JPH0551419A - High refractive index synthetic resin optical material - Google Patents

Abstract

PURPOSE:The subject material produced by copolymerizing a monomer mixture containing a sulfur-containing diacrylate compound and a comonomer copolymerizable with the compound in a specific ratio, having a specific refractive index and a specified Abbe number, low dispersibility and excellent dyeability. CONSTITUTION:(A) A sulfur-containing diacrylate compound or sulfur-containing dimethacrylate compound of the formula (X is H, methyl; n is 1-3) and (B) a monomer copolymerizable with the component A [e.g. styrene, phenyl (meth) acrylate] are compounded with each other in an A/B weight ratio of (1-8)/1 and subsequently polymerized to obtain the objective material comprising the copolymer having a refractive index of >=1.62 and an abbe number of >=27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin optical material having a high refractive index, and particularly to a high refractive index synthetic resin optical material having a low dispersibility and an excellent dyeing property.

[0002]

2. Description of the Related Art Conventionally, various inorganic glass lenses have been used for optical equipment, but recently, synthetic resin lenses are light in weight, workability, stability, dyeability, mass productivity, and cost. Due to its potential for reduction, it is beginning to be widely used with inorganic glass lenses.

Among various physical properties required for an optical lens, high refractive index, low dispersion and excellent dyeability are extremely important. According to a lens made of an optical material having a high refractive index, for example,
A lens system that occupies an important position in an optical device such as a microscope, a photographic machine, a telescope, or a spectacle lens can be made compact, and it is possible to reduce the weight and suppress aberrations due to a spherical surface or the like. On the other hand, the low dispersion of the optical material is extremely important in that the chromatic aberration of the lens is reduced.

However, even in synthetic resin lens materials,
Like inorganic glass lens materials, high refractive index materials tend to have high dispersion, while low refractive index materials tend to have low dispersion. Further, a synthetic resin lens material having a high refractive index generally has a large proportion of an aromatic group, and therefore has a problem that it does not have good dyeability. For example, the most widely used synthetic resin lens material for spectacles at present is a diethylene glycol bisallyl carbonate resin called "CR-39". Although this resin has a high Abbe number of 60 (that is, a low dispersion), its refractive index (a value at a temperature of 20 ° C., the same applies below) is extremely low at 1.50. Further, polymethylmethacrylate used in some fields as a lens material also has a high Abbe number of 60 but a low refractive index of 1.49.

On the other hand, polystyrene, which is said to have a relatively high refractive index and low dispersion, has a refractive index of 1.59 and an Abbe number of 30.4. Similarly, polycarbonate has a refractive index of 1.59 and an Abbe number. The number is 29.5. However, these synthetic resins are not satisfactory in other physical properties as a lens material. For example, polystyrene has a low surface hardness and lacks solvent resistance and dyeability, and polycarbonate has a low surface hardness and also lacks impact resistance. Furthermore, the refractive index is 1.6
4 polynaphthyl methacrylate and a refractive index of 1.6
Polyvinylnaphthalene of 8 has an Abbe number of 24
And 20, which are considerably low and have no dyeing property, neither of which is a good optical material.

[0006]

As described above, in the conventional art, it has excellent optical characteristics such as high refractive index and low dispersion, good physical characteristics, and excellent dyeability. There is no known synthetic resin optical material. The present invention has been made based on these circumstances, and an object thereof is to have not only excellent optical characteristics such as a high refractive index but also low dispersion, good physical characteristics, and excellent Another object of the present invention is to provide a high refractive index synthetic resin optical material having excellent dyeability.

[0007]

The high refractive index synthetic resin optical material of the present invention comprises a component A comprising a sulfur-containing diacrylate compound or a sulfur-containing dimethacrylate compound represented by the following chemical formula 2, and a copolymerization with the component A. The refractive index is 1.62 or more, which is obtained by polymerizing a monomer mixture containing a component B containing a possible monomer in a weight ratio of the component A to the component B of 1 to 8. In addition, it is characterized by being composed of a copolymer having an Abbe number of 27 or more.

