JPH05194672A - High refractive index optical material - Google Patents

Abstract

PURPOSE:To obtain a high refractive index optical material having light weight, high refractive index, excellent transparency and shock resistance by curing a polymer produced from a specific bis(meth)acrylate, mercapto compound and styrenic compound. CONSTITUTION:The objective optical material is obtained by subjecting a composition comprising (A) 50 to 98wt.% of bis(meth)acrylate such as p-bis(beta- acyloyloxyethylthio)xylylene of formula I (R<1> is H, methyl; R<2> is 1 to 6C alkyl; Ar is 6 to 30C arylene; X<0> is S; Y is SO2; m, n are 1 to 5; p is 0 to 10), (B) 1 to 30wt.% of a mercapto compound of formula II (R<3> is CH2, etc.; R<4> is 2 to 15C hydrocarbon residue; q is 2 to 6), formula III and formula IV (R<3>, R<4> are 1 to 3C alkylene) and (C) 1 to 49wt.% of a styrene of formula V (R<6> is H; X<2> is halogen) to polymerization and curing reactions in the presence of a photopolymerization initiator.

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 high refractive index optical material, particularly a lens resin having a high refractive index and excellent impact resistance.

[0002]

2. Description of the Related Art Conventionally, a diethylene glycol bisaryl carbonate resin has been widely used as a plastic lens resin. 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 a lens is required to obtain the same refraction as glass. There was a drawback that it became thick.

On the other hand, various diacrylates or dimethacrylates (hereinafter, both are collectively referred to as di (meth) acrylate) are known to be easily radically polymerized to give a lens resin having excellent transparency. Has been. For example, di (meth) having a bromine-containing bisphenol A skeleton
Acrylate (JP 59-184210 A, JP 5
No. 9-193915), di (meth) acrylates having a sulfur-containing aromatic skeleton (JP-A-60-2601).
No. 0, JP-A-62-195357 and the like), it is known that the resin for lenses has a high refractive index and an excellent optical characteristic in a high balance of Abbé numbers.

Generally, a cured resin having a highly crosslinked structure obtained by polymerization of such various di (meth) acrylate compounds is excellent in heat resistance, abrasiveness and transparency, but on the other hand, it is cured. There is a drawback that the resin tends to be brittle. As a means for improving this drawback, it has been proposed to use a bromine-containing bisphenol A derivative which has been urethane (meth) acrylated (JP-A-60-5).
1706), this resin has a problem that the specific gravity is large and the weather resistance is deteriorated because it contains a bromine atom.

Further, in JP-A-2-141702, polymerization is carried out by adding a polyfunctional thiol such as pentaerythritol tetrakis (β-thiopropionate) to bis- (meth) acryloxymethyl-tricyclodecane. Although a resin having improved impact resistance has been proposed, this resin has a drawback that it has a relatively high refractive index of 1.55 or less, although it has a high Abbe number. Also, JP-A-63-309509
In the publication, there is a proposal to use a polymerizable monomer obtained by the reaction of thiol and divinylbenzene, but in this case, there are problems to be overcome such as the need to treat the radical end with pyrogallol. is there.

[Summary of Invention]

DISCLOSURE OF THE INVENTION The present invention is intended to provide an optical material which is improved in various drawbacks of conventional resin for lenses, is lightweight, has a high refractive index, and is excellent in transparency and impact resistance. To do.

[0007]

[Means for Solving the Problems]

<Summary> The high refractive index optical material according to the present invention comprises a composition containing the following compounds A, B and C, which is used as a radical generator for heat and / or active energy rays and / or ethylenically unsaturated bonds. It is made of a resin that is solidified by being subjected to an action.

[0008]

(In the formula, 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 ⁰ represents -O- or -S-. Y is -S when X ⁰ represents -O-.
- or -SO ₂ - indicates, ^{if X 0} represents a -S- is -S -, _- SO 2 -, - CO-, or an alkylene group, an aralkylene group having a carbon number of 1 to 12 both, A group selected from an alkylene ether group, an aralkylene ether group, an alkylene thioether group and an aralkylene thioether group is shown. m and n are each 1 to 5
Indicates an integer. p shows the number of 0-10. The plurality of groups may be the same or different. )

[0010]

(In the formula, R ³ is —CH ₂ — or —CH
₂ CH ₂ - shows a. R ⁴ has 2 to 15 carbon atoms.
Represents a hydrocarbon residue or an alkyl ether residue. q
Represents an integer of 2 to 6. A plurality of groups may be the same or different. )

