HK1237360A1 - Polycarbonate resin and optical lens - Google Patents

Description

Polycarbonate resin and optical lens

Technical Field

The present invention relates to a novel polycarbonate resin and an optical lens formed therefrom. The present invention also relates to an optical lens having a high abbe number, low birefringence, high transparency, and a high glass transition temperature (heat resistance) in a well-balanced manner.

Background

As a material of an optical element used in an optical system of various cameras such as a camera, a film-integrated camera, and a video camera, optical glass or optically transparent resin can be used. Optical glass is excellent in heat resistance, transparency, dimensional stability, chemical resistance and the like, and there are many kinds of materials having various refractive indices (nD) and abbe numbers (ν D), but there are problems that not only material cost is high, but also molding processability is poor and productivity is low. In particular, when processing an aspherical lens used for aberration correction, an extremely advanced technique and high cost are required, and therefore, this is a large practical obstacle.

On the other hand, optical lenses made of optical transparent resins, particularly thermoplastic transparent resins, can be mass-produced by injection molding, and have the advantage that they are easy to manufacture aspherical lenses, and are now used for camera lenses. For example, polycarbonate containing bisphenol A, polystyrene, poly-4-methylpentene, polymethyl methacrylate, amorphous polyolefin, or the like can be exemplified.

However, when an optical transparent resin is used as an optical lens, transparency, heat resistance, and low birefringence are required in addition to the refractive index and abbe number, and therefore, there is a disadvantage that the use site is limited in accordance with the property balance of the resin. For example, polystyrene has low heat resistance and large birefringence, poly-4-methylpentene has low heat resistance, polymethyl methacrylate has low glass transition temperature, low heat resistance and small refractive index, and thus the field of use is limited, and polycarbonate containing bisphenol A has a weak point such as large birefringence, and thus the site of use is limited, which is not preferable.

On the other hand, if the refractive index of the optical material is generally high, it is possible to realize a lens element having the same refractive index by a surface having a small curvature, and therefore, it is possible to reduce the amount of aberration generated on the surface, and it is possible to realize a reduction in size and weight of the lens system by a reduction in the number of lenses, a reduction in the decentering sensitivity of the lens, and a reduction in the thickness of the lens, and therefore, it is useful to increase the refractive index.

In addition, it is known that chromatic aberration is corrected by using a plurality of lenses having different abbe numbers in combination in the optical design of the optical unit. For example, a lens made of an alicyclic polyolefin resin having an abbe number of 45 to 60 and a lens made of a polycarbonate resin containing bisphenol a having a low abbe number (nD 1.59, vd 29) are combined to correct chromatic aberration.

Among transparent resins for optical use which have been put into practical use in optical lens applications, there are high abbe number resins such as polymethyl methacrylate (PMMA) and cycloolefin polymers. In particular, cycloolefin polymers are widely used for optical lens applications because of their excellent heat resistance and excellent mechanical properties.

Examples of the resin having a low abbe number include polyesters and polycarbonates. For example, the resin described in patent document 1 is characterized by a high refractive index and a low abbe number.

There is a difference in water absorption expansion rate between a cycloolefin polymer having a high abbe number and a polycarbonate resin which is a polymer having a low abbe number, and if a lens unit is formed by combining the lenses of both, a difference occurs in the size of the lens when water is absorbed in a use environment of a smartphone or the like. The performance of the lens is compromised due to this difference in expansion.

Patent documents 2 to 4 describe polycarbonate copolymers having a perhydroxydimethanol naphthalene skeleton, but since the dihydroxymethyl groups are present at both 2-and 3-positions, the strength is weak and they are not suitable for optical lens applications. In addition, the polycarbonates described in patent documents 2 to 4 have a problem in heat resistance because of their low glass transition temperature (Tg). For example, the HOMO polycarbonate described in example 1 of patent document 4 has a glass transition temperature (Tg) as low as 125 ℃, although the number average molecular weight is 38000.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2014/73496

Patent document 2: japanese laid-open patent publication No. 5-70584

Patent document 3: japanese laid-open patent publication No. 2-69520

Patent document 4: japanese laid-open patent publication No. 5-341124

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a high-Abbe number resin having a small difference in water absorption expansion coefficient with respect to a polycarbonate resin having a high refractive index and a low Abbe number. And an optical lens made of the resin.

Means for solving the problems

The present inventors have made extensive studies to solve the above problems, and as a result, have found that a polycarbonate resin comprising decahydro-1, 4:5, 8-dimethanol naphthalene diol (D-NDM) as a raw material can solve the above problems, and have completed the present invention.

That is, the present invention relates to a polycarbonate resin and an optical lens shown below.

< 1 > a polycarbonate resin comprising a constituent unit represented by the following general formula (1).

(in the general formula (1), R is H, CH₃Or C₂H₅。)

< 2 > the polycarbonate resin as described above < 1 > comprising-CH in the above general formula (1)₂Isomers in which O-group is bonded at 6-position (isomers at 2, 6-position) and-CH in the above general formula (1)₂The O-group is bound to a mixture of isomers at the 7-position (isomers at the 2, 7-positions).

< 3 > the polycarbonate resin as described above < 2 >, the content ratio of the above isomer at the 2, 6-position and the above isomer at the 2, 7-position being 1.0: 99.0-99.0: 1.0.

< 4 > the polycarbonate resin according to any one of the above < 1 > to < 3 >, wherein the polycarbonate resin has a water swelling ratio of 0.01 to 0.5%.

[ 5 ] the polycarbonate resin according to any one of the above [ 1] to [ 4 ], wherein the Abbe number of the polycarbonate resin is 25 or more.

< 6 > the polycarbonate resin according to any one of the above < 1 > to < 5 >, wherein the polycarbonate resin has a glass transition temperature of 110 to 160 ℃.

< 7 > the polycarbonate resin according to any one of the above < 1 > to < 6 >, wherein the polycarbonate resin has a weight average molecular weight of 5,000 to 50,000.

< 8 > an optical lens obtained by molding the polycarbonate resin as defined in any one of the above < 1 > to < 7 >.

< 9 > A method for producing a polycarbonate resin, which comprises a step of reacting a diol compound represented by the following general formula (2) with a carbonic acid diester.

(in the general formula (2), R is H, CH₃Or C₂H₅。)

< 10 > the method for producing a polycarbonate resin according to < 9 >, wherein the diol compound contains-CH in the general formula (2)₂Isomers in which OH group is bonded at 6-position (isomers at 2, 6-position) and-CH in the above general formula (2)₂The OH group is bound to a mixture of isomers at the 7 position (isomers at the 2,7 positions).

Isomers at the 2,6 position

Isomers in the 2,7 positions.

