JPS6239624A - Optical disk substrate consisting of polycarbonate - Google Patents

Abstract

PURPOSE:The titled substrate, obtained by using a polycarbonate consisting of specific bisphenol constituent units, etc., under mild conditions and having improved transparency and small optical strain. CONSTITUTION:A substrate obtained by molding a polycarbonate consisting of (A) 60-100wt% carbonate bonding constituent units expressed by formula I (Y and Z are H or 1-6C aliphatic hydrocarbon; X and W are 1-6C aliphatic hydrocarbon) and, as necessary, (B) carbonate bonding constituent units expressed by formula II (Y' and Z' are H or 1-100C hydrocarbon). For example, a bisphenol compound, e.g. 2,2-bis(4-hydroxy-3-methylphenyl)propane and, as necessary, another diol compound, e.g. bisphenol A, are (co)polymerized normally in an inert solvent, e.g. methylene chloride, in the presence of an acid acceptor, e.g. triethylamine, at 0-100 deg.C while introducing phosgene thereinto the produce a polycarbonate having preferably 12,000-22,000 average molecular weight, which is then molded to afford the aimed substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to materials used in the production of optical disk substrates that exhibit erosion of optical properties, particularly for the production of molded articles that exhibit erosion of optical properties and low optical distortion. Concerning materials used in

Conventional technology Molded products used in optical discs, such as plate shapes.

The sheet-like molded product is required to be transparent and to have small optical distortion. Particularly when using digital signals to provide optical information materials, that is, optical discs, such as digital audio discs, digital video discs, and even discs intended for reading and writing information, transparency requirements are extremely strict. Regarding the distortion, it is required that the birefringence in the actual molded product is 1×10' or less.

Usually, injection molding is employed as a simple method for molding such a shape.

Problems to be Solved by the Invention However, increasing the temperature of the molten resin causes various troubles due to thermal deterioration of the resin, and this has not been a sufficient solution.

Means for Solving the Problems This invention was developed after intensive study on a method for constructing an optical disk with excellent transparency and low optical distortion. It has been discovered that a small optical disk substrate can be constructed, and the problems of the prior art described above have been solved.

That is, the present invention provides that among the units constituting the carbonate bond, the unit represented by the following general formula (r) is more than 30% by weight based on the total carbonate bond constituent units.
This is an optical disc substrate made of polycarbonate containing approximately 0.00% by weight.

General formula (1) However, Y and 2 are hydrogen atoms! This is an aliphatic hydrocarbon group with a carbon number of /~B, and X and W are aliphatic hydrocarbon groups with a carbon number of /~B.

By the way, the carbonate bond as used in this invention refers to the 10-C-O- bond obtained by reacting an alcoholic hydroxyl group or a phenolic hydroxyl group with, for example, phosgene. The term "unit" refers to a structural unit formed between such carbonate bonds, and when other bond species 1 such as ester bond, amide bond, carbamate bond, ether bond, etc. are present in the structural unit between the carbonate bonds. There is no problem even if it is included.

The method for manufacturing such polycarbonate is as follows:
A method is proposed in which phosgene is blown into seven or more types of diol compounds including a bisphenol compound giving the structure of general formula (r) and the solution is brought together at the interface. Examples of bisphenol compounds that give the structure represented by general formula (1) include 2,2-bis-(couhydroxy-3
-methylphenyl)propane, λ, 2-bis-(couhydroxy-3-ethylphenyl)propane, 2,2-bis-(gubitroxy-3-imbutylphenyl)propane, core 2-bis-guhydroxy-3- Examples include sec-butylphenyl)propane, sec-2-bis-(4t-hydroxy-3-tert-butylphenyl)propane, and the like.

