JP2950877B2 - Monomer composition for producing optical resin and optical resin - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical resin having a high refractive index and to a diethylenically unsaturated monomer composition providing the same. More specifically, the present invention relates to an optical resin that is lightweight, has excellent heat resistance, optical uniformity, cast polymerization moldability, etc., and has a high refractive index.

<Prior Art> Techniques relating to resins that provide high refractive index plastic lenses are disclosed. Among them, acrylic polymerizable compounds such as diacrylate or dimethacrylate compounds can be easily radically polymerized, and the polymer is known to give a lens having excellent transparency.

Halogenated aromatic-containing acrylic compounds, such as diallylate or dimethacrylate compounds having a bromine-containing bisphenol skeleton, have been shown to give polymers exhibiting high refractive indices (n _D = 1.60 or more) (Japanese Patent Application Laid-Open No.
59-184210, JP-A-59-193915, etc.). However, many of these compounds are fixed or viscous high-viscosity liquids at room temperature, and thus greatly hinder casting polymerization used in producing lens resins. In addition, since the specific gravity of the obtained resin is large, it is extremely disadvantageous as a lens resin which is required to be reduced in weight. As already known, such a problem is solved by the above-mentioned halogenated aromatic-containing acrylic compound with a radical polymerizable aromatic monomer having a low viscosity and a polymer having a high refractive index, such as styrene. A method has been proposed in which the compound is dissolved to improve casting workability and then radical copolymerization is performed.
Although the refractive index is maintained by this method, copolymerization occurs between compounds having functional groups with different radical polymerizabilities, so that properties such as optical distortion due to partial differences in the degree of polymerization depend on the conditions during casting polymerization. Therefore, in order to obtain a practically usable lens resin, it is necessary to control polymerization conditions at a very high level. Further, the reduction in specific gravity is insufficient.

On the other hand, a sulfur-containing acrylic compound, for example, a sulfur-containing aromatic diacrylate or dimethacrylate compound (Japanese Patent Application Laid-Open No. 62-195357) gives a light-weight cured product having a small specific gravity or a high refractive index (n _D = 1.60). It has been revealed that the compound is a liquid compound having excellent optical properties, such as the above, and an extremely low viscosity. Therefore, the workability at the time of casting polymerization is good, and a high quality lens resin is obtained by easily performing radical polymerization. However, by leaving the obtained lens resin at a high temperature (for example, several hours at 130 ° C. or more), the hue is reduced, that is, yellowing is likely to occur, and an annealing process for removing optical distortion,
Care must be taken when performing operations such as surface coating. It is desired to improve the heat stability of a lens resin obtained from the above-mentioned sulfur-containing acrylic compound.

As described above, plastics that have excellent optical properties such as refractive index, are lightweight, and can withstand various use environments
At present, there are still many problems to be overcome in order to obtain a lens resin, and further improvement in casting workability is desired.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned problems, and has a high refractive index and a light weight, is excellent in optical uniformity and heat resistance, and causes a decrease in hue and optical distortion even at a high temperature. It is an object of the present invention to provide an optical resin having excellent optical characteristics and a monomer composition for providing the same.

[Summary of the Invention]

<Means for Solving the Problems> The monomer composition for producing an optical resin according to the present invention comprises a halogenated aromatic-containing acrylic compound represented by the following formula [I]:
50 to 10% by weight and 50 to 10% by weight of a sulfur-containing acrylic compound represented by the following formula [II] (% by weight is
0% by weight) of a radical polymerizable compound selected from the group consisting of radical polymerizable compounds represented by the following formulas [III] and [IV] with respect to 100 parts by weight of the acrylic compound It is a liquid at room temperature, comprising parts by weight.

(Here, R ¹ and R ² each represent a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and a represents a number of 1 to 10. A plurality of R ¹ , R ² , X And a
May be the same or different).

(However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and R ³ and R ⁴
Represents a hydrocarbon group having 1 to 12 carbon atoms, and p represents 0 or an integer of 1 to 4. A plurality of R ^{1 to} R ⁴ , X and p may be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, q represents 0 or an integer of 1 to 5, and m represents an integer of 1 or 2.) (However, R ¹ represents a hydrogen atom or a methyl group, and m is 1
Or R 2 represents an integer of 2 and R ⁵ represents an m-valent hydrocarbon group having 1 to 12 carbon atoms, or an m-valent hydrocarbon group containing any one of an ether group, a thioether group and an ester group. The optical resin according to the present invention relating to the use of the monomer composition may have a repeating unit of 50 to 90 represented by the following formula [Ia]:
% By weight and a repeating unit represented by the following formula [IIa]: 50 to 10
For 100 parts by weight of a repeating unit consisting of% by weight (the total amount of both is 100% by weight), a group consisting of repeating units represented by the following formulas [IIIa] and [IVa] is used. the repeating unit selected comprising a ratio of 5 to 30 parts by weight, substantially insoluble and infusible, but the refractive index n _D is 1.58 or more.