< 11 > the process for producing a polycarbonate resin, according to the above < 10 >, wherein the content ratio of the isomer at the 2, 6-position to the isomer at the 2, 7-position is 1.0: 99.0-99.0: 1.0.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a high abbe number resin having a small difference in water absorption expansion coefficient with respect to a polycarbonate resin having a high refractive index and a low abbe number. An optical lens made of the resin can also be obtained.

Drawings

FIG. 1 shows the results of 1H-NMR measurement of the main reaction product obtained in monomer synthesis example 1.

FIG. 2 shows the results of 13C-NMR measurement of the main reaction product obtained in monomer synthesis example 1.

FIG. 3 shows the results of COSY-NMR measurement of the main reaction product obtained in monomer synthesis example 1.

FIG. 4 shows the results of 1H-NMR measurement of the polycarbonate resin obtained in example 3.

Detailed Description

(A) Polycarbonate resin

The polycarbonate resin of the present invention contains a constitutional unit represented by the general formula (1) (hereinafter, referred to as "constitutional unit (1)"). For this purpose, a constituent unit derived from decahydro-1, 4:5, 8-dimethanol naphthalene diol (sometimes referred to as D-NDM) can be exemplified. As described later, the constituent unit (1) is obtained by reacting a diol compound represented by the general formula (2) with a carbonic diester.

The polycarbonate resin of the present invention may contain other constituent units in addition to the polycarbonate resin composed of only the constituent unit (1).

Other constituent units that may be contained are constituent units obtained by reacting a diol compound other than the general formula (2) with a carbonic acid diester, and examples of the diol compound other than the general formula (2) include bisphenol a, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, and the like. Among them, 9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene is preferable.

The polycarbonate resin of the present invention preferably has a polystyrene-equivalent weight average molecular weight (Mw) of 5,000 to 300,000. The polystyrene-equivalent weight average molecular weight (Mw) is more preferably 30,000 to 120,000. In another preferred embodiment, the polystyrene-reduced weight average molecular weight (Mw) is preferably 5,000 to 50,000, and more preferably 7,000 to 45,000. Further, preferable lower limit values of the polystyrene-equivalent weight average molecular weight (Mw) include 35,000 and 41,000. If the Mw is less than 5,000, the optical lens becomes brittle and is not preferable. If Mw is more than 300,000, melt viscosity becomes high, and it is difficult to draw out the resin after production, and fluidity becomes poor, and injection molding in a molten state becomes difficult, which is not preferable.

The polycarbonate resin of the present invention has a reduced viscosity (. eta.sp/C) of 0.20dl/g or more, preferably 0.23 to 0.84 dl/g.

Further, to the polycarbonate resin of the present invention, an antioxidant, a mold release agent, an ultraviolet absorber, a fluidity modifier, a crystal nucleating agent, a reinforcing agent, a dye, an antistatic agent, an antibacterial agent, or the like is preferably added.

(B) Process for producing diol compound represented by general formula (2)

The diol compound represented by the general formula (2) can be synthesized, for example, by a route represented by the following formula (3) using dicyclopentadiene or cyclopentadiene and an olefin having a functional group as raw materials.

(in the formula (3), R is H, CH₃Or C₂H₅。R₁Is COOCH₃、COOC₂H₅、COOC₃H₇、COOC₄H₉Or CHO. )

[ production of a monoolefin having 13 to 19 carbon atoms represented by the formula (C) ]

The monoolefin having 13 to 19 carbon atoms represented by the formula (C) can be produced by performing Diels-Alder (Diels-Alder) reaction of an olefin having a functional group and dicyclopentadiene.

Examples of the olefin having a functional group used in the diels-alder reaction include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methacrolein, acrolein, and the like, and more preferred examples of the olefin include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrolein, and acrolein.

The dicyclopentadiene used in the diels-alder reaction is preferably a highly pure product, and it is desirable to avoid butadiene, isoprene, and the like as much as possible. The purity of dicyclopentadiene is preferably 90% or more, more preferably 95% or more. Furthermore, dicyclopentadiene is known to depolymerize under heating to cyclopentadiene (so-called monocyclopentadiene), and thus cyclopentadiene can be used instead of dicyclopentadiene. It is considered that the monoolefin having 13 to 19 carbon atoms represented by the formula (C) is substantially produced by the monoolefin having 8 to 14 carbon atoms represented by the following formula (4) (the 1 st stage diels-alder reaction product), and the produced monoolefin of the formula (4) is produced as a novel Dienophile compound (Dienophile) by the diels-alder reaction (the 2 nd stage diels-alder reaction) with cyclopentadiene (Diene) present in the reaction system to produce the monoolefin having 13 to 19 carbon atoms represented by the formula (C).

(wherein R is H, CH₃Or C₂H₅。R₁Is COOCH₃、COOC₂H₅、COOC₃H₇、COOC₄H₉Or CHO. )

In order to efficiently carry out the Diels-Alder reaction of the above-mentioned stage 2, it is important that cyclopentadiene is present in the reaction system, and therefore the reaction temperature is preferably 100 ℃ or higher, more preferably 120 ℃ or higher, and particularly preferably 130 ℃ or higher. On the other hand, in order to suppress by-production of high-boiling substances, it is preferable to carry out the reaction at a temperature of 250 ℃ or lower. In addition, hydrocarbons, alcohols, esters, and the like can be used as the reaction solvent, and aliphatic hydrocarbons having 6 or more carbon atoms, cyclohexane, toluene, xylene, ethylbenzene, mesitylene, propanol, butanol, and the like are preferable.

As the reaction method of the diels-alder reaction, various reaction methods such as a batch method using a tank reactor or the like, a semi-batch method in which a substrate or a substrate solution is supplied to a tank reactor under reaction conditions, and a continuous flow method in which substrates are circulated under reaction conditions in a tubular reactor can be adopted.

The reaction product obtained by the diels-alder reaction can be used as it is as a raw material for the subsequent hydroformylation reaction, but may be purified by a method such as distillation, extraction, or crystallization, and then supplied to the next step.

[ production of a bifunctional compound having 14 to 20 carbon atoms represented by the formula (B) ]

The bifunctional compound having 14 to 20 carbon atoms represented by the formula (B) in the formula (3) can be produced by subjecting a monoolefin having 13 to 19 carbon atoms represented by the formula (C), carbon monoxide and hydrogen to a hydroformylation reaction in the presence of a rhodium compound and an organophosphorus compound.

