JPH03102657A - Optical card - Google Patents

Abstract

PURPOSE:To provide the optical card which has the small double refractions to diagonal incidence, is optically homogeneous and is excellent in bending strength by forming the optical card of an arom. polycarbonate copolymer having specific two kinds of constituting units. CONSTITUTION:At least the protective layer of the base material layer and protective layer of the optical card having at least the base material layer, a recording layer and the protective layer is formed of the arom. polycarbonate copolymer having the constituting unit expressed by formula I and the constituting unit expressed by formula II. In the formula I, A denotes an alkylene group, cycloalkylene group, etc.; X and Y denote a halogen atom, hydrogen atom, alkyl group, etc.; (m) and (n) denote 1 or 2 integer; in the formula II, R7 to R10 denote a hydrogen atom, alkyl group, aryl group, cycloalkyl group. The optical card which has the small double refractions to the diagonal incidence, is optically homogeneous and is excellent in the bending strength is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical card useful for heat mode optical recording and reproduction.

[Prior Art and Problems to be Solved by the Invention] Conventionally, magnetic recording cards and the like have been known as card-shaped f/i information recording media. This magnetic recording card is used as a banking card, credit card, telephone card, etc. because it is easy to record, erase, and reproduce information and is excellent in portability. However, in this magnetic recording card, not only the storage capacity of the magnetic storage section is as small as 72 bytes, but also the recorded information is disturbed by the magnetic field, resulting in insufficient reliability.

On the other hand, an optical card has been proposed as an information recording medium for optically recording and reproducing information. This optical card has a storage capacity of about 2 MB or more and is characterized by high reliability of recorded information.

Therefore, it can be used for a wide range of purposes including those mentioned above, such as electronic publishing,
It is expected that it will be put into practical use as computer software, medical management cards, prepaid cards, maintenance management cards, etc.

This optical card usually has a structure in which a base layer and a protective layer are laminated with a recording layer interposed therebetween. Furthermore, there are known types of optical cards, one for playback only and one for additional recording. In a read-only optical card, a plurality of bands are generally arranged in parallel in the longitudinal direction of the card, forming an information area. In each band, tracks containing several bytes of data are formed in orthogonal directions, and the bands and tracks constitute bit cells. Further, information is recorded in the bit cell as a binary signal depending on the presence or absence of a low reflection part and the position of the low reflection part. Additionally, in add-on recording type optical cards, a track for recording data linearly is usually formed in the longitudinal direction of the card, and a guide for recording data at an appropriate position is formed parallel to the track. ing. Furthermore, information regarding addresses and the like is preformatted at the end of each track.

Further, reproduction or additional recording of information recorded on the optical card is performed by irradiating laser light from the protective layer side and detecting changes in the amount of reflected light from the recording layer. Therefore, in order to improve recording and reproducing accuracy, the protective layer is required to have excellent optical homogeneity and low photoelastic constant and birefringence. Furthermore, since information recording and reproduction using laser light is normally performed while condensing the light using an objective lens, the light enters the protective layer from an oblique direction. Therefore, the protective layer is required to have optical homogeneity against oblique incidence. Furthermore, optical cards are not only required to be thin from the point of view of portability, but also because information is recorded and reproduced while the card moves back and forth, the card must not be deformed during the back and forth movement. Excellent strength is required.

On the other hand, the protective layer is usually made of bisphenol A polycarbonate, which has excellent optical properties and mechanical strength. Further, the base material layer is formed of an acrylic resin such as polymethyl methacrylate, the above-mentioned bisphenol A type polycarbonate, polyamide, or the like.

However, bisphenol A type polycarbonate constituting the protective layer has large birefringence and does not have sufficient accuracy in recording and reproducing information. That is, although birefringence is expressed as the product of photoelastic constant and residual stress, bisphenol A polycarbonate has a large photoelastic constant, so birefringence becomes large. Furthermore, when a protective layer made of the above-mentioned polycarbonate is laminated on the recording layer, due to residual stress etc.
Birefringence becomes even greater. Especially the above bisphenol A
Type polycarbonate has large birefringence against oblique incidence. Furthermore, there is a problem in that the bisphenol A type polycarbonate constituting the protective layer still does not have sufficient bending strength.

