JP2966236B2 - Optical element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element ,
More specifically, for optical elements such as spectacle lenses, optical lenses, optical prisms, optical fibers, optical disks, and magnetic disks.
Related .

[0002]

2. Description of the Related Art Polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS) and the like are commercially available as optical resins used for optical elements. Further, those using a (meth) acrylate having an alicyclic ring in the side chain (JP-A-61-73705),
Using an alkyl methacrylate (Japanese Unexamined Patent Publication No. 1-2)
No. 07307), those using mercaptomethylstyrene (JP-A-4-264113), those using a polyether containing an arylene group (JP-A-4-2926).
No. 53) is also known.

[0003]

Basically important properties required for a resin for an optical element are transparency, refractive index, dispersion characteristics, and the like. For example, an organic polymer used for an eyeglass lens, an optical lens, and the like is It is required to have a high refractive index and excellent dispersion characteristics (high Abbe number).
As described in Vol. 3, March, pp. 266 to 273 (1984), it is usually difficult to simultaneously achieve a high refractive index and a high Abbe number in an organic polymer. There was a trade-off between increasing the Abbe number and decreasing the other.

[0004] This relationship also holds for the above-mentioned commercially available optical resins. That is, when a lens is manufactured, PMMA has a high Abbe number but a low refractive index of 1.49, and cannot cope with various optical designs with such a low refractive index. Further, PC and PS have a higher refractive index of 1.59 than PMMA, but have a low Abbe number and tend to have chromatic aberration. Further, birefringence is likely to occur due to the orientation during molding. Further, Japanese Patent Application Laid-Open Nos. 61-73705 and 1-2
The resins disclosed in JP-A-07307, JP-A-4-264113, and JP-A-4-292635 have also been improved in the balance between the refractive index and the Abbe number as compared with commercially available optical resins. The refractive index and Abbe number have not been increased to the extent that the optical design can be used. Therefore, the appearance of an optical element having a high refractive index and a high Abbe number has been desired.

Accordingly, a first object of the present invention is to provide an optical element having a high refractive index and a high Abbe number. A second object of the present invention is to provide an optical element having a high refractive index and a high Abbe number and having a lower water absorption than the optical element that achieves the first object. Further, a third object of the present invention is to provide an optical element having a high refractive index and a high Abbe number and having better heat resistance than the optical element that achieves the first object.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to:
formula

Embedded image (Wherein X is hydrogen or a methyl group, and n is an integer of 1 or 2) .
-A polymer obtained by polymerization as a component.
This has been achieved by an optical element (hereinafter referred to as an optical element (A)) .

A second object of the present invention is to provide an equation

Embedded image (Wherein, X is hydrogen or a methyl group, and n is an integer of 1 or 2), and a copolymer obtained by copolymerizing a polymerizable monomer and an unsaturated fatty acid ester.
(Hereinafter referred to as optical element (B))
Achieved by

[0008] A third object of the present invention is to provide an equation

Embedded image (Wherein, X is hydrogen or a methyl group, and n is an integer of 1 or 2) comprising a copolymer obtained by copolymerizing a polymerizable monomer represented by the following formula and an N-substituted maleimide.
(Hereinafter referred to as optical element (C)) .

Hereinafter, the present invention will be described in detail. An optical element of the present invention having a high refractive index and a high Abbe number, which achieves the first object
The child (A) has the formula

Embedded image (Wherein, X is hydrogen or a methyl radical, n is an is an integer of 1 or 2) polymerizing a polymerizable monomer represented by the obtained
It is characterized in comprising a are polymer. Here, the polymer includes a homopolymer of the polymerizable monomer of the formula (I) and a copolymer of the polymerizable monomer of the formula (I) and another comonomer.

Specific examples of the polymerizable monomer of the formula (I) which is a monomer component of the optical element (A) of the present invention include acryloyl thiazolidine (X = H, n = 1 in the formula (I)), acryloyl thiol Morpholine (X = H, n = 2), methacryloyl thiazolidine (X = CH ₃ , n = 1), and methacryloyl thiomorpholine (X = CH ₃ , n = 2).

The optical element (A) of the present invention comprises a radical addition polymerization using the polymerizable monomer of the formula (I) as an essential monomer component.
Obtained by, available for example bulk polymerization in the presence of a polymerization initiator, a solution polymerization. Examples of the initiator used for polymerization include benzoyl peroxide, organic peroxides such as lauroyl peroxide, azobisisobutyronitrile,
Any azo compound such as 2,2'-azobis (2,4-dimethylvaleronitrile) that can be used for ordinary radical polymerization can be used.

