JPH07309947A - Sulfur-containing polymer - Google Patents

Abstract

PURPOSE:To obtain a sulfur-contg. polymer which has a high refractive index and an excellent heat resistance and is suitable for applications such as an optical lens, a phase difference plate, an antireflection film, and a permselective membrane. CONSTITUTION:A sulfur-contg. polymer having a wt.-average mol.wt. of 10,000 or higher is produced from 40-55mol% dithiol of the formula (wherein R<1> and R<2> are each H, 1-3C alkyl, 1-3C alkoxy, phenyl, hydroxyl, Cl, or Br provided they may be the same or different from each other; and n is an integer of 1-3) and 60-45mol% diviny1 compds. comprising 10-90mol% divinylbenzene and 90-10mol% arom. diacrylate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sulfur-containing polymer having a high refractive index, excellent heat resistance, and suitable for use in optical lenses, retardation plates, antireflection films, selective transmission films and the like.

[0002]

2. Description of the Related Art Plastic optical materials are lighter in weight than inorganic glass materials, less prone to cracking, and have excellent moldability.
In recent years, it has rapidly spread as an optical element such as a spectacle lens and a camera lens.

Materials widely used as the above-mentioned plastic optical materials are, for example, those obtained by radical polymerization of diethylene glycol bisallyl carbonate. These have excellent properties such as light weight, excellent impact resistance, easy dyeing, and good workability such as cutting and polishing, but have a refractive index higher than that of inorganic glass of 1.52. Since it is as low as 1.50, it is necessary to increase the center thickness, edge thickness, curvature, etc. of the lens, for example, in order to obtain optical properties equivalent to those of a glass lens. It had a drawback that was not possible.

A higher refractive index of 1.70 or more is required for use as an optical multilayer film such as a selective reflection film and a selective transmission film, but the highest commercially available plastic optical material is manufactured by ICI. Polyethersulfone 1.
64, the number of plastic optical materials having a high refractive index is scarce, and even if it has a refractive index of more than 1.70, it has problems such as transparency and coloring of the material, and can be actually used. There was nothing. Therefore, the optical multilayer film currently used is formed by vapor deposition of inorganic glass, but it is difficult to deposit a large area and the cost is high. It has not been reached yet, and there has been an increasing demand for a plastic optical material having a high refractive index capable of forming a coating film by a simple coating method.

On the other hand, a retardation film, which is one of the members for liquid crystal display, tends to be selected for a material having a high refractive index with the use of a fast response liquid crystal. The range is up to 1.75, and therefore, a material having a high refractive index has been desired even for a retardation film material.

Aromatic sulfur-containing polymers are excellent in heat resistance and chemical resistance, and are useful as engineering plastics. Further, due to the high atomic refraction of sulfur and the high molecular refraction of the aromatic ring, the polymer has a high refractive index and has been expected as an optical material.

The aromatic sulfur-containing polymer is obtained by polymerizing an aromatic compound such as divinylbenzene and various dithiol compounds. For example, JP-A-62-270627 discloses divinylbenzene and benzenedithiol. The sulfur-containing polymer is disclosed in JP-A-63-277242 as a sulfur-containing polymer composed of divinylbenzene and pyridinedithiol, and in JP-A-63-277243 as a sulfur-containing polymer composed of divinylbenzene and thiophenedithiol. Each is disclosed.

However, the refractive index of the sulfur-containing polymer composed of divinylbenzene and benzenedithiol is about 1.
Although it is as high as 8, the glass transition temperature (T
g) is below room temperature, which is a serious problem in practical use. Further, the sulfur-containing polymer composed of divinylbenzene and pyridinedithiol and the sulfur-containing polymer composed of divinylbenzene and thiophenedithiol have high values of refractive index and glass transition temperature, but there is a problem that the yield of polymer formation is low. It was

[0009]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an optical material having a high refractive index and excellent heat resistance.

[0010]

DISCLOSURE OF THE INVENTION The gist of the present invention is to use a sulfur-containing polymer as a dithiol 40-5 represented by the general formula (I).
5 mol% and divinylbenzene 10 to 90 mol%
And 60 to 45 mol% of a divinyl compound composed of 90 to 10 mol% of an aromatic diacrylate, and a weight average molecular weight of 10,000 or more.

[0011]

[Chemical 2]

In the formula, R ¹ and R ² are the same or different and each represent hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a phenyl group, a hydroxyl group, Cl or Br.
n represents an integer of 1 to 3.