[0012]

[Chemical 4]

[0013]

[0014]

[Chemical 5]

(In the formula, R ³ and R ⁴ represent the same or different alkylene groups having 1 to 3 carbon atoms. D and e each represent 0 or 1, and f represents 1 or 2.
The plurality of groups may be the same or different. )

C. 1 to 49% by weight of a styrene compound represented by the following general formula [V]

[0017]

[Chemical 6]

(In the formula, R ⁵ represents a hydrogen atom or a methyl group, X ² represents a halogen atom other than fluorine, z represents 0 or an integer of 1 to 5. A plurality of groups may be the same or different. You may.)

<Effect> The resin obtained by polymerizing and curing the three specific compounds A, B and C has a high refractive index,
Moreover, it has excellent impact resistance.

[Detailed Description of the Invention] <Chemical substance of cured product> The optical material according to the present invention comprises:
Compounds A, B and C are polymerized and cured by subjecting them to heat and / or an active energy ray and / or an exciting action of a radical generator acting on an ethylenically unsaturated bond.

Since the compounds A and C have an ethylenically unsaturated bond, it is considered that the compounds are polymerized by polyaddition of the ethylenically unsaturated bond by the above-mentioned excitation action. Although it is not always clear how the non-ethylenically unsaturated compound C coexisting in such a polymerization site behaves, the thiol group of the compound B is not a compound A and / or
The so-called Michael type addition to the ethylenically unsaturated compound of C may possibly combine with the compounds A and / or C existing under the polymerization conditions.

The bis (meth) acrylate represented by the general formula [I] can be polymerized by itself, but the resulting cured resin has a drawback that it has poor impact resistance. However, according to the present invention, this and the general formula [I
By copolymerizing the mercapto compound represented by I], [III] and / or [IV] with the compound represented by the general formula [V], the cured resin obtained can prevent coloration, and Not only the surface accuracy of the cured product is improved, but also the impact resistance is significantly improved.

<Compound A> Compound A is a bis (meth) acrylate represented by the general formula [I]. here,
As mentioned above, the "(meth) acrylate" means acrylate and methacrylate.

[0024]

(In the formula, 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 ⁰ represents -O- or -S-. Y is -S when X ⁰ represents -O-.
- or -SO ₂ - indicates, ^{if X 0} represents a -S- is -S -, _- SO 2 -, - CO-, or an alkylene group, an aralkylene group having a carbon number of 1 to 12 both, A group selected from an alkylene ether group, an aralkylene ether group, an alkylene thioether group and an aralkylene thioether group is shown. m and n are each 1 to 5
Indicates an integer. p shows the number of 0-10. The plurality of groups may be the same or different. )

This bis (meth) acrylate is a sulfur-containing aromatic bis (meth) acrylate, as is clear from the definition of each group in the formula.

The sulfur-containing aromatic (meth) acrylate represented by the above general formula [I] used in the present invention has a structure in which acrylic acid, methacrylic acid or their methyl esters are continuous with a chain containing sulfur. Yes, two or more kinds can be used together.

Specific examples of the bis (meth) acrylate of the general formula [I] include the following.

(A) 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, 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-methacryloyloxyethylthio) diphenyl sulfide,
4,4'-bis (β-acryloyloxyethylthio)
Diphenyl sulfone, 4,4'-bis (β-methacryloyloxydiethylthio) diphenyl sulfone, 4,
4'-bis (β-methacryloyloxyethylthio) diphenyl ketone, β, β'-bis (p-acryloyloxyphenylthio) diethyl ether, β, β'-bis (p-methacryloyloxyphenylthio) diethyl ether, β , Β'-bis (p-methacryloyloxyphenylthio) diethyl ether, β, β'-bis (p-
Methacryloyloxyphenylthio) diethylthioether.

(B) X ⁰ in the general formula [I] is -S.
In the case of-, the formula -Ar-(-Y-Ar-) _p- is the general formula

[0031]

[Chemical 7]

(In the formula, R ⁶ represents an alkylene group having 1 to 12 carbon atoms, preferably 1 to ⁶ carbon atoms, which may have an ether bond in the chain, and g represents an average degree of oligomerization. An oligomer represented by the formula:

[0033]

[Chemical 8]

(In the formula, h is a number of 1 to 5 which represents the average degree of oligomerization.)