(Here, R ¹ and R ² each represent a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and a represents a number of 1 to 10. A plurality of R ¹ , R ² , X And a
May be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and R ³ and R ⁴
Represents a hydrocarbon group having 1 to 12 carbon atoms, and p represents 0 or an integer of 1 to 4. A plurality of R ^{1 to} R ⁴ , X and p may be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, q represents 0 or an integer of 1 to 5, and m represents an integer of 1 or 2.) (However, R ¹ represents a hydrogen atom or a methyl group, and m is 1
Or R 2 represents an integer of 2 and R ⁵ represents an m-valent hydrocarbon group having 1 to 12 carbon atoms, or an m-valent hydrocarbon group containing any one of an ether group, a thioether group and an ester group. <Effects of the Invention> The above object is achieved. That is, the optical resin according to the present invention has a high refractive index, that is, has n _D ≧ 1.58, is lightweight, has excellent heat resistance, and has excellent optical uniformity. Absent. The monomer composition that gives it is a liquid having a low viscosity at room temperature, and can be cast-polymerized by itself without using a solvent (for example, styrene), and has excellent casting workability. I have.

[Specific description of the invention]

<Monomer> The optical resin according to the present invention comprises the acrylic compound represented by the formula [I] and the formula [II] and the formula [III]
Or a radical polymerizable compound represented by the formula (IV),
Can be formed by polymerization of a specific monomer composition.

(A) Bis (meth) acrylate (I) The halogenated aromatic-containing acrylic compound represented by the formula [I] contained in the monomer composition is obtained by converting tetrahalobisphenol A to an acrylic acid via an alkylene ether bond. Or it has a methacrylic esterified structure.

Specific examples of the compound of the formula [I] include the following. 2,2, -bis [4- (β-acryloyloxyethoxy) -3,5-dibromophenyl]
Propane, 2,2-bis [4- (β-methacryloyloxyethoxy) -3,5-dibromophenyl] propane, 2,2
-Bis [4- (β-acryloyloxypropoxy)-
3,5-dibromophenyl] propane, 2,2-bis [4-
(Β-methacryloyloxypropoxy) -3,5-dibromophenyl] propane, 2,2-bis [4- (β-acryloyloxyethoxyethoxy) -3,5-dibromophenyl] propane, 2,2-bis [4 -(Β-methacryloyloxyethoxyethoxy) -3,5-dibromophenyl] propane and the like. These can be used in combination of two or more.

The halogenated aromatic-containing acrylic compound is, for example, a corresponding tetrahalogenobisphenol A, that is, 2,2
2-bis [4-hydroxy-3,5-dihalogenophenyl]
It can be produced by esterifying an addition compound of ethylene oxide and / or propylene oxide of propane with acrylic acid or methacrylic acid or a functional derivative thereof.

The functional derivative of acrylic acid or methacrylic acid can be any that can form an ester bond with a hydroxyl group, and specifically includes acid halides (eg, acid chlorides), acid anhydrides (mixed anhydrides). Containing), lower alkyl esters, and others.

(B) Bis (meth) acrylate (II) The sulfur-containing acrylic compound represented by the formula [II] contained in the monomer composition has a structure in which acrylic acid or methacrylic acid is linked by a thioether chain. There is a divalent group of a benzene derivative having a side chain of a hydrocarbon group in the thioether chain. The divalent group of the benzene derivative may have a hydrogen atom substituted by a halogen atom (excluding a fluorine atom). The bonding position of the thioether chain to the divalent group of the benzene derivative is o-, m-
-Or p-, but m- and p are typical.

This sulfur-containing acrylic compound is obtained by esterifying a sulfur-containing polyol represented by the following formula [V] with acrylic acid, methacrylic acid, or a derivative thereof.

