JPH07145236A - Material having high refractive index - Google Patents

Abstract

PURPOSE:To obtain a material consisting of a polyphenylene sulfide copolymer having a specific structure, having transparency and high refractive index, excellent in heat resistance and capable of especially utilizing to optical lens and optical multilayer films. CONSTITUTION:This material consists of 10-90mol% of a recurring unit of formula I and 90-10mol% of a recurring unit of formula II. The material is preferably obtained by polymerizing, e.g. a monomer providing an unit I of 4,4'-dichlorodiphenyl sulfone, etc., and a monomer providing an unit II of 4,4'- dichlorodiphenyl sulfide in the presence of potassium carbonate or sodium carbonate in an amide-based solvent such as DMF or a sulfone-based solvent such as sulfolane under an inert gas atmosphere at 100-350 deg.C for 1-24hr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high refractive index folding material which has a high refractive index and can be suitably used for an optical lens, an antireflection film and the like.

[0002]

2. Description of the Related Art Plastic optical materials are lighter in weight, harder to crack, and easier to process than inorganic materials.
It is rapidly becoming popular as an optical element such as an eyeglass lens and a camera lens.

Resins which are widely used for these purposes are, for example, those obtained by radical polymerization of diethylene glycol bisallyl carbonate as disclosed in JP-A-61-28513. This resin is said to be excellent in heat resistance, high refractivity, low shrinkage and releasability. However, the refractive index n of this resin
_D is as small as 1.51 to 1.53, and at the same time, the above resin has a low glass transition temperature of 87 ° C, and is heat resistant for applications exposed to high temperatures (150 ° C or higher) such as lenses for laser printers. It also had a drawback that it could not be applied due to lack of.

On the other hand, for use as an optical multilayer film (selective reflection film, selective transmission film, etc.), a higher refractive index (for example,
Although a refractive index exceeding 1.65 is required, there are few plastic materials having such a high refractive index (for example,
Among the transparent materials currently on the market, the one having the highest refractive index is polyether sulfone manufactured by ICI and its refractive index is 1.64. ), And the high refractive index material has a problem of transparency and coloring, which is not suitable for practical use.

For this reason, currently used optical multilayer films are formed by vapor deposition of inorganic materials. Therefore, it is difficult to vapor-deposit a large area and the cost is high. It has not been used universally. Therefore, there has been an increasing demand for a plastic high refractive index material capable of forming a coating film by a simple coating method.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems.
It is to provide a high refractive index material having a high refractive index exceeding 1.65 and being excellent in heat resistance.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that polyphenylene sulfide resin having a specific structure is transparent and has a high refractive index exceeding 1.65. The present invention has been completed and the present invention has been completed, and the present invention has been completed.

That is, the present invention consists essentially of 10 to 90 mol% of the repeating unit represented by the general formula (I) and 90 to 10 mol% of the repeating unit represented by the general formula (II). And a high refractive index material.

[0009]

[Chemical 3]

In the present invention, the repeating unit represented by the general formula (I) is 10 to 90 mol% and the repeating unit represented by the general formula (II) is 90 to 10 mol%.
The present invention provides a high-refractive-index material characterized in that the repeating unit represented by II) consists essentially of 30 mol% or less.

[0011]

[Chemical 4]

The repeating units of the general formulas (I) to (III) forming the high refractive index material of the present invention can be obtained by polymerizing a monomer having a structure shown below by a nucleophilic substitution polycondensation method. .

Examples of the monomer forming the repeating unit of the general formula (I) include 4,4'-dichlorodiphenyl sulfone and 4,4'-dihydroxydiphenyl sulfone. Examples of the monomer forming the repeating unit of the general formula (II) include 4,4'-dichlorodiphenyl sulfide and 4,4'-dihydroxydiphenyl sulfide. Further, as the sulmonomer forming the repeating unit of the general formula (III), 4,4 ′ ″-
Dihydroxy-P-quaterphenyl, 4, 4'4,
4 '''-dibromo-P-quaterphenyl and the like can be mentioned.

