JPH01225603A - Resin material having high refractive index - Google Patents

Abstract

PURPOSE:To prepare easily the title material suitably used for an optical lens having a high refractive index and a low density, by copolymerizing isopropenylnaphthalene monomer and a halogen-substd. (meth)acrylate. CONSTITUTION:5-70wt.% isopropenylnaphthalene of formula I, 10-60wt.% halogen-substd. (meth)acrylate of formula II (wherein X is Cl or I; Y is H or CH3; n is 1-5; and m is 0-7) (e.g., 1-methacryloxyethoxy-2,4,6- trichlorobenzene) and 0-50wt.% other radical polymerizable monomer (e.g., styrene or divinylbenzene) are copolymerized. A resin material useful for a material of an optical lens having a high refractive index and a low density can be easily prepd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high refractive index resin material, and particularly to a high refractive index resin material suitable as a material for an optical lens.

[Background of the invention]

Traditionally, inorganic glass lenses have been widely used as optical lenses, but recently lenses made of synthetic resin have become more popular.
Due to its light weight, impact resistance, workability, and other features, it has begun to be widely used together with inorganic glass lenses.

On the other hand, there are various requirements regarding the physical properties of lenses, and among them, there is an extremely high requirement that the material have a high refractive index. This is because a material with a high refractive index allows lenses with equivalent performance to be manufactured with a smaller thickness. By using lenses with a high refractive index, lens systems that play an important role in optical equipment such as microscopes, cameras, and telescopes can be made compact and lightweight. Since it is possible to reduce the weight and the so-called edge thickness, great practical advantages can be obtained. As described above, it is extremely significant to have a lens with a high refractive index, and there is a strong desire to provide a resin material with a high refractive index.

However, considering transparency, lightness, etc., which are important characteristics of lenses, no satisfactory resin material has yet been provided. To be more specific, materials such as diethylene glycol bisallyl carbonate resin and polymethyl methacrylate are used as materials for resin lenses for eyeglasses, which are currently in widespread use, but both have a refractive index of 1. It is low, around 50.

On the other hand, as a resin material with a relatively high refractive index, there is polystyrene with a refractive index of nW=1.59, and it is known that it can be used as a copolymer component of a resin material for lenses. In terms of refractive index, it is desirable to have a refractive index as high as or higher than polystyrene, but resin materials with such a high refractive index usually have a relatively high specific gravity. . Against this background, there is a strong desire for a lens that has a sufficiently high refractive index and is lightweight.

[Prior art]

In the patent application related to JP-A No. 62-276501, the present inventors obtained a polymeric material obtained from a polymerizable material containing an isopropenylnaphthalene monomer represented by the following structural formula (I) in a proportion of 20 to 100% by weight. A polymer with a refractive index of 1.
By dissolving it in other monomers giving a polymer of 50 or more, and casting-polymerizing the polymerizable composition thus obtained,
5-70% by weight of isopropenylnaphthalene component
The present invention provides a method for producing a high refractive index resin lens made of a copolymer containing a copolymer in a proportion of .

Structural Formula (I) [Problem to be Solved by the Invention] However, in this method, an isopropenylnaphthalene copolymer is separately prepared by, for example, an anionic polymerization method, dissolved in a polymerizable monomer, and then This is a time-consuming method of casting polymerization. The reason why such a complicated method is necessary is that the above-mentioned isopropenylnaphthalene has poor radical copolymerizability with other monomers.

[Summary of the invention]

An object of the present invention is to solve the above-mentioned problems and provide a high refractive index resin material that has a high refractive index, a low specific gravity, and can be easily manufactured.

Such purpose is to combine 5 to 70% by weight of isopropenylnaphthalene monomer represented by the following structural formula (I) and the following structural formula (
A copolymer obtained by copolymerizing 10 to 60% by weight of halogen-substituted acrylate or halogen-substituted methacrylate represented by If) and 0 to 50% by weight of another radically polymerizable monomer. This is achieved by using a high refractive index resin material.

