JPH01217019A - Resin material for lens - Google Patents

Abstract

PURPOSE:To provide the subject material of excellent impact resistance and high refractive index, with the other characteristics balanced, consisting of a copolymer produced by polymerization between each specific two kinds of crosslinkable monomer component and an aromatic vinyl compound in specified proportion. CONSTITUTION:The objective material can be obtained by polymerization of a monomer mixture containing (A) 5-80wt.% of a di(meth)acrylate compound of formula I (n is 1-6; R<1> and R<2> are each H or methyl), (B) 5-50wt.% of an ethylene glycol dimethacrylate compound of formula II (m is 1-8), and (C) 5-50wt.% of an aromatic vinyl compound with the amounts of the components A, B and C totalling >=40wt.%. The polymerization process is, in general, pref. a cast polymerization process capable of directly obtaining a copolymer of aimed shape. The component B is e.g., ethylene glycol dimethacrylate, while the component C is e.g., styrene.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a resin material for lenses that has excellent impact resistance and a high refractive index, and more specifically, a resin material for lenses that has a specific crosslinkable monomer as a component. The present invention relates to a resin material for lenses whose main feature is that it is made of a copolymer.

[Conventional technology]

In general, resin lenses have features such as being easy to mold and being lightweight, so they have been used in a wide range of optical products.However, resin lenses are usually compared to inorganic glass lenses. and has a low refractive index,
Therefore, when molded into lenses, they have the disadvantage of being extremely thick, and they generally have poor solvent resistance and poor heat resistance compared to inorganic glass lenses.

Currently, diethylene glycol bisallyl carbonate resin is most commonly used as a resin material for optical lenses. However, the major drawback of this resin lens is that its refractive index is as low as approximately 1.5.Moreover, when trying to obtain excellent impact resistance that passes the US FDA standard falling ball test, the center of the lens must be It is necessary to increase the thickness to 1.7 or more, and the Izot impact value must also be 3 to 4 kg.
cm/Cm, and the impact resistance is not sufficiently high.

On the other hand, in recent years, research has been conducted in various fields to obtain resin materials for lenses with a high refractive index, and for example, polyvinylnaphthalene, polyvinylcarbazole, polynaphthyl methacrylate, and the like have been proposed. However, although these polymers have a high refractive index, they have low impact resistance and also have shortcomings such as poor heat resistance and solvent resistance.

In general, optical lenses need to have high impact resistance in addition to a high refractive index, as well as heat resistance, solvent resistance, light weight, and easy dyeing and hard coating treatment. It is practically important to have a good balance of various physical properties or characteristics, such as excellent durability.

JP-A-61-140901 discloses a resin material for lenses with a high refractive index that has relatively good impact resistance, but it is still not sufficient in terms of actual impact resistance. Therefore, a satisfactory lens resin material has not yet been found. Under these circumstances, it is strongly desired to provide a resin material for lenses that has excellent impact resistance, a high refractive index, and a good balance of other physical properties and characteristics.

The present invention provides a monomer consisting of a specific diacrylate compound or dimethacrylate compound, a monomer consisting of a dimethacrylate compound having an ethylene glycol group,
This invention was made based on the discovery that a copolymer of a monomer mixture containing an aromatic vinyl compound monomer as an essential component has excellent properties that satisfy the above requirements.

[Purpose of the invention]

An object of the present invention is to provide a resin material for lenses that has excellent impact resistance and a high refractive index, and also has well-balanced other properties.

[Structure of the invention]

The monolithic material for lenses according to the present invention has the following structural formula (I):
A monomer (■) consisting of a diacrylate compound or a dimethacrylate compound represented by 5 to 80% by weight, and a monomer (II) consisting of an ethylene glycol dimethacrylate compound represented by the following structural formula (II) from 5 to 80% by weight 50% by weight
and monomer (III) consisting of an aromatic vinyl compound 5
-50% by weight, and the total amount of monomer (I), monomer (II) and monomer (I[I) is at least 40% by weight or more. It is characterized by being made of a copolymer obtained by polymerizing.

Structural formula (r) (In the formula, n is 1 to 6, and R' and R2 each represent a hydrogen atom or a methyl group.) Structural formula (II) (In the formula, m is 1 to 8.) [Effect ] The resin material for lenses according to the present invention has excellent impact resistance and a refractive index of n! = 1.52 or higher, which is relatively high.
It also has excellent heat resistance and solvent resistance.