The rhodium compound used in the hydroformylation reaction is not limited in its precursor form as long as it forms a complex compound with an organic phosphorus compound and exhibits hydroformylation activity in the presence of carbon monoxide and hydrogen. Rhodium acetylacetonate dicarbonyl (hereinafter, referred to as Rh (acac) (CO))₂)、Rh₂O₃、Rh₄(CO)₁₂、Rh₆(CO)₁₆、Rh(NO₃)₃The catalyst precursor substance and the organic phosphorus compound may be introduced into the reaction mixture together to form a catalytically active rhodium metal hydride phosphorus carbonyl complex in the reaction vessel, or the rhodium metal hydride phosphorus carbonyl complex may be prepared in advance and introduced into the reactor. A preferred specific example thereof includes Rh (acac) (CO)₂A method in which the rhodium-organophosphorus complex is reacted with an organophosphorus compound in the presence of a solvent and then introduced into a reactor together with an excess of the organophosphorus compound to produce a rhodium-organophosphorus complex having catalytic activity.

It is unexpected for the inventors of the present invention that the relatively large molecular weight 2-stage diels-alder reaction product with internal olefins as shown in formula (C) is hydroformylated with a very small amount of rhodium catalyst. The amount of the rhodium compound used in the hydroformylation reaction is preferably 0.1 to 30. mu. mol, more preferably 0.2 to 20. mu. mol, and still more preferably 0.5 to 10. mu. mol, based on 1mol of the monoolefin having 13 to 19 carbon atoms represented by the formula (C) which is a substrate of the hydroformylation reaction. By using the rhodium compound in an amount of less than 30 micromoles per 1 mole of the monoolefin having 13 to 19 carbon atoms, the cost of the rhodium catalyst can be reduced without providing a recovery and circulation facility for the rhodium complex, and the economic burden on the recovery and circulation facility can be reduced.

In the hydroformylation reaction, as the rhodium compound and the hydroformylation catalyst for the organic phosphorus compound, can be cited to form a general formula P (-R)₁)(－R₂)(－R₃) Phosphine OR P (-OR) as shown₁)(－OR₂)(－OR₃) The phosphites indicated. As R₁、R₂、R₃Specific examples of the (B) include aryl groups which may be substituted with an alkyl group or alkoxy group having 1to 4 carbon atoms, alicyclic alkyl groups which may be substituted with an alkyl group or alkoxy group having 1to 4 carbon atoms, and triphenylphosphine and triphenyl phosphite are preferably used. The amount of the organic phosphorus compound to be used is preferably 500 to 10000 times, more preferably 700 to 5000 times, and still more preferably 900 to 2000 times, the molar amount of the rhodium metal. If the amount of the organic phosphorus compound used is less than 500 times by mol as much as the rhodium metal, the stability of the rhodium metal hydride phosphorus carbonyl complex as the catalyst active material is impaired, and as a result, the progress of the reaction is slowed, which is not preferable. Further, when the amount of the organic phosphorus compound to be used is more than 10000 times by mol based on the rhodium metal, the cost for the organic phosphorus compound increases, which is not preferable.

The hydroformylation reaction can be carried out without using a solvent, but can be more suitably carried out by using a solvent inactive to the reaction. The solvent is not particularly limited as long as it is a solvent that dissolves the monoolefin having 13 to 19 carbon atoms, dicyclopentadiene or cyclopentadiene represented by formula (C), the rhodium compound, and the organophosphorus compound. Specifically, there may be mentioned hydrocarbons such as aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, esters such as aliphatic esters, alicyclic esters and aromatic esters, alcohols such as aliphatic alcohols and alicyclic alcohols, and solvents such as aromatic halides. Among these, hydrocarbons are preferably used, and among them, alicyclic hydrocarbons and aromatic hydrocarbons are preferably used.

The temperature at which the hydroformylation reaction is carried out is preferably 40 to 160 ℃ and more preferably 80 to 140 ℃. When the reaction temperature is 40 ℃ or higher, a sufficient reaction rate can be obtained, and the residue of the monoolefin as the raw material can be suppressed. Further, by setting the reaction temperature to 160 ℃ or lower, the production of by-products derived from the raw material monoolefin or the reaction product can be suppressed, and the reaction performance can be prevented from being lowered.

In carrying out the hydroformylation reaction, it is necessary to use carbon monoxide (hereinafter sometimes referred to as "CO") and hydrogen (hereinafter sometimes referred to as "H") in the hydroformylation reaction₂") the reaction is carried out under pressure. CO and H₂The gases may be introduced into the reaction system independently from each other, or may be introduced into the reaction system as a mixed gas prepared in advance. CO and H introduced into the reaction System₂Molar ratio of gas (═ CO/H)₂) Preferably 0.2 to 5, more preferably 0.5 to 2, and still more preferably 0.8 to 1.2. If CO and H₂If the molar ratio of the gas deviates from this range, the reaction activity of the hydroformylation reaction and the selectivity of the desired aldehyde may decrease. CO and H introduced into the reaction System₂The gas gradually decreases with the progress of the reaction, so if pre-prepared CO and H are used₂The mixed gas of (3) may facilitate reaction control.

The reaction pressure of the hydroformylation reaction is preferably 1to 12MPa, more preferably 1.2 to 9MPa, and still more preferably 1.5 to 5 MPa. When the reaction pressure is set to 1MPa or more, a sufficient reaction rate can be obtained, and the residue of the monoolefin as the raw material can be suppressed. Further, when the reaction pressure is 12MPa or less, expensive equipment having excellent pressure resistance is not required, and thus, the reaction pressure is in the rangeIs economically advantageous. In particular, when the reaction is carried out in a batch or semi-batch manner, it is necessary to add CO and H after the completion of the reaction₂Gas discharge, pressure drop, lower pressure, CO and H₂The less the loss of gas, and therefore economically advantageous.

The reaction system for carrying out the hydroformylation reaction is preferably a batch reaction or a semi-batch reaction. The semi-batch reaction can be carried out by adding a rhodium compound, an organic phosphorus compound and the above solvent to a reactor to utilize CO/H₂The gas is pressurized, heated, etc. under the above-mentioned reaction conditions, and then the monoolefin or its solution as the raw material is supplied to the reactor.

The reaction product obtained by the hydroformylation reaction may be used as it is as a raw material for the subsequent reduction reaction, but may be purified by, for example, distillation, extraction, crystallization, or the like, and then supplied to the next step.

[ production of a bifunctional compound having 14 to 16 carbon atoms represented by the formula (A) ]

The C14-16 bifunctional compound represented by the formula (A) in the formula (3) can be produced by reducing a C14-20 bifunctional compound represented by the formula (B) in the presence of a catalyst having hydrogenation ability and hydrogen.

In the reduction reaction, as the catalyst having a hydrogenation ability, a catalyst containing at least one element selected from the group consisting of copper, chromium, iron, zinc, aluminum, nickel, cobalt, and palladium can be used. Examples of such catalysts include a Cu-Cr catalyst, a Cu-Zn-Al catalyst, and the like, and further include a Raney-Ni catalyst, a Raney-Co catalyst, and the like.