[0008]

[Chemical 2] (In the formula, X represents a hydrogen atom or a methyl group, and n is 1 to
Represents an integer of 3. )

The present invention will be described in detail below. The high refractive index synthetic resin optical material of the present invention is a copolymer obtained from a monomer mixture of an A component made of a specific monomer and a B component made of a monomer copolymerizable with the A component. It consists of The main component of this copolymer is formed by the sulfur-containing diacrylate compound or sulfur-containing dimethacrylate compound of the component A shown in Chemical formula 2 above.
The magnitude of the value of n in the chemical formula 2 is importantly related to the optical material properties of the obtained copolymer. That is, when the value of n is 4 or more, the obtained optical material has excellent dyeability, but the heat resistance tends to decrease. Therefore, depending on the purpose of use of the optical material, the value of n should be 1 to
It can be selected within the range of 3.

Chemical formula 2 relating to the monomer used as the component A
In the above, the substitution positions of the two methylene groups in the aromatic group are not particularly limited, but, for example, a copolymer obtained by a monomer having a substitution position in the para position is a monomer having other substitution positions. The refractive index is slightly higher than that of the copolymer obtained by the body. On the other hand, when the substitution position of the methylene group is in the meta position or the ortho position, the refractive index of the copolymer is slightly lower than that of the substitution position in the para position. Since the compatibility with a certain component B is generally high, it is possible to obtain an optical material having extremely high transparency. Therefore, depending on the intended use of the optical material, a sulfur-containing diacrylate compound or a sulfur-containing dimethacrylate compound at various substitution positions can be used as the A component.

The sulfur-containing diacrylate compound or sulfur-containing dimethacrylate compound represented by Chemical formula 2 is an ester of a dithiol compound represented by Chemical formula 3 below with acrylic acid or methacrylic acid.

[0012]

[Chemical 3] (In the formula, n represents an integer of 1 to 3.)

Specific examples of the dithiol compound represented by Chemical formula 3 include the following. (1) 1,4-bis (2-mercaptoethylenethio) xylylene (2) 1,3-bis (2-mercaptoethylenethio) xylylene (3) 1,4-bis (2-mercaptothioethoxyethylenethio) xylylene (4) 1,3-bis (2-mercaptothioethoxyethylenethio) xylylene (5) 1,2-bis (2-mercaptothioethoxyethylenethio) xylylene (6) 1,4-bis (2-mercaptodithioethoxy) Ethylenethio) xylylene (7) 1,3-bis (2-mercaptodithioethoxyethylenethio) xylylene The structures of the above dithiol compounds are as shown in Chemical Formula 4 below.

[0014]

[Chemical 4]

The ester of the dithiol compound as described above can be obtained by a known method. For example, there are a method of reacting acrylic acid chloride or methacrylic acid chloride with a dithiol compound, a method of esterifying acrylic acid or methacrylic acid with a dithiol compound by an acid catalyst, and the like.

By using the component A composed of the sulfur-containing diacrylate compound or the sulfur-containing dimethacrylate compound as a copolymer component, the optical material of the present invention has a refractive index of 1.62 or more and an Abbe number of It is 27 or more and has excellent dyeability.

However, since the sulfur-containing diacrylate compound or the sulfur-containing dimethacrylate compound as the component A is usually a solid or viscous liquid, only the component A is suitable as a method for producing a synthetic resin lens. It is difficult to apply the polymerization method. Therefore, in the present invention, B composed of a monomer copolymerizable with the A component is used.
The components are used as comonomers.

As the component B in the present invention, when it is mixed with the component A, a liquid monomer mixture having a viscosity and fluidity suitable for the cast polymerization method is formed, and the resulting copolymer is produced. Which has excellent physical properties such as good dyeability, heat resistance and transparency, and in which the specific gravity of the copolymer does not become so large is preferably used. Therefore, the monomer used as the component B in the present invention is preferably a liquid at room temperature.

Specific examples of the monomer as the component B include aromatic vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, divinylbenzene, vinyltoluene, vinylnaphthalene, phenylstyrene and trivinylbenzene. , Phenyl (meth) acrylate,
Benzyl (meth) acrylate, chlorophenyl (meth) acrylate, bromophenyl (meth) acrylate, tribromophenyl (meth) acrylate, (meth) acryloxyethoxybenzene, (meth) acryloxyethoxytribromobenzene, (meth) acryl Roxydiethoxybenzene, (meth) acryloxydiethoxytribromobenzene, 2,2-bis {4- (meth) acryloxyethoxy-3,5-dibromophenyl} propane, 2,2-bis {4- (meth ) (Meth) acrylates having an aromatic group such as acryloxyethoxyphenyl} propane and 2,2-bis {4- (meth) acryloxypolyethoxyphenyl} propane, and other various aliphatic (meth) acrylates Can be mentioned.
However, it is not limited to these.
The monomer constituting the B component does not have to be only one type, and two or more types of monomers can be combined and used as the B component.

The above component A and component B are mixed and the resulting monomer mixture is polymerized to obtain a copolymer. The high refractive index synthetic resin optical material of the present invention is constituted by this copolymer. Here, the ratio of the A component and the B component in the monomer mixture is such that the value of the weight ratio α of the A component (A component / B component) to the B component is 1
The value of α is preferably 1.5 to 5.
The range is If the value of α is less than 1, then A
Since the ratio of the components becomes small, it is possible to obtain a target copolymer having a high refractive index and a low dispersion, specifically, a copolymer having a refractive index of 1.62 or more and an Abbe number of 27 or more. Is difficult. On the other hand, when the value of α exceeds 8, it becomes difficult to obtain a liquid monomer mixture having a viscosity or fluidity suitable for the casting polymerization method, and thus a suitable casting polymerization method is applied. Becomes difficult. Specifically, it is difficult to inject the monomer mixture into the casting polymerization container due to its high viscosity, and it is difficult to remove the trapped air bubbles to obtain a good optical material. I can't. In practice, it is preferable that the monomer mixture of the component A and the component B used in the casting polymerization method has a viscosity at a temperature of 25 ° C. of, for example, 200 centipoise or less, and such a monomer mixture is formed. Therefore, the types and proportions of the A component and the B component are determined so as to be so.

The polymerization reaction of the monomer mixture of the A component and the B component proceeds with a usual radical polymerization initiator. Therefore, the polymerization method and reaction conditions for this polymerization reaction may be the same as in the case of a normal radical polymerization reaction. However, the resulting copolymer is a cross-linked product, and it is virtually impossible to carry out a treatment involving dissolution or melting of the copolymer, so that the desired shape of the optical material can be directly obtained. It is generally preferred to utilize the cast polymerization methods that are employed.

The cast polymerization method is a well-known technique and can be applied to the present invention as it is. As the casting polymerization container, plate-shaped, lens-shaped, cylindrical, prismatic, conical, spherical,
Other molds or molds and other containers designed according to the purpose or use are used. The material can be selected from inorganic glass, plastic, metal, and any other material depending on the purpose. The actual polymerization reaction can be carried out by charging a monomer mixture consisting of the components A and B and the polymerization initiator into a casting polymerization container and heating the mixture, but using another reaction container. Alternatively, the monomer mixture may be reacted to some extent in advance, and the prepolymer or syrup having a high viscosity may be charged into a casting polymerization container to complete the polymerization. The required monomer components and the polymerization initiator may be mixed at once at once, or may be mixed stepwise. The monomer mixture contains an antistatic agent, a colorant, a filler, a UV absorber, a heat stabilizer, an antioxidant, and other auxiliary materials depending on the intended use of the resulting copolymer. be able to.

[0023]

The copolymer according to the optical material of the present invention contains a specific sulfur-containing diacrylate compound or sulfur-containing dimethacrylate compound as its monomer component, and therefore has a high refractive index and low dispersion. That has a refractive index of 1.62 or more and an Abbe number of 27 or more, and that this copolymer has excellent dyeability and can be easily dyed. You can The dyeing method may be carried out by immersing the optical material to be dyed in a solution of a water-soluble dye of various colors or a dispersion of a water-dispersible dye at room temperature or under heating according to a usual method. The degree of color can be changed by adjusting the temperature, concentration and immersion time of the dye solution or dispersion.

The optical material of the present invention is characterized in that the copolymer is composed of the specific monomer components as described above. Therefore, in order to obtain an actual optical material from the copolymer, Can apply the means conventionally used. That is, it is possible to use a means for directly obtaining an optical material having a specific shape by a cast polymerization method, a means for shaving an optical material having a desired shape from a plate or a lump, and the like. This optical material can be further subjected to surface polishing treatment, antistatic treatment, and other post-treatments, if necessary, to obtain an optical material having desired performance. Further, in order to increase the surface hardness of the optical material, it is possible to coat the surface with an appropriate inorganic material or an organic coating agent by dipping or the like.

[0025]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these.

