth)acrylate having an aromatic ring, a diisocyanate compound, and a styrene monomer. is proposed. However, in these cases as well, the refractive index is 1.
Although it is high at around 60, it is difficult to control the polymerization reaction, the specific gravity is large, and there are problems with weather resistance.

〈IG that invention tries to solve! The object of the present invention is to provide a resin material that has desirable optical transparency, high refractive index, and excellent weather resistance, solvent resistance, and impact resistance as a resin material for plastic lenses or other optical applications,
Moreover, it is an object of the present invention to provide a high refractive index optical resin having a small specific gravity.

<Means for Solving the Problems> According to the present invention, an N-substituted 2-benzothiazoline-2-thione monomer represented by the following general formula (I) and a monomer other than the general formula (I) There is provided a high refractive index optical resin having a refractive index of 1.60 or more obtained by copolymerizing a raw material material including a vinyl thread material.

The present invention will be explained in more detail below.

The high refractive index optical resin of the present invention uses an N-substituted penzothiazoline-2-thione monomer represented by the following general formula (I) as an essential raw material monomer.

-CH, CH, COOCH=CH, or -CH, CH,
Indicates C00CH, CH=CH.

That is, the monomer represented by the general formula (I) is.

N-vinylbenzothiazoline-2-thione, N-allylbenzothiazoline-2-thione, N-(m or p-vinylbenzyl)penzothiazoline-2-thione, N-(
Vinyloxycarbonylethyl)benzothiazoline-2
-thione, N-(allyloxycarbonylethyl)benzothiazoline-2-thione, which can be used alone or as a mixture. In order to prepare the 7mer represented by formula (I), for example, a rearrangement reaction of 2-alkylthiobenzothiazole, a sodium dehalogenation reaction between benzothiazoline-2-thione sodium salt and an alkyl halide, or It can be synthesized by a Michael addition reaction with thiazoline-2-thione and an unsaturated alkyl group.

The high refractive index optical resin of the present invention uses a vinyl monomer as an essential raw material monomer in addition to the N-substituted penzothiazoline-2-thione monomer. The vinyl monomer is a vinyl monomer other than the N-substituted penzothiazoline-2-thione monomer, such as styrene, p-methylstyrene, p-chlorostyrene, O-
Chlorstyrene, p-bromustyrene, 0-bromustyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl acrylate, benzyl methacrylate, bromphenyl methacrylate, acrylonitrile, methacrylonitrile, 2,2-bis(4-
methacryloyloxyethoxyphenyl)propane, 2
, 2-bis(4-acryloyloxyethoxyphenyl)propane, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, etc., but the solvent resistance, heat resistance,
In order to improve physical strength such as impact resistance and weather resistance, it is desirable to use at least one type of crosslinkable polyfunctional vinyl heptamer. Examples of the crosslinkable polyfunctional vinyl hetamine include diallyl phthalate, diallyl phthalate, p-divinylbenzene, m
- Divinylbenzene, divinylbiphenyl, ethylene glycol bis methacrylate, diethylene glycol bis methacrylate, ethylene glycol bis acrylate, diethylene glycol bis acrylate, dipropylene glycol bis methacrylate, triethylene glycol bis acrylate, tetraethylene glycol bis acrylate, bisphenol A bis methacrylate, diallyl phthalate , diallyl tetrachlorphthalate, diallyl isophthalate, allyl methacrylate, propylene glycol bisacrylate.

Preferred examples include hexaethylene glycol bisacrylate, octaethylene glycol bisacrylate, and decaneethylene glycol bisacrylate.

In the present invention, the blending ratio of the N-substituted benzothiazoline-2-thione monomer and the vinyl monomer is 1
It is preferable that the weight ratio is 99.9:0.1 to 30:0. If the weight ratio of the NfiR-converted benzothiazolinthione monomer exceeds 99.9, the mechanical strength of a lens will decrease, and if it is less than 30, the refractive index will decrease, which is not preferable. Further, the refractive index of the high refractive index optical resin of the present invention is 1.60 or more, and the molecular weight is preferably in the range of 10,000 to 1oooooo.

The high refractive index optical resin of the present invention can be prepared, for example, by heating and copolymerizing the monomers described above in the presence of a radical polymerization initiator. As the radical polymerization initiator, an organic peroxide or an azo compound having a 10-hour half-life temperature of 120° C. or lower can be used, and specifically, for example, diisopropyloxydicarbonate.

Polymerization selected from the group consisting of tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy pivalate, tert-butyl peroxy diisobutyrate, lauroyl peroxide, azobisisobutyronitrile, mixtures thereof, etc. Preferred examples include initiators.

The amount of the radical polymerization initiator used is 1.
The amount is preferably 10 parts by weight or less, particularly preferably 1 part by weight or less, based on 00 parts by weight.

To carry out the heating copolymerization, for example, each of the seven polymers and a radical polymerization initiator as needed are directly charged into a desired mold, and the copolymerization is carried out by heating preferably at 0 to 200°C for 1 to 48 hours. Can be polymerized. At this time, the polymerization system is preferably carried out under an inert gas atmosphere such as nitrogen, carbon dioxide, or helium. Also,
Before the copolymerization, the amount on the raw material is, for example, 0 to 20
0℃.

Prepolymerization can also be carried out for 0.5 to 48 hours.

<Effects of the Invention> The high refractive index optical resin of the present invention has a high refractive index of 1.60 or more, and has excellent optical transparency, heat resistance, solvent resistance, and impact resistance. Furthermore, it has a small specific gravity and can be made lightweight, and furthermore, it is easy to control during curing and polymerization, so it can be used as a resin material for plastic lenses such as eyeglass lenses, camera lenses, and optical materials, or for other optical resin materials. It is useful as

<Examples> The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

A 7-mer composition was obtained by mixing 0.3 g of diisopropyl peroxydicarbonate with a raw material containing 8 g of N-vinylbenzothiazoline-2-thione and 2 g of divinylbenzene. Next, the monomer composition was placed in two glass molds, placed in a constant temperature bath at 40°C, heated at a curing temperature of 40°C for 15 hours, and then heated to 100°C for another 3 hours.
Increase the temperature to.

Finally, an annealing treatment was performed at 100° C. for 2 hours to obtain a cured resin. The obtained cured resin is taken out from the mold,
The refractive index, Atsube's number and transparency were measured according to the following methods. The results are shown in Table 1.

・Refractive index and Atsube number: Atsube refractometer (manufactured by Atago Co., Ltd.) ・Transparency: 0 if it is transparent when observed with the naked eye
and those that were slightly cloudy were designated as Δ.

A cured resin was prepared in the same manner as in Example 1, except that the raw materials shown in Table 1 were used, and each measurement was performed.

The results are shown in Table 1.

A cured resin was obtained in the same manner as in Example 1, except that only the vinyl monomer shown in Table 1 was used without using the double N-substituted benzothiazoline-2-thione monomer, and each measurement was performed. Ta. The results are shown in Table t.

Claims (1)

[Claims] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, R is -CH=CH_2, -CH_2CH=CH_2, ▲Mathematical formulas, chemical formulas, tables, etc.) etc. ▼-CH_2CH_2COO
CH=CH_2 or -CH_2CH_2COOCH_2
CH=CH_2) and an N-substituted benzothiazoline-2-thione monomer of the general formula (I
A high refractive index optical resin having a refractive index of 1.60 or more obtained by copolymerizing raw material monomers containing vinyl monomers other than ).