JPS6210160A - Material for optical instrument - Google Patents

Abstract

PURPOSE:To provide a material for optical instruments, which has excellent heat resistance, moldability, etc. and a low photoelastic coefficient and is suitable for use as a material for an optical memory disc, etc., by mixing two polycarbonate polymers contg. specified repeating units. CONSTITUTION:1-99wt% polymer (A) contg. a repeating unit of formula I (wherein R<1>, R<2> are each a 1-5C alkyl, phenyl ; X<1>, X<2> are each a 1-4C alkyl, a 1-4C alkoxyl, halogen) is mixed with 99-1wt% polymer (B) contg. a repeating unit of formula II (wherein R<3>, R<4> are each a 1-5C alkyl, phenyl) to obtain the desired material for optical instruments. Component A is prepd. by reacting a bisphenol of formula III with phosgene. Component B is prepd. by reacting a bisphenol of formula IV with phosgene.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to materials for optical equipment, particularly heat resistance.

It relates to a material that has excellent moldability and is suitable for digital audio discs, optical memory discs, etc.

[Prior Art and Problems to be Solved by the Invention] In general, materials for optical devices such as those described above are required to have various performances. For example, transparency.

It is necessary to have excellent heat resistance, low moisture permeability, mechanical strength, etc., as well as excellent optical properties.

Conventionally, methacrylic resin has been known as one of the materials having such properties, but this resin has the disadvantage that it is still difficult to say that it is sufficient in terms of heat resistance, low moisture permeability, impact resistance, etc. be.

It is also known that polycarbonate resin obtained by reacting bisphenol A (2,2-bis(4°-hydroxyphenyl)propane) with phosgene, diphenyl carbonate, etc. can be used as a material for optical equipment. Although this material has excellent heat resistance, low moisture permeability, and impact resistance, it has a relatively large photoelastic coefficient and a low flow value, which indicates fluidity during molding. Therefore, the distortion of the molded product due to residual stress after the molding process is large, and due to these, the birefringence of the molded product becomes large, and a fully satisfactory disk cannot be obtained.

Therefore, the present inventors maintained the excellent properties of polycarbonate resin such as heat resistance 2 and mechanical strength, and in particular improved the disadvantages of polycarbonate resin such as fluidity and photoelastic coefficient, thereby improving optical properties. In order to develop this material, we conducted extensive research.

[Means for solving problems]

As a result, it was discovered that a composition formed by blending two types of polycarbonate polymers having specific repeating units could achieve the above object, and based on this knowledge, the present invention was completed. Ta.

That is, the present invention is based on the general formula [wherein R' and Rt each represent an alkyl group having 1 to 5 carbon atoms or a phenyl group, and Xl and xZ each represent an alkyl group having 1 to 4 carbon atoms, and 1 to 4 carbon atoms] represents an alkoxyl group or a halogen atom. A polymer having repeating units represented by [A31 to 99% by weight] and the general formula [wherein Rt R4 represents an alkyl group having 1 to 5 carbon atoms or a phenyl group, respectively]. ] Polymer [B] 99-1 having a repeating unit represented by
The object of the present invention is to provide a material for optical equipment comprising a composition containing % by weight.

The polymer [A] having a repeating unit represented by the general formula CI) has various types depending on the types of R1, R2 and )(+, x2. Specific examples thereof include R1
, R2 is a methyl group, an ethyl group, an n-propyl group,
i-propyl group, n-butyl group, i-butyl group, 5e
c-butyl group, tert-butyl group.

n-amyl group, i-amyl group, 5ec-amyl group.

Examples include tert-amyl group and phenyl group.

Here, R1 and R1 may be the same or different. Further, specific examples of xl and xt include a methyl group, an ethyl group, and an n-propyl group.

i-propyl group, n-butyl group, i-butyl group.

5ec-butyl group, tert-butyl group or methoxyl group, ethoxyl group, n-propoxyl group, i-propoxyl group, n-butoxyl group, i-butoxyl group I
5ec-butoxyl group, tert-butoxyl group,
Further examples include chlorine, bromine, and iodine. )(1 and xl may also be the same or different.

The degree of polymerization of the above polymer [A] may be determined as appropriate depending on the type of optical equipment and the blending ratio of the repolymer in the composition consisting of polymers [A] and [B]. The reduced viscosity [η1/c] of a methylene chloride solution with a concentration of 0.5 g/a at 25°C is 0.3 to 1.0 dl.
/g, preferably 0.35-0.8d17g of polymer.

On the other hand, there are various polymers [B] having repeating units represented by the above-mentioned general formula (n) depending on the types of R3 and R4. As a specific example of R3 and R4, the above-mentioned R
The same thing as in the case of 1 and R2 can be mentioned. However, R:l
, R4 do not necessarily have to be the same, and may be different from each other.

Moreover, the degree of polymerization of this polymer [B] is the same as that of the above-mentioned polymer [A].
], the viscosity indicating the degree of polymerization is the reduced viscosity of a methylene chloride solution with a concentration of 0.5 g/dI at 25°C [η1/
C] from 0.3 to 1.0 di/g, preferably 0.3
The polymerization should be between 5 and 0.8 aJ/g of polymer.

The composition in the present invention is composed of the above-mentioned polymer [A] and polymer [B], and the blending ratio of both is 1 to 99% by weight for polymer [A] and 99 to 99% by weight for polymer [B]. It may be appropriately selected within the range of 1% by weight. In particular, it is convenient to set the polymer [A] to 80 to 99% by weight and the polymer [B] to 20 to 1% by weight in order to obtain a material with a small photoelastic coefficient.

Although the above-mentioned polymers [A] and [B] can be produced by various methods, they can usually be produced in the same manner as general polycarbonate resins using bisphenol A as a starting material. For example, to produce the polymer [A], the general formula [wherein R1, R2, xl, and x2 are the same as above] is used. ]
The phosgene method can be used, in which phosgene is added to bisphenols represented by and reacted in an appropriate solvent in the presence of an alkali and, if desired, a molecular weight regulator. It can also be produced by a transesterification method using diphenyl carbonate or the like instead of phosgene. On the other hand, polymer [B] is produced using bisphenols represented by the general formula (R3 and R4 are the same as above) as raw materials, and in the same manner as the production method of polymer [A] described above. can do.

The composition in the present invention comprises the above polymer [A] and polymer C.
It can be obtained by blending B) in a predetermined ratio, but generally these polymers [A] and [B] are mixed in a suitable solvent such as methylene chloride or tetrachloroethane.

It is obtained by dissolving it in a halogenated hydrocarbon such as chlorophenol and thoroughly mixing it, and then removing the solvent by an appropriate means such as removal under reduced pressure.

In addition, when molding a disk or the like using this composition, usual additives such as antioxidants and ultraviolet absorbers may be added.

〔Effect of the invention〕

The composition of the present invention obtained in this way has a smaller photoelastic coefficient than conventional polycarbonate resins, has good moldability, and has little molding distortion, so it has low birefringence and extremely excellent optical properties. It is something. Moreover, it has excellent heat resistance and mechanical strength. Therefore, if the composition of the present invention is used as a material for various optical devices, it will be possible to obtain optical devices that have improved optical properties, have high sensitivity in reading information recorded on disks, and are less prone to errors. Additionally, since it is a material that is good both thermally and mechanically, optical devices made using it operate stably under a variety of conditions.

Therefore, the material of the present invention can be effectively used as a material for optical equipment such as digital audio discs and optical memory discs.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 2,2-bis(3'-methyl-
41-hydroxyphenyl)propane 25.6 g (0,
1 mol) in 250 nl of 2N aqueous sodium hydroxide solution
of methylene chloride and 250 ml of methylene chloride. p-tert-butylphenol as molecular weight regulator 0.2
g and 0.5 mj of triethylamine as a catalyst!
and while stirring vigorously, add 300 mj of phosgene!
The supply of phosgene gas was stopped when the pH inside the flask reached 9. Thereafter, the reaction was carried out with stirring for 1 hour. After the reaction was completed, the reaction product was diluted with 200ml of methylene chloride, washed in the order of water, 0.01N hydrochloric acid, and water, and the organic layer was separated and poured into methanol to form a product represented by the following formula. Repeat unit (
A polycarbonate (polymer [A]) containing I[[] was obtained.

This polymer [A] has a concentration of 0.
Reduced viscosity of 5g/a solution at 25°C [ηsp/c)
was 0.834/g.

Commercially available polycarbonate (polymer [B]) having 4.75 g of the above polymer [A] and a repeating unit (IV) represented by the following formula (reduced viscosity measured under the above conditions: 0.5 d!/g) 0,.
After completely dissolving 25 g in 200 m6 of methylene chloride, the solvent methylene chloride was removed under reduced pressure to obtain a polycarbonate composition. By hot pressing the composition thus obtained at 270°C, the thickness of the composition was 9.
A 3 mm sheet was obtained.

Using this sheet, the photoelastic coefficient at a wavelength of 633 nm was measured. The glass transition temperature of this material was also measured to evaluate its heat resistance. These results are shown in Table 1.

Example 2 In Example 1, the polymer [A
] was changed to 4.5 g, and polymer CB) was changed to 0.5 g, but the same operation as in Example 1 was performed. The results are shown in Table 1.

Example 3 In Example 1, polymer [A
] was changed to 4.0 g, and the same operation as in Example 1 was performed, except that the amount of polymer [B] was changed to 1.0 g. The results are shown in Table 1.

Example 4 In Example 1, the polymer [A
] was changed to 0.5 g, and the polymer [B] was changed to 4.5 g, but the same operation as in Example 1 was performed. The results are shown in Table 1.

Example 5 In Example 1, 2,2-bis(3°-methy/L/-
3,3- instead of 4'-hydroxyphenyl)propane
The same reaction as in Example 1 was carried out except that 28.4 g (0.1 mol) of bis(3°-methyl-4°-hydroxyphenyl)pentane was used, and the repeating unit (V ) having polycarbonate (polymer [A
]) was obtained.

The reduced viscosity [η, /C) of this polymer [A] measured under the same conditions as in Example 1 was 0.75 d1/g.

Completely dissolve 4.75 g of the above polymer [A] and 0.25 g of the same polymer [B] as in Example 1 in 200 ml of methylene chloride, and then perform the same operations as in Example 1 to form a sheet. and various physical properties were measured. The results are shown in Table 1.

Example 6 Polymer [A] dissolved in methylene chloride in Example 5
The same operation as in Example 5 was performed except that the amount of polymer CB) was 4.5 g and the amount of polymer CB) was 0.5 g.

The results are shown in Table 1.

Comparative Example 1 Table 1 shows various physical properties of the commercially available polycarbonate (polymer [B]) having the repeating unit (IV) used in Example 1.

Claims (4)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^1 and R^2 each represent an alkyl group or phenyl group having 1 to 5 carbon atoms, and X^1 and Each represents an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, or a halogen atom. ] Polymer [A] having repeating units represented by 1 to 99% by weight and general formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^3 and R^4 each have 1 to 5 carbon atoms Indicates an alkyl group or a phenyl group. ] Polymer [B] 99-1 having a repeating unit represented by
A material for optical equipment consisting of a composition containing % by weight. (2) The blending ratio of polymer [A] in the composition is 80 to 9
The material for optical equipment according to claim 1, wherein the content is 9% by weight. (3) The viscosity of the polymer [A] at 25°C is 0.
Reduced viscosity of 5 g/dl methylene chloride solution [η_s_p
/c] is 0.3 to 1.0 dl/g. (4) The viscosity of the polymer [B] at 25°C is 0.
Reduced viscosity of 5 g/dl methylene chloride solution [η_s_p
/c] is 0.3 to 1.0 dl/g.