The first component constituting the sulfur-containing polymer of the present invention is dithiol represented by the general formula (I). Examples of the dithiol include 1,4-benzenedithiol, 1,3-benzenedithiol, 1,2-benzenedithiol, 2-methyl-1,4-benzenedithiol, 2-ethyl-1,4-benzenedithiol, 2-methoxy-1,4-benzenedithiol, 2-chloro-
1,4-benzenedithiol, dimercaptodiphenyl sulfide, bis- (4-mercapto-3-methyl-phenyl) sulfide, bis- (4-mercapto-3-methoxyphenyl) sulfide, bis- (4-mercapto-3-) Examples thereof include chlorophenyl) sulfide, 4,4′-dimercaptodiphenyl sulfide, and 1,4-bis- (4-mercaptophenylthio) benzene. These compounds may be used alone or in combination of two or more. The mixing ratio of the dithiol is
It is 40 to 55 mol% in all monomers. If it is less than 40 mol%, a polymer having a high refractive index cannot be obtained, and if it exceeds 55 mol%, the degree of polymerization of the polymer is lowered, so that it is limited to the above range.

The second component constituting the sulfur-containing polymer of the present invention is divinylbenzene. The divinylbenzene can be used in any of an ortho form, a meta form, and a para form, but the meta form and the para form are preferable from the viewpoint of easy availability. These isomer compounds can be used alone or in admixture of two or more.

The third component constituting the sulfur-containing polymer of the present invention is aromatic diacrylate. The aromatic diacrylate is a compound having one or more aromatic rings in its molecule and two acryloyl groups or methacryloyl groups. Examples of the aromatic diacrylate include 2,2-bis (4- (meth) acryloyloxyphenyl) propane and 2,2-bis (4- (ω-
(Meth) acryloyloxypolyethoxy) phenyl)
Propane, 2,2-bis (4- (meth) acryloyloxydibromophenyl) propane, 2,2-bis (4-
(Ω- (meth) acryloyloxypolyethoxy) dibromophenyl) propane, 2,2-bis (4- (ω-
(Meth) acryloyloxypolypropoxy) phenyl) propane, 2,2-bis (4- (meth) acryloyloxyphenyl) sulfone, 2,2-bis (4- (ω)
-(Meth) acryloyloxypolyethoxy) phenyl) sulfone, 2,2-bis (4- (meth) acryloyloxydibromophenyl) sulfone, 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene, 9, 9-bis (4- (ω- (meth) acryloyloxypolyethoxy) phenyl) fluorene, 1,4-dihydroxyphenyldi (meth) acrylate, 4,4 '
-Dihydroxy-p-diphenyldi (meth) acrylate, 4,4 "-dihydroxy-p-terphenyldi (meth) acrylate, 4,4"'-dihydroxy-
p-quaterphenyl di (meth) acrylate, 1,
3-dihydroxynaphthalene di (meth) acrylate,
1,5-dihydroxynaphthalene di (meth) acrylate, 2,3-dihydroxy naphthalene di (meth) acrylate, 2,6-dihydroxy naphthalene di (meth) acrylate, 2,7-dihydroxy naphthalene di (meth) acrylate, etc. To be These compounds are
They may be used alone or in combination of two or more.

The blending ratio of the above-mentioned divinylbenzene and the above-mentioned aromatic diacrylate is 90 to 10 mol% of the aromatic diacrylate in the combination of both monomers.
It is more preferably 80 to 20 mol%. When the amount of aromatic diacrylate is less than 10 mol%, the heat resistance of the polymer is not sufficiently improved, and when it exceeds 90 mol%, a high refractive index cannot be obtained.

The weight average molecular weight of the sulfur-containing polymer composed of the above three components is 10,000 or more in terms of polystyrene. If it is less than 10,000, the moldability and the film-forming property are deteriorated, so the content is limited to the above range. Further, when the sulfur-containing polymer of the present invention is used for a curable coating film, the upper limit of the molecular weight is not particularly limited, but when the moldability as a thermoplastic resin is required, the molecular weight is 1,000,000 or less. Is preferred.

The method for producing the sulfur-containing polymer of the present invention is not particularly limited. For example, the above-mentioned dithiol, divinylbenzene and aromatic diacrylate are blended and heated in the presence or absence of a radical polymerization initiator, The above-mentioned sulfur-containing polymer can be easily obtained by a method such as ultraviolet irradiation. In this case, the polymerization may be carried out in bulk or in solution. The solvent is not particularly limited as long as it is a good solvent for these monomers, and examples thereof include benzene, toluene, xylene, and tetrahydrofuran. Examples of the radical polymerization initiator include benzoyl peroxide, -tert-butyl peroxide, lauroyl peroxide, diisopropyl peroxycarbonate, 2,
2'-azobisisobutyronitrile, azobiscyclohexanecarbonyl and the like can be mentioned. The amount used is preferably 0.1 to 10 mol%, more preferably 0.5 to 5 mol% based on the total amount of divinylbenzene and aromatic diacrylate.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 Preparation of Sulfur-Containing Polymer p-Divinylbenzene 0.39 purified by vacuum distillation
g (3 mmol), dimercaptodiphenyl sulfide 1.22 g (5 mmol), 2,2-bis (4-methacryloyloxyphenyl) propane 0.73 g (2 mm
ol), 0.036 g (0.022 mmol) of 4,4′-azobisisobutyronitrile as a polymerization initiator, and 20 ml of toluene as a polymerization solvent were charged in the flask. After that, the flask was sufficiently cooled in a dry ice-methanol bath, and the operations of decompressing and introducing nitrogen were repeated three times. Next, the flask was placed in a constant temperature bath of 70 ° C. and reacted while stirring for 7 hours. After completion of the reaction, the polymerization liquid was dropped into methanol to precipitate a polymer, which was then collected. Then, the solvent was separated by decantation and centrifugation, and washing with methanol was repeated to remove unreacted substances.
The yield was 93%. The blending amounts and yields of the above monomers are shown in Table 1.

