JPH05142501A - High refractive index spectacle lens - Google Patents

Abstract

PURPOSE:To obtain a lightweight plastic lens low in chromatic aberration by polymerizing a mixed monomer consisting essentially of specified dimethacrylic compd. and sulfur compd. using a radical polymerization initiator and using the obtained polymer for the lens. CONSTITUTION:From 30 to 80 pts.wt. of a methacrylic thioester shown by formula I, 20-50 pts.wt. of trimethylolpropane-tris(beta-thiopropionate) having three thiol groups and shown by formula II and 8-50 pts.wt. of divinylbenzene are radical-polymerized to obtain a high refractive index spectacle lens having a large Abbe's number. In this case, the radical polymerization initiator is not specified, and an optional initiator used in ordinary polymerization can be utilized. A monomer contg. an appropriate amt. of the initiator is injected into a common glass mold and heated, and the monomer is polymerized to form the lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high refractive index spectacle lens. More specifically, the present invention relates to a high-refractive-index spectacle lens having a large Abbe number and containing a specific sulfur compound as a main component.

[0002]

Demand for spectacle lenses is rapidly changing from glass to plastic. The reason for this is that plastic has light, strong and safe characteristics that glass does not have. However, in general, the refractive index of plastic is lower than that of glass, and in particular, plastic lenses for spectacle lenses are desired to have a high refractive index, because plastic spectacle lenses of high number are thick. In order to make a plastic material have a high refractive index, a method using a material containing many aromatic groups and a method using a compound containing many chlorine or bromine atoms are generally known. However, the former method causes chromatic aberration, and the latter method becomes heavy because it contains many chlorine and bromine atoms, and it becomes difficult to achieve the lightness that is a characteristic of a plastic material.
From this point of view, there is a demand for a plastic spectacle lens made of a plastic material having a high refractive index, a small weight, and a small chromatic aberration, that is, a material having a large Abbe number.

[0003]

Under the above circumstances, the present invention provides a plastic spectacle lens made of a plastic material having a high refractive index, a light weight, and a small chromatic aberration, that is, a large Abbe number. Is to provide.

[0004]

The present invention provides a specific dimethacryl compound containing an aromatic group and a sulfur atom and a specific sulfur having three thiol groups in order to simultaneously achieve a high refractive index and a high Abbe number. By using a material obtained by polymerizing a mixed monomer containing a compound as a main component using a radical polymerization initiator, it is a plastic material, has a high refractive index, is lightweight, and has small chromatic aberration. It has led to the provision of plastic spectacle lenses made of large materials. Hereinafter, the present invention will be described in detail.

The three components of the present invention have respective roles, and even if any one of them is lacking, it is made of a plastic material made of a material having a high refractive index, light weight and small chromatic aberration of the present invention, that is, a material having a large Abbe number. It is impossible to make a spectacle lens. First, the dimethacrylthioester of 4,4′-thiobisbenzenethiol represented by the following Chemical Formula 3 (Structural Formula 1) has a high content in the spectacle lens material of the present invention because it contains an aromatic group and a sulfur atom. It is essential for making the refractive index.
However, the compound of Chemical formula 3 (Structural Formula 1) has a small Abbe number because of its high refractive index, and cannot be a good lens by itself. Moreover, the compound of Chemical formula 3 (Structural formula 1) is a solid at room temperature and is not suitable as it is for the cast polymerization of the present invention.

[0006]

[Chemical 3]

The following compound represented by Chemical Formula 4 (Structural Formula 2) is an aliphatic compound having three thiol groups and is used in the present invention to increase the Abbe number of a lens. Trimethylolpropane tris (β-thiopropionate) of Chemical formula 4 (Structural formula 2) is a viscous liquid and is an aliphatic compound, but has a high affinity with the compound of Chemical formula 3 (Structural formula 1), It is possible to mix and dissolve very uniformly and it is necessary to make a uniform lens.

[0008]

[Chemical 4]

Next, in the present invention, divinylbenzene is used as the third component. The reason for using divinylbenzene is to improve the cross-linking density of the lens of the present invention so as to provide a large heat resistance, and to use the compound of Chemical formula 3 (Structural formula 1) and Chemical formula 4 (Structural formula 2) with a low viscosity liquid. This is because the viscosity of the lens monomer can be adjusted relatively arbitrarily by adding divinylbenzene. Further, divinylbenzene has an effect of lowering the density of the lens of the present invention, and is essential to the present invention. As described above, three specific types of compounds having respective roles are used as essential components in the present invention, but their proportions are naturally limited. That is, 30 to 80 parts by weight of methacrylthioester represented by Chemical formula 3 (Structural formula 1) and trimethylolpropane tris (β-thiopropionate) 20 to 5 having three thiol groups represented by Chemical formula 4 (Structural formula 2)
A composition of 0 parts by weight and 8 to 50 parts by weight of divinylbenzene is used in the present invention. If the methacrylthioester represented by Chemical Formula 3 (Structural Formula 1) is less than 30 parts by weight, the intended lens having a high refractive index cannot be obtained. 80
When used in excess of parts by weight, the Abbe number becomes small.