Example 1 80 parts by weight of a sulfur-containing dimethacrylate compound (A-1) represented by the following chemical formula 5 was mixed with 20 parts by weight of divinylbenzene, and tert-butylperoxy as a polymerization initiator was mixed with the mixture. 1.2 parts by weight of neodecanoate was added and mixed well to prepare a monomer mixture. The value of the weight ratio α of the A component to the B component in this monomer mixture was 4, and the viscosity of the monomer mixture at a temperature of 25 ° C. was about 70 centipoise. This monomer mixture was poured into a glass lens mold and heated at 50 ° C. for 10 hours, 60 ° C. for 8 hours, 80 ° C. for 3 hours, and 100 ° C. for 2 hours at different temperatures. The polymerization was completed, which produced a -2.00 diopter colorless transparent lens.

[0027]

[Chemical 5]

This lens had a refractive index of 1.638 and an Abbe number of 33, and had a sufficiently high refractive index and a sufficiently low dispersion. Further, this lens was completely insoluble in acetone and benzene and had a high resistance to organic solvents. Furthermore, the surface hardness of this lens (JIS
According to pencil hardness according to K5400. The same applies below. ) Is 3H, the penetration temperature showing heat resistance (JIS K72
The temperature at which the penetration measured according to 06 is 0.4 mm. The same applies below. ) Was 102 ° C., which were all excellent. From these facts, the copolymer according to this lens has excellent optical characteristics, and also has a sufficiently high degree of polymerization and high mechanical strength and good physical characteristics. It's clear that it's very balanced.

In addition, the dye "Sumikaron Blue E-FB"
When this lens was immersed in a dyeing solution consisting of a 0.15% by weight aqueous solution of "L" (manufactured by Sumitomo Chemical Co., Ltd.) at 90 ° C for 5 minutes, the lens was easily dyed in bright blue.
The total light transmittance (based on JIS K7105) in the visible region of the lens before the dyeing treatment was 91%, but it was 64% after the dyeing treatment. From this, it was confirmed that the lens had excellent dyeability.

Comparative Example 1 Sulfur-containing dimethacrylate compound (A-
The amount of 1) was changed to 45 parts by weight and the amount of divinylbenzene was changed to 55 parts by weight to prepare a monomer mixture. The value of the weight ratio α of the A component to the B component was 0.82, and the viscosity of the monomer mixture at a temperature of 25 ° C. was about 30 centipoise. Then, polymerization was carried out in the same manner as in Example 1 except that this monomer mixture was used to produce a lens. This lens had an Abbe number of 29, but had a low refractive index of 1.614. This is because the proportion of the A component is small.

Comparative Example 2 Sulfur-containing dimethacrylate compound (A-
The amount of 1) was changed to 92 parts by weight and the amount of divinylbenzene was changed to 8 parts by weight to prepare a monomer mixture. Here, the value of the weight ratio α of the A component to the B component is 1
1.5, the viscosity of the monomer mixture at a temperature of 25 ° C. was about 2000 centipoise. Then, polymerization was carried out in the same manner as in Example 1 except that this monomer mixture was used to produce a lens. The obtained lens had bubbles that could not be removed due to the high viscosity of the monomer mixture and could not be put to practical use.

Example 2 A monomer mixture was prepared by mixing 70 parts by weight of a sulfur-containing dimethacrylate compound (A-2) represented by the following chemical formula 6 with 30 parts by weight of divinylbenzene. The value of the weight ratio α of the component A to the component B was 2.3, and the viscosity of the monomer mixture at a temperature of 25 ° C. was about 60 centipoise. Then, polymerization was carried out in the same manner as in Example 1 except that this monomer mixture was used to produce a +2.25 diopter colorless and transparent lens.

[0033]

[Chemical 6]

This lens had a refractive index of 1.642 and an Abbe number of 32.9, and had a sufficiently high refractive index and a sufficiently low dispersion. This lens was insoluble in acetone and benzene, had a surface hardness of 3H and a penetration temperature of 110 ° C. When this lens was subjected to the same dyeing treatment as in Example 1, the total light transmittance, which was 91% before the dyeing treatment, was reduced to 51%. From the above, it was confirmed that this lens has good optical properties, excellent solvent resistance and heat resistance, and excellent dyeability.