(However, the definition of the substituent is the same as that of the formula [II]. A plurality of R ³ , R ⁴ , X and p may be the same or different.) The sulfur-containing polyol shown is
Known reactions, for example, N. Karasch:
Organic Sulfur Compounds (Organic Su
lfur Compounds), Vol. 1, Chapter 11, pages 97 to 111, and U.S. Pat. No. 3,824,293.

That is, specifically, a reaction between a polyhalogen compound represented by the following formula [VI] and a hydroxyl group-containing aliphatic mercaptan compound may be used.

(However, Xa represents a chlorine atom or a bromine atom, and the definitions of the other substituents are the same as in the case of formula [II].) Specific examples of the sulfur-containing acrylic compound represented by formula [II] include For example, the following can be mentioned. p-bis (β-acryloyloxyethylthio) xylylene, p-bis (β-methacryloyloxyethylthio) xylylene, m-bis (β-acryloyloxyethylthio) xylylene, m-bis (β-methacryloyloxyethylthio) Xylylene, α, α'-bis (β
-Acryloyloxyethylthio) -2,3,5,6-tetrachloro-p-xylylene, α, α'-bis (β-methacryloyloxyethylthio) -2,3,5,6-tetrachloro-p-xylylene etc. These can be used alone or in combination of two or more.

(C) Styrene monomer (III) Specific examples of the radical polymerizable compound represented by the formula [III] include the following. Styrene, 2-chlorostyrene, 3, -chlorostyrene, 4-
Chlorostyrene, 2,4-dichlorostyrene, 3,4-dichlorostyrene, 3,5-dichlorostyrene, 2,3,4-trichlorostyrene, 2,3,5-trichlorostyrene, 2,3,6-trichlorostyrene 3,4,5-trichlorostyrene, 2-bromostyrene, 3-bromostyrene, 4-bromostyrene, 2,4-dibromostyrene, 3,4-dibromostyrene,
3,5-dibromostyrene, 2,3,4-tribromostyrene,
2,3,5-tribromostyrene, 2,3,6-tribromostyrene, 3,4,5-tribromostyrene, divinylbenzene,
m-diisopropenylbenzene, and the like. These can be used in combination of two or more. Preferred is styrene, 4
-Chlorostyrene, dibromostyrene (including each isomer), and divinylbenzene.

(D) (meth) acrylate (IV) Specific examples of the radical polymerizable monomer represented by the formula [IV] include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate,
Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl acrylate, benzyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Examples include diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, neobentyl glycol diacrylate, and neoventil glycol dimethacrylate. These are 2
More than one species can be used in combination. Specific examples preferably used include methyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate.

<Monomer Composition for Producing Optical Resin> The monomer composition for producing an optical resin according to the present invention is a halogenated aromatic-containing acrylic compound represented by the formula [I].
50-90% by weight, preferably 60-80% by weight, and the formula [I
100 to 100 parts by weight of an acrylic compound composed of 50 to 10% by weight, preferably 40 to 20% by weight (weight% is based on the total amount of the acrylic compounds of the formulas [I] and [II]) For formulas (III) and (I
V], containing 5 to 30 parts by weight, preferably 10 to 20 parts by weight, of a radically polymerizable compound selected from the group consisting of radically polymerizable compounds represented by the formula (V), and being liquid at ordinary temperature.

In this monomer composition, when the amount of the acrylic compound of the formula [I] is less than 50% by weight of the total amount of the acrylic compounds of the formulas [I] and [II], the acrylic compound is obtained by polymerization of the monomer composition. The heat resistance of the optical resin is poor. If the content exceeds 90% by weight, the viscosity of the monomer composition itself becomes too high, and the casting operation into the casting becomes extremely difficult during the casting polymerization. Further, even if such a monomer composition is polymerized, the specific gravity of the obtained optical resin becomes large, and the lens cannot be reduced in weight.

When the radical polymerizable compound (compound of the formula [III] or the formula [IV]) is less than 5 parts by weight based on 100 parts by weight of the acrylic compound (the total amount of the compounds of the formulas [I] and [II]),
The viscosity of the monomer composition becomes high, and the casting operation becomes extremely difficult. Exceeds 30 parts by weight, lowering and occurrence of optical distortion of the refractive index n _D of the optical resin obtained by polymerization becomes remarkable.

<Polymer> The optical resin according to the present invention can be formed by polymerization of the monomer composition.