Measurement of Weight Average Molecular Weight (Mw) The obtained sulfur-containing polymer was measured for its molecular weight in terms of polystyrene by gel permeation chromatography (GPC) method. Column chromatography
It was performed by a Tosoh GPC system. The results are shown in Table 1.

Measurement of glass transition temperature (Tg) It was measured by a differential scanning calorimeter manufactured by Seiko Instruments. The results are shown in Table 1.

Measurement of Refractive Index The obtained polymer was dissolved in dichloromethane and cast on a smooth film-forming plate to prepare a cast film, and the refractive index of this film was measured by an ellipsometer (Mizojiri Optical Co., Ltd.).
At 23 ° C. The results are shown in Table 1.

Measurement of each monomer composition ratio in the polymer The ¹ H-NMR measurement (tetramethylsilane standard, ppm unit) of the sulfur-containing polymer obtained in Example 1 was carried out, and the results are shown below. Group a: 7.2 to 6.7 M (multiple lines) Group b: 2.7 to 3.2 M (multiple lines) Group c: 1.9 S (single line) Group d: 1.6 S (single line) Line) The above a to d respectively correspond to protons in the following formula.
When the monomer composition ratio in the polymer was obtained from these, it was confirmed that the polymer was composed of monomers having almost the same composition as the charged composition.

[0025]

[Chemical 3]

Examples 2 to 6 Polymerization was carried out in the same manner as in Example 1 except that the monomer composition shown in Table 1 was used except for p-divinylbenzene. The weight average molecular weight, glass transition temperature and refractive index of the obtained polymer were measured, and the results are shown in Table 1. Further, for each of the obtained polymers, ¹ H-NM was prepared in the same manner as in Example 1.
R measurement was carried out, and it was confirmed that it was composed of a monomer having almost the same composition as the charged composition.

Example 7 A sulfur-containing polymer was obtained in the same manner as in Example 1 except that the polymerization solvent was changed from toluene to tetrahydrofuran.
The weight average molecular weight, glass transition temperature, and refractive index were measured, and the results are shown in Table 1. Further, the obtained sulfur-containing polymer was subjected to ¹ H-NMR measurement in the same manner as in Example 1, and it was confirmed that the sulfur-containing polymer was composed of a monomer having almost the same composition as the charged composition.

Example 8 After charging the monomer components in the same manner as in Example 1, the reaction mixture was kept at 60 ° C. and ultraviolet rays (450 W high pressure mercury lamp).
Was irradiated for 5 hours to polymerize. After the polymerization, the same treatment as in Example 1 was carried out. The weight average molecular weight of the obtained polymer,
The glass transition temperature and the refractive index were measured, and the results are shown in Table 1. Further, the obtained sulfur-containing polymer was subjected to ¹ H-NMR measurement in the same manner as in Example 1, and it was confirmed that the sulfur-containing polymer was composed of a monomer having almost the same composition as the charged composition.

Comparative Examples 1 to 3 In Comparative Examples 1 and 2, 5 mmol of p-divinylbenzene was used.
In Comparative Example 3, p-divinylbenzene was not added, and the remainder was charged in the composition shown in Table 1 to carry out polymerization in the same manner as in Example 1. The weight average molecular weight of the obtained polymer,
The glass transition temperature and the refractive index were measured, and the results are shown in Table 1. Further, ¹ H-NMR measurement was performed on the obtained polymer in the same manner as in Example 1, and it was confirmed that the polymer was composed of a monomer having almost the same composition as the charged composition.

[0030]

[Table 1]

[0031]

Industrial Applicability The sulfur-containing polymer of the present invention is composed of the above-mentioned three kinds of monomers, has a high refractive index and is excellent in heat resistance, and can be used in optical lenses, retardation plates, antireflection films, selective transmission films, etc. It can be suitably used as an optical material.

Claims (1)

[Claims] 1. A dithiol 40 represented by the general formula (I).
.About.55 mol%, and 60 to 45 mol% of a divinyl compound consisting of 10 to 90 mol% of divinylbenzene and 90 to 10 mol% of an aromatic diacrylate, and having a weight average molecular weight of 10,000 or more. Sulfur polymer. [Chemical 1] In the formula, R ¹ and R ² are the same or different and each represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms,
It represents a phenyl group, a hydroxyl group, Cl or Br. n is 1 to 3
Represents the integer.