JPH11183701A - Synthetic resin lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin lens comprising an optical lens material having high refractive index, low density and good optical characteristics such as dye-affinity and transparency and easy handling property. SOLUTION: This lens consists of a copolymer prepared by copolymn. of a compd. comprising 10 to 90 wt.% component (C) and 90 to 10 wt.% component (D) which is a monomer copolymerizable with the component (C). The component (C) is obtd. by the reaction of 80 to 100 wt.% hydroxyl group in 1,2-bis(2- hydroxyethylthio) ethane as a component (A) expressed by the formula of HO- CH2 CH2 SCH2 CH2 SCH2 CH2 -OH and 100 wt.% isocyanate group in an isocyanate compd. having radical polymerizable unsatd. group as a component (B). The obtd. lens has >=1.58 refractive index and <=1.20 specific gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin lens, and more particularly to a lightweight synthetic resin lens made of a copolymer having good optical and mechanical properties.

[0002]

2. Description of the Related Art Conventionally, various inorganic glasses and synthetic resins have been used for optical lenses. Optical lens materials are required to have various physical properties, and among them, having a high refractive index and a low specific gravity is extremely important. That is, if the lens used has a high refractive index and a low specific gravity, for example, a lens used in an optical device such as a microscope or a photographer or an eyeglass can be reduced in thickness and weight.

For this reason, recent optical lens materials tend to have a higher refractive index and a lower specific gravity. Particularly, in the case of synthetic resin lenses which are extremely advantageous in that they are lighter in weight than inorganic glass, they are particularly low. Specific gravity is increasing.

[0004]

A lens made of diethylene glycol bisallyl carbonate resin called "CR-39", which is widely used as a material for synthetic resin lenses for spectacles, has a specific gravity of 1.31 (at 20 ° C.). Value, the same applies hereinafter), which is relatively high. A synthetic resin lens containing a halogen atom (JP-A-58-28117 and JP-A-58-176691), which is used as a material for a high refractive index lens, has a specific gravity of 1.0.
It is about 3-1.4, which is relatively high. on the other hand,
As a synthetic resin lens material having a low specific gravity, a specific gravity of 1.02
Polystyrene and a polycarbonate having a specific gravity of 1.19 are known. However, at present, they do not have sufficient optical characteristics required for practical use.

As a synthetic resin lens material excellent in various physical properties such as heat resistance and mechanical strength, a copolymer having a crosslinked structure is introduced.
The lens material made of a sulfur-containing urethane-based resin proposed in Japanese Patent Application Laid-Open No. Hei. However, these synthetic resin lens materials are
Since it is a two-pack type, there are problems that handling is extremely inconvenient, odor is generated at the time of lens processing, and dyeability is low.

As described above, the conventional synthetic resin lens materials have problems that the specific gravity is not sufficiently reduced, that they do not have sufficient optical characteristics, and that they are inconvenient to handle. It is the present situation.

Accordingly, an object of the present invention is to provide a lens made of a synthetic resin made of an optical lens material which has a high refractive index and a low specific gravity, has good optical properties such as dyeability and transparency, and is easy to handle. Is to provide.

[0008]

The synthetic resin lens of the present invention comprises a 1,2-A component represented by the following structural formula (1).
Hydroxyl group 8 in bis (2-hydroxyethylthio) ethane
0 to 100% by weight and isocyanate group 1 in the isocyanate compound having a radical polymerizable unsaturated group of component B
A composition comprising 10 to 90% by weight of a C component, which is a reaction product obtained by reacting 00% by weight, and 90 to 10% by weight of a D component, which is a monomer copolymerizable with the C component. It is composed of a copolymer obtained by copolymerizing a product and has a refractive index of 1.58 or more and a specific gravity of 1.20 or less.

HO—CH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ —OH Structural formula (1)

The synthetic resin lens of the present invention has a high refractive index and a low specific gravity, and has good optical properties such as dyeability and transparency while maintaining high heat resistance and impact resistance.
It is made of an optical lens material that is one-pack type and easy to handle.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a compound represented by the structural formula (1)
1,2-bis (2-hydroxyethylthio) represented by
Ethane (hereinafter, referred to as SZ) is used as an essential component. In the present invention, first, the SZ of the component A is reacted with an isocyanate compound having a radically polymerizable unsaturated group of the component B in order to form a radically polymerizable SZ. That is, the C component is obtained as a reaction product of the A component and the B component.

At this time, examples of the component B include m-isopropenyl-α, α-dimethylbenzyl isocyanate (m-TMI) and methacryloyl isocyanate (MA
I), methacryloyloxyethyl isocyanate (M
OI) and the like, but are not limited thereto.