That is, by polymerizing a specific monomer composition, the repeating unit represented by the formula [Ia] is 50 to 90% by weight, preferably 60 to 80% by weight, and the repeating unit represented by the formula [IIa]. 50 to 10% by weight, preferably 40 to 20% by weight (% by weight is based on the total amount of the repeating units of the formulas [Ia] and [IIa]) with respect to 100 parts by weight of the repeating unit [III]
a) and 5 to 30 parts by weight of a repeating unit selected from the group consisting of repeating units represented by the formula (IVa), preferably 10 to
20 parts by weight, is substantially insoluble and infusible, has a refractive index n _D of 1.58 or more, and has excellent optical characteristics such as high light transmittance and no optical distortion, and excellent heat resistance. Optical resin can be formed.

The polymerization is performed by a radical polymerization method using a general radical polymerization initiator, and can be performed by a known technique such as a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method.

Moreover, it can also be performed by a photopolymerization method using a general photopolymerization initiator.

For example, for a lens resin, a mixture of a monomer composition and a peroxide (radical polymerization initiator) and / or a photopolymerization initiator is injected into a casting mold, and heated and / or heated. It is formed by radical polymerization by irradiation with ultraviolet rays.

The radical polymerization initiator used in the polymerization is not particularly limited, and a general initiator can be used. For example,
(A) Use peroxides such as benzoyl peroxide, diisopropyl peroxycarbonate, lauroyl peroxide, tertiary butyl peroxypivalate, dicumyl peroxide, and azo compounds such as (b) azobisisobutyronitrile. be able to.

The photopolymerization initiator used in the polymerization is not particularly limited, and a general polymerization initiator can be used, but the following compounds are preferable.

For example, benzophenone, benzoin ethyl ether,
Benzyl, acetophenone, anthraquinone, diphenyl sulfite, thiocarbamate and the like.

The radical polymerization initiator and the photopolymerization initiator are used in an amount of 0.01 to 20 parts by weight, preferably 100 parts by weight, based on the total amount of the acrylic compounds represented by the formulas (I) and (II) in the monomer composition. It is appropriate to use 0.05 to 10 parts by weight.

Note that the optical resin according to the present invention can be directly formed into a final optical product, but a material may be made from the optical resin and then processed into the final optical product.

For example, a lens material having a shape other than the shape of the lens is made of an optical resin, processed, and formed into a lens-shaped resin of a final product.

<Experimental Examples> Experimental examples will be shown below to specifically explain the present invention. Parts and% in the experimental examples indicate parts by weight and% by weight, respectively.

In the experimental examples, the obtained physical properties were measured by the following test methods.

(1) Light transmittance: A light transmittance of 500 nm is shown using a test piece having a thickness of 3 mm.

(2) Optical strain: Measured with a Toshiba strain measuring machine (manufactured by Toshiba Glass Co., Ltd.). ：: no optical distortion, x: optical distortion.

(3) Refractive index and Abbe number: Measured at 25 ° C. using an Abbe refractometer (manufactured by Atago).

(4) Heat resistance: Measured with a DMA tester (manufactured by DuPont),
Shows the tan δ peak temperature.

(5) Heat stability: The test piece was placed in an air oven at 130
After standing at 5 ° C. for 5 hours, the change in hue was visually determined. ；: No change, x: yellowing.

Example 1 60 parts of 2,2-bis [4- (β-methacryloyloxyethoxy) -3,5-dibromophenyl] propane, p-bis (β-methacryloyloxyethylthio) xylylene
To a mixture obtained by blending 20 parts of triethylene glycol dimethacrylate with an acrylic compound consisting of 40 parts, 0.2 part of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy) and 0.2 part of benzoyl peroxide are added. After uniformly stirring and mixing, the system was evacuated and degassed, and the pressure was returned to normal pressure with nitrogen. After repeating this deaeration operation three times, the mixture was passed through a 0.3 μm filter to sufficiently remove bubbles. This liquid was poured into a mold having a diameter of 5 cm and a thickness of 5 mm composed of a glass plate and silicone rubber.

Next, using a high-pressure mercury lamp with an output of 80 w / cm, a height of 40 cm
UV light was applied through the surface of the glass plate for 10 minutes (5 minutes on each side of the glass plate) from the distance shown in FIG. The obtained polymer was demolded, and the temperature was gradually raised from 100 to 130 ° C. for 2 hours in an air oven, and post-cured. Various physical properties of the obtained lens resin were measured.

Examples 2 and 3 A lens resin was obtained in the same manner as in Example 1 except that the proportions of the acrylic compound and the radically polymerizable compound were variously changed. Various physical properties were measured.

Examples 4 and 5 A lens resin was obtained in the same manner as in Example 1 except that styrene was used instead of triethylene glycol dimethacrylate in Example 1 and the proportions of the acrylic compound and the radically polymerizable compound were variously changed. Various physical properties were measured.

Comparative Example 1 A lens resin was obtained in the same manner as in Example 1, except that triethylene glycol dimethacrylate was not used. Various physical properties were measured. Since a low-viscosity radical polymerizable compound was not contained, the injection operation was very difficult due to high viscosity. The specific gravity of the cured product also showed a large value.

Comparative Example 2 A lens resin was obtained in the same manner as in Example 1, except that triethylene glycol dimethacrylate in Example 1 was replaced with styrene, and the ratios of the acrylic compound and the radically polymerizable compound were variously changed. Various physical properties were measured. It turned yellow in the heat stability test.

Comparative Examples 3 and 4 A lens resin was obtained in the same manner as in Example 1 except that p-bis (β-methacryloyloxyethylthio) xylylene was not used and the ratios of the acrylic compound and the radically polymerizable compound were variously changed. Was. Various physical properties were measured. In the case of Comparative Example 3, the refractive index was significantly reduced, and in the case of Comparative Example 4, the specific gravity of the cured product was large, and optical distortion occurred.

Continuation of the front page (56) References JP-A-3-217407 (JP, A) JP-A-62-195357 (JP, A) JP-A-64-26613 (JP, A) JP-A-60-2610 (JP, A) JP-A-1-254655 (JP, A) JP-A-3-217411 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 290/06 C08F 220 / 38,220 / 20 C08F 20 / 38,20 / 20 G02B 1/04

Claims (2)

(57) [Claims] 1. A halogenated aromatic-containing acrylic compound represented by the following formula [I]: 50 to 90% by weight and a sulfur-containing acrylic compound represented by the following formula [II]: 50 to 10% by weight (% by weight is the total of both). 100 parts by weight of an acrylic compound comprising the following formulas [III] and [IV]
A monomer composition for producing an optical resin at room temperature, which is a liquid at room temperature, comprising a radical polymerizable compound selected from the group consisting of the radical polymerizable compounds represented by formula (1) in a ratio of 5 to 30 parts by weight. (Here, R ¹ and R ² each represent a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and a represents a number of 1 to 10. A plurality of R ¹ , R ² , X And a
May be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and R ³ and R ⁴
Represents a hydrocarbon group having 1 to 12 carbon atoms, and p represents 0 or an integer of 1 to 4. A plurality of R ^{1 to} R ⁴ , X and p may be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, q represents 0 or an integer of 1 to 5, and m represents an integer of 1 or 2.) (However, R ¹ represents a hydrogen atom or a methyl group, and m is 1
Or R 2 represents an integer of 2 and R ⁵ represents an m-valent hydrocarbon group having 1 to 12 carbon atoms, or an m-valent hydrocarbon group containing any one of an ether group, a thioether group and an ester group. (However, in the above formulas [I] to [IV], the symbols are independently defined between the formulas.) 2. A repeating unit represented by the following formula [Ia]: 50 to 90.
% By weight and a repeating unit represented by the following formula [IIa]: 50 to 10
For 100 parts by weight of a repeating unit consisting of% by weight (weight% is 100% of the total amount of both), selected from the group consisting of repeating units represented by the following formulas [IIIa] and [IVa] comprising the repeating units in a proportion of 5 to 30 parts by weight, substantially insoluble and infusible, refractive index n _D is the optical resin is 1.58 or more. (Here, R ¹ and R ² each represent a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and a represents a number of 1 to 10. A plurality of R ¹ , R ² , X And a
May be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and R ³ and R ⁴
Represents a hydrocarbon group having 1 to 12 carbon atoms, and p represents 0 or an integer of 1 to 4. A plurality of R ^{1 to} R ⁴ , X and p may be the same or different. ) (However, R ¹ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, q represents 0 or an integer of 1 to 5, and m represents an integer of 1 or 2.) (However, R ¹ represents a hydrogen atom or a methyl group, and m is 1
Or R 2 represents an integer of 2 and R ⁵ represents an m-valent hydrocarbon group having 1 to 12 carbon atoms, or an m-valent hydrocarbon group containing any one of an ether group, a thioether group and an ester group. (However, in the above formulas [Ia] to [IVa], the symbols are independently defined between the formulas.)