The carbonate bond structural unit represented by the general formula (1) introduced by such a bisphenol compound (hereinafter referred to as carbonate bond unit A) is more than 60% by weight (70 ONflk) based on the total carbonate bond structural units.
Diol compounds that can be used to introduce carbonate bonding units other than carbonate bonding units, which range from
In particular, the aromatic diols include bis-(4t-hydroxyphenyl)methane, /,/-bis-(terhydroxyphenyl)ethane, 2. λ-Bis(terhydroxyphenyl)propane (bisphenol A'), 2.2-
Bis-(4t-hydroxyphenyl)butane%co, 2-
His-(4t-hydroxyphenyl)pentane, =, 2
-bis-(4t-hydroxyphenyl)-3-methylbutane, 2-bis-(4t-hydroxyphenyl)hexane1. ? ,,! -Bisu(terhydroxyphenyl)
-termethylpentane, /, /-bis-(g-hi)”0
xyphenyl) phenylmethane, /, /-bis-(4t
-Hydroxyphenyl)cyclohexane%, 2.2-
Bis-(4t-hydroxy-3-aryalophenyl)propane1. ! ,,2-bis-(4t-hydroxy-3,r
-dimethylphenyl)propane, kai g'-dihyde axydiphenyl ether, beg'! '-dihydroxydiphenylsulfone%4t, <t'-) human mixidiphenylsulfide, or hydroquinone, resorcinol,
Examples of bisphenol compounds such as 0-methylresorcin and θ-cumylresorcin are 2' (in the formula, Y' and Z' are hydrogen atoms and the return prime number/~1
Of the compounds that provide the units constituting the carbonate bond represented by 0 hydrocarbon group, bisphenol A is the most suitable raw material in terms of reactivity and operability during polycarbonate synthesis. In some cases, acid chlorides such as inphthalic acid chloride, terephthalic acid chloride, adipic acid chloride, sebacic acid chloride, and diamines such as piperazine may be used in combination with bisphenol A. Also, these carbonate bonding units A
When introducing into polycarbonate, it may be copolymerized to the extent that it satisfies the requirements of this invention, or if it is separately polymerized, it may be appropriately mixed afterwards so as to meet the requirements of this invention. In this case, if the carbonate bonding unit A is less than 10% by weight based on the total carbonate bonding structural units, the degree of improvement in melt fluidity will be small, and this will be a hindrance to stably obtaining a molding material with small optical distortion.

In carrying out the present invention, the method for producing polycarbonate resin from a bisphenol compound having the structure of the general formula (D) and phosgene is specifically, in the presence of an inert solvent such as methylene chloride or 7,2-dichloromethane, Add an alkaline water bath solution or pyridine as an acid acceptor to the bisphenol section, and react while introducing phosgene.

When using an alkaline aqueous solution as an acid acceptor, use a tertiary amine such as trimethylamine or triethylamine as a catalyst.
Alternatively, the reaction rate can be increased by using a secondary ammonium compound such as tetrabutylammonium chloride or benzyltributylammonium bromide. If necessary, phenol, p-tertiary
A -valent phenol such as butylphenol is allowed to coexist.

The reaction temperature is 0-100°C.

The catalyst may be added from the beginning, or any method may be used, such as adding it after the oligomer is produced to increase the molecular weight.

Further, as a method for copolymerizing a bisphenol compound giving the structure of general formula (1) and a bisphenol compound giving the structure of general formula (II), a) first, they are simultaneously reacted with phosgene and polymerized.

+al One is first reacted with phosgene, and after a certain degree of reaction, the other is added and polymerized.

(c) Oligomers are prepared by separately reacting with phosgene, and the oligomers are reacted and polymerized.

Any method can be used.

Furthermore, methods for mixing separately polymerized materials include mixing the respective powders or granules and then melting the mixture in an extruder, kneader 1 kneading aar, etc., solution blending method, etc. You can take the following method.

Further, the polycarbonate used in the present invention preferably has an average molecular weight of /2θ0θ to 22,000. The average molecule-i (M) here means polymer 6.0
This value is determined from η8p measured at −20° C. using a 2μ methylene chloride f8 solution using the following equations and equations.

ηap/c=[:η] ('ηsp to /+)...
・・・・・・・・・／) [η)=KM＆ ・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・2) In the formula, O polymer # degree?
/1 [v] Intrinsic viscosity' 0. ．． 2F K/,, 2J'
x 10-5α 0. ! If the average molecular weight is less than 3 M, that is, /20θ0, it is unfavorable in terms of mechanical properties, and if it exceeds 1.22,000, it will be difficult to obtain a molding material with low sensitivity to optical distortion.

When molding the polycarbonate of this invention, 0.00% of the sulfurous acid ester is added to the resin. It is preferable to add θ/~2 weight range in order to suppress discoloration and decrease in transparency due to decomposition of 4tl fingers.

Such phosphites include tributyl phosphite, tris(-monoethylhexyl) phosphite, tridecyl phosphite, tristearyl phosphite,
Examples include triphenyl phosphite, tricresyl phosphite, coethylhexyl diphenyl phosphite, decyl diphenyl phosphite, tricyclohexyl phosphite, distearyl pentaerythrityl diphosphite, and the like. Methods for incorporating such phosphite include a tri-blend method, a method of melt-mixing when pelletizing with an extruder, or a method in which a master pellet with a high phosphite concentration is created and a tri-blend with unadded Robelette. Here are some ways to do it.