The present invention will be specifically explained below.

In the present invention, monomer (I), monomer (I[), and monomer (II[)] are each contained in proportions within a specific range, and the total of these single monomers is 40% by weight or more. A monomer mixture containing the following proportions is made of 1lAl, and a copolymer obtained by polymerizing this is used as a resin material for lenses.

Monomer (I) Monomer (I) which is the first component of the copolymer according to the present invention
is a diacrylate compound or dimethacrylate compound represented by the above structural formula (I).

This monomer (I) has two polymerizable functional groups,
Therefore, it is a crosslinkable monomer component. This monomer (I) is
The moiety between two polymerizable functional groups is a relatively long chain having 1 to 6 aromatic ring units consisting of diethyl meta-, ortho-, or paraphthalate. The polymer has both a crosslinking effect and excellent impact resistance.

On the other hand, when a monomer in which the moiety between the polymerizable functional groups is a long-chain alkyl having no aromatic ring is used, the resulting copolymer has a low refractive index.

Therefore, monomer (I) has n in its structural formula (I).
The value of n is important; if n is large, the resulting copolymer will have high impact resistance, but the crosslinking effect will tend to decrease. In particular, if n exceeds 6, the crosslinking effect will be poor, resulting in a copolymer with poor solvent resistance. On the other hand, if n is small, the copolymer will have an excellent crosslinking effect, but its impact resistance will be somewhat reduced. Therefore, in the present invention, monomers (I) in which n in structural formula (I) has a value of 1 to 6, preferably 2 to 4, are used.

As long as n is in the range of 1 to 6, a plurality of monomers (I) having different values of n may be used together.

The above monomer (I) is used in a proportion of 5 to 80% by weight of the monomer mixture to be subjected to polymerization, particularly 8 to 70% by weight.
A ratio of . If the proportion of monomer (I) is less than 5% by weight, a sufficient crosslinking effect cannot be obtained, resulting in a copolymer having low solvent resistance and low heat resistance. On the other hand, 80% by weight
If it exceeds , the copolymer will be relatively hard but will have low impact resistance and will have a somewhat high specific gravity.

Monomer (II) Monomer (U) which is the second component of the copolymer according to the present invention
is a fil1 body represented by the above structural formula (IT),
Like monomer (I), it has two polymerizable functional groups and is therefore a crosslinkable l1LI component. The portion between the two polymerizable functional groups in this monomer (II) is an ethylene glycol unit, and the length of the repeating unit is that of the monomer (
I) and, as a result, the 1i wide body (I) forms a long-chain bridge (a structure), whereas this monomer (II) forms a short-chain and therefore a so-called internal bridge segment. It is believed that the copolymer of the present invention containing this monomer (U) has significantly greater resistance to Ji than a polymer containing only monomer (I).

Since monomer (II) has a function as an internal crosslinking segment, m in structural formula (TI)
The value of . It becomes what it is. Furthermore, when the value of m is small, the crosslinking effect is extremely large and the copolymer has high hardness, but the impact resistance is somewhat reduced. From this point of view, in the present invention, m is 1 to
8 is used as monomer (II), preferably 1 to 6 are used. If m is in the range of 1 to 8, a plurality of monomers having different values of m may be used together.

Specific examples of monomer (II) include polyethylene glycol dimethacrylates such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate.

This monomer (II) is 5 to 50% by weight of the monomer mixture.
It is preferably used in a range of 10 to 40% by weight. If this proportion is less than 5% by weight, the crosslinking effect will be low, resulting in a decrease in impact resistance, heat resistance, and solvent resistance in the resulting copolymer. On the other hand, monomer (II)
If the proportion exceeds 50% by weight, the proportion of other monomer components becomes relatively small, making it impossible to obtain a high refractive index, etc.
Unable to obtain balanced characteristics.

trL-mer (III) Monomer (I[
[) is an aromatic vinyl compound. Polymers made of aromatic compounds generally exhibit a high refractive index, and therefore, by using this monomer (III) as a component of the copolymer, the resulting copolymer has a high refractive index.

Specific examples of monomer (III) include styrene, α-methylstyrene, divinylbenzene, impropenylbenzene, p-methylstyrene, vinylnaphthalene, chlorostyrene, and bromostyrene.

