JPH10130361A - Optical material made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical material made of an synthetic resin having a high thermal stability and excellent in transparency, solvent resistance and mechanical characteristics. SOLUTION: This optical material made of an synthetic resin comprises an acrylic cross-linked polymer obtained by performing urethanization of (A) a component of a (meth)acrylic acid ester-based monomer having secondary hydroxide group, (B) a component of at least one kind of diisocyanate compound selected from dicyclohexylmethane-4,4'-diisocyanate and isophoronediisocyanate and (C) a component of a monomer radically copolymerizable with the component A, and further performing radical polymerization of the product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical material made of synthetic resin. More specifically, the present invention relates to a synthetic resin optical material having excellent transparency, heat resistance, and solvent resistance.

[0002]

2. Description of the Related Art Conventionally, glass materials have been used as optical materials such as lenses and prisms. Recently, however, optical materials made of synthetic resins have been used for their light weight, workability, dyeability and cost. Due to their potential for reduction, they have begun to be widely used with glass optical materials.

[0003] As synthetic resin optical materials, those made of a thermoplastic resin and those made of a thermosetting resin are known. However, since the thermoplastic resin has low heat resistance and low solvent resistance, for example, in the case of forming an eyeglass lens using a thermoplastic resin, in a post-process such as formation of a hard coat layer, it is contacted with a heat history or an organic solvent. By doing so, the spectacle lens may be deformed. Further, the thermoplastic resin has a drawback that optical anisotropy such as birefringence easily occurs. On the other hand, thermosetting resins having a crosslinked structure have higher heat resistance and solvent resistance than thermoplastic resins, and have the potential as a substitute for glass optical materials. Optical materials made of resin have been proposed. For example, JP-A-63-2001
JP, JP-A 1-163702, JP-A 1-2
No. 42612 and JP-A-2-58511 disclose:
An optical material made of a synthetic resin comprising a crosslinked copolymer having a urethane bond is described.

However, these synthetic resin optical materials are mainly used for spectacle lenses, do not have high heat resistance, and are not sufficient as substitutes for glass optical materials. Therefore, development of a synthetic resin optical material having excellent transparency, solvent resistance, and mechanical properties, and having high heat resistance is strongly desired.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object of the present invention is to provide a synthetic resin optical material having high heat resistance, and excellent in transparency, solvent resistance, and mechanical properties.

[0006]

The synthetic resin optical material of the present invention is obtained by subjecting the following component (A), the following component (B), and the following component (C) to a urethanization reaction and a radical polymerization reaction. It is characterized by comprising the obtained acrylic cross-linked copolymer. Further, the synthetic resin optical material of the present invention comprises a (meth) acrylate compound having a urethane bond obtained by a urethanization reaction of the following component (A) and the following component (B): From an acrylic cross-linked copolymer obtained by subjecting the compound to a radical polymerization reaction.

Component (A): (meth) having a secondary hydroxyl group
Acrylic ester monomers. Component (B): at least one diisocyanate compound selected from dicyclohexylmethane-4,4'-diisocyanate and isophorone diisocyanate. Component (C): a monomer capable of being radically copolymerized with component (A).

In the synthetic resin optical material of the present invention,
It is preferable to use a (meth) acrylate compound having a glycidyl group as a part or all of the component (C).

In the synthetic resin optical material of the present invention, it is preferable to use dicyclohexylmethane-4,4'-diisocyanate as a part or all of the component (B). Furthermore, it has a secondary hydroxyl group (meth)
A represents the number of moles of hydroxyl groups derived from the acrylate monomer, b represents the number of moles of isocyanate groups derived from dicyclohexylmethane-4,4'-diisocyanate, and c represents the number of moles of isocyanate groups derived from isophorone diisocyanate. In this case, it is preferable that the following conditions (1) and (2) are satisfied. Condition (1) 0.8 <(b + c) / a <1.2. Condition (2) 0 ≦ c / (b + c) <0.85.

In the present specification, “primary hydroxyl group” means
A hydroxyl group attached to a primary carbon atom. here,
"Primary carbon atom" refers to a carbon atom that is bonded to only one other carbon atom. In addition, “secondary hydroxyl group”
A hydroxyl group attached to a secondary carbon atom. here,
"Secondary carbon atom" refers to a carbon atom that is bonded to two other carbon atoms. Further, “tertiary hydroxyl group” refers to a hydroxyl group bonded to a tertiary carbon atom. Here, the “tertiary carbon atom” refers to a carbon atom bonded to three other carbon atoms.

In this specification, “(meth) acrylic acid” means “acrylic acid” or “methacrylic acid”, and “(meth) acrylate” means “acrylate” or “methacrylate”. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the synthetic resin optical material of the present invention will be described in detail. The synthetic resin optical material of the present invention comprises a component (A) composed of a specific (meth) acrylate monomer, a component (B) composed of a specific diisocyanate compound, and a radical copolymer of the component (A). It comprises an acrylic cross-linked copolymer obtained by subjecting component (C) composed of a polymerizable monomer to a urethanization reaction and a radical polymerization reaction.