The amount of the hydrogenation catalyst used is 1to 100% by weight, preferably 2 to 50% by weight, and more preferably 5 to 30% by weight, based on the substrate, which is a bifunctional compound having 14 to 20 carbon atoms represented by the formula (B). By setting the amount of the catalyst to be used within these ranges, the hydrogenation reaction can be suitably carried out. When the amount of the catalyst used is small, the reaction is not completed, and as a result, the yield of the target product is lowered. In addition, when the amount of the catalyst used is large, the effect of increasing the reaction rate commensurate with the amount of the catalyst to be supplied to the reaction cannot be obtained.

The reaction temperature of the reduction reaction is preferably 80-250 ℃, and more preferably 100-230 ℃. By setting the reaction temperature to 250 ℃ or lower, the occurrence of side reactions and decomposition reactions can be suppressed, and the target product can be obtained in high yield. Further, by setting the reaction temperature to 80 ℃ or higher, the reaction can be completed in an appropriate time, and a decrease in productivity and a decrease in the yield of the target product can be avoided.

The reaction pressure of the reduction reaction is preferably 1to 20MPa, more preferably 2 to 15MPa, as the hydrogen partial pressure. By setting the hydrogen partial pressure to 20MPa or less, the target product can be obtained in a high yield while suppressing the occurrence of side reactions and decomposition reactions. Further, by setting the hydrogen partial pressure to 1MPa or more, the reaction can be completed in an appropriate time, and a decrease in productivity and a decrease in the yield of the target product can be avoided. Further, a gas (for example, nitrogen or argon) inert to the reduction reaction can be made to coexist.

A solvent can be used in the reduction reaction. As the solvent, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, alcohols, and the like can be used, and alicyclic hydrocarbons, aromatic hydrocarbons, and alcohols are preferable. Specific examples thereof include cyclohexane, toluene, xylene, methanol, ethanol, and 1-propanol.

As the reaction method of the reduction reaction, various reaction methods such as a batch type using a tank reactor or the like, a semi-batch type in which a substrate or a substrate solution is supplied to a tank reactor under reaction conditions, and a continuous flow type in which a substrate or a substrate solution is circulated under reaction conditions in a tubular reactor packed with a molded catalyst can be employed.

The reaction product obtained by the reduction reaction can be purified by, for example, distillation, extraction, crystallization, or the like.

(C) Method for producing polycarbonate resin

The polycarbonate resin of the present invention can be produced by a melt polycondensation method using a diol compound represented by the general formula (2) and a carbonic acid diester as raw materials. In the diol compound represented by the general formula (2), there is a mixture of isomers of hydroxymethyl groups at positions 2,6 and isomers at positions 2, 7. These isomers are isomers at the 2,6 positions in mass ratio: isomer at 2, 7-position ═ 0.1: 99.9-99.9: 0.1. from the viewpoint of resin physical properties such as strength, tensile elongation, appearance of a molded article, etc., the 2, 6-position isomers: 2, 7-isomer ═ 1.0: 99.0-99.0: 1.0, more preferably isomers in 2,6 position: isomer at 2, 7-position ═ 20: 80-80: 20, particularly preferably the isomers in the 2,6 position: isomer at 2, 7-position ═ 50: 50-80: 20. further, other diol compounds may be used in combination. This reaction can be produced in the presence of a basic compound catalyst, a transesterification catalyst, or a mixed catalyst containing both as a polycondensation catalyst.

Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate. Among these, diphenyl carbonate is particularly preferable from the viewpoint of reactivity and purity. The carbonic acid diester is preferably used in a ratio of 0.97 to 1.20 mol, more preferably 0.98 to 1.10 mol, based on 1mol of the diol component. By adjusting the molar ratio, the molecular weight of the polycarbonate resin is controlled.

Examples of the basic compound catalyst include alkali metal compounds, alkaline earth metal compounds, nitrogen-containing compounds, and the like.

Examples of the alkali metal compound used in the present invention include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, and the like of alkali metals. Specifically, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenylboronate, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogenphosphate, dipotassium hydrogenphosphate, dilithium hydrogenphosphate, disodium phenylphosphate, disodium salt, dipotassium salt, dicesium salt, dilithium salt, sodium salt, potassium salt, cesium salt, lithium salt of phenol, and the like can be used. From the viewpoints of catalyst effect, price, throughput, influence on the color of the resin, and the like, sodium carbonate and sodium bicarbonate are preferable.

Examples of the alkaline earth metal compound include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, and the like of the alkaline earth metal compound. Specifically, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogencarbonate, calcium hydrogencarbonate, strontium hydrogencarbonate, barium hydrogencarbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium benzoate, magnesium phenylphosphate, and the like can be used.

Examples of the nitrogen-containing compound include quaternary ammonium hydroxides, salts thereof, and amines. Specifically, bases or basic salts such as quaternary ammonium hydroxides having an alkyl group or an aryl group, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide, tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine, secondary amines such as diethylamine and dibutylamine, primary amines such as propylamine and butylamine, imidazoles such as 2-methylimidazole, 2-phenylimidazole and benzimidazole, or bases or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium tetraphenylborate and tetraphenylammonium tetraphenylborate can be used.

As transesterification catalysts, preference is given to using salts of zinc, tin, zirconium, lead, which may be used individually or in combination. In addition, the alkali metal compound and/or the alkaline earth metal compound can be used in combination.

Specific examples of the transesterification catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyl tin dilaurate, dibutyl tin oxide, dibutyl tin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, tetrabutoxyzirconium, lead (II) acetate, and lead (IV) acetate.

These catalysts were used in an amount of 1 × 10 based on 1 mole of the total diol compounds^-9～1×10^-3The molar ratio is preferably 1 × 10^-7～1×10^-4Molar ratios were used.

The melt polycondensation method is a method of performing melt polycondensation by using the above-mentioned raw materials and a catalyst under heating under normal pressure or reduced pressure by an ester exchange reaction while removing by-products. The reaction is usually carried out in a multistage process of two or more stages.

Specifically, the reaction in the first stage is carried out at a temperature of 120 to 260 ℃, preferably 180 to 240 ℃ for 0.1 to 5 hours, preferably 0.5 to 3 hours. Then, the reaction of the diol compound and the carbonic acid diester is carried out at an elevated reaction temperature while increasing the reduced pressure of the reaction system, and finally, the polycondensation reaction is carried out at a reduced pressure of 1mmHg or less and a temperature of 200to 350 ℃ for 0.05 to 2 hours. Such a reaction may be carried out continuously or batchwise. The reaction apparatus used for carrying out the reaction may be a vertical type including an anchor-type stirring paddle, a large-sized wide-blade (Maxblend) stirring paddle, a ribbon-type stirring paddle, or the like, a horizontal type including a paddle-type blade, a lattice blade, a spectacle-type blade, or the like, or an extruder type including a screw, and it is preferable to carry out the reaction using a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer.

