JP6294114B2 - Aromatic-aliphatic polycarbonate and plastic lens composed thereof - Google Patents

Description

  The present invention provides an aromatic-aliphatic polycarbonate having a high Abbe number and a low birefringence, and further having heat resistance sufficient for practical use, and a plastic lens thereof.

In recent years, polycarbonates made from bisphenols have been used in many fields as materials having mechanical properties such as heat resistance, transparency and impact resistance.
In particular, in the lens field, it has been attracting attention because of its productivity and processability, and is widely used and studied for automotive headlamp lenses, CD, CD-ROM pickup lenses, Fresnel lenses, camera lenses, eyeglass lenses, etc. Has been.
However, polycarbonate made of bisphenol A is
Since the Abbe number is as low as 30, the problem of chromatic aberration tends to occur. In addition, the molded article has a large optical distortion and has optical defects.

In order to solve such drawbacks of polycarbonate, Patent Document 1 discloses a polycarbonate composed of an aromatic diol and an aliphatic diol, or a plastic lens composed thereof. However, this technique still has problems such as low Abbe number and heat resistance, and high birefringence of the molded product.
Furthermore, Patent Document 2 discloses an aromatic polycarbonate composed of spiroindane having a specific structure and bisphenol having a specific structure. However, this technique has low birefringence and high heat resistance, but has a problem that the Abbe number is low.
Until now, a resin having a high Abbe number and a low birefringence and satisfying all of heat resistance has not been obtained.

JP 2003-90901 A JP 2006-131788 A

  Accordingly, an object of the present invention is to provide an aromatic-aliphatic polycarbonate having a high Abbe number and a low birefringence, and also having practically sufficient heat resistance, and a plastic lens thereof.

  The present inventors have intensively studied to achieve this object. As a result, by using an aliphatic diol having a characteristic structure and a diol component having a spiro ring having a specific structure, an aromatic-aliphatic polycarbonate satisfying all the characteristics of high Abbe number, low birefringence, and high heat resistance is obtained. The present invention has been found.

で表される構成単位（Ｉ）および下記式（ＩＩ）

（式中のＲ_１〜Ｒ_２は、夫々独立して水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。）
で表される構成単位を含み、一般式（Ｉ）と一般式（ＩＩ）の割合がモル比で（Ｉ）：（ＩＩ）＝８０：２０〜４０：６０の範囲であり、０．７ｇを１００ｍｌの塩化メチレンに溶解し、２０℃で測定した比粘度が０．１２〜０．４０であり、ガラス転移温度が９０〜１７０℃であるポリカーボネート。
２．上記式（ＩＩ）で表される構成単位におけるＲ_１〜Ｒ_２が夫々独立して水素原子である前記１に記載のポリカーボネート。
３．上記式（ＩＩ）で表される構成単位が、６，６’−ジヒドロキシ−３，３，３’，３’−テトラメチル−１，１’−スピロビインダンに由来する構造である前記１または２に記載のポリカーボネート。
４．一般式（Ｉ）と一般式（ＩＩ）の割合がモル比で（Ｉ）：（ＩＩ）＝６０：４０〜５０：５０の範囲であり、０．７ｇを１００ｍｌの塩化メチレンに溶解し、２０℃で測定した比粘度が０．１２〜０．４０である前記１〜３のいずれかに記載のポリカーボネート。
５．アッベ数が３０〜５０である前記１〜４のいずれかに記載のポリカーボネート。
６．配向複屈折が０〜６×１０^−３である前記１〜５のいずれかに記載のポリカーボネート。
７．フェノール含有量が１〜５００ｐｐｍである前記１〜６のいずれかに記載のポリカーボネート。
８．前記１〜７のいずれかに記載のポリカーボネートを含むプラスチックレンズ。
９．式（ＩＩＩ）、（ＩＶ）で表されるジオールと炭酸エステル形成化合物とを反応させて得ることを特徴とする前記１〜７のいずれかに記載のポリカーボネートの製造方法。

（式中のＲ_３〜Ｒ_４は、夫々独立して水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。） That is, the present invention
1. Formula (I)

A structural unit (I) represented by the formula (II)