In carrying out this reaction, the molar ratio between isocyanate groups and hydroxyl groups does not necessarily have to be 1: 1. This is because, because SZ of the component A is a diol represented by the structural formula (1), radical polymerization becomes possible if at least one of the two hydroxyl groups has reacted with the isocyanate group. However, when the hydroxyl group is 80
If the reaction is less than 5% by weight, not only is it difficult to obtain sufficient impact resistance and heat resistance as an optical lens, but also because SZ of the component A cannot be completely dissolved,
In some cases, a transparent optical lens cannot be obtained. Therefore, it is necessary that 80% by weight or more of the hydroxyl groups in the SZ of the component A have reacted with the isocyanate groups of the component B.

The urethane reaction generated at this time can be carried out without heating under heating, but it is preferable to accelerate the urethane reaction by using a catalyst. Here, as the catalyst, those known in the field of polyurethane chemistry can be used. Examples thereof include tertiary amine catalysts such as triethylamine, and organometallic catalysts such as dibutyltin dilaurate.

In the present invention, in addition to the C component, which is a reaction product of the A component and the B component, one or more types of the D component, which is a monomer copolymerizable with the C component, may be used depending on the purpose. Can be mixed.

At this time, examples of the D component include styrene (St), α-methylstyrene (α-MeSt), and α-methylstyrene.
Vinyl compounds such as methylstyrene dimer (MSD), 2-methylstyrene (2-MeSt) and divinylbenzene (DVB), benzyl methacrylate (BzM
A), methacrylates such as 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (BPE-500), 2-hydroxyethyl methacrylate (HEMA), benzyl acrylate (BzA),
Nonaethylene glycol diacrylate (9-EGD
A), acrylic esters such as 2-phenylphenol polyethoxy acrylate (OPP-1), and the like, but are not limited thereto.

At this time, the weight ratio of the component C to the component D is 9
It is necessary to be 0:10 to 10:90, preferably 80:20 to 20:80. When the component C exceeds 90% by weight, it becomes difficult to lower the viscosity of the mixture. On the other hand, when the component D exceeds 90% by weight, sufficient impact resistance and heat resistance as an optical lens are obtained. Is difficult to obtain.

The synthetic resin lens of the present invention comprises a C component and a D component.
It can be obtained by radical polymerization of a mixture of components, but by appropriately combining the above components, it is possible to make the viscosity of the composition sufficiently low and make the fluidity sufficiently high. For this reason, it can be carried out collectively, for example, in a casting container, and therefore can be manufactured easily and at low cost.

As a casting polymerization method or a casting reaction method using a casting container, a well-known technique can be used, and the casting container may be used in a plate shape, a lens shape, a cylindrical shape, or the like. A mold or a mold frame designed according to the above can be used, and any material such as inorganic glass, plastic, and metal can be used.

When the synthetic resin lens of the present invention is obtained by the cast polymerization method, the above components may be charged together with a polymerization initiator into a casting container to carry out the polymerization. And radical polymerization may be carried out simultaneously, or it is also possible to carry out one of radical polymerization or urethane reaction first and then carry out the other of radical polymerization or urethane reaction. The radical polymerization can be performed at room temperature or in a heated state using a known radical polymerization initiator, whereby a high molecular weight copolymer can be obtained. In carrying out the casting polymerization method, each component may be charged at once in a casting container, or, if necessary, a radical polymerization or a urethane reaction is performed in advance using another container to obtain a prepolymer. Alternatively, a lens can be obtained by putting syrup into a casting container and completing the radical polymerization and the urethane reaction.

The mixture of each component may contain a coloring agent, an ultraviolet absorber, a heat stabilizer, and other auxiliary materials as necessary. Further, it is also possible to apply a hard coat, a non-reflection coat or another surface coat to the surface of the obtained copolymer.

The synthetic resin lens of the present invention is characterized by being composed of the above-mentioned copolymer. Therefore, in addition to the casting polymerization method, it is also possible to obtain a plate or other form of copolymer. It can also be manufactured by a shaving method.

[0023]

The present invention will be described in more detail with reference to the following examples.
The present invention is not limited to these. In addition, the evaluation method of various physical properties of the obtained copolymer is as follows.

A test piece having a refractive index of 10 mm × 20 mm × 3 mm was prepared, and the refractive index at room temperature (20 ° C.) was determined using α-bromonaphthalene as a contact liquid using “Abe Refractometer 1T” manufactured by Atago. It was measured.

Abbe Number The Abbe number was measured by the same measuring device and measuring method as in the above-mentioned refractive index measurement.