In the method for producing a polycarbonate resin of the present invention, after completion of the polymerization reaction, the catalyst may be removed or deactivated in order to maintain thermal stability and hydrolytic stability. Generally, a method of deactivating the catalyst by adding a known acidic substance is preferably carried out. Specifically, esters such as butyl benzoate, aromatic sulfonic acids such as p-toluenesulfonic acid, aromatic sulfonic acid esters such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate, phosphoric acids such as phosphorous acid, phosphoric acid and phosphonic acid, triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di-n-propyl phosphite, di-n-butyl phosphite, di-n-hexyl phosphite, dioctyl phosphite and monooctyl phosphite, phosphoric acid esters such as diphenyl phosphate, monophenyl phosphate, dibutyl phosphate, dioctyl phosphate and monooctyl phosphate, phosphonic acids such as diphenylphosphonic acid, dioctylphosphonic acid and dibutylphosphonic acid, phosphonic acid esters such as diethyl phenylphosphonate, phosphines such as triphenylphosphine and bis (diphenylphosphine) ethane, boric acids such as boric acid and phenylboronic acid, etc., are preferably used, Aromatic sulfonic acid salts such as tetrabutylphosphonium dodecylbenzenesulfonate, organic halides such as stearoyl chloride, benzoyl chloride and p-toluenesulfonyl chloride, alkyl sulfates such as dimethyl sulfate, and organic halides such as benzyl chloride. Butyl p-toluenesulfonate is preferably used from the viewpoint of deactivation effect, hue and stability of the resin. The amount of the deactivator is 0.01 to 50 times by mol, preferably 0.3 to 20 times by mol, based on the amount of the catalyst. If the amount of the catalyst is less than 0.01-fold mol, the deactivation effect becomes insufficient, which is not preferable. Further, if the amount of the catalyst is more than 50 times by mole, the heat resistance is lowered, and the molded article is liable to be colored, which is not preferable.

After the deactivation of the catalyst, a step of devolatilizing and removing low boiling point compounds in the polymer at a pressure of 0.1 to 1mmHg and a temperature of 200to 350 ℃ may be provided, and for this purpose, a horizontal apparatus or a thin film evaporator having a paddle blade, a lattice blade, a spectacle blade or the like having an excellent surface renewal ability may be suitably used.

The polycarbonate resin of the present invention is preferably filtered to remove molten raw materials and filtered to remove catalyst liquid, because the content of foreign matters is desirably as small as possible. The pore size of the filter is preferably 5 μm or less, more preferably 1 μm or less. Further, filtration of the produced resin through a polymer filter is preferably performed. The pore diameter of the polymer filter is preferably 100 μm or less, more preferably 30 μm or less. The step of collecting the resin pellets is, of course, required to be performed in a low-dust environment, and is preferably grade 1000 or less, and more preferably grade 100 or less.

(D) Physical Properties of polycarbonate resin

The optical lens of the present invention has a high abbe number, high transparency, an appropriate water absorption rate, and an appropriate water swelling rate.

The polycarbonate resin of the present invention preferably has a glass transition temperature (Tg) of 95 to 180 ℃, more preferably 110 to 160 ℃, and particularly preferably 120 to 160 ℃. The lower limit of the glass transition temperature (Tg) is preferably 130 ℃ and 140 ℃, and the upper limit of the glass transition temperature (Tg) is preferably 150 ℃. If Tg is less than 95 ℃, it is not preferable because the range of the use temperature of the lens and the camera becomes narrow. In addition, if the temperature exceeds 180 ℃, the molding conditions for injection molding become severe, which is not preferable.

The polycarbonate resin of the present invention preferably has a refractive index of 1.50 to 1.65, more preferably 1.52 to 1.55, as measured by JIS-K-7142 after molding.

The abbe number of the polycarbonate resin of the present invention measured by the method of JIS-K-7142 after molding is 25 or more, preferably 40 or more, and more preferably 50 or more. The upper limit of the Abbe number is about 60.

The polycarbonate resin of the present invention has a total light transmittance of 85.0% or more, preferably 87.0% or more, as measured by integrating sphere type photoelectric photometry after molding. The upper limit of the total light transmittance is about 99%.

The polycarbonate resin of the present invention preferably has a water absorption of 0.2 to 0.5%, more preferably 0.3 to 0.4%, as measured by JIS-K-7209.

The polycarbonate resin of the present invention preferably has a water absorption swelling ratio of 0.01 to 0.5%, more preferably 0.03 to 0.4%.

The water absorption expansion ratio was measured by a micrometer (1 mm in 1000 min). The diameter of the disk used for the water absorption measurement was measured, and the change (%) in diameter before and after water absorption was defined as the water absorption expansion ratio.

(E) Optical lens

The optical lens of the present invention can be obtained by injection molding the polycarbonate resin of the present invention in a lens shape by an injection molding machine or an injection compression molding machine. The molding conditions for injection molding are not particularly limited, and the molding temperature is preferably 180 to 280 ℃. In addition, the injection pressure is preferably 50to 1700kg/cm²。

In order to avoid the mixing of foreign substances into the optical lens as much as possible, the molding environment must be a low-dust environment, and is preferably class 1000 or less, and more preferably class 100 or less.

The optical lens of the present invention is preferably used in the form of an aspherical lens as necessary. Since the aspherical lens can substantially zero spherical aberration in 1 lens, it is not necessary to remove spherical aberration in a combination of a plurality of spherical lenses, and weight reduction and reduction in production cost can be achieved. Therefore, the aspherical lens is useful as an optical lens, particularly a camera lens. The astigmatism of the aspherical lens is preferably 0to 15m lambda, and more preferably 0to 10m lambda.

The thickness of the optical lens of the present invention can be set in a wide range depending on the application, and is not particularly limited, but is preferably 0.01 to 30mm, and more preferably 0.1 to 15 mm. The surface of the optical lens of the present invention may be provided with a coating layer such as an antireflection layer or a hard coat layer, as required. The antireflection layer may be a single layer or a plurality of layers, may be organic or inorganic, and is preferably inorganic. Specifically, oxides or fluorides of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium fluoride, and the like can be exemplified. Among these, silica and zirconia are more preferable, and a combination of silica and zirconia is more preferable. The antireflection layer is not particularly limited to a combination of a single layer and a plurality of layers, a combination of these components and thicknesses, or the like, but preferably has a 2-layer structure or a 3-layer structure, and particularly preferably has a 3-layer structure. The antireflection layer may be formed to have a thickness of 0.00017 to 3.3% of the thickness of the optical lens, specifically 0.05 to 3 μm, and particularly preferably 1to 2 μm.