Therefore, an object of the present invention is to provide an optical card that has low birefringence with respect to oblique incidence, is optically homogeneous, and has excellent bending strength.

[Structure of the Invention] As a result of intensive studies, the present inventors discovered that a specific aromatic polycarbonate copolymer has excellent optical homogeneity and bending strength, and completed the present invention. That is, the present invention provides an optical card having at least a base material layer, a recording layer, and a protective layer.
l1-position, [wherein A may have a substituent]
, S Alkylene group having 1 to 10 carbon atoms, cycloanolekylene group, cycloalkylidene group, oxygen atom, sulfur atom, sulfinyl group, sulfonyl group, group -81 -D-82 CB+ and B2 are the same or different, and are an oxygen atom , represents a sulfonyl group, D represents anolekylene group, cycloalkylidene group, or arylene group having 2 to 6 carbon atoms), (Rl , R2 , R3 and R4 are each the same or different from C, hydrogen atom, carbon number 1) ~8 alkynole groups, optionally substituted aryl groups, and cycloalkyl groups; R5 represents anolekylene groups having 1 to 6 carbon atoms)
, Group -CONHR6 NHCO - (Rs represents an alkylene group having 2 to 10 carbon atoms) R1 Direct R2 (R+ and R2 are the same as above) Represents a group selected from group h). X and Y are the same or different from C and represent a halogen atom, a hydrogen atom, an anolekyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group.

m and n represent integers of 1 or (2) In the groove unit E formula represented by the following general formula (II), Rv
, Re, Rg and R(are each the same or different and represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, or a cycloanolequinole group, and E represents a cycloalkylene group or an arylene group.

The above-mentioned problem is solved by an optical card formed of an aromatic polycarbonate copolymer having the following formula:

The optical card of the present invention has a base layer, a recording layer formed on the base layer, and a protective layer formed on the recording layer.

The recording layer can be selected as appropriate depending on the information recording/reproducing method, that is, read-only, additional recording, or rewritable type. The recording layer is not limited to one layer, and may be configured in combination with other recording layers, underlayers, etc. For example, the recording layer may be composed of a reflective layer made of aluminum or the like and a layer having a non-reflective part,
A cluster layer constituting the recording layer of Son Laser Ca'd, an organic dye and its composition, etc. may be used.

As the organic dye, a dye that absorbs data writing and reading wavelengths can be appropriately selected. Examples of such dyes include conventionally used dyes, such as cyanine dyes, phthalocyanine dyes, anthraquinone dyes, azo dyes, indathrene dyes, triarylmethane dyes, voluphyline dyes, biryllium or thiavirylium salt dyes. Pigments, naphthoquinone dyes, especially the applicant's patent application published in 1982
Examples include naphthoquinone dyes proposed in JP-A-288088 and JP-A-83-104888.

Furthermore, the composition containing the above-mentioned dye usually contains a binder. As this binder, various conventionally known polymers such as acrylic resin, styrene resin,
Polyester resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal such as polyvinyl butyral, polyvinyl formal, cellulose derivatives such as polyurethane, polyamide, nitrified cotton, acetic cotton, etc. is exemplified. In addition, the said composite may contain additives, such as a stabilizer, an antistatic agent, a surfactant, and a plasticizer. Further, the above composition usually contains an organic solvent. Examples of this organic solvent include methanol, ethanol,
Alcohols such as isobrobanol, alicyclic hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as chloroform, dichloromethane and carbon tetrachloride, acetone,
Ketones such as methyl ethyl ketone, cellosolves such as methyl cellosolve, ethers such as diethyl ether and tetrahydrofuran, esters such as methyl acetate and ethyl acetate, and mixed solvents thereof can be used.