The polycarbonate thus obtained is used as a material for optical disk thin plates. Here, the optical disk includes read-only types such as compact disks and laser disks, write-once types used as book files, still image files, and video files, and erasable types such as magneto-optical disks.

EXAMPLES Hereinafter, specific methods for producing polycarbonate and oligomers thereof used in the present invention will be illustrated as examples. It should be noted that all parts indicating the components of each composition below are parts by weight.

In addition, for the resin ζ obtained in Examples and Comparative Examples, λ ethylhexyl diphenyl phosphite was added /304 7J
After Rl, a disk of thickness type /, 2 hours, diameter / θm was molded under the molding conditions shown in the table with injection molding of 10z (Nissei Baking Co., Ltd.) at a molding temperature of 3g and 0°C, and a shear rate of 3°C and a shear rate. /θ3. ．． ．． -1
The apparent melt viscosity ηa was determined as if'tll and used as a measure of melt station mobility.

Regarding birefringence, 2,0 mouths and g from the center of the disk,! α
The tiger was evaluated by birefringence at tilt (hereinafter abbreviated as Δn2.OTΔn45).

Birefringence was measured using a polarizing microscope manufactured by Nippon Optical Co., Ltd. Moisture permeability was measured according to JIS Z020F.

Examples/(a) Polycarbonate oligomer 〇 structure, 2-bis-(4t-human axy-3-methylphenyl)propane 700871, acclimatized sodium
50 parts water
? 70 parts methylene chloride 5
30 p-Tertiary-butylphenol ``-' Part I'' 2. Pour the above mixture into a reactor equipped with a stirrer? Stir at 00 rpm. 70 parts of phosgene was blown into this for 2 hours to perform interfacial polymerization. After the reaction is complete, collect only the methylene chloride solution containing the polycarbonate oligomer.

The analysis results of the methylene chloride solution of the six oligomers obtained were as follows.

Oligomer 4th grade (Note/) 2y, o weight 1 Terminal roloformate group concentration (Note 2) .

(Note 2) Neutralization titration of aniline hydrochloride obtained by reaction with aniline with 0.2N aqueous sodium hydroxide solution.

(Note 3) Colorimetric determination of color development when titanium tetrachloride is not dissolved in acetic acid solution using j4t6nm.

The oligomer solution obtained by the above method is hereinafter abbreviated as oligomer solution-A.

1 portion) Production of polycarbonate Oligomer solution A 700 parts methylene chloride (0 parts) was charged into a reactor equipped with a stirrer and stirred at 100 ml. Further, the following clear aqueous solution was charged and interfacial polymerization was carried out for 3 hours.

Sodium hydroxide Part Triethylamine 0.7 part Water
Subsequently, the reaction mixture was separated into 30 parts, and the methylene chloride solution containing polycarbonate'M14 resin was washed with water, an aqueous hydrochloric acid solution, and then water, and finally the methylene chloride was evaporated to take out the resin. The average molecular weight of this resin is /7. θQθ. Table 1 shows the physical properties of the molded product.

Example C (a) Production of small recarbonate oligomer 7 g, 6% aqueous solution of sodium bisphenol A prepared by dissolving bisphenol A in aqueous sodium hydroxide solution
700 parts p-tert-butylphenol 0.
23 parts methylene chloride 4! O part Phosgene 7 parts A mixture having the above composition was quantitatively supplied to a pipe reactor to perform interfacial polymerization.

The reaction mixture was separated and only the methylene chloride solution containing the polycarbonate oligomer was collected.

The analysis results of the obtained oligomer solution in methylene chloride were as follows.

Oligomer concentration 2g! Heavy iso terminal
o Homeate group concentration 7.3N Song end phenolic hydroxyl group concentration 0.3N
The oligomer solution is hereinafter abbreviated as oligomer solution-B.

(b) Production of copolymerized polycarbonate Oligomer solution-A 1trQ part oligomer solution-B
rO part methylene chloride
700 p-tert-butylphenol
0.3 part was charged into a reactor equipped with a stirrer and stirred at jrOrpm.

Furthermore, an aqueous solution with the following composition was charged and interfacial polymerization was carried out for 3 hours.