Structural formula (I) Structural formula (ff) (X represents a chlorine atom, bromine atom or iodine atom, Y represents a hydrogen atom or a methyl group, n is an integer of 1 to 5, m is 0
It is an integer of ~7. ) [Effect] The present invention provides an isopropenylnaphthalene monomer represented by the above structural formula (I) (hereinafter referred to as "monomer (I)"), and a halogen-substituted acrylate represented by the above structural formula (II) or We discovered that it has good copolymerizability with halogen-substituted methacrylate (hereinafter referred to as "monomer (■)"),
Furthermore, by copolymerizing the monomer (If), other radically polymerizable monomers (hereinafter referred to as "monomers (■)") can be copolymerized with monomer (I). This method was completed by discovering that even when the material does not have sufficient copolymerizability, it can be copolymerized satisfactorily. Therefore, the copolymer according to the present invention can be easily produced by a conventional method, and the copolymer can be used to form a component consisting of the monomer (I) having an impropenyl group as a substituent and a monomer. By containing the component according to (II>), it is possible to provide a lens that has a high refractive index and a relatively low specific gravity, and therefore has a high overall refractive index and is lightweight.

[Detailed description of the invention]

The present invention will be explained in detail below.

The above monomer (I) is used as an essential monomer for obtaining the copolymer of the high refractive index resin material of the present invention. That is, by containing the component of this monomer (I), the resulting copolymer has a higher level of polymerization than the polymer or copolymer of naphthyl methacrylate described in, for example, JP-A No. 60-15414. Since the functional group is an isopropenyl group, it has a higher refractive index. Incidentally, for example, the refractive index of a homopolymer of 2-naphthyl methacrylate that does not have an impropenyl group is around nM = 1.63 to 1.64, but 2-isopropenylnaphthalene, which is a type of monomer (I), The homopolymer has a fairly high refractive index of about nW=1.67 or more.

On the other hand, the specific gravity of the homopolymer of this monomer (I) is relatively small, about 1.1-1.15, and therefore, by containing the component of this monomer (I), the copolymer has the advantage of being lightweight despite its high refractive index.

Specific examples of monomer (I) used in the present invention include 1-isopropenylnaphthalene, 2-isopropenylnaphthalene, 3-isopropenylnaphthalene, 4-isopropenylnaphthalene,
Isopropenylnaphthalene and mixtures thereof may be exemplified.

Even if these monomers (I) are used in a relatively small amount in the monomer composition, it is possible to obtain a copolymer having a considerably high refractive index. I) is used in an amount of 5 to 70% by weight based on the total monomer.

If the amount of monomer (I) used is less than 5% by weight, a copolymer with a sufficiently high refractive index cannot be obtained, and if it exceeds 70% by weight, the monomer (I) and monomer (If
) and the monomer (III). Therefore, from this point of view, it is particularly preferable to keep the content to 60% by weight or less.

The monomer (II) used in the present invention is the monomer (I) described above.
) has good copolymerizability with This monomer (II
), X represents a halogen atom selected from a chlorine atom, a bromine atom, and an iodine atom,
If other conditions are the same, the refractive index of the resulting copolymer increases in the order of α<Or<I for X of the monomer (II), but the specific gravity of the resulting copolymer increases. . Therefore,
Depending on the use or purpose of the optical material formed from the obtained copolymer, it is necessary to select the halogen atom of the monomer (II>) and the value of the number n of substituents.

Furthermore, as the value of m increases, the resulting copolymer becomes more flexible and its impact resistance improves, but the refractive index tends to decrease as m increases. Therefore, in the present invention, monomers (n) in which m is in the range of θ to 7 are used.

Specific examples of the monomer (I[) used in the present invention include 4-chlorophenyl methacrylate, 4-
Bromophenyl acrylate, 2.4゜6-dribromophenyl methacrylate, 2-iodophenyl methacrylate), 2,4.6-)lichlorophenylacrylate, 1-methacryloxyethoxy-4-bromobenzene,
1-acryloxyethoxy-2,4,6-)libromobenzene, 1-acryloxyethoxy-4-iodobenzene, ■-acryloxyethoxy-2,4,6-)lichlorobenzene, l-acryloxypolyethoxy -2,4,
6-) Ribromobenzene, 1-methacryloxypolyethoxy-2,4,6-)! J 7' lomobenzene, l-
Examples include acryloxypolyethoxy-2,4,6-)lichlorobenzene, but these are just examples and are not limited to these.