Examples

The present invention is illustrated below by way of examples, but the present invention is not limited to these examples. The measurement values in the examples were measured by the following methods and apparatuses. 1) Polystyrene-reduced weight average molecular weight (Mw):

a calibration curve was prepared using GPC and tetrahydrofuran as a developing solvent, using standard polystyrene having a known molecular weight (molecular weight distribution of 1). Calculated from the retention time of the GPC according to the standard curve.

2) Glass transition temperature (Tg):

measured by Differential Scanning Calorimetry (DSC).

3) Refractive index nD, abbe number ν D:

the polycarbonate resin was press-molded (molding conditions: 200 ℃ C., 100 kgf/cm)²2 minutes) ofA circular plate having a thickness of 3mm was cut out at a right angle and measured by KPR-200 manufactured by Kalnew.

4) Total light transmittance:

measured by MODEL1001DP manufactured by Nippon Denshoku industries Co., Ltd. Here, the total light transmittance was measured for a disk (thickness: 3mm) obtained by press molding.

5) Saturated water absorption

The disk obtained by press molding (thickness: 3mm) was measured in accordance with JIS-K-7209.

6) Water absorption expansion ratio

The diameter of the sample used for the water absorption measurement was measured before and after water absorption by a micrometer (1 mm with an accuracy of 1000 min, manufactured by Mitutoyo), and the rate of change (%) of the diameter was calculated from the following equation (1).

The coefficient of water swelling at saturation { (disk diameter at saturation absorption) - (disk diameter before water absorption measurement) } × 100/(disk diameter before water absorption measurement) · · mathematical formula (1)

< example 1 of monomer Synthesis

173g (2.01mol) of methyl acrylate and 167g (1.26mol) of dicyclopentadiene were charged into a500 ml stainless steel reactor, and the reaction was carried out at 195 ℃ for 2 hours. A reaction solution containing 96g of a monoolefin represented by the following formula (3a) was obtained, purified by distillation, and a part thereof was supplied to the subsequent reaction.

Using a 300ml stainless steel reactor, using CO/H₂Mixed gas (CO/H)₂1) and subjecting the mixture to a hydroformylation reaction of a monoolefin represented by the formula (3a) purified by distillation. Into a reactor were charged 70g of a monoolefin of the formula (3a), 140g of toluene, 0.50g of triphenyl phosphite, and Rh (acac) (CO) prepared additionally₂550. mu.l (concentration 0.003mol/L) of the toluene solution. The nitrogen and CO/H utilization are respectively carried out for 3 times₂After replacement of the gas mixture, CO/H is used₂The mixed gas pressurizes the system, and the reaction is carried out for 5 hours at 100 ℃ and 2 MPa. After the completion of the reaction, gas chromatography analysis of the reaction solution was carried out to confirm that the reaction solution contained 76g of the bifunctional compound represented by the following formula (2a) and 1.4g of the monoolefin represented by the formula (3a) (conversion: 98%, selectivity: 97%), and after the distillation purification, a part thereof was supplied to the subsequent reaction.

50g of a bifunctional compound represented by the formula (2a) purified by distillation, 10g of a Cu-Zn-Al catalyst (manufactured by Nikkiso Co., Ltd.: E-01X) and 150g of toluene were added to a 300ml stainless steel reactor, and the system was pressurized with hydrogen gas and reacted at 215 ℃ under 10MPa for 8 hours. After the reaction, the resulting slurry was diluted with methanol, and the catalyst was filtered through a membrane filter having a pore size of 0.2 μm, and then the solvent was distilled off using an evaporator, and the product was analyzed by gas chromatography and GC-MS, whereby 43g of a main product having a molecular weight of 222 was confirmed (yield of the main product was 96%). The product is further distilled and refined to obtain a main product.

(wherein Me represents a methyl group.)

< identification of product >

NMR analysis, gas chromatography analysis and GC-MS analysis of the components obtained in monomer Synthesis example 1 were carried out. NMR spectra are shown in FIGS. 1to 3.

1) NMR measurement conditions

An apparatus: JNM-ECA 500(500MHz) manufactured by Japan electronic Co., Ltd

Measurement mode: 1H-NMR, 13C-NMR, COSY-NMR

Solvent: CD (compact disc)₃OD (deuterated methanol)

Internal standard substance: tetramethylsilane

2) Gas chromatography measurement conditions

An analysis device: capillary gas chromatography GC-2010 Plus manufactured by Shimadzu corporation

Analytical column: InertCap1(30m, 0.32mm I.D., film thickness 0.25 μm) manufactured by GL Sciences K.K

Column box temperature: 60 ℃ (hold for 0.5 min) -15 ℃/min temperature-280 ℃ (hold for 4 min) · detector: FID, temperature 280 deg.C

3) GC-MS measurement conditions

An analysis device: GCMS-QP 2010Plus manufactured by Shimadzu corporation

Ionization voltage: 70eV

Analytical column: DB-1 (30m, 0.32mmI.D., film thickness 1.00 μm), manufactured by Agilent Technologies

Column box temperature: 60 ℃ (hold for 0.5 min) -15 ℃/min ramp-280 ℃ (hold for 4 min) detector temperature: 280 deg.C

From the results of GC-MS analysis and NMR analyses shown in FIGS. 1to 3, it was confirmed that the main product obtained in monomer synthesis example 1 was a diol compound (D-NDM) represented by the above formula (1 a). Further, the analysis by gas chromatography confirmed that the obtained diol compound was an isomer mixture in which the isomer of the hydroxymethyl group at the 2, 6-position was 76 mass% and the isomer at the 2, 7-position was 24 mass%.

< example 2 of monomer Synthesis

Instead of using methyl acrylate of monomer synthesis example 1, 141g (1.93 mol/purity 96%) of methacrolein was used to obtain a reaction solution containing 86g of a monoolefin represented by the following formula (3b), and after distillation purification thereof, a part of the reaction solution was supplied to the subsequent reaction.

Using a 300ml stainless steel reactor, using CO/H₂Mixed gas (CO/H)₂Molar ratio of 1) is subjected to hydroformylation of the monoolefin represented by the formula (3 b). Into a reactor were charged 70g of a monoolefin of the formula (3b), 140g of toluene, 0.55g of triphenyl phosphite, and Rh (acac) (CO) prepared additionally₂580. mu.l (concentration 0.003mol/L) of toluene solution. The nitrogen and CO/H utilization are respectively carried out for 3 times₂After substitution of the gas mixture, CO/H is used₂The mixed gas was pressurized in the system, and the reaction was carried out at 100 ℃ and 2MPa for 6 hours. After the reaction, the reaction solution was analyzed by gas chromatography. It was confirmed that the reaction mixture contained 77g of the bifunctional compound represented by the following formula (2b) and 1.3g of the monoolefin represented by the formula (3b) (conversion: 98%, selectivity: 98%)

50g of the bifunctional compound represented by the formula (2b) purified by distillation, 150g of toluene, and 10ml of a Raney cobalt catalyst were charged in a 300ml stainless steel reactor. The system was pressurized with hydrogen and reacted at 100 ℃ under 4MPa for 5 hours. After the reaction, the resulting slurry was diluted with methanol, and the catalyst was filtered through a membrane filter having a pore size of 0.2 μm. The solvent was distilled off using an evaporator, and analysis by gas chromatography and GC-MS confirmed that 49g (yield 96%) of the main product having a molecular weight of 236 was contained.

It was confirmed that the obtained main product was a bifunctional compound represented by the following formula (1 b).

< example 3 of monomer Synthesis

The synthesis of the monoolefin represented by the formula (3a) and the distillation purification were carried out in the same manner as in monomer synthesis example 1.

Using a 300ml stainless steel reactor, using CO/H₂Mixed gas (CO/H)₂Molar ratio of 1) is subjected to hydroformylation of the monoolefin represented by the formula (3 a). Into a stainless steel tank were charged 70g of a monoolefin represented by the formula (3a) and 100g of toluene, and nitrogen and CO/H were separately used 3 times₂After substitution of the gas mixture, CO/H is used₂The mixed gas slightly pressurizes the system. In addition, 40g of toluene, 0.13g of triphenyl phosphite, and Rh (acac) (CO) prepared separately were charged into a 300ml stainless steel reactor₂120. mu.l (concentration: 0.003mol/L) of toluene solution (2) was subjected to 3 times of nitrogen utilization and CO/H utilization, respectively₂After substitution of the gas mixture, CO/H is used₂The mixed gas pressurizes the system, and the system is maintained at 100 ℃ and 2 MPa. The toluene solution of monoolefin represented by the formula (3a) was fed from the stainless steel tank to the reactor over a period of 2 hours (during which the reactor was controlled at 100 ℃ C. and 2MPa), and after the completion of the feeding, the solution was aged at 100 ℃ C. and 2MPa for 3 hours. After the reaction, the reaction solution was analyzed by gas chromatography. It was confirmed that the reaction mixture contained 78g of the bifunctional compound represented by the formula (2a) and 0.73g of the monoolefin represented by the formula (3a) (conversion: 99%, selectivity: 99%)

In the same manner as in monomer synthesis example 1, the diol compound represented by formula (2a) was subjected to a reduction reaction (reaction yield 96%) and purified by distillation to obtain the diol compound represented by formula (1a) (D-NDM). The obtained diol compound was confirmed to be an isomer mixture in which the isomer of the hydroxymethyl group at the 2, 6-position was 52 mass% and the isomer at the 2, 7-position was 48 mass% by analysis with a gas chromatograph.

< example 4 of monomer Synthesis

A reaction solution containing 14g of a monoolefin represented by the following formula (3c) was obtained using 52g (0.61 mol/purity: 99%) of ethylacrolein in place of the methyl acrylate of monomer synthesis example 1. This reaction was carried out 2 times, and after distillation purification, a part of the reaction mixture was supplied to the subsequent reaction.

A300 ml stainless steel reactor was used, using CO/H₂Mixed gas (CO/H)₂Molar ratio of 1) to carry out the hydroformylation of the monoolefin represented by the formula (3 c). Into the reactor were charged 21.3g of the monoolefin of the formula (3c), 20g of toluene, 518mg of triphenylphosphine and Rh (acac) (CO) prepared in addition₂128. mu.l (concentration 0.0384mol/L) of toluene solution. The nitrogen and CO/H utilization are respectively carried out for 3 times₂After substitution of the gas mixture, CO/H is used₂The mixed gas was pressurized in the system, and the reaction was carried out at 110 ℃ and 2MPa for 1.5 hours. After the completion of the reaction, the reaction solution was analyzed by gas chromatography under the above-mentioned conditions. As a result, it was confirmed that 23.8g of a reaction solution containing the bifunctional compound represented by the following formula (2c) was contained (yield 98%).

A300 ml stainless steel reactor was charged with a reaction solution containing 22.7g of the bifunctional compound represented by the formula (2c), 38g of cyclohexanol, and 2.2g of Cu-Zn-Al catalyst (manufactured by Nissan catalyst Kabushiki Kaisha: E-01X). The system was pressurized with hydrogen and reacted at 140 ℃ under 3MPa for 1.5 hours. After the reaction, the resulting slurry was diluted with methanol, and the catalyst was filtered through a membrane filter having a pore size of 0.2 μm. The solvent was distilled off using an evaporator, and analyzed by gas chromatography and GC-MS under the above-mentioned conditions. The GC-MS analysis confirmed that the resulting main product was a bifunctional compound represented by the formula (1 c). In addition, it was also confirmed that the amount of the bifunctional compound represented by the formula (1c) produced was 22g (yield 96%).

< example 1 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 23.53g (0.106 mol), diphenyl carbonate: 23.02g (0.107 mol) and sodium bicarbonate: 0.07mg (0.8. mu. mol) was charged into a 300mL reactor equipped with a stirrer and a distilling device, and the mixture was heated to 215 ℃ for 1 hour under a nitrogen atmosphere of 760Torr and stirred. The transesterification reaction was started from 200 ℃ by heating with an oil bath. Stirring was started 5 minutes after the start of the reaction, and after 20 minutes, the pressure was reduced from 760Torr to 200Torr for 10 minutes. While reducing the pressure, the temperature is heated to 210 ℃, in the reaction start 70 minutes after, heating to 220 ℃, from 80 minutes after 30 minutes reduced pressure to 150Torr, the temperature is increased to 240 ℃, and reduced pressure to 1Torr, then maintained for 10 minutes, get polycarbonate resin.

The obtained polycarbonate resin had Mw of 8,000 and Tg of 110 ℃. The polycarbonate resin had a refractive index of 1.536 and an Abbe number of 55.2. The total light transmittance was 90%. The saturated water absorption was 0.38%, and the water absorption expansion rate at saturation was 0.038%. The results are shown in tables 1 and 2.

< example 2 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 23.20g (0.104 mol), diphenyl carbonate: 22.62g (0.106 moles) and sodium bicarbonate: 0.26mg (3.1. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 15,000 and Tg of 127 ℃. The refractive index was 1.534, and the Abbe number was 56.0. The total light transmittance was 90%. The saturated water absorption was 0.34%, and the water absorption expansion rate at saturation was 0.036%.

