JP2579653B2 - Optical molding materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] Polycarbonate resins are excellent in heat resistance and impact resistance and have good transparency, so that substrates for optically readable information such as compact discs and optical discs can be used. , Lenses, mirrors, etc. are widely used as optical molding materials.

[Prior Art] Such an optical material is used after a reflector of a metal such as aluminum or Tb / Gd / Fe or a film of an information medium is formed by vacuum evaporation or sputtering. Also,
For applications such as lenses, an organosilicon compound or the like is often coated for antireflection.

Generally, in the polycarbonate resin, a solvent containing methylene chloride or a chlorine-containing compound such as a compound having a chloroformate group as an unreacted residue slightly remains, but these compounds have a temperature of 280 ° C. or higher. When melt-processed at a high temperature, it decomposes to generate an acidic substance, which causes mold corrosion or changes the surface properties of the molded product, thereby lowering the adhesion strength of the coating at the time of coating. In addition, when used with a gold layer film, it may cause deterioration of the film.

It is possible to heat the polycarbonate resin in advance to volatilize the remaining chlorine compounds, but to reduce it until a sufficient effect is obtained, it takes a lot of heating time, which is not only industrially extremely disadvantageous. In addition, deterioration and coloring of the polycarbonate resin occur during heating, which significantly impairs the commercial value.

Further, in order to prevent coloring deterioration at the time of melt processing at a high temperature, addition of an organic phosphite is widely performed, and it is possible to reduce coloring at the time of melt processing. However, when an organic phosphite is blended, when the molded article is exposed to a high temperature and high humidity state, the molecular weight of the polycarbonate is significantly reduced, and the metal film to be contacted is adversely affected.

It is also known that an epoxy compound is compounded to suppress the influence on the metal film (Japanese Patent Application Laid-Open No. 60-89845). However, the compounding amount of the epoxy compound is required to be 0.01% by weight or more. Coloring of the resin occurs during processing, which significantly impairs commercial value.

Therefore, optical polycarbonate material that suppresses the generation of malignant acidic substances at the time of melt processing at high temperature, prevents color deterioration, and has a small effect on the metal film with a small decrease in molecular weight even in a high temperature and high humidity state, It was not obtained industrially.

[Object of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to suppress the generation of an acidic substance that affects a metal, and to reduce the molecular weight even when used in a high-temperature and high-humidity atmosphere. Goods.

[Configuration of the invention]

 Hereinafter, the present invention will be described specifically.

The bis (hydroxyphenyl) alkane-based polycarbonate resin used in the present invention is a polymer or a copolymer obtained by reacting various dihydroxydiaryl compounds with a carbonate precursor. And polycarbonate resins produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bisphenol A, bis (4-hydroxyphenyl) methane, 1,1-bis (4-vidroxyphenyl) ethane, 2,2
-Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5dibromo Phenyl) propane, 2,2-bis (4-hydroxy-
Bis (hydroxyaryl) alkanes such as 3,5 dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane ) Cycloalkanes, dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenylether, 4,4'-dihydroxy-3,3'-dimethyldiphenylether, 4,4'-dihydroxydiphenylsulfide, 4,4'- Dihydroxy diaryl sulfides such as dihydroxy-3,3'-dimethyl diphenyl sulfide, 4,4'-dihydroxy diphenyl sulfoxide, dihydroxy diaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfoxide 4,4'-dihydroxydiphenyl Sulfone, 4,
And dihydroxydiarylsulfones such as 4'-dihydroxy-3,3'-dimethyldiphenylsulfone.

These may be used alone or as a mixture of two or more kinds. In addition, piperazine, dipiperidyl, hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be used in combination.

These polycarbonates are 6.0 g /
Η measured with a Ostwald viscometer for a methylene chloride solution of
_{From sp} , the formula η _sp / C = [η] (1 + K'η _SP ) And equation [η] = KM ^α It is necessary that the average molecular weight calculated by the above is in the range of 12000 to 18000.

If the average molecular weight is less than 12,000, the strength of the obtained molded article is low and it cannot be put to practical use. If it is more than 18,000, problems are likely to occur in the optical properties of the molded article, particularly, optical distortion and color tone.

The methylene chloride remaining in the polycarbonate resin can be volatilized and reduced by drying at a high temperature, and when phosphites, alicyclic epoxy compounds, and ester compounds of a saturated aliphatic carboxylic acid are melt-kneaded and compounded. Also, the reduction can be achieved by using a vented extruder.

It is preferable that the residual amount of methylene chloride is small because the generation of an acidic substance that adversely affects the metal is small, and the residual amount in the polycarbonate resin is required to be 0.01% by weight or less, and further by 0.005% by weight or less. ,
An extremely large effect can be obtained.

However, to reduce volatility by drying at high temperature,
Long-time heating is required, and further, the deterioration of the resin during heating is accelerated, and the resin is colored to impair optical characteristics.

Therefore, the residual amount of methylene chloride in the final product is 0.01% by weight or less, preferably 0.005% by weight in the resin.
The following is acceptable.

The phosphite used in the present invention is a diester or a triester of phosphorous acid and an alcohol or a phenol, and R ¹ and R ² in the general formula shown above include a butyl group, a hexyl group, and an octyl group. And alkyl groups such as 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, octadecyl group, pentaerythrityl group and cyclohexyl group, and aryl groups such as phenyl group, toluyl group and nonylphenyl group. Or, as R ³ , a hydrogen atom or the above-mentioned alkyl group or aryl group can be mentioned.

Specific examples of the phosphite include tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, tristearyl phosphite, triphenyl phosphite, tricresyl phosphite, and tris (nonylphenyl) phosphite. Fight, 2-
Ethylhexyl diphenyl phosphite, decyl diphenyl phosphite, phenyl di-2-ethylhexyl phosphite, phenyl didecyl phosphite, tricyclohexyl phosphite, distearyl pentaerythrityl diphosphite, diphenyl pentaerythrityl diphosphite, and the like. Particularly, phosphites having at least one alkyl group are suitable.

The amount of phosphite is 100
0.005 to 0.5 parts by weight, preferably 0.01 to 0.
2 parts by weight.

If the amount of the phosphite is too small, it is not possible to suppress deterioration and coloring due to decomposition of the resin, and if it is too large,
Phosphorous ester itself decomposes to easily generate gas during molding, and promotes hydrolysis of the resin in a high-temperature, high-humidity atmosphere, resulting in strength deterioration and significantly affecting the metal film in contact with it. give.

The alicyclic epoxy compound used in the present invention has the formula A compound having at least one 1,2-epoxy group represented by: specifically, 3,4-epoxycyclohexylmethyl-3,4 epoxycyclohexanecarboxylate, 2,3-epoxycyclohexylmethyl-3,4 -Epoxycyclohexanecarboxylate.

Such an epoxy compound is a polycarbonate resin 10
0.001 to 0.01 parts by weight based on 0 parts by weight. 0.001
If the amount is less than 0.01 part by weight, there is no effect. If the amount exceeds 0.01 part by weight, the resin is colored and the molecular weight is reduced during molding at a high temperature, which is not preferable as an optical material.

The complete aliphatic ester compound used in the present invention is specifically a complete ester compound of a di- or trivalent aliphatic alcohol such as ethylene glycol, propylene glycol, or glycerin and an aliphatic carboxylic acid. Examples of the aliphatic carboxylic acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linolenic acid, behenylic acid and montanic acid.

In particular, a diester of an aliphatic carboxylic acid having 16 to 18 carbon atoms with ethylene glycol and a triester with glycerin are desirable.

A partial ester compound containing a carboxylic acid group and / or a hydroxyl group, such as a monoester of ethylene glycol, a monoester with glycerin, or a diester, suppresses acidic substances that affect metals when an epoxy compound is used in combination. Surprisingly, the aliphatic complete ester compound substantially containing no carboxylic acid group or hydroxyl group can suppress the adverse effect on the metal film when used in combination with the alicyclic epoxy compound. In addition, the compounding amount of the alicyclic epoxy compound can be suppressed to a very small amount, and the coloring deterioration during the melt processing of the resin, which is a disadvantage of the epoxy compound, can be minimized.

Such an aliphatic complete ester compound is blended in an amount of 0.005 to 0.2 parts by weight based on 100 parts by weight of the polycarbonate resin. If the compounding amount is small, there is no effect, and if it exceeds 0.2 parts by weight, the decomposition of the resin during melt processing becomes severe.

The compounding of (a) a phosphite, (b) an alicyclic epoxy compound, and (c) a complete aliphatic ester compound is performed by a mixing method well known to those skilled in the art, for example, a tumbler, a super mixer, an extruder. , V-type blender or the like can be used.

〔Example〕

 Hereinafter, specific examples will be described.

 In addition, the measuring method of a physical property follows the following method.

◎ Amount of methyl chloride Dioxane 5% solution is prepared and Electron Catcher D
Gas chromatography with an etector (Shimadzu Corporation GC-9
A) ◎ Yellowness index Measured according to JIS K 7103 ◎ Influence on aluminum film The area where the aluminum film has discolored or peeled is measured with an area meter, and the percentage of the total area as the influence I do.

Examples 1 to 4, Comparative Examples 1 to 5 As a polycarbonate resin, a bisphenol A type polycarbonate resin having an average molecular weight of 15,300 and a residual methylene chloride amount of 330 ppm was used. b) Epoxy compound (c) Aliphatic complete ester compound is blended, and the degree of vacuum of the vent is 65 with an extruder equipped with a 40 mmφ vent.
The mixture was melted and mixed at 0 Torr and a resin temperature of 260 ° C. to obtain pellets.
The pellets were dried at 120 ° C. for 6 hours, and were heated at a resin temperature of 350 ° C. and a mold temperature of 100 ° C. for 120 mm using an injection molding machine having a mold clamping force of 70 tons.
A φ, 1.2 mm thick disk was injection molded.

The molecular weight, yellowness index and residual methylene chloride content of the obtained molded article were measured. In addition, an aluminum film is vacuum-deposited on the surface of the disk using a bell jar vacuum evaporation machine, and an ultraviolet-curing acrylic coating agent is applied. After curing, the aluminum film is exposed to an atmosphere of 70 ° C and 90% RH. Was observed. The molecular weight of the disc after 500 hours was measured. Table 2 shows the results.

Example 5 Examples 1 to 4 except that the degree of vent vacuum was set to 100 Torr.
And the results are shown in Table 2.

Comparative Examples 6 to 11 The same procedures as in Examples 1 to 4 were carried out except that monoesters and diesters of glycerin and stearic acid or various known lubricants were blended as aliphatic partial ester compounds. Table 2 shows the results.

[Effects of the Invention] As described above, according to the present invention, an optical molding material can be obtained without little influence on the metal film and without any decrease in coloring or molecular weight.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G11B 7/24 526 8721-5D G11B 7/24 526G 8721-5D 526R

Claims (1)

(57) [Claims] (1) relative to 100 parts by weight of a bis (hydroxyphenyl) alkane-based polycarbonate resin having an average molecular weight of 12,000 to 18,000 (a) 0.005 to 0.5 parts by weight of a phosphite represented by the formula (b) 0.001 to 0.01 parts by weight of an alicyclic epoxy compound (c) A saturated aliphatic carboxylic acid having 12 to 32 carbon atoms and a di- or trivalent aliphatic alcohol Complete aliphatic ester compound with
Optical molding material containing 0.005 to 0.2 parts by weight.