The high refractive index material of the present invention is substantially composed of repeating units of the general formulas (I) and (II) or the general formulas (I) to (III). The repeating units represented by (I) and (II) are from 10 to 90
Mol%, preferably 20 to 80 mol%, the general formula (II
The repeating unit represented by I) is 30 mol% or less, preferably 1 to 30 mol%, more preferably 5 to 25 mol%.

The repeating unit represented by the general formula (I) is
When it is less than 10 mol%, the effect of increasing the refractive index is not obtained, which is not preferable, and when it exceeds 90 mol%, the heat resistance is lowered, which is not preferable. Similarly, if the repeating unit represented by the general formula (II) is less than 10 mol%, the heat resistance is lowered, which is not preferable, and if it exceeds 90 mol%, the effect of increasing the refractive index is lost, which is not preferable. Further, the refractive index of the repeating unit represented by the general formula (III) increases as the proportion increases, but if it exceeds 30 mol%, the copolymer becomes crystalline and the light transmittance decreases. Therefore, it cannot be used as an optical material.

Further, as a monomer copolymerizable with the high refractive index material of the present invention, 4-hydroxy-4 '(p
-Hydroxyphenyl) diphenyl sulfone, 4-chloro-4 '(p-hydroxyphenyl) diphenyl sulfone, 4-chloro-4' (p-chlorophenyl) diphenyl sulfone, bisphenol A, bisphenol F, p
-Hydroxyphenol, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-p-terphenyl,
4,4'-dihydroxydiphenyl ether, 4,4 '
-Dihydroxydiphenylketone, 4,4'-dichlorodiphenylsulfone, 4,4'-dichlorodiphenylketone and the like can be mentioned, but the fraction thereof is preferably less than 30 mol% for the reason of lowering the refractive index. .

The molecular weight of the high refractive index material of the present invention can be expressed by using the reduced viscosity as a standard, and the reduced viscosity is 0.35 dl / dl when measured at a concentration of 1 g / dl in dimethylformamide at 30 ° C. g-0.7dl / g
Is preferred. When the reduced viscosity is less than 0.35 dl / g, the mechanical strength of the optical material obtained by using the high-refractive material is not sufficient, and when it exceeds 0.7 dl / g, the moldability as an optical material and the optical multilayer film are obtained. Is not preferable because the coating film forming property of is reduced.

The high refractive index material of the present invention can be subjected to a nucleophilic substitution polycondensation method in which polymerization is carried out in a polar solvent in the presence of an alkali metal salt. As the alkali metal salt, sodium carbonate, potassium carbonate, rubidium carbonate, potassium oxalate, potassium bicarbonate and the like are preferable, but potassium carbonate or sodium carbonate is particularly preferable. As the polar solvent, sulfolane, diphenyl sulfone,
A sulfone-based solvent such as dimethyl sulfoxide or an amide-based solvent such as dimethylacetamide, dimethylimidazoline or dimethylformamide is preferably used. The polymerization temperature is usually in the range of 80 to 400 ° C, preferably 100 to 350 ° C. When the reaction temperature is lower than the above temperature range, the intended polymerization reaction does not proceed at a speed that can be practically used, and it is difficult to obtain a polymer having a required molecular weight. On the other hand, when the reaction temperature is higher than the above range, side reactions other than the intended polymerization reaction cannot be ignored, and the resulting polymer is significantly colored. The time required for the polymerization reaction depends on the type of reaction raw material components,
It varies depending on the type of polymerization reaction and the like, but usually 10 minutes to 100
The time is in the range of 1 hour to 24 hours. In the production of the polymer, it is preferable that oxygen is not present as an atmosphere during the reaction,
Good results are obtained when performed in nitrogen or other inert gas. This is because the alkali metal salt reacted with the hydroxyl group is easily oxidized when heated in the presence of oxygen, which hinders the intended polymerization reaction and makes it difficult to increase the molecular weight.
This is because it also causes coloring of the produced polymer.