As the solvent in the solution polymerization, N, N '
Aprotic polar solvents such as -dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide,
Aromatic hydrocarbon solvents such as benzene, toluene and xylene can be used. Other polymerization conditions are not particularly limited,
Conventional radical addition polymerization conditions are used as appropriate.

The optical element (A) of the present invention obtained by polymerizing the polymerizable monomer of the formula (I) has an amide group having a thiazolidine ring or a thiomorpholine ring introduced into a side chain, It is considered that this structure makes it possible to impart a high refractive index and a high Abbe number to the optical element.

In the polymerizable monomer of the formula (I),
The reason why n is limited to an integer of 1 or 2 is that when n is 3 or more, the proportion of sulfur atoms in the repeating unit of the polymer decreases, and the Abbe number increases but the refractive index decreases. .

Next, the light of the present invention which achieves the second object will be described.
The chemical element (B) will be described. By copolymerizing the monomer of the formula (I) and the unsaturated fatty acid ester, the light of the present invention having a high refractive index and a high Abbe number and having a lower water absorption than the optical element (A) The chemical element (B) can be obtained. In addition, the unsaturated fatty acid ester has an effect of further increasing the Abbe number while suppressing a decrease in the refractive index as much as possible, as will be apparent from Examples described later.

The unsaturated fatty acid ester used together with the monomer of the formula (I) includes methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, Acrylate-sec-butyl, acrylate-ter
alkyl acrylates such as t-butyl, hexyl acrylate, and 2-ethylhexyl acrylate; cycloalkyl acrylates such as cyclopentyl acrylate, cyclohexyl acrylate, methylcyclohexyl acrylate, dicyclopentanyl acrylate, and isobornyl acrylate Esters: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, hexyl methacrylate, Alkyl methacrylates such as 2-ethylhexyl methacrylate; cyclopentyl methacrylate, cyclohexyl methacrylate, methyl cyclohexyl methacrylate, dimethacrylate Kuropentaniru, methacrylic acid cycloalkyl esters such as methacrylic acid isobornyl;
Examples include dimethyl maleate, diethyl maleate, dipropyl maleate, diisopropyl maleate, dibutyl maleate, and alkyl maleates such as dihexyl maleate. In particular, by selecting a highly hydrophobic comonomer in which the ester residue constituting the unsaturated fatty acid ester is a long-chain alkyl group or a cycloalkyl group having a relatively large number of carbon atoms, the water absorption of the optical element can be further improved. Can be reduced.

The mixing ratio of the monomer of the formula (I) and the unsaturated fatty acid ester is not particularly limited.
mol%, the latter being preferably 50 to 10 mol%. The reason is that the former is less than 50 mol% and the latter is 5 mol%.
If it exceeds 0 mol%, both the refractive index and Abbe number cannot be increased, while if the former exceeds 90 mol% and the latter is less than 10 mol%, it becomes difficult to lower the water absorption. It is particularly preferred that the former is 60 to 80 mol% and the latter is 40 to 20 mol%.

The copolymerization of the monomer of the formula (I) with the unsaturated fatty acid ester for obtaining the optical element (B) is a usual radical addition polymerization, and is a copolymerization using two kinds of monomers. Except for certain, it is carried out in the same manner as in the homopolymerization of the monomer of the formula (I).

Next, the light of the present invention which achieves the third object will be described.
The chemical element (C) will be described. The monomer of formula (I) and N
-By copolymerizing the substituted maleimide, it is possible to obtain an optical element (C) having a high refractive index and a high Abbe number and having improved heat resistance as compared with the optical element (A).

The N- used with the monomer of formula (I)
Examples of the substituted maleimide include N-methylmaleimide and N-methylmaleimide.
Ethyl maleimide, Nn-propyl maleimide, N-
Isopropyl maleimide, Nn-butyl maleimide,
Examples thereof include N-isobutylmaleimide, N-tert-butylmaleimide, N-hexylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

The mixing ratio of the monomer of the formula (I) and the N-substituted maleimide is not particularly limited.
ol%, and the latter is preferably 50 to 10 mol%. The reason is that the former is less than 50 mol% and the latter is 5 mol%.
If it exceeds 0 mol%, both the refractive index and Abbe number cannot be increased, while if the former exceeds 90 mol% and the latter is less than 10 mol%, the heat resistance is hardly improved. The former is 60 to 80 mol%, and the latter is 40 to 2
It is particularly preferred to be 0 mol%.