Next, if the amount of the compound represented by Chemical formula 4 (Structural formula 2) is less than 20 parts by weight, the desired lens having a high Abbe number cannot be obtained. Further, if it is used in an amount of more than 50 parts by weight, the lens cannot have a high refractive index. Also, if divinylbenzene is less than 8 parts by weight,
The cross-linking is small and the lens has poor heat resistance. Conversely, 50
If it is used in excess of parts by weight, crosslinking will proceed too much, resulting in a brittle and weak lens. From this meaning, in the present invention,
Methacrylthioester 30 represented by (Structural Formula 1)
80 parts by weight, trimethylolpropane tris (β-thiopropionate) 20-50 represented by Chemical formula 4 (Structural formula 2)
A composition of 8 parts by weight and 8 to 50 parts by weight of divinylbenzene is used as a preferable range. Next, in the present invention, the above three types of compounds are mixed in a specific composition range to form a lens monomer. After adding the ultraviolet absorber and other additives to this, a radical polymerization initiator is added.

In the present invention, there is no particular limitation on the radical polymerization initiator, and any initiator generally used for radical polymerization can be used. The amount of the initiator is usually 1
0.3 to 5.0 parts by weight is used as a preferable amount per 00 parts by weight. Next, a monomer containing an appropriate amount of a radical polymerization initiator is poured into a mold, which is usually made of glass, and the temperature is raised to start polymerization, whereby a lens can be obtained. This process is not special and does not replace the usual method for producing a plastic lens. The polymerization temperature is often in the range of room temperature to about 150 degrees. In this way, a desired diopter spectacle lens can be manufactured, but the refractive index of the lens of the present invention is 1.
It is 58 or more, and preferably 1.6 or more. Further, it is more desirable that the Abbe number is 25 or more, preferably 27 or more. The present invention employs the above-described method to adopt a composition of three specific ranges within a specific range, thereby producing a plastic material having a high refractive index, light weight, and small chromatic aberration, that is, a material having a large Abbe number. It is possible to provide a plastic spectacle lens made of the same material. Hereinafter, the present invention will be described with reference to examples.

[0012]

【Example】

Example (1) 50 parts by weight of a dimethacrylthioester of 4,4′-thiobisbenzenethiol represented by Chemical Formula 3 (Structural Formula 1),
40 parts by weight of trimethylolpropane tris (β-thiopropionate) represented by (Structural Formula 2) and 10 parts by weight of divinylbenzene (purity 81%) were mixed well, and 1.1 parts by weight of benzoyl peroxide was added thereto. , Even better mixed. The monomer having this composition was injected into two molds made of glass and supported by a gasket and having different curvatures, and the temperature was applied thereto to carry out radical polymerization. The added temperature is 60 ° C. for 24 hours, 80 ° C. for 5 hours, and 90 ° C. for 5 hours. In this way, a concave lens of -3.00 diopter with a center thickness of 1.7 mm was obtained. This lens was colorless and transparent and had a visible light transmittance of 91%. The characteristics of this lens are shown below. Refractive index 1.628 Abbe number 28 Density 1.28 g / cm ³

Example (2) 65 parts by weight of a dimethacrylthioester of 4,4'-thiobisbenzenethiol represented by Chemical Formula 3 (Structural Formula 1),
25 parts by weight of trimethylolpropane tris (β-thiopropionate) represented by (Structural Formula 2) and 10 parts by weight of divinylbenzene (purity 81%) were mixed well, and 1.1 parts by weight of benzoyl peroxide was added thereto. , Even better mixed. +1.25 by the polymerization method according to Example (1).
A diopter convex lens was obtained. This lens was colorless and transparent and had a visible light transmittance of 91%. The characteristics of this lens are shown below. Refractive index 1.652 Abbe number 28 Density 1.18 g / cm ³

[0014]

The present invention is a plastic material,
It is possible to provide a plastic spectacle lens made of a material having a high refractive index, light weight, and small chromatic aberration, that is, a large Abbe number.

Claims (1)

[Claims] 1. A methacrylthioester represented by the following chemical formula 1 (structural formula 1) in an amount of 30 to 80 parts by weight, and a chemical formula 2 (structural formula 2).
And 20 to 50 parts by weight of trimethylolpropane tris (β-thiopropionate) having three thiol groups and 8 to 50 parts by weight of divinylbenzene are radically polymerized and have a high Abbe number and high refractive index glasses. Lens [Chemical 1] [Chemical 2]