Among the monomers represented by the above general formula [I], from the viewpoint of optical properties such as the refractive index of the polymer and handling properties such as the viscosity of the monomer, the particularly preferable monomers are as follows. It is a sulfur-containing bis (meth) acrylate represented by the formula [I ′].

[0036]

[Chemical 9]

(In the formula, R ¹ represents a hydrogen atom or a methyl group. R ⁷ and R ⁸ each represent a divalent hydrocarbon residue having 1 to 4 carbon atoms, and Z represents a halogen atom other than fluorine. I represents 0 or an integer of 1 to 4. The plural groups may be the same or different.)

Specific examples of the monomer represented by the general formula [I '] include p-bis [β- (meth) acryloyloxyisopropylthio] xylylene and m-
Bis [β- (meth) acryloyloxyethylthio] ethylphenylene, p-bis [β- (meth) acryloyloxybutylthio] tetrachloroxylylene, p-bis [β- (meth) acryloyloxyethylthio] xylylene, And m-bis [β- (meth) acryloyloxyethylthio] xylylene, etc., and even more preferred monomers are the latter two.

<Compound B> The compound B is represented by the general formula [II],
It is at least one of the mercapto compounds represented by [III] and [IV]. As is apparent from the formula, this compound is a polythiol compound.

(Wherein R ³ is —CH ₂ — or —CH
₂ CH ₂ - shows a. R ⁴ has 2 to 15 carbon atoms.
Represents a hydrocarbon residue or an alkyl ether residue. q
Represents an integer of 2 to 6. A plurality of groups may be the same or different. )

[0041]

[Chemical 10]

[0042]

[0043]

[Chemical 11]

(In the formula, R ³ and R ⁴ represent the same or different alkylene groups having 1 to 3 carbon atoms. D and e each represent 0 or 1, and f represents 1 or 2.
The plurality of groups may be the same or different. ) These compounds can be used together in each group.

(A) The compound represented by the general formula [II] is a divalent to hexavalent thioglycolic acid or thiopropionic acid ester. Specific examples of the compound [II] include:
For example, pentaerythritol = tetrakis (β-thiopropionate), pentaerythritol = tetrakis (thioglycolate), trimethylolpropane = tris (β-thiopropionate), trimethylolpropane = tris (thioglycolate), Diethylene glycol = bis (β-thiopropionate), diethylene glycol = bis (thioglycolate), triethylene glycol = bis (β-thiopropionate), triethylene glycol = bis (thioglycolate), dipentaerythritol = Hexakis (β-thiopropionate), dipentaerythritol = hexakis (thioglycolate) and the like can be mentioned.

(B) Compound III Specific examples of the compound represented by the general formula [III] include, for example, tris [2- (β-thiopropionyloxy)
Ethyl] triisocyanurate, tris (2-thioglyconyloxyethyl) isocyanurate, tris [2-
(Β-Thiopropionyloxydiethoxy) ethyl] triisocyanurate, Tris (2-thioglyconyloxyethoxyethyl) triisocyanurate, Tris [3-
Examples include (β-thiopropionyloxy) propyl] triisocyanurate and tris (3-thioglyconyloxypropyl) triisocyanurate.

(C) Specific examples of the compound represented by the general formula [IV] include benzene dimercaptan, xylylene dimercaptan, and 4,4'-dimercaptodiphenyl sulfide.

<Compound C> Specific examples of the compound represented by the general formula [V] include styrene, α-methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene and pentabromostyrene.

<Monomer composition> The composition to be "polymerized and cured" according to the present invention comprises compounds A, B and C in the following ratios.

More specifically, the bis (meth) acrylate [I] of the present invention and the general formulas [II] and [II]
The composition ratio with the mercapto compound represented by I] and / or [IV] is 50 to 98 parts by weight of the former, 1 to 30 parts by weight of the latter, preferably 60 to 85 parts by weight of the former. The latter is in the range of 2 to 20 parts by weight. Generally, if the proportion of the mercapto compound is too small, the effect of improving the impact resistance of the cured resin cannot be obtained, and conversely, if it is too large, the heat resistance of the cured resin becomes low.

On the other hand, bis (meth) acrylate (formula I)
And the other monomer (formula V) that can be copolymerized therewith, the latter is 1 to 49 parts by weight, preferably 50 to 98 parts by weight, preferably 60 to 85 parts by weight of the former. The latter is 5 to 35 parts by weight. If this proportion is too small, the effect of improving the impact resistance of the cured resin cannot be obtained, and conversely, if this proportion is too large, the heat resistance of the cured resin becomes low.

This monomer composition comprises compounds A, B and C. As used herein, "comprising" means that the resulting polymerized cured product does not excessively impair the characteristics of the optical material of the present invention of high refractive index and high impact resistance.
A small amount of an ethylenically unsaturated monomer copolymerizable with the compounds A and C, for example, up to about 10 parts by weight per 100 parts by weight of the total amount of the compounds A + B + C, and a suitable auxiliary material,
It means that it may be included. Examples of such a monomer may include lower alkyl methacrylate, divinylbenzene, di (meth) acrylate and the like which belong to the above-mentioned known art. Such auxiliary materials include antioxidants, UV absorbers, dyes and pigments, and others.

<Polymerization and curing> A composition containing a compound B which is not an ethylenically unsaturated compound is further added to the action of the radical generator for heat and / or active energy rays and / or ethylenically unsaturated bonds. And cured in multiple steps to produce an optical material according to the present invention.

The term "heat" as used herein as an exciting action for the polymerization and curing of the compounds A, B and C includes not only the mere application of heat but also the combined use of a thermal polymerization initiator (detailed later). , "Active energy rays" include not only the simple application of ultraviolet rays, ionizing radiation and other energy rays, but also the combined use of a photopolymerization initiator (detailed later), and the "radical generator" means the above-mentioned heat. It may overlap with the polymerization initiator and includes not only the use of the agent but also the case of forming a so-called redox system in which it is combined with a reducing agent when it is composed of an oxidizing agent such as a peroxide. is there.

The polymerization-curing step can be carried out by applying the above-mentioned exciting action to the monomer composition. Specifically, it can be carried out, for example, by a known radical polymerization in which an initiator that generates a free radical is added, but in order to improve its productivity, UV curing or a combination of UV curing and heat polymerization is used. Is desirable. For example, a composition to which a photopolymerization initiator and a thermal polymerization initiator are added is injected into a mold, cured by UV irradiation to an extent sufficient for demolding, and then, after demolding, further heat-polymerized in an oven. ..

Examples of the photopolymerization initiator used at that time include benzophenone, benzoin methyl ether,
Examples thereof include benzoin isopropyl ether, diethylthioxanthone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

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

The amount of photopolymerization initiator and thermal polymerization initiator used is in the range of about 0.01 to 5%, preferably 0.03 to 2%, based on the total weight of the composition. If the amount used is too small, the curing will be inadequate, and if it is too large, the cured resin will tend to turn yellow and it will be difficult to control polymerization.

As described above, in the present invention, an antioxidant, an ultraviolet absorber, etc. can be added to the composition before polymerization and curing to cure it.

The optical material obtained by the present invention comprises the above-mentioned polymerized and cured product. This polymerized cured product has a large refractive index, and its value is usually about 1.58 to 1.62. The Abbe number of this polymerized cured product is about 34 to 38. Further, this polymerized cured product has a high impact strength (see Examples below). Furthermore, this polymerized and cured product has good transparency (see Examples below).

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

Such an optical element may be not only a molded product of the polymerized and cured product of the present invention, but also one whose surface is subjected to a surface treatment such as a hard coat or an antireflection coat.

[0063]

EXAMPLES The following examples and comparative examples are intended to further illustrate the present invention. “Part” in these examples
Means parts by weight. The physical properties of the resins in these examples are measured by the following test methods. Appearance Visual inspection. Refractive index A value measured at 25 ° C. with an Atsube refractometer. Impact resistance 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 based on the FDA standard, and there was no damage, ○, The case of damage was rated as x. The measurement temperature is 25 ° C. Hardness Depends on pencil hardness.

Example 1 75 parts of p-bis (β-methacryloyloxyethylthio) xylylene, pentaerythritol = tetrakis (β
-Thiopropionate) 8 parts, styrene 17 parts, benzophenone 0.05 parts, t-butylperoxy-2-ethylhexanoate (NOF Corporation trade name "Perbutyl O") 0.3 parts with stirring and mixing. It is injected into a pacer consisting of a glass plate and silicon rubber with a diameter of 40 mm and a thickness of 2 mm, and a height of 4 W is obtained using a high pressure mercury lamp with an output of 80 W / cm ^2.
Irradiation was performed from 0 cm on each side of the glass once for 10 minutes, for a total of 6 times. After removing the obtained cured product from the mold, 80 ° C in an oven
After heating for 1 hour at 100 ° C. for 2 hours, a cured product was obtained. The results of measuring the physical properties of the cured product are shown in Table 1.