A test piece having a specific gravity of 10 mm × 20 mm × 3 mm was prepared, and the specific gravity at room temperature (20 ° C.) was measured using “SGM-6” manufactured by METTLER TOLEDO.

Stainability A dye solution is prepared by mixing 1 g each of Seiko Plux Brown manufactured by Hattori Seiko and an auxiliary agent with 1000 ml of pure water, and the obtained lens is added to the dye solution at 92 ° C. for 10 minutes. Dyeing by immersion, UV-visible spectrophotometer "UV-2200" manufactured by Shimadzu Corporation
Was used to measure the total light transmittance, and those having 40% or less were evaluated as good.

Transparency A flat plate having a center thickness of 2.0 mm and a radius of 60 mm was prepared, and the haze was measured using "HGM-2DP" manufactured by Suga Test Instruments.

Example 1 35 g of St, 8 g of DVB, 16 g of BPE500,
25 g of MOI, 16 g of SZ, and the above were measured in a 200 ml Erlenmeyer flask, and 100 g of the preparation, 0.1 g of urethane polymerization initiator dibutyltin dilaurate,
One stirrer was added, and the mixture was stirred at 55 ° C. for 3 hours to perform prepolymerization of a hydroxyl group and an isocyanate group. Thereafter, 1.0 g of a radical polymerization initiator PB-ND (Perbutyl ND, manufactured by NOF Corporation) was added. The polymerization was carried out by pouring into a casting mold composed of a glass plate and a gasket. The polymerization was performed by gradually raising the temperature from 45 ° C. to 100 ° C. in a hot air circulating furnace over 10 hours, and maintaining the temperature at 100 ° C. for 2 hours.
Cooled slowly to ° C. Thereafter, the copolymer was taken out of the casting mold to obtain a molded product.

The obtained copolymer had a refractive index of 1.58 or more and a specific gravity of 1.20 or less, and a molded article was obtained which was colorless and transparent, and had no striae or blemishes.

Examples 2 to 4 and Comparative Examples 1 and 2 Polymer compositions were prepared at the composition ratios shown in Table 1, and 0.1 g of a urethane polymerization initiator dibutyltin dilaurate was added to 100 g of the prepared composition. Pre-polymerization of hydroxyl groups and isocyanate groups by stirring at 3 ° C. for 3 hours, followed by radical polymerization initiator PB-ND (perbutyl N
D, manufactured by Nippon Yushi Co., Ltd.), and the mixture was poured into a casting mold composed of two glass plates and a gasket to perform polymerization. The polymerization is carried out in a hot air circulating furnace from 45 ° C to 100 ° C for 1 hour.
The temperature was gradually raised over 0 hours, kept at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. Thereafter, the copolymer was taken out of the casting mold to obtain a molded product.

The obtained copolymers were able to obtain physical properties as shown in Table 1. In each of Examples 2 to 4, a molded article having a refractive index of 1.58 or more and a specific gravity of 1.20 or less, and was colorless and transparent, and had no striae or distortion was obtained. In Comparative Example 1, the refractive index was less than 1.58, and in Comparative Example 2, distortion was confirmed because unpolymerized material remained, and problems were also confirmed in heat resistance and the like.

[0033]

[Table 1] SZ: 1,2-bis (2-hydroxyethylthio) ethane MOI: methacryloyloxyethyl isocyanate MAI: methacryloyl isocyanate m-TMI: m-isopropenyl-α, α-dimethylbenzyl isocyanate St: styrene DVB: divinylbenzene BPE500: 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane

[0034]

The synthetic resin lens of the present invention has not only improved the problems of the conventional high refractive index lens, such as low dyeability, odor during processing, and inconvenience in handling, but also It also has the feature of having both high refractive index and low specific gravity, so that it is possible to reduce the thickness and weight at the same time. Therefore, an optical lens having sufficient optical characteristics as an optical lens and having both thinness and lightness can be obtained.

Claims (1)

[Claims] 1. A compound represented by the following structural formula (1), wherein 80 to 100% by weight of hydroxyl groups in 1,2-bis (2-hydroxyethylthio) ethane of component A and radically polymerizable unsaturated component B. 100% by weight of an isocyanate group in an isocyanate compound having a group, 10 to 90% by weight of a C component which is a reaction product obtained by reacting the isocyanate group, and D component which is a monomer copolymerizable with the C component 90 to 10% by weight
A lens made of a synthetic resin, comprising a copolymer obtained by copolymerizing a composition comprising: having a refractive index of 1.58 or more and a specific gravity of 1.20 or less. _{HO-CH 2 CH 2 SCH 2} CH 2 SCH 2 CH 2 -OH Formula (1)