Further, when carrying out the copolymerization, in addition to the method of collectively charging all the monomers into the polymerization tank, a part of the monomers may be charged in the latter stage of the polymerization for the purpose of controlling the molecular structure,
It is possible to use any method such as adding a polymer that has been separately polymerized during the polymerization.

As a method for obtaining an optical element such as a lens using the high refractive index material of the present invention, for example, a method of press molding the high refractive index material or dissolving the high refractive index material in a solvent such as dimethylformamide. A method of forming the solution into a film or the like by a casting method can be mentioned.

[0021]

The present invention will be further described with reference to Examples.

Examples 1 to 5 and Comparative Examples 1 to 3 In a reaction vessel equipped with a stirrer, a gas introduction pipe, a thermometer and a condenser having a receiver at the tip, the number of parts of the polymerization monomer shown in Table 1 and anhydrous 15.2 parts by weight of potassium carbonate, N-methyl-
2-Pyrrolidone (500 parts by weight) and toluene (200 parts by weight) were charged, and the atmosphere was replaced with nitrogen. Next, under a nitrogen atmosphere, stirring and temperature increase were started, and toluene was distilled off at 170 ° C. to remove water in the system. Further raise the temperature 1
The polymerization reaction was carried out at 80 ° C. for 5 hours. The obtained polymerization solution was cooled and poured into a mixed solvent of acetone and methanol to precipitate only the polymer. Potassium chloride is removed by further washing with water, and then dried in a vacuum dryer at 120 ° C for 2
After drying for 4 hours, a film is formed by the casting method, and the refractive index of this film is Abbe's refractometer (4T manufactured by Atago Co., Ltd.).
Type) was used to measure diiodomethane as a contact liquid. Further, in order to measure heat resistance, the glass transition temperature of the polymer powder was set to 2 in a nitrogen atmosphere with a DSC manufactured by Seiko Denshi KK
The measurement was performed under a temperature rising condition of 0 ° C./min. Further, the polymer powder was molded into a 0.5 mm plate by press molding, and its transparency was visually evaluated. The results are shown in Table 1.

Comparative Example 4 Polyethersulfone manufactured by ICI (trade name: VICTR
A molded plate was obtained in the same manner as in Example 1 except that (EX PES) was used instead of the polymer powder, and this molded plate was evaluated in the same manner as in Example 1. The results are shown in Table 1.
It was shown to.

Comparative Example 5 To 100 parts by weight of diethylene glycol bisallyl carbonate, 3 parts by weight of diisopropyl peroxydicarbonate was added, and the mixture was poured into a mold of 50 × 50 × 105 mm and placed in an oven at 40 ° C. under a nitrogen atmosphere for 24 hours. Held for hours. Then, it was kept at 80 ° C. for 4 hours and further at 120 ° C. for 2 hours to complete the curing. The evaluation results of the refractive index are shown in Table 1.

[0025]

[Table 1]

[0026]

As described above, the high refractive index material of the present invention is a polyphenylene sulfide copolymer, and the high refractive index material comprising the polyphenylene sulfide copolymer is 1.6.
As a material having a high refractive index of 5 or more and heat resistance of 150 ° C. or more, it can be used for various optical materials, particularly optical lenses and optical multilayer films, and has great industrial utility value.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toranosuke Saito 5-17-21 Yamatedai, Ibaraki City (72) Inventor Hiroki Kadomachi 1-11-3 Minamikasugaoka, Ibaraki City

Claims (2)

[Claims] 1. A high content of the repeating unit represented by the general formula (I) consisting essentially of 10 to 90 mol% and 90 to 10 mol% of the repeating unit represented by the general formula (II). Refractive index material. [Chemical 1] 2. The repeating unit represented by the general formula (I) is 10 to 90 mol%, the repeating unit represented by the general formula (II) is 90 to 10 mol%, and the repeating unit represented by the general formula (III) is A high-refractive-index material characterized by being substantially composed of units of 30 mol% or less. [Chemical 2]