(Wherein R _{1 and} R ₂ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number) A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)
The ratio of the general formula (I) and the general formula (II) is in the range of (I) :( II) = 80: 20 to 40:60, and 0.7 g A polycarbonate having a specific viscosity of 0.12 to 0.40 measured at 20 ° C. and a glass transition temperature of 90 to 170 ° C. dissolved in 100 ml of methylene chloride.
2. _2. The polycarbonate according to 1 above, wherein R _{1 to} R ₂ in the structural unit represented by the formula (II) are each independently a hydrogen atom.
3. In the above 1 or 2, the structural unit represented by the formula ( II ) is a structure derived from 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane. The polycarbonate described.
4). The ratio of general formula (I) to general formula (II) is in the range of (I) :( II) = 60: 40 to 50:50 in molar ratio, 0.7 g is dissolved in 100 ml of methylene chloride, 20 4. The polycarbonate according to any one of 1 to 3 above, wherein the specific viscosity measured at ° C is 0.12 to 0.40.
5. The polycarbonate in any one of said 1-4 whose Abbe number is 30-50.
6). 6. The polycarbonate according to any one of 1 to 5 above, wherein the orientation birefringence is 0 to 6 × 10 ⁻³ .
7). The polycarbonate in any one of said 1-6 whose phenol content is 1-500 ppm.
8). A plastic lens comprising the polycarbonate according to any one of 1 to 7 above.
9. 8. The method for producing a polycarbonate according to any one of 1 to 7 above, which is obtained by reacting a diol represented by the formulas (III) and (IV) with a carbonate ester-forming compound.

(In the formula, R _{3 to} R ₄ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number. A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)

  The polycarbonate of the present invention has all the characteristics of high Abbe number, low birefringence and heat resistance by using an aliphatic diol component having a specific structure and an aromatic diol component having a spiro ring. The industrial effect is exceptional.

2 is a proton NMR of the polycarbonate obtained in Example 3.

<Polycarbonate>
Hereinafter, each component which comprises the polycarbonate of this invention, those compounding ratios, the adjustment method, etc. are demonstrated concretely one by one.
The polycarbonate of the present invention contains a carbonate unit represented by the following formula (I).

The upper limit of the content of the carbonate unit represented by the formula (I) is 80 mol%, more preferably 70 mol%, and most preferably 60 mol%.
Moreover, a lower limit is 40 mol%, More preferably, it is 45 mol%, Most preferably, it is 50 mol%. When the proportion of the structural unit represented by the general formula (I) is larger than the upper limit value, the heat resistance is poor, which is not preferable. Moreover, if it is smaller than the lower limit value, the Abbe number becomes small, which is not preferable.
Moreover, the carbonate unit represented by following formula (II) is contained.

（式中のＲ_１〜Ｒ_２は、夫々独立して水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。）

(Wherein R _{1 and} R ₂ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number) A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)

The upper limit of the content of the carbonate unit represented by the formula (II) is 60 mol%, more preferably 55 mol%, and most preferably 50 mol%.
Moreover, a lower limit is 20 mol%, More preferably, it is 30 mol%, Most preferably, it is 40 mol%. When the proportion of the structural unit represented by the general formula (II) is larger than the upper limit value, the Abbe number becomes small, which is not preferable. On the other hand, if it is smaller than the lower limit, the heat resistance becomes poor, which is not preferable.
The total of the carbonate unit represented by the formula (I) and the carbonate unit represented by the formula (II) is preferably 70 mol% or more, more preferably 80 mol% or more based on all repeating units, Preferably it is 90 mol% or more.

The specific viscosity of the polycarbonate of the present invention is 0.12 to 0.40, preferably 0.15 to 0.40, and more preferably 0.18 to 0.35. Specific viscosity is measured at 20 ° C. by dissolving 0.7 g of polycarbonate in 100 ml of methylene chloride. If the specific viscosity is less than 0.12, the molded product becomes brittle. If the specific viscosity is higher than 0.40, the melt viscosity becomes high when injection molding is performed, and it is difficult to handle the molded product.
In the polycarbonate of the present invention, R _{1 to} R ₂ in the structural unit represented by the above formula (I) are preferably hydrogen atoms.
The structural unit represented by the above formula (I) in the polycarbonate of the present invention has a structure derived from 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane. Things are more preferable.

<Abbe number>
The Abbe number (ν) of the polycarbonate of the present invention is preferably in the range of 30 to 50, more preferably 35 to 50, and still more preferably 35 to 44. The Abbe number is calculated from the refractive index at 25 ° C., wavelengths 486 nm, 589 nm, and 656 nm using the following formula. If the Abbe number is lower than 30, chromatic aberration is likely to occur, and the usable applications are limited.
v = (nD-1) / (nF-nC)
nD: Refractive index at a wavelength of 589 nm nF: Refractive index at a wavelength of 656 nm nC: Refractive index at a wavelength of 486 nm

<Orientation birefringence>
The orientation birefringence (Δn) of the polycarbonate of the present invention is preferably in the range of 0 to 6 × 10 ⁻³ , more preferably 0 to 4 × 10 ⁻³ , and still more preferably 0 to 3 × 10 ⁻³ . The orientation birefringence (Δn) is measured at a wavelength of 589 nm when a cast film having a thickness of 100 μm obtained from the polycarbonate is stretched twice at Tg + 10 ° C. When the orientation birefringence (Δn) exceeds 6 × 10 ⁻³ , when used for injection molding, optical distortion occurs in the molded product, which is not preferable.

<Glass-transition temperature>
The glass transition temperature (Tg) of the polycarbonate of the present invention is preferably 90 to 170 ° C, more preferably 100 to 160 ° C, and still more preferably 120 to 150 ° C. The glass transition temperature (Tg) is measured at a heating rate of 20 ° C./min. When the Tg is less than 90 ° C, the heat resistance is not sufficient depending on the use of the plastic lens formed using the polycarbonate. On the other hand, when the Tg is higher than 170 ° C, the melt viscosity becomes high and the molded product is formed. Handling is difficult and not preferred.

<Transmissivity>
The spectral transmittance of the polycarbonate of the present invention is preferably 80% or more, more preferably 81% or more, and further preferably 82% or more. The transmittance is measured at a wavelength of 395 nm on a molded plate having a thickness of 1 mm. A spectral transmittance of less than 80% is not preferable as a plastic lens.

<Phenol content>
The amount of residual phenol in the polycarbonate of the present invention is preferably 1 to 500 ppm, more preferably 1 to 400 ppm, and still more preferably 1 to 300 ppm. The molding fluidity can be improved without impairing the heat resistance. However, if it exceeds 500 ppm, the thermal stability when melted by heating is poor, and further, mold contamination during resin injection molding becomes severe, which is undesirable because it causes a decrease in wet heat resistance. Furthermore, phenol has a property of coloring when oxidized, and the hue of polycarbonate deteriorates.

<Production method of polycarbonate>
The polycarbonate of the present invention can be produced by reacting a diol component and a carbonate precursor.

(Diol component)
One of the diol components in the polycarbonate of the present invention is a diol represented by the following formula (III).

The upper limit of the content of the diol represented by the formula (III) is 80 mol%, more preferably 70 mol%, and most preferably 60 mol%.
Moreover, a lower limit is 40 mol%, More preferably, it is 45 mol%, Most preferably, it is 50 mol%. When the ratio of the diol represented by the formula (III) is larger than the upper limit value, the heat resistance becomes poor, which is not preferable. Moreover, if it is smaller than the lower limit value, the Abbe number becomes small, which is not preferable.
One of the diol components in the polycarbonate of the present invention is a diol represented by the following formula (IV).

（式中のＲ_３〜Ｒ_４は、夫々独立して水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。）

(In the formula, R _{3 to} R ₄ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number. A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)

The upper limit of the content of the diol represented by the formula (IV) is 60 mol%, more preferably 55 mol%, and most preferably 50 mol%.
Moreover, a lower limit is 20 mol%, More preferably, it is 30 mol%, Most preferably, it is 40 mol%. When the proportion of the diol represented by the formula (IV) is larger than the upper limit value, the Abbe number becomes small, which is not preferable. On the other hand, if it is smaller than the lower limit, the heat resistance becomes poor, which is not preferable.
The total of the diol represented by the formula (III) and the diol represented by the formula (IV) is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol based on the total diol. % Or more.

In the polycarbonate of the present invention, R _{3 to} R ₄ in the structural unit represented by the above formula (IV) are preferably hydrogen atoms.
The structure represented by the general formula (IV) in the polycarbonate of the present invention is more preferably 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane.

The polycarbonate of the present invention may be copolymerized with other diols. Examples of other diol components include aliphatic diols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and tricyclo [5.2. 1.0 ^2,6 ] decanedimethanol, cyclohexane-1,4-dimethanol, decalin-2,6-dimethanol, norbornanedimethanol, pentacyclopentadecanedimethanol, cyclopentane-1,3-dimethanol, spiro Alicyclic diols such as glycol, 1,4: 3,6-dianhydro-D-sorbitol, 1,4: 3,6-dianhydro-D-mannitol, 1,4: 3,6-dianhydro-L-iditol, Bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxy Enyl) ethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, 2 , 2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1, 1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxyphenyl) diphenylmethane, 1 , 1-Bis (4-hydroxyphenyl) -1-phenyl ester Tan, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, α, ω-bis [2- (p-hydroxyphenyl) ethyl] polydimethyl Siloxane, α, ω-bis [3- (o-hydroxyphenyl) propyl] polydimethylsiloxane, 4,4 ′-[1,3-phenylenebis (1-methylethylidene) droxyphenyl] -1-phenylethane, Examples include aromatic diols such as 10,10-bis (4-hydroxyphenyl) anthrone and bisphenol A.

  The molar ratio of the diol component containing the general formula (III) and the diol component containing the general formula (IV) is in the range of 80:20 to 40:60, and the Abbe number of the plastic lens containing polycarbonate is large. Heat resistance is also sufficient, and birefringence is particularly small, which is preferable. More preferably, it is 70: 30-40: 60, More preferably, it is 60: 40-50: 50.

(Carbonate precursor)
As the carbonate precursor, phosgene, bischloroformate of 9,9-bis [4- (2-hydroxyethoxy) -3-phenylphenyl] fluorene, diphenyl carbonate, di-p-tolyl carbonate, phenyl-p- Examples include carbonic acid diesters such as tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Of these, diphenyl carbonate is preferred.

(Production method)
In the reaction of diol and phosgene, the reaction is performed in a non-aqueous system in the presence of an acid binder and a solvent. Examples of the acid binder include pyridine, dimethylaminopyridine, tertiary amine and the like. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. It is desirable to use a terminal terminator such as phenol or p-tert-butylphenol as the molecular weight regulator. The reaction temperature is usually 0 to 40 ° C., and the reaction time is preferably several minutes to 5 hours.

  In the transesterification reaction, diol and bisaryl carbonate are mixed in the presence of an inert gas, and usually 120 to 350 ° C. under reduced pressure in the presence of a mixed catalyst containing an alkali metal compound catalyst or an alkaline earth metal compound or both. The reaction is preferably performed at 150 to 300 ° C. The degree of vacuum is changed stepwise, and finally the alcohol produced at 133 Pa or less is distilled out of the system. The reaction time is usually about 1 to 4 hours.

As a polymerization catalyst, an alkali metal compound or an alkaline earth metal compound may be used as a main component, and a nitrogen-containing basic compound may be used as a subsidiary component if necessary.
Examples of the alkali metal compound used as the catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogen carbonate and the like.
Examples of the nitrogen-containing basic compound used as a promoter include tetramethylammonium hydroxide and tetraethylammonium hydroxide.
These catalysts may be used alone or in combination of two or more, and the amount of these polymerization catalysts used is in a ratio of 10 ⁻⁹ to 10 ⁻³ mol with respect to 1 mol of the total diol component. . Moreover, you may add antioxidant, a heat stabilizer, etc. for a hue improvement.

In the polycarbonate of the present invention, the catalyst may be removed or deactivated after the polymerization reaction in order to maintain thermal stability and hydrolysis stability. As for the alkali metal compound or the alkaline earth metal compound, generally, a method of deactivating the catalyst by adding a known acidic substance is preferably carried out. Specific examples of the deactivation include esters such as butyl benzoate, organic halides such as aromatic sulfonic acids such as p-toluenesulfonic acid, alkyl sulfates such as dimethyl sulfate, and benzyl chloride. An organic halide or the like is preferably used. These deactivators are used in an amount of 0.01 to 50 times mol, preferably 0.3 to 20 times mol for the amount of catalyst. When the amount is less than 0.01 times the amount of the catalyst, the deactivation effect is insufficient, which is not preferable. Moreover, when it is more than 50 times mole with respect to the amount of catalyst, since heat resistance falls and it becomes easy to color a molded object, it is unpreferable.
After deactivation of the catalyst, a step of devolatilizing and removing the low boiling point compound in the polycarbonate at a pressure of 133 to 13.3 Pa and a temperature of 200 to 320 ° C may be provided.

<Additive>
In order to impart various properties to the polycarbonate of the present invention within a range not impairing the object of the present invention, various additives may be contained to form a composition. Additives include mold release agents, heat stabilizers, UV absorbers, bluing agents, antistatic agents, flame retardants, heat ray shielding agents, fluorescent dyes (including fluorescent whitening agents), pigments, light diffusing agents, reinforcing fillers Other resins and elastomers can be blended.

The content of the release agent in the composition using the polycarbonate of the present invention is preferably in the range of 0.005 to 2.0 parts by weight, and in the range of 0.01 to 0.6 parts by weight with respect to 100 parts by weight of the polycarbonate. Is more preferable, and the range of 0.02 to 0.5 parts by weight is even more preferable.
Examples of the heat stabilizer include a phosphorus heat stabilizer, a sulfur heat stabilizer, and a hindered phenol heat stabilizer.
As for content of each stabilizer in the polycarbonate of this invention, 0.001-0.2 weight part is preferable with respect to 100 weight part of polycarbonate.
The phosphorus stabilizer and the hindered phenol heat stabilizer can be used in combination.
As the ultraviolet absorber, at least one ultraviolet absorber selected from the group comprising benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, cyclic imino ester-based ultraviolet absorbers, and cyanoacrylate-based ones. preferable.

Examples of the bluing agent include Macrolex Violet B and Macrolex Blue RR manufactured by Bayer and polysynthremble-RLS manufactured by Clariant. The bluing agent is effective for eliminating the yellow color of the resin. In particular, in the case of polycarbonate imparted with weather resistance, since a certain amount of ultraviolet absorber is blended, there is a reality that the molded body tends to be yellowish due to the action and color of the ultraviolet absorber, which is particularly natural for sheets and lenses. In order to impart transparency, the blending of the bluing agent is very effective.
The blending amount of the bluing agent is preferably 0.05 to 1.5 ppm, more preferably 0.1 to 1.2 ppm based on the polycarbonate.

Well-known methods can be used to add various additives to the polycarbonate of the present invention. For example, a method of mixing each component in a solution state and evaporating the solvent or precipitating in the solvent can be mentioned. From an industrial point of view, a method of kneading each component in a molten state is preferable. For melt kneading, generally used kneading apparatuses such as a single or twin screw extruder and various kneaders can be used. A biaxial high kneader is particularly preferable. In melt kneading, the cylinder set temperature of the kneading device is preferably in the range of 200 to 340 ° C, more preferably 250 to 320 ° C. When the temperature is higher than 320 ° C., the polycarbonate is decomposed, and coloring and defective molding due to the decomposition product increase, which is not preferable. Furthermore, if it is less than 200 degreeC, the viscosity of a polycarbonate is high and cannot disperse | distribute various additives uniformly. The melt kneading may be performed in a vacuum state. Melting and kneading in a vacuum state is preferable because low molecular weight substances such as residual PhOH of polycarbonate can be reduced and molding defects can be reduced. The degree of vacuum is preferably a pressure of 13.3 kPa or less, and more preferably 1.3 kPa or less.
At the time of kneading, each component may be mixed uniformly in advance with a device such as a tumbler or a Henschel mixer, or if necessary, a method of omitting the mixing and separately supplying each of the components separately to the kneading device is also used. be able to.

(Plastic lens)
The plastic lens using the polycarbonate of the present invention is an optical lens such as an eyeglass lens, an automotive headlamp lens, a CD, a CD-ROM pickup lens, a Fresnel lens, an fθ lens for a laser printer, a camera lens, or a projection lens for a rear projection television. Optical molded products such as lenses, optical disks, optical elements of image display media, optical films, films, substrates, various optical filters, prisms and the like.
The plastic lens using the polycarbonate of the present invention can be molded by, for example, injection molding, compression molding, injection compression molding, or casting of the polycarbonate of the present invention.

The plastic lens using the polycarbonate of the present invention is characterized by small optical distortion. A plastic lens containing a general bisphenol A type polycarbonate has a large optical distortion. Although it is not impossible to reduce the value depending on molding conditions, the condition width is very small and molding is very difficult. The polycarbonate of the present invention has very little optical distortion caused by orientation and also has a small molding distortion. Therefore, a good plastic lens can be obtained without setting molding conditions strictly. Particularly useful for eyeglass lenses, the Abbe's number is sufficiently large, so that the focal blur due to chromatic aberration is difficult to occur, and the optical anisotropy of the molded product due to the small birefringence is small, and the imaging focal point is shifted. The problem that the image performance deteriorates is less likely to occur.
When the plastic lens using the polycarbonate of the present invention is produced by injection molding, it is preferably molded under conditions of a cylinder temperature of 260 to 320 ° C and a mold temperature of 100 to 140 ° C.

A coating layer such as an antireflection layer or a hard coating layer may be provided on the surface of the plastic lens using the polycarbonate of the present invention, if necessary. The antireflection layer may be a single layer or a multilayer, and may be organic or inorganic, but is preferably inorganic. Specific examples include oxides or fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxide, and magnesium fluoride. As the hard coat layer, either thermosetting or active energy curable is preferably used.
Moreover, the plastic lens using the polycarbonate of the present invention may be molded by any method such as mold forming, cutting, polishing, laser processing, electric discharge processing, and edging. Furthermore, mold molding is more preferable.

The following examples further illustrate the present invention.
Examples 1-5, Comparative Examples 1-5
An evaluation sample was prepared by the following method.
(A) Cast film:
5 g of the obtained polycarbonate is dissolved in 50 ml of methylene chloride and cast on a glass petri dish. After sufficiently drying at room temperature, it was dried at a temperature of 20 ° C. or lower from the Tg of the polycarbonate for 8 hours to prepare a cast film.
(B) Plastic lens:
The obtained polycarbonate was vacuum-dried at 120 ° C. for 8 hours, and the molding temperature was Tg + 130 ° C., the mold temperature was Tg−10 ° C., and the molding machine NISSEI ES4000 was used. An eyeglass lens molded article of -1.2 was molded.
(C) Molded Piece As in the case of (b) above, a molded piece having a width of 2.5 cm, a length of 5 cm and a thickness of 1 mm was injection molded.

Evaluation was based on the following method.
(1) Specific viscosity: The obtained polycarbonate was sufficiently dried, and the specific viscosity (η _sp ) at 20 ° C. of the solution was measured from a solution obtained by dissolving 0.7 g of the polycarbonate in 100 ml of methylene chloride.

(2) Copolymerization ratio: The obtained polycarbonate was measured by using proton NMR of JNM-AL400 manufactured by JEOL Ltd. For example, in the case of Examples 1-4, the peak resulting from 3.7 to 4.2 ppm of cyclohexanedimethanol and 2.0 to 2.4 ppm of 6,6′-dihydroxy-3,3,3 ′, 3 ′ -It calculated | required from the integration ratio of the peak resulting from tetramethyl-1,1'- spirobiindane.

(3) Glass transition point (Tg): The obtained polycarbonate was measured by a DuPont 910 type DSC at a heating rate of 20 ° C./min.

(4) Spectral transmittance: A 1 mm-thick molded piece injection-molded by the method (c) was measured using a spectrophotometer U-3310 manufactured by Hitachi. Evaluation was performed as follows.
The transmittance at 395 nm is 80% or more:
Transmittance at 395 nm is below 80%: x

(5) Oriented birefringence (Δn): A cast film having a thickness of 100 μm prepared by the method of (a) was stretched twice at Tg + 10 ° C., and the position at 589 nm was measured using an ellipsometer M-220 manufactured by JASCO Corporation. The phase difference (Re) was measured, and the orientation birefringence (Δn) was determined from the following formula.
Δn = Re / d
Δn: orientation birefringence
Re: Phase difference (nm)
d: Thickness (nm)

(6) Refractive index (nd), Abbe number (ν): A molded piece having a thickness of 1 mm obtained by injection molding according to the method of (c) was used at 25 ° C. using an ATAGO DR-M2 Abbe refractometer. The refractive index (wavelength: 589 nm) and Abbe number were measured.

(7) Optical distortion: A plastic lens molded by the method of (b) was sandwiched between two polarizing plates, and optical distortion was evaluated by visually observing light leakage from behind by the orthogonal Nicol method. Evaluation was performed according to the following criteria.
A: There is almost no light leakage.
○: Slight light leakage is observed.
X: Light leakage is remarkable.

(8) Phenol content: The phenol content in the obtained polycarbonate was measured on a column of Develosil ODS-7 manufactured by Nomura Chemical, using a mixture of eluent acetonitrile and 0.2% aqueous acetic acid, and a column temperature of 30 ° C. HPLC analysis with a gradient program at a detector of 277 nm. Phenol was quantified by preparing a calibration curve using a standard. The measurement was performed by dissolving 1.5 g of polycarbonate in 15 ml of methylene chloride, adding 135 ml of acetonitrile, stirring, concentrating with an evaporator, filtering through a 0.2 μm filter, and injecting 10 μl of this measurement solution.

Example 1
115.37 parts by weight of cyclohexanedimethanol (hereinafter sometimes abbreviated as “CHDM”), 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane (hereinafter “CHDM”) SBI ″ may be abbreviated) 61.68 parts by weight, DPC 222.79 parts by weight, sodium hydroxide 1.00 × 10 ⁻³ parts by weight and tetramethylammonium hydroxide 1.82 × 10 ⁻² parts by weight And it put into the reaction kettle with a distillation apparatus, heated to 180 degreeC under nitrogen atmosphere normal pressure, and stirred for 20 minutes. Thereafter, the pressure reduction degree in the kettle was adjusted to 20 to 30 kPa over 20 minutes, and the temperature was raised to 260 ° C. at a rate of 60 ° C./hr to perform a transesterification reaction. Thereafter, while maintaining the temperature at 260 ° C., the pressure was reduced to 0.13 kPa or less over 120 minutes, and the polymerization reaction was performed with stirring for 1 hour under the conditions of 260 ° C. and 0.13 kPa or less. The polycarbonate had a molar ratio of CHDM to SBI of 80:20, a specific viscosity of 0.250, and a residual PhOH of 300 ppm.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Example 2
Polymerization was carried out in the same manner as in Example 1 except that the reaction time under conditions of 100.95 parts by weight of CHDM, 92.53 parts by weight of SBI, 222.79 g of DPC, 260 ° C. and 0.13 kPa or less was 0.5 hour.
The polycarbonate had a CHDM to SBI molar ratio of 70:30, a specific viscosity of 0.240, and a residual PhOH of 330 ppm.
The prepared polycarbonate was vacuum-dried at 123 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Example 3
Polymerization was carried out in the same manner as in Example 1 except that the reaction time under the conditions of 86.53 parts by weight of CHDM, 123.37 parts by weight of SBI, 222.79 g of DPC, 260 ° C. and 0.13 kPa or less was 0.5 hour.
The polycarbonate had a molar ratio of CHDM to SBI of 60:40, a specific viscosity of 0.265, and a residual PhOH of 310 ppm.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Example 4
Polymerization was conducted in the same manner as in Example 1 except that CHDM 72.11 parts by weight and SBI 154.21 parts by weight were used.
The polycarbonate had a molar ratio of CHDM to SBI of 50:50, a specific viscosity of 0.255, and a residual PhOH of 300 ppm.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Example 5
Polymerization was conducted in the same manner as in Example 1 except that 57.68 parts by weight of CHDM and 185.05 parts by weight of SBI were used.
The polycarbonate had a molar ratio of CHDM to SBI of 40:60, a specific viscosity of 0.260, and a residual PhOH of 320 ppm.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Comparative Example 1
Polymerization was conducted in the same manner as in Example 1 except that CHDM was 378.43 parts by weight and SBI was 129.79 parts by weight.
The polycarbonate had a CHDM to SBI molar ratio of 90:10 and a specific viscosity of 0.250.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Comparative Example 2
Polymerization was conducted in the same manner as in Example 1 except for 43.26 parts by weight of CHDM and 215.89 parts by weight of SBI.
The polycarbonate had a CHDM to SBI molar ratio of 30:70 and a specific viscosity of 0.255.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Comparative Example 3
The amount of CHDM used is 43.37 parts by weight, the amount of bisphenol A (hereinafter sometimes referred to as “BPA”) is 68.67 parts by weight, DPC 132.39 parts by weight, sodium hydroxide 2.40 × 10 ^{− 3} parts by weight and 2.73 × 10 ⁻² parts by weight of tetramethylammonium hydroxide were placed in a reaction kettle equipped with a stirrer and a distillation apparatus, heated to 180 ° C. under a nitrogen atmosphere of 760 Torr, and stirred for 20 minutes. Thereafter, the pressure reduction degree in the kettle was adjusted to 13.4 kPa over 20 minutes, the temperature was raised to 200 ° C. at a rate of 60 ° C./hr, and held for 40 minutes. Then, it heated up to 240 degreeC over 60 minutes, and transesterification was performed. Thereafter, the pressure was reduced to 1 Torr or less over 80 minutes, and the polymerization reaction was carried out under stirring at 240 ° C. and 1 Torr or less for 1 hour. Then, after adding 14.06 mg of dodecylbenzenesulfonic acid tetrabutylphosphonium salt as a deactivator and stirring at 240 ° C. and 1.33 × 10 ⁴ Pa for 20 minutes, the produced polycarbonate resin was extracted while pelletizing. The polycarbonate resin had a CHDM to BPA ratio of 50:50 in molar ratio and a specific viscosity of 0.280.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Comparative Example 4
43.26 parts by weight of CHDM, 93.12 parts by weight of 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as “Bis-TMC”), DPC132. 39 parts by weight, 2.40 × 10 ⁻³ parts by weight of sodium hydroxide and 2.73 × 10 ⁻² parts by weight of tetramethylammonium hydroxide mg were put into a reaction kettle equipped with a stirrer and a distillation apparatus, and under a nitrogen atmosphere of 760 Torr, Heat to 180 ° C. and stir for 20 minutes. Thereafter, the degree of vacuum was adjusted to 13.4 kPa over 20 minutes, the temperature was raised to 200 ° C. at a rate of 60 ° C./hr, and held for 40 minutes. Then, it heated up to 240 degreeC over 60 minutes, and transesterification was performed. Thereafter, the pressure was reduced to 1 Torr or less over 80 minutes, and the polymerization reaction was carried out with stirring for 30 minutes under the conditions of 240 ° C. and 1 Torr or less. After adding 14.06 mg of dodecylbenzenesulfonic acid tetrabutylphosphonium salt as a deactivator and stirring at 240 ° C. and 1.33 × 10 ⁴ Pa for 20 minutes, the produced polycarbonate resin was extracted while pelletizing. The polycarbonate had a molar ratio of CHDM to Bis-TMC of 50:50 and a specific viscosity of 0.255.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

Comparative Example 5
19.51 parts of SBI, 2.54 parts of BPA, 24.60 parts of 48.50% aqueous sodium hydroxide solution and 107.70 parts of distilled water were charged into a reactor equipped with a stirrer and dissolved. To this, 82.60 parts of methylene chloride was added, the mixed solution was cooled to 20 ° C., and 10.00 parts of phosgene was blown in over 40 minutes. Thereafter, 0.11 part of p-tert-butylphenol was dissolved in methylene chloride to the reaction solution, 3.09 part of 48.5% aqueous sodium hydroxide solution and 0.03 part of triethylamine were added, and the reaction was continued by stirring for 2 hours. finished. After completion of the reaction, the lower layer polycarbonate methylene chloride solution was separated from the reaction solution, and this solution was washed with an aqueous hydrochloric acid solution and distilled water, and then methylene chloride was removed by evaporation to obtain a polycarbonate.
The polycarbonate had a molar ratio of structural units of SBI and BPA of 85:15 and a specific viscosity of 0.319.
The prepared polycarbonate was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.05% and pentaerythritol tetrastearate were added based on the weight of the obtained polycarbonate composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder.

  The polycarbonates obtained in Examples 1 to 5 have a large Abbe number and high heat resistance. Furthermore, since the orientation birefringence is low, the optical distortion of the plastic lens obtained by injection molding is small. On the other hand, the polycarbonates obtained in Comparative Examples 1, 3, and 4 have a large orientation birefringence and a large optical distortion of the molded product, so that the uses that can be used are limited. Further, Comparative Example 1 has poor heat resistance, and Comparative Examples 2 and 5 have a small Abbe number.

  The polycarbonate of the present invention has a high Abbe number and low birefringence, and further has heat resistance sufficient for practical use, and thus is useful for a plastic lens. In particular, it can be used in fields where expensive glass lenses have been used, such as eyeglass lenses, automotive headlamp lenses, CDs, CD-ROM pickup lenses, Fresnel lenses, fθ lenses for laser printers, and camera lenses. It is.

Claims (9)

Formula (I)

A structural unit (I) represented by the formula (II)

(Wherein R _{1 and} R ₂ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number) A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)
The ratio of the general formula (I) and the general formula (II) is in the range of (I) :( II) = 80: 20 to 40:60, and 0.7 g A polycarbonate having a specific viscosity of 0.12 to 0.40 measured at 20 ° C. and a glass transition temperature of 90 to 170 ° C. dissolved in 100 ml of methylene chloride. The polycarbonate according to claim 1, wherein R _{1 to} R ₂ in the structural unit represented by the formula (II) are each independently a hydrogen atom. The structural unit represented by the formula ( II ) is a structure derived from 6,6'-dihydroxy-3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane. Polycarbonate.   The ratio of general formula (I) to general formula (II) is in the range of (I) :( II) = 60: 40 to 50:50 in molar ratio, 0.7 g is dissolved in 100 ml of methylene chloride, 20 The polycarbonate according to any one of claims 1 to 3, which has a specific viscosity measured at ° C of 0.12 to 0.40.   The polycarbonate according to any one of claims 1 to 4, having an Abbe number of 30 to 50. The polycarbonate according to any one of claims 1 to 5, wherein the orientation birefringence is 0 to 6 x ^10-3 .   The polycarbonate according to any one of claims 1 to 6, wherein the phenol content is 1 to 500 ppm.   The plastic lens containing the polycarbonate in any one of Claims 1-7. The method for producing a polycarbonate according to any one of claims 1 to 7, which is obtained by reacting a diol represented by the formulas (III) and (IV) with a carbonate ester-forming compound.

(In the formula, R _{3 to} R ₄ are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a carbon number. A alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms.)

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