Example 3 Sulfur-containing dimethacrylate compound (A-
2) 65 parts by weight, 10 parts by weight of α-methylstyrene,
15 parts by weight of 2,4,6-tribromophenyl methacrylate and 10 parts by weight of chlorostyrene were sufficiently mixed,
A monomer mixture was prepared by dissolving 1.0 part by weight of azobisisobutyronitrile as a polymerization initiator in this. Here, the value of the weight ratio α of the A component to the B component is 1.9,
The viscosity of the monomer mixture at a temperature of 25 ° C. is about 120.
It was a centipoise. Then, polymerization was carried out in the same manner as in Example 1 except that this monomer mixture was used, and -4.50.
Diopter colorless and transparent lenses were produced. This lens has a refractive index of 1.633 and an Abbe number of 32.8,
It had a sufficiently high refractive index and a sufficiently low dispersion. This lens was insoluble in acetone and benzene, had a surface hardness of 2H and a penetration temperature of 105 ° C.
When this lens was subjected to the same dyeing treatment as in Example 1, the total light transmittance, which was 90% before the dyeing treatment, was reduced to 59%. From the above, it was confirmed that this lens has good optical properties, excellent solvent resistance and heat resistance, and excellent dyeability.

Example 4 Sulfur-containing diacrylate compound (A
-3) 70 parts by weight, 5 parts by weight of α-methylstyrene,
10 parts by weight of acryloxyethoxy-2,4,6-tribromobenzene and 15 parts by weight of divinylbenzene were sufficiently mixed, and 1.0 part by weight of lauroyl peroxide as a polymerization initiator was added thereto to prepare a simple mixture. A monomer mixture was prepared. The value of the weight ratio α of the A component to the B component was 2.3, and the viscosity of the monomer mixture at a temperature of 25 ° C. was about 84 centipoise. Then, polymerization was performed in the same manner as in Example 1 except that this monomer mixture was used.
A colorless transparent lens of 4.25 diopters was produced.

[0037]

[Chemical 7]

This lens had a refractive index of 1.640 and an Abbe number of 34.1, and had a sufficiently high refractive index and a sufficiently low dispersion. This lens was insoluble in acetone and benzene, had a surface hardness of 3H and a penetration temperature of 103 ° C. When this lens was subjected to the same dyeing treatment as in Example 1, the total light transmittance, which was 90.5% before the dyeing treatment, was reduced to 43%. From the above, it was confirmed that this lens has good optical properties, excellent solvent resistance and heat resistance, and excellent dyeability.

Example 5 70 parts by weight of the sulfur-containing dimethacrylate compound (A-4) represented by the following chemical formula 8 and 30 parts by weight of divinylbenzene were sufficiently mixed at 60 ° C. to prepare a monomer mixture.
Here, the value of the weight ratio α of the A component to the B component is 2.
3. The viscosity of the monomer mixture at a temperature of 25 ° C is about 1
It was 60 centipoise. When this monomer mixture was left for a while, a white sulfur-containing dimethacrylate compound (A-4) was precipitated. This was dissolved to form a uniform solution state, and polymerization was carried out in the same manner as in Example 1 except that this was used to produce a colorless and transparent lens of -2.25 diopter.

[0040]

[Chemical 8]

This lens had a refractive index of 1.656 and an Abbe number of 33.9, and had a sufficiently high refractive index and a sufficiently low dispersion. This lens was insoluble in acetone and benzene, had a surface hardness of 2H and a penetration temperature of 100 ° C. When this lens was subjected to the same dyeing treatment as in Example 1, the total light transmittance, which was 89% before the dyeing treatment, decreased to 67%. From the above, it was confirmed that this lens has good optical properties, excellent solvent resistance and heat resistance, and excellent dyeability.

[0042]

As described above, the optical material according to the present invention is
The copolymer has a high refractive index of 1.62 or more, an Abbe number of 27 or more, which is sufficiently low dispersion, and has high colorless transparency, and has optical characteristics particularly suitable as a lens. It has excellent physical properties such as solvent resistance, heat resistance, and surface hardness, and has a very good performance balance, and it also has excellent dyeability and can be easily dyed. Is.

Claims (1)

[Claims] 1. An A component composed of a sulfur-containing diacrylate compound or a sulfur-containing dimethacrylate compound represented by the following chemical formula 1 and a B component composed of a monomer copolymerizable with the A component, A copolymer having a refractive index of 1.62 or more and an Abbe number of 27 or more, which is obtained by polymerizing a monomer mixture containing the components in a weight ratio of 1 to 8 High refractive index synthetic resin optical material. [Chemical 1] (In the formula, X represents a hydrogen atom or a methyl group, and n is 1 to
Represents an integer of 3. )