The larger the proportion of monomer (I[[) used, the higher the copolymer with a higher refractive index can be obtained.
Also, the crosslinking effect of the monomer (U) decreases, resulting in a decrease in impact resistance, heat resistance, and solvent resistance in the resulting copolymer.

Therefore, the proportion of monomer (III) in the monomer mixture is 5 to 50% by weight, preferably 10 to 40% by weight.

In the present invention, monomer (I) in the monomer mixture
, the proportions of monomer (I[) and monomer ([[I) are within the above range, and monomer (I), monomer (
■) and monomer (III) if the total amount is 40% by weight or more, other copolymerizable monomers may be added depending on the properties required for the final resin lens. Monomer (
(2), monomer (II), and monomer (I[[) can be copolymerized. However, monomer (I),
If the total proportion of monomer (II) and monomer ([[) is less than 40% by weight, it will not be possible to obtain a high refractive index copolymer with excellent impact resistance, resulting in The purpose of the invention cannot be achieved.

Specific examples of monomer (I), monomer (II), and other copolymerizable monomers copolymerized with monomer (I) include the following.

(I) Acrylates or methacrylates, e.g.
Methyl acrylate, methyl methacrylate, naphthyl acrylate, naphthyl methacrylate, phenyl acrylate, phenyl methacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene glycol diacrylate,
1.3-butylene glycol dimethacrylate, ■, 6
-hexanethiol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, dicyclopentenyloxyethyl acrylate, tribromphenyl acrylate, tribromphenyl methacrylate), 2,2-bis-(4-acryloxyethoxy-) 3,5-dibromphenyl)propane, 2,2-bis-(4-methacryloxyethoxy-
3,5-dibromphenyl)propane, 2,2-bis-
(4-acryloxy-3,5-dibromphenyl)propane, 2,2-bis-(4-methacryloxy-3,5-
dibromphenyl)propane, 2.2-bis-(4-methacryloxyphenyl)propane, 2.2-bis-(4
-acryloxyethoxyphenyl)propane, others.

(2) Acrylic compounds such as triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diethylene glycol bisallyl carbonate, and others.

The above compounds are only examples of those that can be used as the other copolymerizable monomer, and therefore, the present invention is not limited to these.

For example, a urethane monomer having a thiourethane bond or a urethane bond produced by a urethanization reaction between a polyisocyanate compound and a compound having a radically polymerizable unsaturated group having a thiol group or a hydroxyl group in the molecule. For example, urethane acrylate, urethane methacrylate, thiourethane acrylate or thiourethane methacrylate can be used as copolymerizable monomers such as monomer (■), monomer (II) and monomer (I).
When used together with II), the urethane monomer component can provide a copolymer with even better 1i 'J resistance and a high refractive index, and at the same time, can provide excellent durability. preferable.

It is also useful to use not only one type of the above copolymerizable monomers but also two or more types in combination. Furthermore, it is possible to obtain more preferable effects depending on the type and amount of the copolymerizable monomer used.

Polymerization Reaction The polymerization reaction of the monomer mixture to obtain the copolymer according to the present invention can be carried out using a conventional radical polymerization initiator. The polymerization method may be one used in ordinary radical polymerization reactions. However, since the resulting copolymer has a crosslinked structure due to the crosslinkable monomer component, it is virtually impossible to perform a treatment that involves melting or dissolving it.
From this point of view, it is generally preferable to use a cast polymerization method, which allows a copolymer of the desired shape to be directly obtained.

Since the cast polymerization method is a well-known technique, it will not be described in detail, but cast polymerization containers can be plate-shaped, lens-shaped, cylindrical, prismatic,
Conical, spherical, or other molds or molds designed depending on the purpose are used.

The material may be any suitable material such as inorganic glass, plastic, or metal. The polymerization reaction can be carried out by adding a polymerization initiator to the monomer mixture placed in such a container and heating if necessary, but it is also possible to carry out a certain degree of polymerization using a separate container. The polymerization can also be carried out in such a manner that the obtained prepolymer or syrup is put into a polymerization container to complete the polymerization. The monomer mixture and the polymerization initiator may be mixed all at once or in stages.

Another example of a polymerization method that can be used is
This is a method of carrying out polymerization by suspending a mixture of a monomer mixture and a polymerization initiator or a prepolymer in water, that is, suspension polymerization. This suspension polymerization method is suitable for obtaining spherical lenses of various particle sizes.