The recording layer may usually be formed on the base layer by a dry process such as vapor deposition or sputtering, or by a wet process such as spin coating, dipping, or roller coating.

The recording layer usually has a thickness of 0.01 to 10μ, preferably 0.05μ.
Approximately 1 μm.

At least the protective layer of the base layer and the protective layer constituting the optical card is an aromatic polymer having a structural unit represented by the general formula [I] and a structural unit represented by the general formula [I]. Made of carbonate copolymer.

(11 (I [] The above general formula (
Among the divalent groups A in No. 11, examples of the alkylene group having 1 to 10 carbon atoms include methylene, ethylene, ethylidene, propylene, trimethylene, isopropylidene, probylmethylene, isoprobylmethylene, diethylmethylene, 1- Ethyl-1-methylmethylene, 1-methyl-1
-probylmethylene, 1-isobrobyl-1-methylmethylene, diprobylmethylene, 1-butyl-1-methylmethylene, 1-benzene-1-methylmethylene, 1-hexyl-1-methylmethylene, 1-hebutyl- Examples include linear or branched alkylene groups such as 1-methylmethylene, tetramethylene, hexamethylene, and decamethylene groups.

Substitution of the above alkylene group includes cyclohexyl,
cycloalkyl groups such as cyclooctyl and cyclododecyl groups; aryl groups that may have substituents such as phenyl, p-methylphenyl, p-isobrobylphenyl, and naphthyl groups; halogen atoms such as fluorine, chlorine, and bromine; Alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, proboxycarbonyl, isobroboxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, hexyloxycarbonyl, etc. is exemplified.

Examples of the cycloalkylene group include a 1,4-cyclohexylene group, and examples of the cycloalkylidene group include cyclohexylidene, cyclooctylidene, and cyclododecylene groups.

Examples of the alkyl group include methyl, ethyl, probyl, isobrobyl, butyl, isobutyl, tert-butyl, bentyl, hexyl, heptyl, and octyl groups.

Examples of the aryl group include phenyl and naphthyl groups.

Examples of the substituent for the aryl group which may have a substituent include the above-mentioned alkyl groups; methoxy, ethoxy, broboxy, isoproboxy, butoxy, isopoxy, te
Examples include alkoxy groups such as rt-butoxy, pentyloxy, and hexyloxy groups.

Examples of the cycloalkyl group include cyclohexyl,
Examples include cyclooctyl and cyclododecyl groups.

Examples of the arylene group include 1,4-phenylene,
Examples include 1,3-phenylene, 4,4'-biphenylene, and naphthylene groups.

The halogen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, or cycloalkyl groups of the substituents X and Y that are substituted on the phenylene group of the structural unit represented by the general formula m are as mentioned above. Similar groups are exemplified.

Examples of bisphenol compounds having the structural unit represented by the above general formula (I) include bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, and 1,1-bis(4-hydroxyphenyl)methane. (4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)
Butane, 1,1-bis(4-hydroxyphenyl)isobutane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis( 4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)
Bentane, 2,2-bis(4-hydroxyphenyl)-
4-methylbentane, 2,2-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)pentane, 2. 2-bis(4-hydroxyphenyl)octane, 2.2-bis(4-hydroxyphenyl)nonane, 1.2-bis(4-hydroxyphenyl)
Ethane, 1.10-bis(4-hydroxyphenyl)decane, 1.1-bis(4-hydroxyphenyl)cyclohexane, 1.1-bis(4-hydroxyphenyl)cyclododecane, 2,2-bis (4-hydroxy-3-methylphenyl)brobane, 2,2-bis(4-hydroxy-3-ethylphenyl)propane, 2,2-bis(4
-hydroxy-3-propylphenyl)propane, 2,
2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(4-hydroxy-3-butylphenyl)propane, 2,2-bis(4-hydroxy-3-isobutylphenyl)brovane, 2.2-bis(
4-hydroxy-3-seC. butylphenyl)propane, 2,2-bis(4-hydroxy-3-ter)
tbutylphenyl)broban, 2,2-bis(3.5-
dimethyl-4-hydroxyphenyl)propane, 2-
(4-hydroxy-3-cyclohexylphenyl)-2
- (4-hydroxyphenyl)propane, 2. 2-
Bis(4-hydroxy-3-cyclohexylphenyl)
Propane, 2-(4-hydroxy-3-methoxyphenyl)-2-(4-hydroxyphenyl)propane, 2
,2-bis(4-hydroxy-3-methoxyphenyl)
Propane, 2-(4-hydroxy-3-isoprobylphenyl)-2-(4-hydroxyphenyl)propane, 1.1-bis(4-hydroxy-3.5-dichlorophenyl)methane, 2. 2-bis(4-hydroxy-3
-chlorophenyl)propane, 2.2-bis(4-hydroxy-3.5-dichlorophenyl)propane, 2.
2-bis(4-hydroxy-3-fluorophenyl)propane, 2.2-bis(4-hydroxy-3.5-difluorophenyl)propane, 2.2-bis(4-hydroxy-3-promophenyl)propane , 2.2-bis(
4-hydroxy-3,5-dibromophenyl)propane, 1,1-bis(4-hydroxy-3,5-dichlorophenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-1.1 -Bis(difluorochloromethyl)methane, 2,2-bis(4-hydroxyphenyl)-
4-Ptoxycarbonylbutane, 1,4-bis(4-hydroxyphenyl)cyclohexane, 1-(4-hydroxyphenyl)-4-(4-hydroxyphenylethyl)cyclohexane, 2,2-bis(4- hydroxyphenyl)bicyclo[2.2.11 hebutane, 2.2-bis(4-hydroxy-3.5-dichlorophenyl)bicyclo[2.2.11 hebutane, 4,4'-dihydroxydiphenyl ether, 1.4-bis(4-hydroxyphenoxy)benzene, 4.4'-bis(4-hydroxyphenoxy)biphenyl, 4.4'-dihydroxydiphenyl sulfide, 4.4'-dihydroxy-3,3
'-dimethyldiphenyl sulfide, 4.4'-dihydroxydiphenyl sulfoxide, 4.4'-dihydroxydiphenyl sulfone, 4.4'-dihydroxy-3.3'-dichlorodiphenyl sulfone, 1,4-
bis(4-hydroxyphenylsulfonyl)benzene,
4.4'-bis(4-hydroxyphenylsulfonyl)
Benzene, 1,2-bis(4-hydroxyphenoxy)
Examples include ethane, 1,4-bis(4-hydroxyphenoxy)butane, and phenolphthalein. In addition, instead of the compound having the structural unit represented by the general formula [I] or together with the compound having the structural unit represented by the general formula 0}, hydroquinone, resorcinol, 0-methylresorcinol, 0-cumylresorcinol can also be used.

Among bisphenol compounds having a structural unit represented by the general formula (I), a bisphenol compound having a pendant ryoryl group, that is, a compound having a structural unit represented by the following general formula (1)-1, In particular, general formula (1) -
A compound having a structural unit represented by 2 is preferred.

(1) -1 (1) -2 (wherein Rl+ and RI2 are the same or different and selected from the group consisting of a hydrogen atom, a C1-C6 alkyl group, and an aryl group, and among Rl+ and RI2 At least one of them is an aryl group.
4'-dihydroxytriphenylmethane, 1,1-bis(4-hydroxyphenyl)-1-(4-isobrobyl)phenylmethane, 1.1-bis(4-hydroxyphenyl)-1-naphthylmethane, 4. 4'-dihydroxy-2.2.2-}rifenylethane, 1,1-bis(4
-hydroxyphenyl)-1-naphthylethane, 4.4
Examples include '-dihydroxy-1.1.1-triphenylpropane, 4,4'-dihydroxytetraphenylmethane, and bis(4-hydroxyphenyl)dibenzylmethane.

One or more types of bisphenol compounds having the structural unit represented by the general formula [I] are used.

Further, as a bisphenol compound having a structural unit represented by general formula (II), for example, 1.1'bis(4-
hydroxyphenyl) p-diisobrobylbenzene (
1,4-bis[2-(4-hydroxyphenyl)propyl]benzene), 1,1'-bis(4-hydroxy-3
-chlorophenyl)1 p-diisopropylbenzene (1
, 4-bis[2-(4-11'roxy-3-chlorophenyl)proyl]benzene), 1,1'-bis(4-hydroxy-3-methylphenyl)-p-diisobrobylbenzene (1,4-bis[ 2-(4-hydroxy-3-
methylphenyl)propyl J benzene), 1,4-bis[2- (4-hydroxy-3,5-dichlorophenyl)propyl J benzene, 1,4-bis[:2-(4-hydroxy-3.5 -dimethylphenyl)propyl]benzene, 1.1'bis(4-hydroxyphenyl)-m-
Diisopropylbenzene (1,3-bis[2-(4-hydroxyphenyl)propyl]benzene), 1,3-bis[2-(4-hydroxy-3-chlorophenyl)propyl]benzene, 1,3- Bis[2-(4-hydroxy-3-methylphenyl)probyl]benzene, 1,3-
Bis[2-(4-hydroxy-3-isopropylphenyl>probyl]benzene, 1,3-bis[2-(4-
hydroxy-3,5-dichlorophenyl)propyl]benzene, 1,3-bis[2-(4-hydroxydi-3.
5-dimethylphenyl)probyl]benzene, 1,3-bis[2-(4-hydroxy-3,5-diisopropylphenyl)brobyl]benzene, 1,4-bis(4-
Examples include hydroxyphenylmethyl)benzene.

Among bisphenol compounds having a structural unit represented by the general formula (I []), compounds having a structural unit represented by the following general formula ([1-1], especially those represented by the general formula ([1-2) A compound having a structural unit is preferred.

The folds are extremely small. That is, particularly preferred aromatic polycarbonate copolymers are 4,4'-dihydroxy-2.2.2-triphenylethane represented by the following general formula (f)-'1 and the following general formula (It)- 1 represented by 3,
It is composed of an aromatic polycarbonate copolymer in which 1'-bis(4-hydroxyphenyl)-m-diisobrobylbenzene is carbonate bonded.

(It)-1 (It)-2 (wherein Ry to R1, XSY, m and n are the same as above) The aromatic polycarbonate having the structural unit m and the structural unit (11) The refraction is small.Especially the configuration ilt position (+) -1 and the configuration !l1 position [111 -
Among them, an aromatic polycarbonate copolymer having the structural unit ([1-2) and m-2 at the 111th position of the structure has birefringence (1) -3 ( II
)-3 The structural unit represented by the general formula [1] and the general formula (I
The ratio of the structural unit represented by general formula m/general formula (It
) -1 0/90 to 90/10 mol%, preferably 25/75 to 75/2 5 mol%,
More preferably, it is 40/60 to 70/30 mol%, particularly 55/45 to 65/35 mol%. If the ratio of the structural units represented by the general formula 01 and the structural units represented by the general formula (I[] is outside the above range, optical homogeneity, especially birefringence at oblique incidence, will increase. There is a tendency for the bending strength to decrease.

In addition, the structural unit represented by general formula [I] is 55 to 65 mol%, especially about 60 mol%, and the structural unit represented by general formula [I] is 45 to 35 mol%, especially about 40 mol%. It appears that the aromatic polycarbonate copolymer has extremely low birefringence with respect to oblique human radiation, exhibiting a minimum value.

The aromatic polycarbonate copolymer has an initial elastic modulus of 2. 5 X 1 04~3. OX
104, yield strength is 1000 or more, and bending strength is high. Therefore, even if the thickness is reduced, the reciprocating card will not be deformed during data recording and reproduction, and information can be stably recorded and reproduced.

Furthermore, since the aromatic polycarbonate copolymer has low hygroscopicity, it is excellent in protecting the recording layer.

The aromatic polycarbonate copolymer may have an appropriate molecular weight within a range that does not impair mechanical strength, etc., but usually has a viscosity average molecular weight of 1.3 x 104 to 5. OX10
It is about 4. If the viscosity average molecular weight is less than 1.3 x 104, the polycarbonate copolymer will be brittle.5. OX
If it exceeds 104, the shapeability decreases as the fluidity decreases. In addition, the glass transition temperature of polycarbonate copolymer is
Usually, the temperature is about 110 to 170°C.

The aromatic polycarbonate copolymer usually exhibits a refractive index of about 1.60 to 1.62 and a photoelastic constant of about 45-12 to 55 Brevsters (10 +t?/N).

The above-mentioned protective layer can usually be formed to a thickness of about 0.1 to 1 mm by means such as lamination.

In the optical card having the above structure, it is sufficient that at least the protective layer is formed of the aromatic polycarbonate copolymer, and the material forming the base layer may be other than the aromatic polycarbonate copolymer. , bisphenol A type polycarbonate, acrylic resin such as polymethyl methacrylate, polyamide, polyolefin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyester, and various other polymeric materials can be used. This base material layer usually has a film thickness of 0.
It can be shaped to about 1 to 1 mm.

Note that the laminated structure of the optical card is not limited to the form in which the protective layer and the base material layer are laminated with the recording layer interposed therebetween, and various forms can be adopted. For example, a surface hardening layer for preventing scratches may be formed on the surface of the protective layer in the laminated state,
The above protective layer may be laminated on the surface of the base layer. Furthermore, a protective layer and a surface hardening layer may be sequentially laminated on both sides of the base layer with a recording film interposed therebetween. The surface hardening layer can be formed to a thickness of about 1 to 10 I#.

The aromatic polycarbonate copolymer containing the structural unit represented by the above general formula [I] and the structural unit represented by the general formula [I] can be prepared by a conventional method, such as a transesterification method or a phosgene method. It can be manufactured by

In the transesterification method, a mixture of a bisphenol compound having a structural unit represented by general formula (I) and a bisphenol compound having a structural unit represented by general formula [I] is stoichiometrically equivalent. A polycarbonate copolymer is obtained by adding a slight excess of diphenyl carbonate and reacting in the presence of a conventional carbonation catalyst. In the above reaction, it is preferable to gradually increase the reaction temperature and degree of vacuum under an inert atmosphere as the reaction progresses. More specifically, at the beginning of the reaction, about 160
React at a temperature of ~180°C under normal pressure for about 30 minutes while introducing an inert gas, then gradually raise the temperature while reducing the pressure over about 2 to 3 hours, and at a temperature of about 180 to 220°C. Finally, the pressure is set to 10 Torr, and the precondensation is completed. Thereafter, the temperature and degree of vacuum are increased. For example, pressure 10T
orr, about 30 minutes at a temperature of 270°C, and a pressure of 5 Torr.
, the reaction was carried out at a temperature of 270°C for about 20 minutes, and then the pressure was reduced to 0. 5 Torr or less, preferably 0. 3
Torr~0. A polycarbonate copolymer is obtained by post-condensation under reduced pressure of I Torr and at a temperature of about 270° C. for about 1.5 to 2.0 hours.

Note that carbonation catalysts for carbonate bonding include lithium-based catalysts and potassium-based catalysts. Alkali metal and alkaline earth metal catalysts such as sodium-based catalysts, calcium-based catalysts, and tin-based catalysts are suitable. More specifically, for example, lithium hydroxide, lithium carbonate, potassium borohydride, potassium hydrogen phosphate, sodium hydroxide,
Examples include sodium borohydride, calcium hydride, dibutyltin oxide, and stannous oxide. Among these, potassium-based catalysts are preferred.

In addition, in the phosgene method, a bisphenol compound having a structural unit represented by the general formula m and the general formula (
A polycarbonate copolymer can be obtained by dissolving or suspending a mixture with a bisphenol compound having the structural unit represented by II) in an organic solvent, an aqueous sodium hydroxide solution, etc., and introducing phosgene while stirring. Note that the phosgene method can be carried out by a conventional method, but
Specifically, it is as follows.

As the organic solvent, pyridine, dichloromethane, chloroform, tetrahydrofuran, or a mixed solvent thereof can be used. During the reaction, phosgene is usually introduced under vigorous stirring.

In addition, since phosgene is a highly toxic substance, it must be operated in a strong fume hood. Further, a unit is usually attached to the exhaust end to decompose excess phosgene and detoxify it with, for example, a 10% by weight sodium hydroxide aqueous solution. When introducing phosgene, it is introduced from the cylinder into the flask through an air washing bottle, an air washing bottle containing paraffin, etc. for counting the number of bubbles, and an empty air washing bottle. Salts may be formed depending on the organic solvent, such as pyridine. in this case,
The gas introduction tube is attached to the top of the stirrer, and it is preferable to widen the tip into a funnel shape to prevent it from being blocked by the precipitated pyridine salt. Note that as the gas is introduced, pyridine hydrochloride precipitates and the contents become cloudy.

Although the reaction temperature can be set as appropriate, it is usually carried out at a temperature of 30° C. or lower while controlling the reaction temperature by water cooling or the like. As the condensation reaction progresses, the contents become viscous. After the reaction is completed, a poor solvent such as methanol is added to precipitate the polymer, which is then filtered and dried.

Since the raw polycarbonate copolymer is soluble in methylene chloride, pyridine, chloroform, tetrahydrofuran, etc., it is purified by reprecipitation from these solutions with methanol.

[Effects of the Invention] As described above, according to the optical card of the present invention, the protective layer is
Since it is formed from an aromatic polycarbonate copolymer having a structural unit represented by general formula (I) and a structural unit represented by general formula [I], birefringence against oblique incidence is small and optical It is homogeneous and has excellent bending strength.

[Examples] The present invention will be described in more detail below based on Examples.

Example 1 A 10% by weight aqueous sodium hydroxide solution was injected into a flask equipped with a stirrer, a thermometer, a gas inlet pipe, and an exhaust pipe, and 4,4'-dihydroxy-2.2.2-1liphenyl 10 mol% of ethane and 90% of 1,1'-bis(4-hydroxyphenyl)-m-diisobrobylbenzene
% by mole was added and uniformly dissolved. Dichloromethane was then added and phosgene gas was introduced with vigorous stirring.

Note that phosgene was introduced from the cylinder into the flask through an empty air washing bottle, an air washing bottle containing water, and an empty air washing bottle. Further, the reaction temperature during the introduction of phosgene gas was maintained at 25° C. or lower by water cooling.

After the reaction was completed, the reaction solution was poured into methanol, filtered, washed with water, and this operation was repeated. Then, the purified polycarbonate was dissolved in dichloromethane, poured into methanol, reprecipitated, purified, and dried.

Example 2 Other than using 30 mol% of 4.4'-dihydroxy-2.2.2-1 rifenylethane and 70 mol% of 1.1'-bis(4-hydroxyphenyl)-m-diisopropylbenzene A polycarbonate was obtained in the same manner as in Example 1 above.

Example 3 Other than using 50 mol% of 4.4'-dihydroxy-2.2.2-1 rifenylethane and 50 mol% of 1.1'-bis(4-hydroxyphenyl)-m-diisobrobylbenzene Polycarbonate was obtained in the same manner as in Example 1 above.

Example 4 Except for using 60 mol% of 4,4'-dihydroxy-2.2.2-}rifunylethane and 40 mol% of 1,1'-bis(4-hydroxyphenyl)-m-diisopropylbenzene. Polycarbonate was obtained in the same manner as in Example 1 above.

Example 5 Except for using 90 mol% of 4.4'-dihydroxy-2.2.2-1 rifhenylethane and 10 mol% of 1.1'-bis(4-hydroxyphenyl)1m-diisobrobylbenzene. Polycarbonate was obtained in the same manner as in Example 1 above.

Comparative Example Bisphenol A type polycarbonate (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name S-1000) was used.

The viscosity average molecular weight of the polycarbonate of each example and comparative example was determined using dichloromethane as a solvent at a temperature of 20°C.
It was calculated from the solution viscosity in , and the physical properties of each polycarbonate were measured for the items shown in the table.

The thermal decomposition temperature of the polycarbonate sample is TG-DT.
A (manufactured by Rigaku Denki ■, trade name Thermoflex), the glass transition temperature was measured using a differential scanning calorimeter (manufactured by Perkin-Elmer, trade name DSC-2C), and the water absorption rate was measured in water at a temperature of 25 °C. This is the value after immersion for 24 hours.

Tensile properties and bending properties were measured using Tensilon (manufactured by Toyo Baudouin ■, trade name UTM-I-5000B), and Izod impact strength was measured using an Izod impact strength tester (manufactured by Toyo Seiki Seisakusho ■, trade name Izod Impact Tester). Measured using Moreover, the refractive index is a value measured using visible light using an Appe refractometer (manufactured by Atago Corporation).

Moreover, using the polycarbonate of each example and comparative example,
An optical card was produced as follows. That is, it is made of polycarbonate and has a size of 85.5 x 54 x 0.3 mm.
A card was prepared, and one side of the card was marked with the
5-amino-2,3-dicyano-8- [4- (4-(2.4-di-tert
-bentylphenoxy)ptoxy)anilino] -1.4
- A recording layer was formed by coating a solution of 1.5 parts by weight of nabutoquinone dissolved in 100 parts by weight of methyl isobutyl ketone by a subin coating method and air drying. Next, a polycarbonate film having a thickness of 0.3 M was laminated on the recording layer by heat fusion.

The photoelastic constant and birefringence of the obtained optical card are at wavelength 633.
The measurement was performed under the conditions of n1 and an incident angle of 30''.

The results are shown in the table.

(Hereinafter, blank space) As is clear from this table, the aromatic polycarbonate copolymers of Examples 1 to 5 have higher mechanical strength, especially bending strength, than the bisphenol A polycarbonate of Comparative Example. It was found that the birefringence at oblique incidence was small.

Claims (1)

[Scope of Claims] An optical card having at least a base material layer, a recording layer, and a protective layer, wherein at least the protective layer among the base material layer and the protective layer comprises a structural unit represented by the following general formula [I]. , ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, A is a carbon number of 1 to 1 which may have a substituent.
0 alkylene group, cycloalkylene group, cycloalkylidene group, oxygen atom, sulfur atom, sulfinyl group, sulfonyl group, group -B_1-D-B_2- (B_1 and B_2 are the same or different and represent an oxygen atom, a sulfonyl group) , D is an alkylene group having 2 to 6 carbon atoms,
Cycloalkylidene group, arylene group), Group ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, Group ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1, R_2, R_3 and R_4 are each the same or different, and are , represents an alkyl group having 1 to 8 carbon atoms, an aryl group that may have a substituent, or a cycloalkyl group, and R_5 represents an alkylene group having 1 to 6 carbon atoms)
, Group ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , Group ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Group -CONHR_6NHCO- (R_6 represents an alkylene group having 2 to 10 carbon atoms) Group ▲
There are mathematical formulas, chemical formulas, tables, etc. Indicates a group selected from the group consisting of ▼ (R_1 and R_2 are the same as above). X and Y are the same or different and represent a halogen atom, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group. m and n represent integers of 1 or 2] Constituent unit represented by the following general formula [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_7, R_8, R_9 and R_1_0 are each the same or Differently, it represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, or a cycloalkyl group, and E represents a cycloalkylene group or an arylene group. X, Y, Z
, m and n are the same as defined above.