JPS60124606A - Synthetic resin lens material - Google Patents

Abstract

PURPOSE:The titled lens material having a high refractive index, low dispersion and excellent surface hardness, obtained by copolymerizing a specified monomer with a crosslinking monomer having at least two polymerizable functional groups and styrene. CONSTITUTION:A synthetic resin lens material having a refractive index nD<20> 1.55 and Abbe number nu=27 is obtained by mixing 50-90wt% monomer of the formula (wherein R is H or a 1-2C alkyl, X is a halogen other than F, m is 1- 5, and n is 1-4) with 10-40wt% crosslinking monomer having at least two polymerizable functional groups and being copolymerizable therewith [e.g., diethylene glycol (meth)acrylate], 0-40wt% styrene and, optionally, 0-20wt% other comonomers (e.g., methyl methacrylate) and a radical polymerization initiator, pouring the mixture into a cast polymerization vessel and copolymerizing it by heating.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to synthetic resin lens materials, and more particularly to synthetic resin lens materials having high refractive index and low dispersion.

Conventionally, various types of inorganic glass lenses have been used in optical equipment, but synthetic resin lenses are preferred due to their light weight, processability, stability, dyeability, mass productivity, and low cost. It is beginning to be widely used.

Among the various physical properties required for lenses, high refractive index and low dispersion are extremely important.

Having a high refractive index not only makes lens systems that occupy an important position in optical instruments such as microscopes, cameras, and telescopes, and eyeglass lenses compact and lightweight, but also makes it possible to use spherical surfaces, etc. This has the advantage of keeping the aberrations small.

On the other hand, it goes without saying that low dispersion is extremely important in terms of reducing chromatic aberration.

However, even in the case of - film thickness synthetic resin lenses, similarly to inorganic glass lenses, there is a tendency for high refractive index lenses to have high dispersion and low refractive index lenses to have low dispersion.

For example, diethylene glycol bisallyl carbonate resin (hereinafter referred to as CR-39) is currently the most popular synthetic resin material for eyeglasses.
R-39 has a high Atsube number of ν= (i.e., low dispersion)
However, the refractive index is extremely low at n20 = 1-50.
). Polymethyl methacrylate, which is partially used as a lens material, has a high Abbe number of ν=, similar to CR-39, but a low 20-refractive index of nD-1.49. Boristile y (n”=1.59, ν=20-30,4) and polycarbonate (nD-1,59,
ν=29.5) is unsatisfactory in other physical properties required as a lens material. For example, polystyrene lacks surface hardness and solvent resistance, and polycarbonate lacks surface hardness and impact resistance. Polynaphthyl methacrylate (nD-1,64
) and polyvinylnaphthalene (n ”o = 1-68
) have low Abbe numbers of ν=A and ν=Add, respectively, and there are many problems with both materials.

From these points, refractive index, Atsube number, surface hardness,
There was a demand for a synthetic resin material with balanced solvent resistance.

SUMMARY OF THE INVENTION The present invention aims to provide a solution to the above-mentioned problems, and attempts to achieve this aim by means of a specific crosslinked copolymer.

That is, the H/Z material according to the present invention having a refractive index n Dl -55 or more and an Atsbe number S = 27 or more is expressed by the following formula (
Exceeding the intermonomer weight percent shown in I) and up to the full weight percent, from 10 to 40 weight percent of a crosslinking agent monomer having two or more polymerizable functional groups copolymerizable therewith, and from 10 to 40 weight percent of styrene. It is characterized by being made of a copolymer whose main component is a monomer component.

(In the formula, R represents hydrogen or a C0 to C2 alkyl group, or a halogen atom excluding fluorine, m represents an integer of 1 to 5, and n represents an integer of 1 to 4.) Effect Consisting of the copolymer of the present invention Synthetic resin material is 1.5
It has a high refractive index of 5 or more, a low dispersion of Atsbe's number n or more, and is colorless, transparent, acid resistant, heat resistant, has excellent surface hardness, and has excellent dyeability. /
It is a glass material that solves the problems of the conventional silicon/silica materials mentioned above.

The fact that the copolymer of the present invention has such excellent properties as a lens material was first discovered by the present inventor, Isobara. This is thought to be due to the fact that the polymer contains a large amount of polymer, and that it is a copolymer with a crosslinking agent and, in some cases, with styrene.

3. Detailed Description of the Invention Copolymer The copolymer constituting the synthetic resin lens material according to the present invention is composed of specific Q) comonomer components.

The main 7 components of the copolymer constituting the synthetic 1-removed resin material of the present invention are monomers represented by the following general formula (1).

(In the formula, R is hydrogen or a C1-C2 alkyl group,
represents a halogen atom excluding fluorine, m represents an integer of 1 to 5, and n represents an integer of 1 to 4. ) As the atom (X), chlorine, odor, and iodine are generally used, but chlorine and odor are more preferably used from the viewpoint of the resulting copolymer f) high refractive index and stability over time. It will be done. The value of n has an important meaning on lens characteristics, and if it is 5 or more, the surface hardness of the resulting lens tends to be poor and the refractive index tends to decrease.
An integer selected from the following is used. The value of m has the greatest effect on the refractive index. By changing this value from 1 to 5, you can design a lens with a refractive index that suits your purpose.

Examples of the monomer represented by formula (1) include 1-(meth)acryloxethoxydibrompe/zen 1-(meth)acryloxyethoxy-2,4,6-dribrompe/
Ze/%1-(meth)acryloxyjetoxy-2,4,
6-Tribromobenzene, l-(meth)acryloxyethoxy-4-brompe/-ty, 1-(meth)acryloxyethoxy-2°4.6-)lichlorope/, 1-
Mention may be made of (meth)acryloxyethoxypentabromo and mixtures thereof. here"〔
``(meth)acryloxy'' and ``(meth)acrylate
"Details below]" includes both groups and structures derived from acrylic acid and methacrylic acid.

By using such a monomer as a component of the copolymer, the refractive index r120=1.55 or more and the Atsbe number S=27 can be obtained.
The above copolymers can be obtained. However, the formula (
A homopolymer consisting only of monomers represented by I) is unsuitable as a silicon/dz material. This monomer alone has poor polymerizability and cannot achieve a sufficiently high polymerization yield, and this polymer is relatively easily attacked by organic solvents and lacks solvent resistance. The monomer represented by formula (1) is usually colorless or colored, and the degree of coloration is extremely dependent on the method of purifying the monomer. Therefore, if purification cannot be achieved sufficiently, a polymer containing an extremely large amount of monomer (1) may also retain its coloration in the monomer state and may be unsuitable as a chemical material depending on the degree of purification. There are cases where this occurs.

On the other hand, if the monomer component represented by formula (1) is too small during copolymerization, the copolymer cannot naturally have the above-mentioned refractive index and Abbe number.

It is necessary.

Crosslinking agent monomer In the present invention, in order to increase the solvent resistance, heat resistance, etc. of the homopolymer of the monomer of formula (r), a polymerizable functional group on 2 μm that can be copolymerized with the homopolymer is added. A three-dimensional crosslinked structure is formed by introducing 10 to 40% by weight of the crosslinking monomer.

Examples of crosslinking monomers containing two or more polymerizable functional groups and copolymerizable with the monomer of formula (I) include, for example, polyhydric alcohols and acrylic acid or methacrylic acid. Di- or triallyl compounds such as esters, divinyl compounds, diallyl phthalate, triallyl cyanurate,
Examples include compounds having various allyl groups and methacrylic groups (or acrylic groups). Examples of divinyl compounds include divinylbenzene; compounds having both allyl and acrylic groups include allyl acrylate and allyl methacrylate; examples of esters of polyhydric alcohols with acrylic acid or methacrylic acid include mono- and diethylene glycol (meth)acrylate. , zorobire/glycol di(meth)7crylate, trimethylolfuropane tri(meth)acrylate, 2,2-bis[4
-((meth)acryloxyethoxy)phenyl]propane, 2,2-bisC4-((meth)acryloxypoly(
diltetra) ethoxy) phenyl]
and 2,2-bis[4-((meth)acryloxyethoxy)halokenated phenyl]propa/, 2,2-bis(
4-((meth)acryloxypoly(dyltetra)ethoxy)halogenated phenyl]propane, etc. or mixtures thereof may be mentioned.

Styrene monomer As described above, the object of the present invention can be achieved by using a copolymer of the monomer represented by formula (I) and a crosslinking agent monomer. It can be used within the following range. When styrene is introduced into a copolymer, the coloring derived from monomer (I) disappears even when insufficiently purified monomer (I) is used, and a colorless copolymer can be obtained. There is an advantage. This effect is not observed at all when other monomers are added. Although it is not clear at present why the use of styrene as a component of the copolymer eliminates coloring in the copolymer, it is considered to be an extremely useful discovery.

The amount of styrene used as the third component is O to 40% by weight. Of course, if the monomer of formula (1) is highly purified and colorless, styrene is not required. If Styr/ exceeds 40% by weight, the effects of high refractive index and low dispersion, which are the characteristics of the monomer of formula (1), decrease.

Arbitrary comonomers The copolymer according to the present invention is composed mainly of two or three types of monomers, but as long as the purpose of the present invention is not unduly hindered, the copolymer may not contain any of these two types of monomers. It may be one in which an ethylenically unsaturated monomer (not limited to a monoethylenically unsaturated monomer) which is copolymerized with one or three kinds of monomers is further copolymerized. This optional comonomer class ranges from 0 to 20% by weight of the copolymer, preferably O
It is desirable that it accounts for ~10% of heavy mold.

Such a monomer is preferably one in which the homopolymer thereof provides a transparent polymer with a high refractive index or Abbe's number. Specifically, for example, various alkyl (meth)acrylates such as methyl methacrylate,
Naphthyl methacrylate and aromatic vinyl compounds such as α-methylstyrene/, divinylpe/ze/etc.

Note that the amount (and type) of such optional comonomers should be selected within a range that does not excessively impair the high refractive index, low dispersion, and transparency that are the characteristics of the copolymer of the present invention. It is.

Polymerization The polymerization of the above-mentioned multimonomers proceeds using a conventional radical polymerization initiator. The polymerization method may also be one commonly used for normal radical polymerization. However, since the resulting copolymer is crosslinked and treatment involving melting or dissolution is virtually impossible, cast polymerization is generally preferred from the viewpoint of use in plastic lenses.V).

The casting method 1 is a well-known technique. As the cast polymerization container, plate-shaped, lens-shaped, cylindrical, prismatic, conical, spherical, or other molds or molds designed according to the purpose are used. Its materials include inorganic glass, plastic,
It can be any material for a purpose, such as metal. Polymerization is carried out by heating a mixture of monomers and a polymerization initiator placed in such a container as necessary.

It can also be carried out in such a manner that a prepolymer or syrup obtained by carrying out a certain degree of polymerization in a separate container is charged into a polymerization container to complete the polymerization.

The required monomers and polymerization initiator may be mixed in their entire amounts at once, or may be mixed in stages. The mixture may also contain antistatic agents, colorants, fillers, ultraviolet absorbers, heat stabilizers, antioxidants, and other auxiliary materials, depending on the intended use of the resulting copolymer. good.

Another specific example of the polymerization method of the present invention is a method in which a mixture of required monomers and a polymerization initiator or a prepolymer is suspended in water to carry out polymerization, that is, suspension polymerization. This method is suitable for obtaining spherical particles of various particle sizes. The suspension polymerization method is also a well-known technique, and the present invention may be appropriately carried out according to well-known knowledge.

The obtained copolymer is heated to complete any incomplete polymerization or to increase its hardness, or annealed to remove distortions incorporated by cast polymerization. Needless to say, processing can be carried out.

Lens The lens according to the present invention is essentially the same as conventional synthetic resin lenses, except that the lens material is the crosslinked copolymer of the present invention. Therefore, the present invention can be achieved by directly obtaining the copolymer as a lens by casting polymerization, or by cutting it out from a plate or other material, and subjecting it to surface polishing, antistatic treatment, and other post-treatments as necessary. A product having various properties inherent to the copolymer is obtained. Furthermore, in order to increase the surface hardness, it is of course possible to coat the surface with an inorganic material by vapor deposition or the like or with an organic coating agent by dipping or the like.

Experimental Examples Example 1 Thoroughly purified l-acryloxyethoxy-2°4.6
-) Dibromo 4F 4F 60 overlapped part, 2,2-bis-(4
- Mix 2,740 parts by weight of methacryloxyethoxy-3,5-dibromophenyl) sol and put it in a glass container together with 1 part by weight of lauroyl peroxide as a polymerization initiator, and thoroughly degas the inside of the container and thoroughly replace it with nitrogen. After that, 5
The polymerization was completed by heating at 0° C. for 1 hour, at ω° C. for 15 hours, at 110° C. for 2 hours, and at 110° C. for 1 hour. The copolymer thus obtained was colorless and transparent, completely insoluble in organic solvents such as acetate, benzene, and the like, and highly resistant to organic solvents. Surface hardness is JIS (K5
The pencil hardness was 3H based on 400 mm), and the heat resistance was also poor. When measured with an Atsube refractometer at m°C, the refractive index and Atsube number were 0 - Dl -605 and I/=33.5, respectively.
It showed extremely good para/s values.

Example 2 1-acryloxyethoxy-2,4,6-)ribromope/zene (contains jetoxy, triethoxy compounds)
68 Jushabu, 23 parts by weight of styrene and Divinyl 474
79 parts by weight, 1 part by weight of lauroyl peroxide as a polymerization initiator, an ultraviolet absorber, and an acid rust inhibitor were placed in a glass container, and the inside of the container was thoroughly degassed and well replaced with oxygen, and then heated at 50°C. 1 hour, 15 hours at ω℃, 2 hours at 80℃
The polymerization was completed by heating at 110° C. for 1 hour. The copolymer thus obtained was almost colorless and transparent and had excellent organic solvent resistance. The pencil hardness was 3H and the heat resistance was excellent. The refractive index and Atsube number at 20°C were as follows.

nD-1,598ν=33.5 Example 3 1-Methacryloxyjethoxy-2,4,6-)dibromo 4155 parts by weight, 30 parts by weight of Steref, and 2.
15 parts by weight of 2-bis(4-methacryloxyjethoxy-3,5-dibromophenyl) oxide and 1 part by weight of lauroyl oxide as a polymerization initiator were mixed.
Polymerization was carried out under the same conditions as in Example 1. The obtained copolymer was almost colorless and transparent and insoluble in various organic solvents. The surface hardness was 3H on a pencil hardness scale, and the heat resistance was also poor.

Also, refractive index n L' = 1-596, Atsbe number ν = 32
．． It was 2.

Example 4 Thoroughly purified l-acryloxyethoxy-2°4.6
- 70 parts by weight of tribromopenze/(including jetoxy and triethoxy compounds), 79,730 parts by weight of 2,2-bis(4-acryloxyjetoxyphenyl)furo and 1 part by weight of lauroyl peroxide as a polymerization initiator, and carried out. Polymerization was carried out under the same conditions as in Example 1. The polymer thus obtained was colorless and transparent, had a pencil hardness of 3H, and had excellent solvent resistance and heat resistance. It also showed a refractive index n20-1.5811 and an Abbe number ν=35.0.

Comparative Example 1 Thoroughly purified l-acryloxyethoxy-2°4.6
Polymerization was carried out in the same manner as in Example 1 by adding 1 part by weight of lauroylnozo-oxide as a polymerization initiator to 100 parts by weight of -drizolomope/ze/(containing jetoxy and triethoxy compounds).

The polymer thus obtained after 5K had a low degree of polymerization and some monomers remained. Furthermore, this polymer exhibited rubber-like elasticity and could not be used as a lens material.

Kiyoshi Inomata on behalf of the applicant

Claims (1)

[Scope of Claims] 10 to 40 crosslinking agent monomers having two or more polymerizable functional groups that can be copolymerized with the monomer represented by the following formula (I) exceeding physical strength weight percent and gloss weight percent. Weight% and styrene 10~
A synthetic resin lens material having a refractive index n:= 1.55 or more and an Atsube number ν=υ or more, characterized by being composed of a copolymer having a monomer component of 40% by weight (in the formula, R is H or an alkyl group of c0 to c2, X is a halogen atom excluding fluorine, m is an integer of 1 to 5, and n is 1
Represents an integer from ~4. )