Sodium hydroxide/1 part Triethylamine 0.07 part Water
Subsequently, the reaction mixture was separated, and the methylene chloride solution containing the polycarbonate resin was washed with water, an aqueous hydrochloric acid solution, and then water, and finally the methylene chloride was evaporated to take out the resin. The average molecular weight of this resin is /ta,ta00.

Furthermore, the results of NMR analysis indicate that they are copolymerized. The amount of pisphenolum was determined to be 22 parts/f% by weight. Table 2 shows the physical properties of the molded product.

'-A Example 3 (a) Production of polycarbonate oligomer cocobis-(guhydroxy-j-5ee)'tylphenyl)
Flopan 700 parts Sodium hydroxide
35 parts water
700 parts methylene chloride
! Part r, f Charge the above mixture into a reactor equipped with a stirrer 20
Stirred at 0 rpm. Phosgene was blown into this for a period of <'3[-/h to effect interfacial polymerization.

After the reaction was completed, only the methylene chloride solution containing the polycarbonate oligomer was collected.

The analysis results of the methylene chloride solution of the obtained oligomer were as follows.

Oligomer concentration, 23. ! Weightmost terminal a loformate group concentration 019ON terminal phenolic hydroxyl group concentration 0.0! The oligomer solution obtained by the above method is hereinafter abbreviated as oligomer solution-○.

(b) Production of copolymerized polycarbonate Oligo 7-solution-C100 parts Oligomer solution-g 27 partsmethylene chloride! O part p-tertiary-butylphenol ', 'n is charged into a reactor equipped with a stirrer!
! The mixture was stirred at θrpm.

Furthermore, an aqueous solution having the following composition was charged and interfacial polymerization was performed for 3 hours.

Sodium hydroxide 7 parts Triethylamine 0.7 parts Water
Subsequently, the reaction mixture was separated into 4 parts, and the methylene chloride solution containing the polycarbonate resin was washed with water, an aqueous hydrochloric acid solution, and then water. After washing, the methylene chloride was evaporated to take out the resin. The average molecular weight of this resin is / ! , f 00 and from the NMH analysis results, the amount of copolymerized bisphenol A was f%. Table 1 shows the physical properties of the molded product.

Comparative example/ Polycarbonate production example Polycarbonate oligomer solution-B/40 parts p
-Tertiary butylphenol 0.7 parts Methylene chloride/30 parts The above mixture was charged into a reactor equipped with a stirrer.

! ! The mixture was stirred at Orpm. Furthermore, an aqueous solution having the following composition was added.

4% aqueous solution of sodium salt of bisphenol A, 20 parts hydroxide) ! Aqueous solution of ♂ part 2 parts of aqueous solution of tosoethylamine / part / part / Interfacial polymerization was carried out in the evening, the reaction mixture was separated, and the methylene chloride solution containing the polycarbonate resin was washed with water, an aqueous hydrochloric acid solution, and then water. Finally, methylene chloride was evaporated to remove the resin.

The average molecular weight of this tree is /2. It was 00.

Table 2 shows the physical properties of the molded product.

Comparative Example Example of Copolycarbonate Crafting A polycarbonate was constructed using the same composition as the above-mentioned Specification Example except that p-tert-butylphenol was changed to 7.3 parts.

The average molecular weight of this resin was /4t, 700.

Table 2 shows the physical properties of the molded product.

Effects of the Invention As shown in Table λ of Examples, the polycarbonate resin of the present invention has a low melt viscosity, so when it is injection molded as an optical disk substrate, a substrate with low birefringence can be obtained under mild molding conditions.

Furthermore, the substrate obtained using the polycarbonate resin of the present invention has characteristics such as lower moisture permeability and higher hardness than conventional polycarbonate resins made from bisphenol.

Therefore, the optical disk substrate made of the polycarbonate resin of the present invention can reduce birefringence under mild molding conditions, prevent thermal deterioration of the resin, have excellent transparency, and have small optical distortion. .

Sender: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - Others/names

Claims (2)

[Claims] (1) An optical disc made of polycarbonate, in which, among the units constituting carbonate bonds, units represented by the following general formula (I) are contained in a range from 60% to 100% by weight based on the total carbonate bonding constituent units. substrate. (2) All carbonate bonding structural units are expressed by the following general formula (
I) and an optical disc substrate made of polycarbonate according to claim (I), which is a unit represented by the following general formula (II). General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, Y and Z are hydrogen atoms or aliphatic hydrocarbon groups having 1 to 6 carbon atoms, and X and W are aliphatic hydrocarbon groups having 1 to 6 carbon atoms. Hydrogen group general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ However, Y' and Z' are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms.