JP3121913B2 - High refractive index optical material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Background of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin for a plastic lens, and particularly to a resin for a lens having a high refractive index and excellent surface accuracy of a cured product.

[0002]

2. Description of the Related Art Diethylene glycol bisaryl carbonate resins have been widely used as resins for plastic lenses. This resin has advantages such as excellent impact resistance, transparency, and good light dispersion characteristics, but has a low refractive index of 1.50, and requires a lens to obtain refraction equivalent to glass. However, there was a disadvantage that the thickness became thick.

On the other hand, it is known that various diacrylates or dimethacrylates easily undergo radical polymerization to give a lens having excellent transparency. For example, di (meth) acrylates having a bromine-containing bisphenol A skeleton (JP-A-59-184210, JP-A-59-19)
3915) and di (meth) acrylates having a sulfur-containing aromatic skeleton (JP-A-60-26010 and JP-A-62-195357) have a high refractive index. In addition, it is known to exhibit excellent optical characteristics with a high balance of a high Abebe number.

In general, a cured resin comprising a highly crosslinked structure obtained by polymerization of such various di (meth) acrylate compounds is excellent in heat resistance, abrasiveness, transparency, etc., but on the other hand, There was a disadvantage that the cured resin tended to be brittle. As a means for remedying this drawback, use of a bromine-containing bisphenol A derivative which has been converted to urethane (meth) acrylate has been proposed (JP-A-60-5).
No. 1706). However, although this resin has provided a certain improvement, there are problems such as an increase in specific gravity due to containing a bromine atom and deterioration of weather resistance.

In Japanese Patent Application Laid-Open No. 2-141702, bis- (meth) acryloxymethyltricyclodecane is replaced with pentaerythritol tetrakis (β-
There has been proposed a resin having improved impact properties, which is obtained by adding a polyfunctional thiol such as thiopropionate) and polymerizing. Although this resin has a high Abbe number, it seems to have a problem that the refractive index is relatively low at 1.55 or less. JP-A-63-309509 proposes to use a polymerizable monomer obtained by reacting thiol with divinylbenzene. In this case, it is necessary to treat the radical end with pyrogallol. There seems to be a problem to be overcome.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lightweight, high-refractive-index lens resin which is improved in various disadvantages of the conventional lens resin, and which is excellent in transparency and impact resistance. It is assumed that.

[0007]

[Means for Solving the Problems]

[Summary of the Invention] <Summary> A high refractive index optical material according to the present invention comprises a composition containing the following compounds A and B (however, the total of both is 100 parts by weight), and the heat and / or activity is calculated. It is made of a resin which is polymerized and cured by applying a radical generator to energy rays and / or ethylenically unsaturated bonds.

A: 70 to 99 parts by weight of a sulfur-containing (meth) acrylate represented by the following general formula [I] (Wherein, R ¹ represents a hydrogen atom or a methyl group. R ²
Represents an alkylene group having 1 to 6 carbon atoms. Ar represents an arylene group having 6 to 30 carbon atoms, an aralkylene group, or a group substituted with a halogen atom other than fluorine. X represents -O- or -S-. Y
May, when X is -O- -S- or -SO ₂ - and, X
There is the case of _{-S- -S -, - SO 2 -} , also either shows a -CO-, or alkylene group having a carbon number of 1 to 12 both, aralkylene group, alkylene ether group, aralkylene ether group, It represents a group selected from an alkylenethioether group and an aralkylenethioether group.
m and n each represent an integer of 1 to 5. p is 0
The numbers from 10 to 10 are shown. A plurality of groups may be the same or different. B) 1 to 30 parts by weight of a divalent thiol compound represented by the following general formula [II]

[0009] (In the formula, Ph represents a phenylene group which may be substituted with up to two halogen atoms other than fluorine, and m and n each represent an integer of 1 to 3. A plurality of groups may be the same or different. (In the formula, R ³ represents a hydrogen atom or a methyl group. Each of R ⁴ has 1 to 1 carbon atoms.)
2 represents a group selected from an alkylene group, an aralkylene group, an alkylene ether group, an aralkylene ether group, an alkylene thioether group and an aralkylene thioether group. R ⁵ is a hydrogen atom or a group having 1 to 12 carbon atoms.
Represents an alkyl group or an aralkyl group. q is 1-3
Indicates an integer. A plurality of groups may be the same or different. C) Compounds of at least one compound selected from styrene-based unsaturated monomers and mercapto compounds, which can be copolymerized with the compounds represented by the general formulas [I] and / or [II]. Parts by weight <Effect> The resin for a high refractive index lens according to the present invention not only has a high refractive index, but also has a high Abbe number, and also has high transparency and impact resistance, so that the above-mentioned problems of the prior art are solved. ing. In addition, since the content of a halogen atom is not essential, the cured polymer has a low specific gravity, and the composition before curing can be subjected to thermal polymerization and ultraviolet polymerization, so that the curing time can be shortened. (Specific description of the invention) (Chemical entity of the polymerized cured product) The optical material according to the present invention,
It is obtained by polymerizing and curing a composition comprising compounds A and B by subjecting the composition to heat and / or an active energy ray and / or an excitation action comprising a radical generator action on an ethylenically unsaturated bond. .

Since compound A has an ethylenically unsaturated bond, it is considered that the compound is polymerized by polyaddition of the ethylenically unsaturated bond by the above-mentioned excitation. It is not clear how the non-ethylenically unsaturated compound, mercapto compound B, coexisting in such a polymerization field behaves, but the thiol group of compound B is more reactive than the ethylenically unsaturated compound of compound A. It is conceivable that the so-called Michael-type addition may bind to the compound A under the polymerization conditions.

The sulfur-containing aromatic (meth) acrylate represented by the above general formula [I] can be polymerized by itself, but the cured resin obtained has a drawback of poor impact resistance. However, according to the present invention, a sulfur-containing aromatic (meth) acrylate [I] and a divalent thiol [II]
By copolymerizing the above, the obtained cured resin can be prevented from being colored, and not only can the surface accuracy of the cured product be improved, but also the impact resistance can be significantly improved. [Monomer Component] The resin for an optical material according to the present invention is obtained by polymerizing and curing a composition containing two specific components.

Here, "comprising" a specific two-component means that a monomer copolymerizable with the specific two-component is specifically defined as, for example, this monomer unless the purpose of the present invention is impaired. It means that up to about 10 parts by weight per 100 parts by weight of the specific two components may be used together. Also,
Each of the components may be used in combination between and / or within the components. <Bis (meth) acrylate: Compound A> The monomer forming the basis of the lens resin according to the present invention is a sulfur-containing (meth) acrylate represented by the following formula [I]. In this specification, "(meth) acrylate" is a general term for acrylate and methacrylate.

[0013] The symbols in the formula have the following meanings.

R ¹ : a hydrogen atom or a methyl group.

R ² : C 1-6, preferably 2-4,
Alkylene group.

Ar: an arylene group or an aralkylene group having 6 to 30 carbon atoms, preferably 6 to 15 carbon atoms, or a halogen-substituted product thereof (but halogen is not fluorine). _{Preferably, -Ph '-, - CH 2} -Ph'-CH 2 -, - Ph'
(P) -S-Ph '( p) -, - Ph' (p) -SO 2
-Ph '(p) -, - Ph' (p) -C (CH 3) 2 -
Ph '(p)-, -Ph' (p) -CO-Ph (p)
_{-, - CH 2 -Ph "(} Cl) 4 -CH 2 - (-Ph '-: o-, m- or p- phenylene, -P
h '(p) -: _{phenylene, -Ph "(Cl) 4 -} : o
-, M- or p-tetrachlorophenylene) X: -O
-Or -S-.

[0017] Y: when X is -O- is -S- or _-SO 2 -, when X is -S- is -S -, - SO ₂
-Or -CO-, or both are 1 to 12
A group selected from the group consisting of an alkylene group, an aralkylene group, an alkyl ether group, an aralkylene ether group, an alkylene thioether group and an aralkylene thioether group.

M and n: integers of 1 to 5, preferably 1 to 3, respectively.

P: a number from 0 to 10, preferably 0 to 5.

A plurality of groups, for example, R ¹ in the same molecule may be the same or different.

As is clear from the above formula, the sulfur-containing (meth) acrylate represented by the general formula [I] used in the present invention has a structure in which acrylic acid or methacrylic acid is continuous with a chain containing sulfur and an aromatic ring. It has.

Specific examples of the (meth) acrylate [I] represented by the formula [I] include, for example, (a) p-bis (β-acryloyloxyethylthio) xylylene,
-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, 4,4′-bis (β-acryloyloxyethoxy) diphenyl sulfide, 4,4′-bis (β- (Methacryloyloxyethoxy) diphenyl sulfide, 4,4'-bis (β-acryloyloxyethoxyethoxy) diphenyl sulfone, 4,4'-bis (β-methacryloyloxyethoxyethoxy) diphenyl sulfone, 4,4'-bis (β- Acryloyloxyethylthio) diphenyl sulfide, 4,4'-bis (β-methacryloyloxy) Ethylthio) diphenyl sulfide, 4,4'-bis (beta-acryloyloxy ethyl) diphenylsulfone, 4,4'-bis (beta-
(Methacryloyloxydiethylthio) diphenylsulfone, 4,4'-bis (β-methacryloyloxyethylthio) diphenylketone, and (II) a compound of the formula [I] wherein X is -S-, -Ar-(-Y _{-ar-) p} - is the general formula ^{_{-CH 2 -Ph'-CH 2 - (}} - S-R 3 -S-CH 2 -Ph '-CH 2 -) a - ( wherein, Ph' is o- A, m- or p-phenylene group,
R ³ represents an alkylene group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, which may have an ether bond in a chain;
a is a number from 1 to 5 representing the average degree of oligomerization. )
In oligomer represented or the formula _{-CH 2 -Ph'-CH 2, -} (- S-CH 2 -Ph'-CH 2 -S-CH 2 Ph'-CH 2 -) a - ( wherein, Ph ' Is an o-, m- or p-phenylene group,
a is a number from 1 to 5 representing the average degree of oligomerization. )
And oligomers represented by

Among the monomers represented by the above general formula [I], particularly preferable monomers are those in view of optical properties such as refractive index of the polymer and handling properties such as monomer viscosity. ,
It is a bis (meth) acrylate represented by the general formula [I '].

[0024] (Wherein, Ph _o may be substituted by a halogen atom other than fluorine up to four, o-, shows the m- or p- phenylene, R ¹ represents a hydrogen atom or a methyl group, R ⁴
And R ⁵ each represent a divalent hydrocarbon residue having 1 to 4 carbon atoms. Specific examples of the monomer represented by the general formula [I '] include, for example, p-bis [β- (meth) acryloyloxyethylthio] xylylene, m-bis [β- (meth) acryloyloxyethyl Thio] xylylene, p-bis [β- (meth) acryloyloxyisopropylthio] xylylene, m-bis [β- (meth) acryloyloxyethylthio] ethylphenylene, p-
Bis [β- (meth) acryloyloxybutylthio] tetrachloroxylylene and the like, and more preferred monomers are p-bis [β- (meth) acryloyloxyethylthio] xylylene and m-bis [β- ( (Meth) acryloyloxyethylthio] xylylene. <Divalent thiol compound: Compound B> The compound represented by the general formula [II] used in the present invention is a compound having a structure corresponding to bis ω-mercaptocarboxylate of an ethylene oxide adduct of bisphenol A, It is a divalent thiol compound having a mercapto group.

Compounds wherein m and n are each 1 or 2 are preferred.

Specific examples of the divalent thiol [II] include, for example, 2,2-bis [4- (β-hydroxyethoxy) phenyl] propane = di-β-thiopropionate (m: 1, n : 2), 2,2-bis [4- (β-hydroxyethoxy) phenyl] propane = di-β-thioglycolate (m: 1, n: 1), 2,2-bis [4-
(Β-hydroxyethoxyethoxy) phenyl] propane = di-β-thiopropionate (m: 2, n: 2),
2,2-bis [4- (β-hydroxyethoxyethoxy) phenyl] propane = di-β-thioglycolate (m: 2, n: 1), 2,2-bis [3,5-dibromo-4- (Β-hydroxyethoxy) phenyl] propane = di-β-thiopropionate (Ph: 3,5-dibromophenyl, m: 1, n: 2), 2,2-bis [3,5
-Dibromo-4- (β-hydroxyethoxy) phenyl] propane = di-β-thioglycolate (Ph: 3
5-dibromophenyl, m: 1, n: 1), and the like. <Monomer composition> The composition to be "polymerized and cured" according to the present invention comprises Compounds A and B in the following ratio.

[0027] If the proportion of the compound B, that is, the divalent thiol compound, is too small, the effect of improving the impact resistance of the resulting cured resin will not be obtained, and if it is too large, the heat resistance of the produced cured resin will be low.

This monomer composition comprises compounds A and B. Here, "comprising" means an ethylenically unsaturated monomer copolymerizable with compound A unless the resulting polymer cured product excessively impairs the characteristics of the optical material of the present invention such as high refractive index and high impact resistance. This means that the monomer may contain a small amount, for example, up to about 10 parts by weight based on 100 parts by weight of the total of compounds A + B, and may contain appropriate auxiliary materials. Such monomers include, for example, nucleus and / or side chain substituted such as styrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, divinylbenzene, α-methylstyrene, and unsubstituted styrene, phenyl ( (Meth) acrylate, phenoxyethyl (meth) acrylate, and their halogen-substituted compounds other than fluorine, trimethylolpropane tri (meth) acrylate, 2,2-bis [4 (β-methacryloyloxyethoxy) phenyl] propane , 2,2-bis [4 (β-acroyloxyethoxy) phenyl] propane, triethylene glycol di (meth) acrylate and the like. Of these other monomers, styrene, chlorostyrene, dibromostyrene, divinylbenzene, 4,4'-bis (methacryloyloxyethoxy) diphenylpropane, and mixtures thereof are particularly preferred. Such auxiliary materials include antioxidants, ultraviolet absorbers, dyes and pigments, and the like. <Polymerization Curing> A composition which may contain a mercapto compound which is not an ethylenically unsaturated compound is subjected to heat treatment and / or active energy rays and / or a radical treatment for ethylenically unsaturated bond in one step or in multiple steps. And polymerized and cured to produce the optical material according to the invention.

Here, the “heat” of the excitatory action on the polymerization and curing of the compounds A and B means not only the application of heat but also
The term "active energy ray" includes the combined use of a photopolymerization initiator (described in detail below) in addition to the simple application of ultraviolet rays, ionizing radiation and other energy rays. Also, the term "radical generator" can overlap with the above-mentioned thermal polymerization initiator, and in addition to the mere use of the agent, for example, when it comprises an oxidizing agent such as a peroxide. This includes the case of forming a so-called redox system in combination with a reducing agent.

The polymerization curing step can be carried out by applying the above-described excitation action to the monomer composition. Specifically, for example, the polymerization can be carried out by a known radical polymerization in which an initiator generating free radicals is added. In order to improve the productivity, ultraviolet curing or a combination of ultraviolet curing and heat polymerization is used. Is desirable. For example, a composition obtained by adding a photopolymerization initiator and a thermal polymerization initiator to a composition is poured into a mold, cured by irradiation with ultraviolet rays to a degree sufficient to remove the mold, and then heated again in an oven after the mold is removed. Let it.

The photopolymerization initiator used at this time includes, for example, benzophenone, benzoin methyl ether,
Benzoin isopropyl ether, diethylthioxanthone, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like can be mentioned.

Examples of the thermal polymerization initiator include benzoyl peroxide, diisopropylperoxycarbonate, lauroyl peroxide, t-butylperoxy (2-ethylhexanoate), azoisobutyronitrile and the like.

The use amount of the photopolymerization initiator and the thermal polymerization initiator is in the range of about 0.01 to 20%, preferably 0.03 to 10% based on the total weight of the composition. If the amount is too small, the curing will be insufficient, and if it is too large, the cured resin will be easily yellowed and the polymerization control will be difficult.

As described above, in the present invention, the composition before polymerization and curing can be cured by adding an antioxidant, an ultraviolet absorber and the like.

The optical material obtained by the present invention comprises the above-mentioned cured polymer. The cured polymer has a large refractive index, and its value is usually about 1.58 to 1.61. The Abbe number of the cured polymer is about 30 to 40. Further, this polymer cured product has high surface accuracy (see Examples described later). Furthermore, this polymerized and cured product has good transparency (see Examples below).

The optical material composed of such a polymerized and cured product can be used in the form of various optical elements. Representative optical elements include lenses (including Fresnel lenses, bar lenses, and other shapes), prisms, optical fibers, mirrors, and the like.

Such an optical element may not only be a molded product of the polymerized and cured product of the present invention, but also be one whose surface is subjected to a surface treatment such as a hard coat or an antireflection coat. In addition, it is advantageous to make the molded product itself an optical element by taking advantage of the feature that the polymer cured product according to the present invention has good surface accuracy.However, once a lump is formed, it is processed. It is needless to say that an optical element can be manufactured.

[0038]

The following examples and comparative examples are provided to further illustrate the present invention. "Part" in these examples
Means parts by weight. The physical properties of the resins in these examples were measured by the following test methods. Appearance Visual observation. Refractive index It is a value measured at 25 ° C with an Atsube refractometer. Impact resistance Based on FDA standards, a steel ball (weight: 16.3 g, diameter: 15.9 mm) was dropped vertically from a height of 127 cm on a flat plate with a thickness of 2.0 mm. In the case of damage, it was evaluated as x. The measurement temperature was 25 ° C. Example 1 85 parts of p-bis (β-methacryloyloxyethylthio) xylylene, 15 parts of 2,2′-bis (p-hydroxyethyloxyphenyl) propane = di-β-thiopropionate, 0.05 part of benzophenone , And 0.3 part of t-butylperoxy-2-ethylhexanoate (trade name of “Perbutyl O”, trade name of NOF CORPORATION), and the mixture was heated at 40 ° C. and uniformly stirred and mixed. Then, the mixture was defoamed to form a glass plate and silicone rubber having a diameter of
mm, 2mm deep disk mold, power 80W / cm
From a height 40cm using ^two high-pressure mercury lamp, by 3 minutes once from one side of the glass was irradiated six times on the front and back alternately. After the obtained cured product was released from the mold, it was heated and cured in an oven at 80 ° C. for 1 hour and then at 100 ° C. for 2 hours.

The physical properties of the obtained cured product were measured as shown in Table 1. Example 2 95 parts of p-bis (β-methacryloyloxyethylthio) xylylene and 5 parts of 2,2′-bis (p-hydroxyethyloxyphenyl) propane = di-β-thiopropionate were used. Was obtained in the same manner as in Example 1 and polymerized and cured in the same manner.

The results of measuring the physical properties of the obtained cured product are as shown in Table 1. Example 3 A composition was prepared in exactly the same manner as in Example 1 except that the resin composition was changed as shown in Table 1, and the method of irradiating ultraviolet rays from a high-pressure mercury lamp was alternately applied for 15 minutes each time, alternately, front and back, for a total of 6 times. And polymerized and cured in the same manner.

The measurement results of physical properties of the obtained cured product were as shown in Table 1. Examples 4 to 6 The resin composition was changed as shown in Table 1, and the other conditions were the same as in Example 1 to prepare the compositions, which were polymerized and cured in the same manner.

Table 1 shows the measurement results of the physical properties of the obtained cured products.
Was as shown in FIG. Comparative Example 1 Using 100 parts of p-bis (β-methacryloyloxyethylthio) xylylene, curing was carried out in the same manner as in Example 1.

The measurement results of physical properties of the obtained cured product were as shown in Table 1. Comparative Example 2 50 parts of p-bis (β-methacryloyloxyethylthio) xylylene and 50 parts of 2,2′-bis (p-hydroxyethyloxyphenyl) propane = di-β-thiopropionate were used. A composition was prepared in the same manner as in Example 1, and polymerized and cured in the same manner.

The obtained cured product was very soft and could not be used as a lens resin.

[0045]

[Table 1]

[0046]

The resin for a high refractive index lens according to the present invention comprises:
Not only the refractive index is high, but also the Abbe number is high, the transparency and impact resistance are high, and the content of halogen atoms is not essential. Polymerization and UV polymerization are possible, so that the curing time can be shortened.
Has been described above.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-287050 (JP, A) JP-A-4-159309 (JP, A) JP-A-4-161412 (JP, A) JP-A-5-161 194672 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 1/04 C08F 20/30 C08F 20/38 C08G 75/02 C08F 299/02 CAPLUS (STN)

Claims (1)

(57) [Claims] 1. A composition comprising the following compounds A and B (provided that the total of both is 100 parts by weight) is obtained by heating and / or active energy rays and / or radicals for ethylenically unsaturated bonds. A high-refractive-index optical material made of a resin that is polymerized and cured by the action of a generator. A: 70 to 99 parts by weight of a sulfur-containing (meth) acrylate represented by the following general formula [I] (Wherein, R ¹ represents a hydrogen atom or a methyl group. R ²
Represents an alkylene group having 1 to 6 carbon atoms. Ar represents an arylene group having 6 to 30 carbon atoms, an aralkylene group, or a group substituted with a halogen atom other than fluorine. X represents -O- or -S-. Y
May, when X is -O- -S- or -SO ₂ - and, X
There is the case of _{-S- -S -, - SO 2 -} , also either shows a -CO-, or alkylene group having a carbon number of 1 to 12 both, aralkylene group, alkylene ether group, aralkylene ether group, It represents a group selected from an alkylenethioether group and an aralkylenethioether group.
m and n each represent an integer of 1 to 5. p is 0
The numbers from 10 to 10 are shown. A plurality of groups may be the same or different. B) 1 to 30 parts by weight of a divalent thiol compound represented by the following general formula [II] (In the formula, Ph represents a phenylene group which may be substituted with up to two halogen atoms other than fluorine, and m and n each represent an integer of 1 to 3. A plurality of groups may be the same or different. May be.)