The copolymerization of the monomer of the formula (I) with the N-substituted maleimide to obtain the optical element (C) is a usual radical addition polymerization, and is a copolymerization using two kinds of monomers. Except for certain, it is carried out in the same manner as in the homopolymerization of the monomer of the formula (I).

[0023]

The present invention will be further described with reference to the following examples. The evaluation of the physical properties of the optical elements obtained in the examples was performed by the following methods.す な わ ち That is, the resin obtained in the form of powder in the following examples was treated at a temperature of 260 ° C., a pressure of 200 kg / cm ² and a diameter of 15
The sample was heated and compression molded into a disk having a thickness of 5 mm and a thickness of 5 mm, and used as a sample for measuring the refractive index, Abbe number, birefringence, and water absorption. The evaluation methods for the refractive index, Abbe number, birefringence, and water absorption are as follows.

(I) Refractive index, Abbe number: Measured at a temperature of 23 ° C. using an Abbe refractometer (manufactured by Atago Co., Ltd.). (Ii) Birefringence: The retardation was measured at 546 nm by a Senarmont compensator method using a polarizing microscope. The sample subjected to the heat compression molding under the above conditions was placed between two polarizing films to which a quarter wavelength plate was attached, and the birefringence was examined. (iii) Water absorption: A rectangular parallelepiped of 10 × 10 × 5 mm was cut out from the disk and each surface was polished with a 1 μm abrasive to prepare a sample, which was vacuum-dried at 50 ° C. until a constant weight was obtained, and its weight W1 was measured. We weighed it. The dried sample was kept at 80 ° C. in 25 ml of distilled water, taken out of the distilled water every 24 hours, and weighed similarly to determine the weight W 2. The water absorption was determined from W1 and W2 according to the following equation.

Water absorption (%) = (W 2 −W 1) × 100 / W 1 The glass transition temperature for heat resistance evaluation was determined as follows using the powdered resin obtained in the following example as it is. .

(IV) Glass transition temperature Tg (° C.): Measured by using a differential scanning calorimeter (DSC) (manufactured by Mac Science Co., Ltd.) at a heating rate of 10 ° C./min in an air atmosphere.

Example 1 (Production of Optical Element (A)) Acrylylthiomorpholine (X = H, n = 2 in the general formula (I)) was placed in a polymerization tube equipped with a three-way cock.
g (0.162 mol), N, N-dimethylacetamide 80 ml, azobisisobutyronitrile 0.0268
g was added, mixed and dissolved, and the inside of the polymerization tube was replaced with nitrogen gas. Then, the polymerization tube was sealed and polymerized in an 80 ° C. constant temperature bath for 24 hours. This solution was poured into 1 liter of methanol with stirring to precipitate a resin, which was separated by filtration. This resin is chloroform 2
After dissolving the solution in 00 ml, the solution was poured into 2 liters of methanol with stirring to precipitate a resin. The resin was dissolved in 150 ml of chloroform, and the solution was poured into 1.5 liter of methanol with stirring to precipitate and precipitate the resin, which was separated by filtration and dried to obtain a resin in the form of a white powder.

Example 2 (Production of Optical Element (B)) As in Example 1, 2 g of acryloylthiomorpholine (X = H, n = 2 in the general formula (I)) was added to a polymerization tube.
13 mol), cyclohexyl methacrylate 0.55 g
(0.003 mol), N, N-dimethylformamide 16 ml, azobisisobutyronitrile 0.0027 g
, And polymerized for 24 hours in the same manner as in Example 1.
This solution was poured into 160 ml of methanol with stirring to precipitate a resin. After dissolving this resin in 20 ml of chloroform, this solution was poured into 200 ml of methanol with stirring to precipitate and precipitate the resin, followed by decantation, followed by filtration and drying to obtain a white powdery resin.

Examples 3 and 4 (Production of Optical Element (B)) The same operation as in Example 2 was carried out except that the monomer compositions shown in Table 1 were used, and two kinds of optical elements (B) were used. Obtained.

Example 5 (Production of Optical Element (C)) In the same manner as in Example 1, 1.5 g of acryloylthiomorpholine (X = H, n = 2 in the general formula (I)) was placed in a polymerization tube.
(0.0096 mol), 1.15 g (0.0064 mol) of N-cyclohexylmaleimide, 16 ml of N, N-dimethylformamide and 0.0026 g of azobisisobutyronitrile were added, and polymerization was carried out for 24 hours in the same manner as in Example 1. I let it. This solution was poured into 160 ml of methanol with stirring to precipitate a resin. After dissolving the resin in 20 ml of chloroform, the solution was dissolved in 20 ml of methanol.
The resin was dropped into 0 ml with stirring to precipitate and precipitate the resin. After decantation, the resin was separated by filtration and dried to obtain a white powdery resin.

Table 1 shows the evaluation results of the physical properties of the optical elements obtained in Examples 1 to 5. Table 1 also shows the physical property evaluation results of PMMA of Comparative Example 1, PS of Comparative Example 2, and PC of Comparative Example 3, which are commercially available optical resins. From Table 1, the optical element of Example 1 which is a homopolymer of the monomer of the formula (I) has a refractive index of 1.
59, the Abbe number is 41, but the PS of Comparative Example 2 and the PC of Comparative Example 3 having the same refractive index have Abbe numbers of 31 and 30, respectively, so that a high refractive index and a high Abbe number are simultaneously achieved. It is clear that this is an excellent optical element .

The optical elements of Examples 2 to 4, which are copolymers of the monomer of the formula (I) and the unsaturated fatty acid ester, were prepared while maintaining a high refractive index and a high Abbe number in a well-balanced manner. It is apparent that the optical element of Example 1 has lower water absorption and is superior in water resistance.

The PMMA of Comparative Example 1 had an Abbe number of 52.
In the refractive index is 1.49, the refractive index of the optical element of Example 4 of substantially the same Abbe number (50) and the PMMA is 1.54, the optical element also present invention from this point It can be seen that the optical element has a more balanced refractive index and Abbe number than conventional PMMA.

The optical element of Example 5, which is a copolymer of the monomer of the formula (I) and the N-substituted maleimide, has a high refractive index and a high Abbe number in a good balance.
It is clear that the glass transition point is as high as 48 ° C. and the heat resistance is superior to that of the optical element No. 1.

[0035]

[Table 1] It should be noted that the optical elements of Examples 1 to 4, the commercially available optical resins (PMMA, PS, PC) of Comparative Examples 1 to 3 and JP-A-1-207307 (Example 1), which are cited as prior arts, The refractive index and Abbe number of the optical resin described in JP-A-61-73705 (Example 4), JP-A-4-264113 (Example 4) and JP-A-4-292533 (Example 3) are shown. 1 is shown.

FIG. 1 shows that the commercially available optical resins PC and PS have a high refractive index but a low Abbe number, and PMMA has a high Abbe number but a low refractive index. Also, the optical resins described in each patent publication have a better balance between the refractive index and Abbe number than PC, PS, and PMMA, but are still insufficient.
On the other hand, the optical elements of Examples 1 to 4 are more excellent in the balance between the high refractive index and the high Abbe number than the optical resin disclosed in each of the patent publications, and are clearly excellent optical elements. It is. This means that the refractive index of the optical element of Example 2 having substantially the same Abbe number is 1.57, whereas the refractive index of the optical resin disclosed in JP-A-4-264113 is 1.55. This has been proven.

[0037]

As described above, according to the present invention, an optical element having a high refractive index and a high Abbe number is provided. Further, according to the present invention, an optical element having a high refractive index and a high Abbe number and having low water absorption is provided. Furthermore, according to the present invention, it has a high refractive index and a high Abbe number, and has excellent heat resistance.
An optical element was provided. As a specific example of the optical element of the present invention,
Te is spectacle lenses, optical lenses, optical prisms, optical fibers, optical disk, and a magnetic disk.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the refractive index of various optical elements and the Abbe number.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C07D 277/04 C07D 277/04 279/12 279/12 (56) References JP-A-60-61568 (JP, A) JP-A-62-62569 (JP, A) JP-A-62-230766 (JP, A) JP-A-2-23303 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 20 / 58,120 / 58 C08F 220/58 G02B 1/04 G02C 7/02-7/04 CA (STN)

Claims (4)

(57) [Claims] (1) Formula (1) (Wherein X is hydrogen or a methyl group, and n is an integer of 1 or 2) .
-A polymer obtained by polymerization as a component.
Optical element 2. The formula: (Wherein, X is hydrogen or a methyl group, and n is an integer of 1 or 2), and a copolymer obtained by copolymerizing a polymerizable monomer and an unsaturated fatty acid ester.
An optical element characterized by the above . 3. The formula: (Wherein, X is hydrogen or a methyl group, and n is an integer of 1 or 2) comprising a copolymer obtained by copolymerizing a polymerizable monomer represented by the following formula and an N-substituted maleimide.
An optical element characterized by the above-mentioned . 4. An eyeglass lens, an optical lens or an optical prism.
The optical element according to claim 1, wherein the optical element is a system .