Examples 2 to 9 The composition of the monomer composition was changed as shown in Table 1, and the composition was prepared in the same manner as in Example 1 except that the composition was polymerized and cured in the same manner. The results of measuring the physical properties of the obtained cured products were as shown in Table 1.

Comparative Example 1 Instead of using p-bis (β-methacryloyloxyethylthio) xylylene 75 parts, pentaerythritol = tetrakis (β-thiopropionate) 8 parts and styrene 17 parts in Example 1, p- Using only 100 parts of bis (β-methacryloyloxyethylthio) xylylene,
A cured product was obtained in the same manner as in Example 1 except for the above. The results of measuring the physical properties of the cured product are shown in Table 1.

Comparative Example 2 Instead of using 75 parts of p-bis (β-methacryloyloxyethylthio) xylylene, 8 parts of pentaerythritol = tetrakis (β-thiopropionate) and 17 parts of styrene in Example 1, p- Bis (β-methacryloyloxyethylthio) xylylene 80 parts, styrene 20
Parts were used, pentaerythritol = tetrakis (β-thiopropionate) was not used, and the other conditions were the same as in Example 1 to obtain a cured product.

Comparative Example 3 Instead of 75 parts of p-bis (β-methacryloyloxyethylthio) xylylene in Example 1, 4 parts of the same compound were used.
0 part, and instead of 8 parts of pentaerythritol = tetrakis (β-thiopropionate), 43 parts of the same compound were used, and a composition was prepared in the same manner as in Example 1 except that polymerization and curing were carried out in the same manner. I did it. The obtained cured product was so soft that it could not be used as a resin for lenses.

[0069]

[Table 1]

A: p-bis (β-methacryloyloxyethylthio) xylylene B: p-bis (β-methacryloyloxyethyloxyethylthio) xylylene C: α, α'-bis (β-methacryloyloxyethylthio)- 2,3,5,6-Tetrachloro-p-xylylene D: Pentaerythritol = tetrakis (β-thiopropionate) E: Tris [2 (β-thiopropionyloxy) ethyl] triisocyanurate F: 4,4 ′ -Dimercaptodiphenyl sulfide G: styrene H: p-chlorostyrene I: 2,4-dibromostyrene J: benzophenone K: t-butylperoxy-2-ethylhexanoate

[0071]

As described above in the section of [Summary of the Invention], an optical material comprising a cured and cured product of a specific monomer composition according to the present invention has a high refractive index and a high impact resistance. ..

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Megumi Watanabe 3-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Mitsubishi Petrochemical Co., Ltd. Tsukuba Research Institute

Claims (1)

[Claims] 1. A composition comprising the following compounds A, B and C is polymerized and cured by subjecting it to the action of a radical generator on heat and / or active energy rays and / or ethylenically unsaturated bonds. High refractive index optical material made of resin. (In the formula, 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 ⁰ represents -O- or -S-.
Y is -S- or -SO when X ⁰ represents -O-.
_2-, and when X ⁰ represents -S-, -S-, -S
O ₂ —, —CO—, or a group selected from an alkylene group having 1 to 12 carbon atoms, an aralkylene group, an alkylene ether group, an aralkylene ether group, an alkylene thioether group, and an aralkylene thioether group. m and n each represent an integer of 1 to 5.
p shows the number of 0-10. The plurality of groups may be the same or different. ) (In the formula, R ³ represents —CH ₂ — or —CH ₂ CH ₂ —. R ⁴ represents a hydrocarbon residue having 2 to 15 carbon atoms or an alkyl ether residue. Q represents It represents an integer of 2 to 6. A plurality of groups may be the same or different.) [Chemical 2] (In the formula, R ³ and R ⁴ are the same or different alkylene groups having 1 to 3 carbon atoms. D and e are 0 or 1, and f is 1 or 2. A plurality of groups are It may be the same or different.) C. Styrene compound represented by the following general formula [V] 1 to 49% by weight (In the formula, R ⁵ represents a hydrogen atom or a methyl group, and X ²
Is a halogen atom excluding fluorine, and z is 0 or an integer of 1 to 5. The plurality of groups may be the same or different. )