The above monomer (II) is 10 to 10% of the total monomers.
It is used in a proportion of 60% by weight. This proportion is 10% by weight
If it is less than that, good copolymerizability may not be obtained although it depends on the amount of monomer (I). On the other hand, if the ratio exceeds 60% by weight, the copolymerizability is good, but the resulting copolymer has a high specific gravity.

By using monomer (n) as described above together with monomer (I) as an essential copolymerization component, monomer (I[l)
Even if it does not have good copolymerizability with the monomer (L), it is possible to copolymerize it well.

By using monomer (III), the monomer ([
Depending on the type of [), various suitable properties such as good moldability, dyeability, solvent resistance, heat resistance, and impact resistance can be obtained in the resulting copolymer.

Specific examples of such monomer (III) include aliphatic or aromatic monofunctional acrylates or methacrylates such as methyl acrylate, methyl methacrylate, naphthyl acrylate, naphthyl methacrylate, phenyl methacrylate, mono- and di-ethylene Acrylic acids of fatty acid polyhydric alcohols such as glycol diacrylate, mono- and di-ethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropantry or di-acrylate, trimethylolpropantry or di-methacrylate. Suitable examples include esters or methacrylic acid esters, various aromatic vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, and dipromostyrene, and aromatic divinyl compounds represented by divinylbenzene and diisopropenylbenzene. It can be mentioned as a thing.

' Also, when a crosslinkable monomer is used as the monomer (DI), the resulting copolymer has a crosslinked structure and has excellent mechanical and chemical properties, which is preferable. . In particular, a bifunctional crosslinking agent having a halogen-substituted aromatic ring is preferable since the resulting copolymer has a high refractive index.

Examples of such a bifunctional crosslinking agent having a halogen-substituted aromatic ring include 2.2-bis[4-acryloxyethoxy-3,5-')halophenyl]furopane, 2.2-bis[4-methacryloxyethoxy -3,5-dihalophenyl]furopane, 2,2-bis[4-acryloxypoly
(to the extent of dyltetra) ethoxy) -3,5-dihalophenyl]propane, 2,2-bis[4-methacryloxypoly (to the extent of dyltetra)ethoxy)-3,5-dihalophenyl]furopane, 2.2-bis[4-acryloxy −
3,5-dihalophenyl]propane, 2,2-bis-4
-methacryloxy-3゜5-dihalophenyl]furopane, 2,2-bis(4-acryloxypoly(dyltetra)propoxy-3゜5-dihalophenyl]propane, 2
．． 2-bis(4-methacryloxypoly(dyltetra))
Examples include, but are not limited to, propoxy-3,5-dihalophenyl]propane, mixtures thereof, and others. In addition, I would like to add that
Monomer (I) and monomer (Ir) are often solid at room temperature. Therefore, when molding lenses by cast polymerization, the polymer composition is in a liquid state. As the monomer (I[[), it is desirable to use a liquid material that can dissolve monomer (I) and monomer (n).

The above monomer (I[[) can be used in an amount of 0 to 50% by weight.

The above monomers (I), monomers (n) and monomers (I[
[) is copolymerized, but the polymerization method therefor is not particularly limited, and ordinary radical polymerization methods can be used. As the polymerization initiator, for example, well-known radical polymerization initiators such as diacyl peroxide, dialkyl peroxide, and dialkyl peroxydicarbonate can be used.

In addition to the above-mentioned polymerization initiator, the polymerization composition actually subjected to polymerization includes various antistatic agents, colorants, fillers, ultraviolet absorbers, etc., depending on the expected use of the optical material to be manufactured. It is possible to contain additives, heat stabilizers, antioxidants, and other auxiliary agents.

The type of polymerization is not limited either, and any polymerization method such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization may be used. However, a cast polymerization method in which the resulting monomer composition is directly molded into a lens is one of the preferred manufacturing methods.

Since this cast polymerization method is itself a well-known technique, it can be carried out appropriately under conditions according to well-known knowledge.
A cylindrical, prismatic, conical, spherical, or other mold or formwork designed according to the purpose is used, and the material may be any suitable material such as inorganic glass, plastic, or metal. Then, a polymerization composition prepared by adding monomer (I), monomer (II), monomer (III), a polymerization initiator, and necessary additives is placed in a casting mold as described above. When polymerization is carried out by injecting the polymer into a liquid and heating it as necessary, molding is achieved simultaneously with the completion of polymerization, thereby making it possible to directly obtain the desired optical material such as a lens.

If the copolymer is obtained by a method other than cast polymerization,
The copolymer can be molded into a desired molded product using conventional methods such as press, roll, and calendar extrusion molding. However, if the polymerization composition contains a monomer having a difunctional or higher polymerizable functional group, the resulting copolymer will be a crosslinked product, so it is generally difficult to perform melt molding. Become.

The resin material according to the present invention is subjected to surface polishing, antistatic treatment, and other post-treatments as required, and is used as an optical product for practical use. Further, like a normal resin lens, in order to increase the surface hardness, an inorganic material can be coated on the surface by vapor deposition or the like, or an organic hard coating agent can be coated by dipping or the like. In addition, it is of course possible to apply treatments used in general lenses, such as applying an anti-reflection coating.

〔Example〕

The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example 1 15 g of purified 2-isopropenylnaphthalene with a purity of 99% or more, 30 g of 1-methacryloxy-2,4,6-tribromobenzene, and 1-acryloxyethoxy-2
, 4, 6-) 20 g of rifrombenzene, 10 g of divinylbenzene, and 25 g of styrene were mixed and dissolved, and 1.0 g of lauroyl peroxide was added thereto. Og was added and poured into a glass mold, and polymerization was carried out under different conditions: 50°C for 16 hours, 80°C for 2 hours, and 100°C for 2 hours, to obtain a beautiful colorless and transparent copolymer.

When the refractive index of this copolymer was measured using an Atsube refractometer, n! It showed a high value of =1.625. Further, the specific gravity was 1.38, and it was confirmed that it was a good resin material with a high refractive index and a low specific gravity.

Example 2 25 g of 2-isopropenylnaphthalene similar to that used in Example 1, 30 g of 1-methacryloxy-2゜4.6-tribromobenzene, 15 g of divinylbenzene, and 1-acryloxyethoxy-2, 30 g of 4,6-)lifrombenzene was thoroughly mixed with 1 g of lauroyl peroxide, and polymerization was carried out according to the polymerization method of Example 1 to obtain a transparent copolymer.

This copolymer had an extremely high refractive index of 1.641, and a specific gravity of 1.48.

Example 3 30 g of 2-isopropenylnaphthalene similar to that used in Example 1, 40 g of 1-acryloxyethoxy-4-iodobenzene, and 15 g+ of divinylbenzene! :,
15 g of styrene was thoroughly mixed with 1 g of lauroyl peroxide, and polymerization was carried out according to the polymerization method of Example 1 to obtain a transparent copolymer.

The refractive index of this copolymer is n%i = 1.632,
Further, the specific gravity was extremely small at 1.32.

Claims (1)

[Scope of Claims] 1) 5 to 70% by weight of isopropenylnaphthalene monomer represented by the following structural formula (I) and 10 to 60% by weight of a halogen-substituted acrylate or halogen-substituted methacrylate represented by the following structural formula (II) % and 0 to 50% by weight of another radically polymerizable monomer. Structural formula (I) ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ Structural formula (II) ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (X is a chlorine atom, bromine atom, or iodine atom, Y is a hydrogen atom or a methyl group) where n is an integer from 1 to 5, m is 0
It is an integer of ~7. )