Suspension polymerization is also a well-known technique.

The mixture subjected to the polymerization reaction may contain antistatic agents, colorants, fillers, etc. depending on the expected use of the resulting copolymer.
It can contain ultraviolet absorbers, heat stabilizers, antioxidants, and other auxiliary materials.

The resulting copolymer is heated to complete any incomplete polymerization or to improve its hardness, or annealed to remove distortions incorporated by cast polymerization. Needless to say, processing can be performed.

Lens The resin material for lenses of the present invention has features in the copolymer that is its material, and the specific method for manufacturing the lens is free. Therefore, lenses may be manufactured directly from the copolymer using a cast polymerization method, or a plate or other shaped material of the copolymer may be manufactured and then cut out. . Of course, surface polishing treatment, antistatic treatment, and other post-treatments can be performed as necessary. Furthermore, in order to increase the surface hardness, it is also possible to form a coating film using an organic or inorganic hard coating agent by a spraying method, a dipping method, or the like. Furthermore, it is also possible to perform additional processing such as reducing the surface gloss reflectance by depositing an inorganic material on the surface and applying multi-coating.

Example 1 Structural formula (I-1) below with n value of 3 and 4
60 parts by weight of a diacrylate compound, 25 parts by weight of diethylene glycol dimethacrylate, and 15 parts by weight of α-methylstyrene, and 0.4 parts by weight of the ultraviolet absorber "Tinuvin 328" (manufactured by Ciba Geigy).
parts by weight and 1 part by weight of lauroyl peroxide as a polymerization initiator were added to obtain a polymerizable composition.

Structural formula (f-1) +1 1 -C)1. CI+, -0-C-C=CH.

This composition was placed in a glass mold, and the polymerization conditions were varied by cast polymerization: 40°C for 1 hour, 50°C for 15 hours, 80°C for 2 hours, 100°C for 2 hours, and 110°C for 1 hour. A lens having a center thickness of 1.3 am, an outer diameter of gcm, and a dioptric power of -2.5 was produced.

The lens made of the obtained copolymer was clear and colorless.

This lens was completely insoluble in acetone, tetrahydrofuran, methanol, etc., had an excellent crosslinking effect, and exhibited sufficient solvent resistance. Further, the refractive index and Atsube number of this lens are as shown below.

Refractive index n Suga-1,547 Atsbe number ν=39 Further, when a falling ball test was performed on 15 of these lenses, the number of broken lenses was O. The falling ball test here is based on the US FDA standard ASTM F-659.
A 16 g steel ball is allowed to fall naturally onto a lens sample from a height of 1.27 m at room temperature, and the impact resistance of the lens sample is evaluated based on the percentage of lens samples that are damaged.

In addition, the obtained copolymer was subjected to an Izot impact test (
J I S K 7110) and Izod [
When the i-impact value was measured, it was as follows.

Izotsu impact value am+= 7.3kg-cm/cI++ (with notch)
As described above, this copolymer has excellent impact resistance and a relatively high refractive index.

Example 2 50 parts by weight of the same diacrylate compound as used in Example 1, 20 parts by weight of triethylene glycol dimethacrylate, 15 parts by weight of α-methylstyrene, 1
．． 15 parts by weight of 3-butylene glycol dimethacrylate, 4 parts by weight of the ultraviolet absorber Tinuvin 328J O, and 1 part by weight of lauroyl peroxide as a polymerization initiator.
parts by weight were added and mixed, and cast polymerization was carried out in a glass mold according to Example 1 except for using this, and a lens with a center thickness of 1.3 m+a, an outer diameter of g cm, and a power of -2.5 was prepared. was created.

Regarding this lens, various physical properties were measured and a falling ball test was conducted in the same manner as in Example 1.

Refractive index n snow = 1.539 Abbe number ν = 41 Number of damaged lens samples: 0 Izod impact value a,, = 7.3 kg-cm/Cm (with notch) As is clear from the above, this lens has excellent durability. It has impact resistance and a relatively high refractive index.

Furthermore, this lens was completely insoluble in acetone, methanol, tetrahydrofuran, etc., and had excellent solvent resistance.

Example 3 20 parts by weight of the same diacrylate compound as used in Example 1, 12 parts by weight of diethylene glycol dimethacrylate, 15 m by weight of α-methylstyrene, and 10 parts by weight of methyl styrene were further added with thiourethane. Three compounds forming methacrylate, cyclic trimer of hexamethylene diisocyanate...28.56 parts by weight 2
-Mercaptoethanol...1.88 parts by weight 2-
Hydroxyethyl methacrylate...12.56 parts by weight were mixed to obtain a monomer mixture.

To this monomer mixture, 0.3 parts by weight of n-butyltin dilaurate was added as a catalyst to promote the urethanization reaction.
The reaction was carried out at .degree. C. for 2 hours to produce thiourethane methacrylate containing a cyclic trimer of hexamethylene diisocyanate=2-mercaptoethanol:2-hydroxyethyl methacrylate in a molar ratio of 2:1:4.

Add 0.4 of the ultraviolet absorber "Tinuvin 328" to this mixture.
1 part by weight of lauroyl peroxide was added as a polymerization initiator, and cast polymerization was carried out in a glass mold according to Example 1, with a center thickness of 1.1 cm,
A lens with an outer diameter of 8 Cffi and a power of -2.5 was produced.

Regarding this lens, various physical properties were measured and a falling ball test was conducted in the same manner as in Example 1.

Refraction: 8n snow = 1.546 Atsbe number C 40 Number of fractured lens samples 20 Izot impact value ak+ = 7.3 kg-cm/cm (with notch) As is clear from the above, this lens has excellent impact resistance. and has a relatively high refractive index.

Furthermore, this lens was completely insoluble in acetone, methanol, tetrahydrofuran, etc., and had excellent solvent resistance.

Example 11 The following structural formula (I-2> with n value of 3 and 4
Dimethacrylate compound 30 consisting of a mixture with
parts by weight, 45 parts by weight of tetraethylene glycol dimethacrylate, and 20 parts by weight of impropenylbenzene.
[and 10 parts by weight of tribromphenyl acrylate, 0.20 parts by weight of the ultraviolet absorber "Biosorb 910J (manufactured by Kyodo Yakuhin Co., Ltd.), and tert as a polymerization initiator.
-Butylperoxy 2-ethylhexanoate (1.0 parts by weight) was added and mixed, and cast polymerization was carried out in a glass mold according to Example 1 except that this was used, and the center thickness was 1.0 parts by weight.
．． A lens with a diameter of 4 mm, an outer diameter of 3 cm, and a power of -3.0 was produced.

Structural Formula (I-2) Regarding this lens, each physical property was measured and a falling ball test was conducted in the same manner as in Example 1.

Refractive index n Snow - 1,550 Atsube number C 37 Number of damaged lens samples 20 Izot impact value akl = 7.3 kg-cm/cI11 (with notch) As is clear from the above, this lens has excellent impact resistance. and has a relatively high refractive index.

Furthermore, this lens was completely insoluble in acetone, methanol, tetrahydrofuran, etc., and had excellent solvent resistance.

Example 5 35 parts by weight of a dimethacrylate compound similar to that used in Example 4, 10 parts by weight of ethylene glycol dimethacrylate ff18'B, 30 parts by weight of α-methylstyrene, and 25 parts by weight of synclopentenyloxyethyl acrylate.
A monomer mixture was obtained by mixing parts by weight.

This mixture is further added with the ultraviolet absorber ``Biosorb 91O''.
tert- as 0.20 parts by weight and a polymerization initiator.
1 part by weight of butyl peroxy 2-ethylhexanoate was added, and cast polymerization was carried out in a glass mold according to Example 1, with a center thickness of 1.4 mm and an outer diameter of 8 ca
, a lens with a power of -2.0 was produced.

Regarding this lens, various physical properties were measured and a falling ball test was conducted in the same manner as in Example 1.

Refractive index n snow = 1.548 Abbe number ν = 43 Number of damaged lens samples: 0 Izod impact value a+, +: 6.3 kg-cm/am (with notch) As is clear from the above, this lens has excellent durability. It has impact resistance and a relatively high refractive index.

Furthermore, this lens was completely insoluble in acetone, methanol, tetrahydrofuran, etc., and had excellent solvent resistance.

Comparative Example 1 Ultraviolet absorber "Tinuvin 328" was added to 70 parts by weight of the same diacrylate compound as used in Example 1, 2.5 parts by weight of diethylene glycol dimethacrylate, and 27.5 parts by weight of α-methylstyrene. 0.4 parts by weight and 1 part by weight of lauroyl peroxide as a polymerization initiator were added and mixed, and cast polymerization was carried out in a glass mold in the same manner as in Example 1, except that this was used, and the center thickness was 1. Lenses with three sizes, an outer diameter of 8 cm, and a dioptric power of -2.5 were produced.

Regarding this lens, various physical properties were measured and a falling ball test was conducted in the same manner as in Example 1.

Refractive index n = 1.562 Abbe number ν = 37 Number of damaged lens samples: 15 Izot impact value ak+: 1.2 kg-cm/cm (with notch) As is clear from the above, the copolymer of Comparative Example 1 , monomer (
Since the amount of II) used was small, the impact resistance was inferior to that of the copolymer of Example 1.

Comparative Example 2 A monomer mixture was obtained by mixing 35 parts by weight of a dimethacrylate compound similar to that used in Example 4, 30 parts by weight of α-methylstyrene, and 35 parts by weight of dicyclopentenyloxyethyl acrylate. Ta.

In addition to this mixture is the ultraviolet absorber "Biosorb 91O".
and 1 part by weight of tert-butyl peroxy 2-ethylhexanoate as a polymerization initiator were added, and cast polymerization was carried out in a glass mold according to Example 1. A lens with a diameter of 1.4IIIll, an outer diameter of 8 cm, and a power of -2.0 was produced.

Regarding this lens, various physical properties were measured and a falling ball test was conducted in the same manner as in Example 1.

Refractive index nτ = 1.547 Abbe number ν = 40 Number of broken lens samples: 15 Izot impact value a, = 0.9 kg-cm/am (with notch) As is clear from the above, the copolymer of Comparative Example 2 , monomer (I
Since I) is not used, compared to the copolymer of Example 5,
Impact resistance was poor.

Procedural amendment (voluntary) February 23, 1999 Director General of the Patent Office Yoshi 1) Moon Takeshi 1, Indication of the case Japanese Patent Application No. 63-42223 2, Name of the invention: Resin material for lenses 3, Person making the amendment Case Relationship with Patent Applicant Address 1-9-11 Nihonbashihoridome-cho, Chuo-ku, Tokyo Name (I10) Kureha Chemical Industry Co., Ltd. 5 Column 6 of the detailed description of the invention in the specification subject to amendment Contents: “Cold dimethacrylate, diethylene glycol di” (2) Page 14, line 4 “(2) Acrylic compounds”
should be corrected to "(2) Allyl compounds."

(3) In the same page, page 18, line 15, "polymerizable composition" is corrected to "monomer mixture."

(4) "Composition" in the first line of page 19 is corrected to "mixture."

(5) The 6th line of page 25 is corrected as follows.

"Dimethacrylate consisting of a mixture of structural formula (I-2) with n of 3 and 4" (6) The 14th line of page 27 is corrected as follows.

"Dimethacrylate consisting of a mixture of those in which n is represented by the above structural formula (I-2) and in which the value of n is 3 and 4" Procedural amendment (spontaneous) May 24, 1999 Written by Yoshi, Commissioner of the Japan Patent Office 1) Tsuyoshi Tono 1, Indication of the case Japanese Patent Application No. 63-42223 2, Name of the invention Resin material for lenses 3, Relationship with the person making the amendment Patent applicant address 1-9 IJi Ruemachi, Chuo-ku, Tokyo Japan Number 11
Title <110) Kureha Chemical Industry Co., Ltd. 5, Detailed explanation of the invention in the specification subject to amendment 6, Contents of amendment

Claims (1)

[Claims] 1) A monomer (I) consisting of a diacrylate compound or dimethacrylate compound represented by the following structural formula (I)
)5 to 80% by weight, a monomer (II) consisting of 5 to 50% by weight of an ethylene glycol dimethacrylate compound represented by the following structural formula (II), and a monomer (III) consisting of an aromatic vinyl compound. 5 to 50% by weight, and the total amount of monomer (I), monomer (II) and monomer (III) is at least 40% by weight. A resin material for lenses with excellent impact resistance and a high refractive index, which is made of a copolymer obtained by Structural formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, n is 1 to 6, and R^1 and R^2 each represent a hydrogen atom or a methyl group.) Structural formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, m is 1 to 8.)