<Component (A)> The specific (meth) acrylate monomer used as the component (A) has a secondary hydroxyl group. Such specific (meta)
By using an acrylate monomer, a crosslinked copolymer having high heat resistance and high transparency can be obtained. Specific examples of the (meth) acrylate monomer having a secondary hydroxyl group include 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2-hydroxy-1,3-di (meth) acrylate. ) Acryloxypropane, 2-methacryloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-acryloxypropyl methacrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3
-Phenoxypropyl (meth) acrylate and the like. These compounds can be used alone or in combination of two or more.

When a (meth) acrylate monomer having a primary hydroxyl group such as 2-hydroxyethyl methacrylate is used as a (meth) acrylate monomer for obtaining a crosslinked copolymer, the crosslinked copolymer having high heat resistance is used. No coalescence is obtained, and depending on the type of the component (B) or the component (C) described later, the urethanization reaction or the radical polymerization reaction becomes cloudy, so that a transparent crosslinked copolymer cannot be obtained. . On the other hand, when a monomer having a tertiary hydroxyl group is used as the (meth) acrylic ester monomer, the urethanization reaction between the tertiary hydroxyl group and the isocyanate group of the diisocyanate compound described below is sufficiently performed due to steric hindrance. , The isocyanate group remains in a high proportion in the obtained crosslinked copolymer. As a result, there arises a problem that the weather resistance and storage stability of the obtained cross-linked copolymer are reduced, and that the releasability is remarkably reduced by reacting with the glass constituting the mold in the casting polymerization.

<Component (B)> The specific diisocyanate compound used as the component (B) is at least one diisocyanate compound selected from dicyclohexylmethane-4,4′-diisocyanate and isophorone diisocyanate. By using such a specific diisocyanate compound, a crosslinked copolymer having high heat resistance, excellent weather resistance, and high mechanical strength (flexural modulus) can be obtained. When a compound other than the above specific diisocyanate compound, for example, 1,6-hexane diisocyanate, is used as the diisocyanate compound, a crosslinked copolymer having high heat resistance and high mechanical strength cannot be obtained.

Dicyclohexylmethane-4,4'-diisocyanate and isophorone diisocyanate can be used alone or in combination of both as component (B). When isophorone diisocyanate is used alone, the resulting cross-linked copolymer is used. Since the coalescence tends to be brittle, dicyclohexylmethane-4,4'- is used as part or all of the component (B).
It is preferred to use diisocyanates.

In the present invention, the molar number of the hydroxyl group derived from the (meth) acrylic ester monomer having a secondary hydroxyl group used as the component (A) is a, and the dicyclohexylmethane used as the component (B) is When the number of moles of isocyanate groups derived from 4,4′-diisocyanate is b and the number of moles of isocyanate groups derived from isophorone diisocyanate as component (B) is c, the following conditions (1) and (2) are satisfied. It is preferable to satisfy. Condition (1) 0.8 <(b + c) / a <1.2. Condition (2): 0 ≦ c / (b + c) <0.85.

When the value of (b + c) / a is 0.8 or less, a high ratio of isocyanate groups remains in the obtained crosslinked copolymer. In the mold polymerization, it may react with the glass constituting the mold to remarkably reduce the releasability, or may deteriorate the weather resistance and the stability over time. On the other hand, when the value of (b + c) / a is 1.2 or more, a high ratio of hydroxyl groups remains in the obtained cross-linked copolymer, so that the cross-linked copolymer has hydrophilicity and water absorption. It tends to be expensive. When the value of c / (b + c) is 0.85 or more, the obtained crosslinked copolymer tends to be brittle.

<Component (C)> The component (C) is a monomer (hereinafter referred to as “radical”) that can be radically copolymerized with the (meth) acrylic ester monomer having a secondary hydroxyl group as the component (A). Also referred to as "copolymerizable monomer"). As such a radical copolymerizable monomer, a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having two or more radical polymerizable double bonds can be used.

Specific examples of the monofunctional radical copolymerizable monomer include methyl (meth) acrylate and ethyl (meth) acrylate.
Acrylate, n-butyl (meth) acrylate, te
Alkyl groups such as rt-butyl (meth) acrylate and cyclohexyl (meth) acrylate have 1 to 8 carbon atoms.
(Meth) acrylates such as lower alkyl (meth) acrylates, benzyl (meth) acrylate, and phenoxy (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, and diethylene glycol mono (meth). A) a (meth) acrylate having a lower alkyl group via an ethylene oxide such as an acrylate, a (meth) acrylate having an alkyl group substituted with an isobornyl group such as isobornyl (meth) acrylate, styrene, α-methylstyrene, divinylbenzene, p- Examples include aromatic vinyl compounds such as tert-butylstyrene, and (meth) acrylates having a glycidyl group such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate.

Specific examples of the polyfunctional radical copolymerizable monomer include ethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, 1,
4-butanediol di (meth) acrylate, 1,9-
Nonanediol di (meth) acrylate, 2,2-bis {4-methacryloxyethoxyphenyl} propane,
Examples include polyfunctional (meth) acrylates such as 2,2-bis {3,5-dipromo-4-methacryloxyethoxyphenyl} propane and pentaerythritol tetra (meth) acrylate.

These compounds reduce the viscosity of the solution upon radical polymerization described below, increase the heat resistance of the crosslinked copolymer, lower the water absorption of the crosslinked copolymer, , For the purpose of imparting properties such as hydrophobicity and hydrophilicity of the surface, special reactivity,
It can be appropriately selected and used.

In the synthetic resin optical material of the present invention, the adhesiveness with an adhesive such as an optical adhesive, a vapor-deposited coating layer such as a non-reflective coating layer, a hard coat layer for improving surface hardness, etc. is improved. In view of this, it is preferable to use a (meth) acrylate having a glycidyl group as a part or the whole of the component (C), and the use ratio thereof is determined by the total amount of the component (A), the component (B), and the component (C). Is preferably 1 to 30% by mass.

<Acrylic Cross-Linked Copolymer> The acrylic cross-linked copolymer constituting the resinous optical material of the present invention comprises the above components (A), (B) and (C): It is obtained by a urethanization reaction and a radical polymerization reaction.

In the present invention, a urethanation reaction catalyst and a radical polymerization initiator are added to a monomer mixture consisting of the three components (A), (B) and (C), and under appropriate conditions. It is also possible to produce an acrylic cross-linked copolymer by simultaneously proceeding the urethanization reaction and the radical polymerization reaction. However, at the time of casting polymerization described below, components (A) and (B) are used from the viewpoints of low elution of the sealing material, low polymerization shrinkage, and good release properties from the glass mold. Is reacted in the presence of a urethanization reaction catalyst to produce a (meth) acrylate compound having a urethane bond (hereinafter, also referred to as a “urethane bond-containing prepolymer”), and thereafter, the urethane A solution containing a bond-containing prepolymer, the component (C), and a radical polymerization initiator (hereinafter, referred to as a “radical polymerizable solution”) is prepared, and the radical polymerizable solution is subjected to polymerization treatment. It is preferable to produce an acrylic crosslinked copolymer.

The urethane-bond-containing prepolymer comprises (A)
It can also be produced by adding a urethanization reaction catalyst to a mixture comprising the components and the component (B) and subjecting the components (A) and (B) to a urethanization reaction under appropriate conditions. However, since the obtained urethane bond-containing prepolymer is a considerably viscous liquid or solid, in preparing a radical polymerizable solution, the urethane bond-containing prepolymer is used as a radical copolymerizable monomer as the component (C). It may be difficult to sufficiently dissolve the monomer.
Therefore, when producing the urethane bond-containing prepolymer, it is preferable that the component (A) and the component (B) are subjected to urethanization reaction in the presence of the component (C). In particular,
A urethanization reaction catalyst is added to a mixture of the components (A), (B) and (C), and the components (A) and (B) in the mixture are urethanized. As a result, a solution in which the urethane bond-containing prepolymer as a reaction product is dissolved in the component (C) (hereinafter, referred to as a “reaction product solution”) is obtained. In the above,
When performing the urethanization reaction between the component (A) and the component (B), it is not necessary to use all of the component (C), and the urethanization reaction is performed using a part of the component (C). Component (C) may be added to the reaction product solution.

As the urethanization reaction catalyst, generally used amine catalysts, metal salt catalysts, organometallic catalysts and the like can be used, but specific (meth) acrylate ester catalysts constituting the component (A) can be used. The secondary hydroxyl group of the monomer is
Since the reactivity with the isocyanate group of the specific diisocyanate compound constituting the component (B) is not so high, it is preferable to use a highly active organotin catalyst such as tin octylate, dibutyltin diacetate, and dibutyltin dilaurate. Further, the urethanization reaction between the component (A) and the component (B) can be carried out at the same reaction temperature and reaction time as in a normal urethanization reaction.

By adding a radical polymerization initiator to the reaction product solution thus obtained, a radical polymerizable solution can be prepared. As the radical polymerization initiator, an ordinary organic peroxide-based polymerization initiator can be used. However, tert-butyl peroxy neodecanoate, tert-butyl peroxy neodecanoate, -Butyl peroxypivalate, t
non-aromatic peroxyesters such as tert-butylperoxy-2-ethylhexanoate, tert-butylperoxylaurate, lauroyl peroxide;
It is preferable to use a diacyl peroxide such as 3,5,5-trimethylhexanoyl peroxide. Also, 2,2′-azobis (isobutyronitrile),
2′-azobis (2,4-dimethylvaleronitrile),
An azo radical polymerization initiator such as 1,1'-azobis (cyclohexane-2-carbonitrile) can also be suitably used. Further, an antioxidant, an ultraviolet absorber, a light stabilizer, and other additives can be added to the radical polymerizable solution as needed.

The ratio of the urethane bond-containing prepolymer to the component (C) in the radical polymerizable solution is such that the urethane bond-containing prepolymer: the component (C) is in a weight ratio of 80:20.
２０20: 80 is preferred. If the proportion of the urethane bond-containing prepolymer is too small, the sealing material may be dissolved during casting polymerization described below. On the other hand, if the proportion of the urethane bond-containing prepolymer is too large, the viscosity of the radically polymerizable solution may be too high, making it difficult to obtain an acrylic cross-linked copolymer by cast polymerization.

By subjecting such a radical polymerizable solution to a polymerization treatment, an acrylic cross-linked copolymer constituting the synthetic resin optical material of the present invention is produced. The specific polymerization treatment method is not particularly limited, and a method using a usual polymerization initiator can be adopted.However, since the obtained cross-linked copolymer is difficult to melt-mold,
It is preferable to use a casting polymerization method in which a shape as a target optical material is directly obtained.

When an acrylic crosslinked copolymer is obtained by the cast polymerization method, for example, a pair of glass mold plates and a sealing material such as a gasket or an adhesive tape are used. More specifically, a pair of mold plates,
A cavity is formed by arranging them at regular intervals so as to face each other, and forming a cavity by enclosing the side surfaces of these mold plates with a sealing material. By copolymerizing the urethane bond-containing prepolymer in the radical polymerizable solution with the component (C), a sheet-like, plate-like or other shape resinous optical material made of an acrylic cross-linked copolymer can be obtained. .

In the above, when a component acting as an organic solvent such as styrene is used as the component (C), a sealing material made of a material having solvent resistance, for example, a gasket made of a fluorine-based rubber is used. However, since the urethane bond-containing prepolymer is dissolved in the component (C), the component (C)
Since the erosion properties of the components are reduced, it is not always necessary to use a material made of a material having high solvent resistance as the sealing material. For example, a material made of silicone rubber can be used. Further, the radical polymerization reaction between the urethane bond-containing prepolymer and the component (C) can be carried out at the same reaction temperature and reaction time as those of a usual radical polymerization reaction.

[0033]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these. In the following examples and comparative examples, “parts” means “parts by mass”. “A” is the number of moles derived from a (meth) acrylate monomer having a secondary hydroxyl group, and “b” is the number of moles of isocyanate groups derived from dicyclohexylmethane-4,4′-diisocyanate. ,
"C" represents the number of moles of isocyanate groups derived from isophorone diisocyanate.

Example 1 [Production of urethane bond-containing prepolymer] 14.64 parts of 2-hydroxybutyl methacrylate (component (A))
21.21.11 parts of 2-hydroxy-1,3-dimethacryloxypropane [component (A)] and dicyclohexylmethane-4,4'-diisocyanate [component (B)]
25 parts, 20 parts of styrene [(C) component], 10 parts of α-methylstyrene [(C) component], and 10 parts of glycidyl methacrylate [(C) component] were mixed. In the above, the value of (b + c) / a is 1.0, and c / (b +
The value of c) is 0. The resulting mixture was mixed with di-n-butyltin dilaurate 0.05% as a urethanization reaction catalyst.
And the mixture is subjected to a urethanization reaction between the component (A) and the component (B) in the mixture at 60 ° C. for 4 hours to contain a urethane bond-containing prepolymer as a reaction product. A reaction product solution was obtained.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, tert-butyl peroxy-2 was added to the reaction product solution as a polymerization initiator.
A radical polymerizable solution was prepared by adding 1.0 part of -ethylhexanoate.

[Casting polymerization] Each dimension is 100 mm ×
A pair of glass mold plates of 100 mm × 5 mm,
A mold for casting polymerization was constituted by a sealing material formed of a gasket made of a fluorine-based rubber (Viton rubber) having a thickness of 1 mm and a width of 5 mm. The prepared radical polymerization solution is injected into the cavity of the casting polymerization mold,
8 hours at 0 ° C, 3 hours at 65 ° C, 1 hour at 80 ° C, 10 hours
By heating at 0 ° C. and sequentially at different temperatures for 1 hour,
The radical polymerizable solution was polymerized to obtain a colorless and transparent plate-like optical material having a thickness of 0.9 mm and made of an acrylic cross-linked copolymer.

The specific gravity, refractive index (n _D ) and flexural modulus at 23 ° C. of the obtained optical material were measured, and the following items were evaluated. [Heat resistance] The Vicat softening point temperature was measured according to JIS K7206 B method. In addition, when the Vicat softening point temperature exceeded 150 ° C., the amount of displacement at 150 ° C. was measured. [Solvent resistance] The optical material was immersed in ethyl alcohol, acetone, and toluene at 23 ° C. for 24 hours.Then, the optical material was observed. The case where cracks occurred was evaluated as x. The results are shown in Table 1.

Example 2 [Production of urethane bond-containing prepolymer] 2-hydroxybutyl methacrylate [component (A)] 21.87 parts,
18.13 parts of dicyclohexylmethane-4,4'-diisocyanate [component (B)], 12 parts of isobornyl methacrylate [component (C)], 30 parts of α-methylstyrene [(C) component], 1 part 15 parts of 1,3-butylene glycol dimethacrylate [component (C)] and 3 parts of glycidyl methacrylate [component (C)] were mixed. In the above, the value of (b + c) / a is 1.0, and c /
The value of (b + c) is 0. To the obtained mixture, 0.03 parts of di-n-butyltin dilaurate as a urethanation reaction catalyst was added, and the components (A) and (B) in the mixture were mixed at 60 ° C. for 4 hours. By performing the urethanization reaction of Example 1, a reaction product solution containing a urethane bond-containing prepolymer as a reaction product was obtained.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, 0.8 parts of tert-butyl peroxypivalate is added to the reaction product solution as a polymerization initiator. Thus, a radical polymerizable solution was prepared.

[Polymerization Polymerization] The prepared radically polymerizable solution was poured into the cavity of the casting polymerization mold constructed in the same manner as in Example 1, and was heated at 40 ° C for 10 hours at 65 ° C.
For 4 hours, 1 hour at 80 ° C., and 1 hour at 100 ° C. to perform a polymerization treatment of the radical polymerizable solution, and the thickness of the acrylic cross-linked copolymer is 0.9 mm. A colorless and transparent plate-like optical material was obtained.
The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

<Example 3> [Production of prepolymer containing urethane bond] 2-hydroxy-1,3-dimethacryloxypropane [component (A)]
19.32 parts and dicyclohexylmethane-4,4'-
21.86 parts of diisocyanate [(B) component], 20 parts of styrene [(C) component], and 10 parts of α-methylstyrene [(C) component] were mixed. To the obtained mixture, 0.1 part of di-n-butyltin dilaurate as a urethanization reaction catalyst was added, and the components (A) and (B) in the mixture were mixed at 60 ° C. for 2 hours. 17. a urethanization reaction of 2-hydroxy-3-phenoxypropyl methacrylate [component (A)];
82 parts were added, and the urethane reaction was further performed at 60 ° C. for 2 hours to obtain a reaction product solution containing a urethane bond-containing prepolymer as a reaction product. In the above, the value of (b + c) / a is 1.0, and the value of c / (b + c) is 0.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, 10 parts of glycidyl methacrylate (component (C)) and tert- Butyl peroxy-2
-Radical polymerizable solution was prepared by adding 0.8 parts of ethylhexanoate.

[Polymerization] A pair of circular glass mold plates each having a thickness of 5 mm and a diameter of 120 mm were prepared by:
A glass mold was formed by arranging the mold plates so as to face each other at an interval of 11 mm and surrounding the side surfaces of these mold plates with a sealing material made of an adhesive tape having a silicone-based adhesive layer. The prepared radically polymerizable solution is injected into the cavity of the casting polymerization mold,
10 hours at 0 ° C, 5 hours at 65 ° C, 2 hours at 80 ° C, 1
By heating at 00 ° C. and sequentially at different temperatures for 1 hour, the radical polymerizable solution was polymerized to obtain a colorless and transparent plate-like optical material having a thickness of 10 mm and made of an acrylic cross-linked copolymer. The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 4 [Production of urethane bond-containing prepolymer] 2-hydroxy-1,3-dimethacryloxypropane [component (A)]
22.54 parts, 2-hydroxypropyl methacrylate (component (A)) 14.24 parts, dicyclohexylmethane-4,4'-diisocyanate (component (B)) 8.27
Part and isophorone diisocyanate [component (B)] 1
4.95 parts, 15 parts of styrene [(C) component], and 20 parts of methyl methacrylate [(C) component] were mixed.
In the above, the value of (b + c) / a is 1.0, and c
The value of / (b + c) is 0.68. To the obtained mixture, 0.05 parts of di-n-butyltin dilaurate as a urethanization reaction catalyst was added, and the components (A) and (B) in the mixture were mixed at 50 ° C. for 6 hours. By performing the urethanization reaction of Example 1, a reaction product solution containing a urethane bond-containing prepolymer as a reaction product was obtained.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, 5 parts of glycidyl methacrylate [(C) component] was added to the reaction product solution.
0.2 parts of ethyl-2-cyano-3,3-diphenylacrylate as an ultraviolet absorber and 2,2 as a weight initiator
A radical polymerizable solution was prepared by adding 1.0 part of 2'-azobis (isobutyronitrile).

[Polymerization] A pair of mold plates is 3.3 m long.
A casting polymerization mold was constructed in the same manner as in Example 3 except that the molds were arranged so as to face each other at m intervals. The prepared radically polymerizable solution is poured into the cavity of the casting polymerization mold, and heated at different temperatures sequentially at 40 ° C. for 10 hours, 65 ° C. for 5 hours, 80 ° C. for 2 hours, and 100 ° C. for 1 hour. Thus, the radical polymerizable solution was subjected to a polymerization treatment to obtain a colorless and transparent plate-like optical material having a thickness of 3 mm and made of an acrylic cross-linked copolymer. The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

<Example 5> [Production of prepolymer containing urethane bond] 14.64 parts of 2-hydroxybutyl methacrylate (component (A))
21.21.11 parts of 2-hydroxy-1,3-dimethacryloxypropane [component (A)] and dicyclohexylmethane-4,4'-diisocyanate [component (B)]
25 parts, 10 parts of styrene [(C) component], 10 parts of α-methylstyrene [(C) component], and 20 parts of methyl glycidyl methacrylate [(C) component] were mixed. In the above, the value of (b + c) / a is 1.0, and c /
The value of (b + c) is 0. The resulting mixture was mixed with di-n-butyltin dilaurate as a urethanation reaction catalyst.
By adding 0.05 part and conducting a urethanization reaction between the component (A) and the component (B) in the mixture at 60 ° C. for 4 hours, a urethane bond-containing pre-polymer as a reaction product is obtained. A reaction product solution containing the polymer was obtained.

[Preparation of radical polymerizable solution] After cooling the obtained reaction product solution to room temperature, tert-butyl peroxy-2 was added to the reaction product solution as a polymerization initiator.
A radical polymerizable solution was prepared by adding 1.0 part of -ethylhexanoate.

[Polymerization polymerization] The prepared radically polymerizable solution was poured into the cavity of the casting polymerization mold constructed in the same manner as in Example 1, and was heated at 50 ° C for 10 hours at 65 ° C.
For 4 hours, 1 hour at 90 ° C., and 1 hour at 120 ° C. to carry out polymerization treatment of the radically polymerizable solution, and the thickness of the acrylic cross-linked copolymer is 0.9 mm. A colorless and transparent plate-like optical material was obtained.
The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 6 [Production of urethane bond-containing prepolymer] 39.89 parts of 2-hydroxypropyl methacrylate [component (A)] and dicyclohexylmethane-4,4'-diisocyanate [component (B)] 28 .58 parts, 6.53 parts of isophorone diisocyanate [component (B)], 10 parts of α-methylstyrene [component (C)], and 5 parts of glycidyl methacrylate [component (C)]. In the above,
The value of (b + c) / a is 1.0, and the value of c / (b + c) is 0.21. The resulting mixture was mixed with di-n-butyltin dilaurate 0.05% as a urethanization reaction catalyst.
The mixture is subjected to a urethanization reaction between the component (A) and the component (B) in the mixture under the conditions of 50 ° C. for 4 hours, thereby containing a urethane bond-containing prepolymer as a reaction product. A reaction product solution was obtained.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, tert-butyl peroxy-2 was added to the reaction product solution as a polymerization initiator.
A radical polymerizable solution was prepared by adding 1.0 part of -ethylhexanoate.

[Polymerization Polymerization] The prepared radically polymerizable solution was poured into the cavity of the mold for the polymerization for casting polymerization constructed in the same manner as in Example 1, and was then heated at 65 ° C for 10 hours at 50 ° C.
For 4 hours, 1 hour at 90 ° C., and 1 hour at 120 ° C. to carry out polymerization treatment of the radically polymerizable solution, and the thickness of the acrylic cross-linked copolymer is 0.9 mm. A colorless and transparent plate-like optical material was obtained.
The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 7 Production of urethane bond-containing prepolymer 2-hydroxy-1,3-dimethacryloxypropane [component (A)]
28.76 parts and dicyclohexylmethane-4,4'-
14.60 parts of diisocyanate [component (B)] and 1.64 parts of isophorone diisocyanate [component (B)]
30 parts of styrene [(C) component], 10 parts of 1,3-butylene glycol dimethacrylate [(C) component], and 15 parts of glycidyl methacrylate [(C) component] were mixed. 0.15 parts of di-n-butyltin dilaurate was added as a urethanization reaction catalyst to the resulting mixture,
By performing a urethanization reaction between the component (A) and the component (B) in the mixture at 0 ° C. for 5 hours,
A reaction product solution containing a urethane bond-containing prepolymer as a reaction product was obtained. In the above, (b + c)
The value of / a is 1.0 and the value of c / (b + c) is 0.1
2.

[Preparation of Radical Polymerizable Solution] After the obtained reaction product solution was cooled to room temperature,
A radical polymerizable solution was prepared by adding 1.0 part of tert-butyl peroxy-2-ethylhexanoate as a polymerization initiator.

[Polymerization Polymerization] The prepared radically polymerizable solution was poured into the cavity of the mold for the polymerization for casting polymerization constructed in the same manner as in Example 1, and was heated at 50 ° C for 10 hours at 65 ° C.
For 4 hours, 1 hour at 90 ° C., and 1 hour at 120 ° C. to carry out polymerization treatment of the radically polymerizable solution, and the thickness of the acrylic cross-linked copolymer is 0.9 mm. A colorless and transparent plate-like optical material was obtained.
The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

<Example 8> [Production of prepolymer containing urethane bond] 2-hydroxy-1,3-dimethacryloxypropane [component (A)]
13.95 parts, 11.97 parts of 2-hydroxypropyl methacrylate [component (A)], and dicyclohexylmethane-4,4'-diisocyanate [component (B)]
95 parts and isophorone diisocyanate [(B) component]
4.13 parts, styrene [(C) component] 15 parts, α-
10 parts of methylstyrene [(C) component] and 20 parts of isobornyl methacrylate [(C) component] were mixed. In the above, the value of (b + c) / a is 1.0, and c /
The value of (b + c) is 0.81. In the resulting mixture,
0.1 part of di-n-butyltin dilaurate is added as a urethanization reaction catalyst, and the urethanization reaction between the component (A) and the component (B) in the mixture is performed at 50 ° C. for 5 hours. Thereby, a reaction product solution containing a urethane bond-containing prepolymer as a reaction product was obtained.

[Preparation of Radical Polymerizable Solution] After cooling the obtained reaction product solution to room temperature, 5 parts of glycidyl methacrylate [(C) component] was added to the reaction product solution.
0.2 parts of ethyl-2-cyano-3,3-diphenylacrylate as an ultraviolet absorber and 2,2 as a polymerization initiator
A radical polymerizable solution was prepared by adding 1.0 part of 2'-azobis (isobutyronitrile).

[Polymerization Polymerization] The prepared radically polymerizable solution was poured into the cavity of the casting polymerization mold constructed in the same manner as in Example 4, and heated under the same conditions as in Example 4. The radical polymerizable solution is subjected to a polymerization treatment, and the thickness of the acrylic cross-linked copolymer is 3 mm.
A colorless and transparent plate-like optical material was obtained. The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 9 [Production of a urethane bond-containing prepolymer] 39.89 parts of 2-hydroxypropyl methacrylate [component (A)] and dicyclohexylmethane-4,4'-diisocyanate [component (B)] 28 .58 parts, 6.53 parts of isophorone diisocyanate [component (B)], and 20 parts of methyl methacrylate [component (C)] were mixed. In the above, the value of (b + c) / a is 1.0, and c / (b +
The value of c) is 0.21. To the obtained mixture, 0.05 parts of di-n-butyltin dilaurate as a urethanization reaction catalyst was added, and the mixture was heated at 50 ° C. for 3 hours under the conditions of the component (A) and the component (B). By performing the urethanization reaction of Example 1, a reaction product solution containing a urethane bond-containing prepolymer as a reaction product was obtained.
After cooling the obtained reaction product solution to room temperature, 5 parts of glycidyl methacrylate [component (C)] and 2,2′-azobis (isobutyronitrile) 1 as a polymerization initiator were added to the reaction product solution. A radical polymerizable solution was prepared by adding 0.0 parts.

[Polymerization Polymerization] The prepared radically polymerizable solution is poured into the cavity of a glass mold for casting polymerization constructed in the same manner as in Example 4, and heated under the same conditions as in Example 4. The radical polymerizable solution was subjected to a polymerization treatment to obtain a colorless and transparent plate-like optical material having a thickness of 3 mm and made of an acrylic cross-linked copolymer. The obtained optical material was evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 29.88 parts of 2-hydroxyethyl methacrylate and dicyclohexylmethane-
30.12 parts of 4,4′-diisocyanate, 20 parts of α-methylstyrene and 20 parts of styrene were mixed. To the obtained mixture, 0.03 part of di-n-butyltin dilaurate as a urethanization reaction catalyst was added, and at 40 ° C, 2-hydroxyethyl methacrylate and dicyclohexylmethane-4,4 ′ in the mixture were added. When the urethanization reaction with diisocyanate was performed, the mixture became cloudy when one hour had elapsed after the start of the reaction. After cooling the obtained reaction product solution to room temperature, 5 parts of glycidyl methacrylate and 1.0 part of 2,2′-azobis (isobutyronitrile) as a weight initiator were added to the reaction product solution. Then, cast polymerization was carried out in the same manner as in Example 4, but the obtained copolymer was cloudy. In Comparative Example 1, a methacrylic acid ester monomer having a primary hydroxyl group was used instead of the (meth) acrylic acid ester monomer having a secondary hydroxyl group as the component (A).

Comparative Example 2 25.26 parts of 2-hydroxybutyl methacrylate, 14.74 parts of 1,6-hexane diisocyanate, and isobornyl methacrylate 12
Were mixed with 30 parts of α-methylstyrene, 15 parts of 1,3-butylene glycol dimethacrylate, and 3 parts of glycidyl methacrylate. To the obtained mixture, 0.03 part of di-n-butyltin dilaurate as a urethanation reaction catalyst was added, and at 60 ° C for 4 hours, 2-hydroxybutyl methacrylate and 1,6- A urethanation reaction with hexane diisocyanate was performed. After the obtained reaction product solution was cooled to room temperature, tert.
A radical polymerizable solution was prepared by adding 0.8 parts of -butyl peroxypivalate. The prepared radical polymerizable solution was poured into the cavity of the casting polymerization mold constructed in the same manner as in Example 1,
4 hours at 65 ° C, 1 hour at 80 ° C, 1 hour at 100 ° C
The radical polymerizable solution was polymerized by heating at a temperature sequentially different from the time to obtain a colorless and transparent plate-shaped synthetic resin optical material having a thickness of 0.9 mm. The obtained optical material was evaluated in the same manner as in Example 1.
Table 2 shows the results. In Comparative Example 2, a component other than the specific diisocyanate compound as the component (B) was used as the diisocyanate compound without using the component (B).

Comparative Example 3 20 parts of methyl methacrylate, 30 parts of ethylene glycol dimethacrylate, 20 parts of dimethylol tricyclodecane diacrylate,
10 parts of glycidyl methacrylate and 20 parts of isobornyl methacrylate were mixed. In the resulting mixture,
1.0 part of 2,2′-azobis (isobutyronitrile) was added, and the mixture was poured into the cavity of a casting polymerization mold constructed in the same manner as in Example 4, and was added at 40 ° C. for 10 hours. By heating at 65 ° C. for 5 hours, 80 ° C. for 2 hours, and 100 ° C. for 1 hour at different temperatures, the polymerization treatment was performed. The copolymer could not be obtained. In addition,
Comparative Example 3 is an example in which the component (A) and the component (B) are not used.

<Comparative Example 4> A glass optical material having a thickness of 1 mm was manufactured, and items other than heat resistance and bending strength were evaluated in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 5 An optical material made of a polycarbonate resin having a thickness of 1 mm was manufactured, and items other than heat resistance were evaluated in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 6 An optical material made of a polymethyl methacrylate resin having a thickness of 1 mm was manufactured.
The evaluation was performed in the same manner as described above. Table 2 shows the results.

[0067]

[Table 1]

[0068]

[Table 2]

As is clear from Tables 1 and 2, the optical materials according to Examples 1 to 9 have a refractive index equal to or higher than that of glass optical materials and are excellent in transparency. It was confirmed that. In addition, compared to the optical material made of polycarbonate or optical material made of polymethyl methacrylate, specific gravity is small, mechanical strength is high, especially heat resistance,
It was confirmed that the composition was very excellent in solvent resistance.
On the other hand, the optical material according to Comparative Example 2 has low specific gravity, high refractive index, and excellent transparency, but has low heat resistance because it does not use the specific diisocyanate as the component (B). Met.

[0070]

The synthetic resin optical material of the present invention has a small specific gravity, is excellent in transparency and mechanical properties, and has heat resistance,
Because it is very excellent in solvent resistance, it is useful as a substitute for glass optical materials that have been used conventionally,
For example, it can be suitably used as an optical material such as a lens, a prism, a filter substrate, a mirror substrate, and various window materials.

Claims (5)

[Claims] 1. The following component (A) and the following component (B):
An optical material made of a synthetic resin, comprising an acrylic cross-linked copolymer obtained by subjecting the following component (C) to a urethanization reaction and a radical polymerization reaction. (A) Component: (meth) acrylate monomer having a secondary hydroxyl group (B) Component: At least one diisocyanate compound selected from dicyclohexylmethane-4,4′-diisocyanate and isophorone diisocyanate (C) component: (A) a monomer capable of being radically copolymerized with the component 2. A radical polymerization reaction of a (meth) acrylate compound having a urethane bond obtained by a urethanization reaction of the following component (A) and the following component (B) with the following component (C): An optical material made of a synthetic resin, comprising the obtained acrylic cross-linked copolymer. (A) Component: (meth) acrylate monomer having a secondary hydroxyl group (B) Component: At least one diisocyanate compound selected from dicyclohexylmethane-4,4′-diisocyanate and isophorone diisocyanate (C) component: Monomer capable of radical copolymerization with component A 3. The synthetic resin optical material according to claim 1, wherein a (meth) acrylate compound having a glycidyl group is used as a part or all of the component (C). 4. The synthetic resin optical material according to claim 1, wherein dicyclohexylmethane-4,4′-diisocyanate is used as part or all of the component (B). material. 5. The number of moles of hydroxyl groups derived from the (meth) acrylate monomer having a secondary hydroxyl group is a, the number of moles of isocyanate groups derived from dicyclohexylmethane-4,4′-diisocyanate is b, The number of moles of isocyanate groups derived from isophorone diisocyanate is represented by c
The synthetic resin optical material according to claim 4, wherein the following conditions (1) and (2) are satisfied. Condition (1) 0.8 <(b + c) / a <1.2 Condition (2) 0 ≦ c / (b + c) <0.85