< example 3 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 30.9g (0.139 mol), diphenyl carbonate: 29.8g (0.139 mole) and sodium bicarbonate: 0.09mg (1.1. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 42,000 and Tg of 141 ℃. The refractive index was 1.531, and the Abbe number was 57.3. The total light transmittance was 90%. The saturated water absorption was 0.35%, and the water absorption expansion rate at saturation was 0.033%.

NMR analysis of the obtained polycarbonate resin was performed under the following measurement conditions. The NMR spectrum is shown in FIG. 4.

NMR measurement conditions

An apparatus: JNM-ECA 500(500MHz) manufactured by Japan electronic Co., Ltd

Measurement mode: 1H-NMR

Solvent: deuterated chloroform

Internal standard substance: tetramethylsilane

< example 4 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 28.9g (0.130 mol), 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene: 6.3g (0.014 mol), diphenyl carbonate: 31.5g (0.147 moles) and sodium bicarbonate: 0.09mg (1.1. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 27,000 and Tg of 142 ℃. The refractive index was 1.551, and the Abbe number was 45.5. The total light transmittance was 90%. The saturated water absorption was 0.37%, and the water absorption expansion rate at saturation was 0.038%.

< example 5 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 4.76g (0.021 mol), 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene: 37.6g (0.086 mol), diphenyl carbonate: 23.3g (0.109 moles) and sodium bicarbonate: 0.07mg (0.9. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 32,000 and Tg of 146 ℃. The refractive index was 1.626, and the Abbe number was 25.3. The total light transmittance was 89%. The saturated water absorption was 0.37%, and the water absorption expansion rate at saturation was 0.033%.

< example 6 >

D-NDM represented by the formula (1a) obtained in monomer Synthesis example 1: 11.3g (0.051 mol), 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene: 20.0g (0.046 mol), diphenyl carbonate: 21.0g (0.098 moles) and sodium bicarbonate: 0.05mg (0.6. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 35,000 and Tg of 144 ℃. The refractive index was 1.597, and the Abbe number was 30.0. The total light transmittance was 89%. The saturated water absorption was 0.37%, and the water absorption expansion rate at saturation was 0.038%.

< example 7 >

A polycarbonate resin was synthesized under the same conditions as in example 1, except that D-NDM represented by the formula (1a) obtained in monomer synthesis example 3 was used. The obtained polycarbonate resin had Mw of 38,000, Tg of 140 ℃, a refractive index of 1.532, and an abbe number of 57.2. The total light transmittance was 90%. The saturated water absorption was 0.34%, and the water absorption expansion rate at saturation was 0.033%.

< example 8 >

The isomer mixture of D-NDM represented by the formula (1a) (isomer of hydroxymethyl group at 2,6 position 52 mass% and isomer at 2,7 position 48 mass%) obtained in monomer synthesis example 3 was distilled to obtain D-NDM with 2,6 position isomer 22 mass% and 2,7 position isomer 78 mass%. A polycarbonate resin was synthesized under the same conditions as in example 1, except that this D-NDM was used. The obtained polycarbonate resin had Mw of 41,000, Tg of 137 ℃, a refractive index of 1.531, and an abbe number of 57.0. The total light transmittance was 90%. The saturated water absorption was 0.35%, and the water absorption expansion rate at saturation was 0.033%.

< example 9 >

The isomer mixture of D-NDM represented by the formula (1a) (isomer of hydroxymethyl group at 2,6 position 76 mass% and isomer at 2,7 position 24 mass%) obtained in monomer synthesis example 1 was distilled to obtain D-NDM with isomer at 2,6 position 99.5 mass% and isomer at 2,7 position 0.5 mass%. A polycarbonate resin was synthesized under the same conditions as in example 1, except that this D-NDM was used.

Using the obtained polycarbonate resin, a disc-shaped molded body molded for measuring the refractive index and the abbe number was confirmed to be clouded by crystallization, and was not as large as the degree of evaluation of the refractive index and the abbe number as an optical material. The polycarbonate resin obtained had Mw of 40,000 and Tg of 143 ℃. The saturated water absorption was 0.33%, and the water absorption expansion rate at saturation was 0.031%.

< example 10 >

D-NDM represented by the following formula (1b) obtained in monomer Synthesis example 2: 25.05g (0.106 mol), diphenyl carbonate: 22.78g (0.106 moles) and sodium bicarbonate: 0.26mg (3.1. mu. mol) was charged into a 300mL reactor equipped with a stirrer and a distilling device, and the mixture was heated and stirred at 215 ℃ for 1 hour under a nitrogen atmosphere of 760 Torr. The transesterification reaction was started from 200 ℃ by heating with an oil bath. After 5 minutes from the start of the reaction, stirring was started, and after 20 minutes, the pressure was reduced from 760Torr to 200Torr for 10 minutes. While reducing the pressure, the temperature is heated to 210 ℃, after the reaction starts 70 minutes after the temperature to 220 ℃, from 80 minutes after 30 minutes after decompression to 150Torr, the temperature to 240 ℃ and pressure to 1Torr, after holding for 10 minutes, get polycarbonate resin.

The obtained polycarbonate resin had Mw of 38,000 and Tg of 135 ℃. The polycarbonate resin had a refractive index of 1.533 and an Abbe number of 56.8. The total light transmittance was 90%. The saturated water absorption was 0.33%, and the water absorption expansion coefficient at saturation was 0.035%.

< example 11 >

D-NDM represented by the following formula (1c) obtained in monomer Synthesis example 4: 26.54g (0.104 mol), diphenyl carbonate: 22.78g (0.106 moles) and sodium bicarbonate: 0.26mg (3.1. mu. mol) of the polycarbonate resin was charged in a 300mL reactor equipped with a stirrer and a distilling device, and the same operation as in example 1 was carried out except for the charged amount, thereby obtaining a polycarbonate resin. The obtained polycarbonate resin had Mw of 35,000 and Tg of 133 ℃. The refractive index was 1.534, and the Abbe number was 56.6. The total light transmittance was 90%. The saturated water absorption was 0.32%, and the water absorption expansion rate at saturation was 0.034%.

The purpose of the present invention is to provide a polycarbonate resin with a high Abbe number, which has a small difference in water absorption expansion coefficient, in a polycarbonate resin with a high refractive index and a low Abbe number. The water absorption (%) and water swelling (%) of the resin to be laminated (object 1 and object 2) and the resin having a high abbe number (comparative example 1) during lens formation are shown below.

< object 1 >

The water absorption (%) and the water swelling rate (%) were measured using a bisphenol a polycarbonate resin with a low abbe number (molecular weight Mw 30,000, H-4000, mitsubishi gas chemical). The results are shown in tables 1 and 2.

< comparative example 1 >

The water absorption (%) and the water swelling rate (%) were measured using a cycloolefin polymer resin having a high abbe number (molecular weight Mw 140,000, ZEONEX 330R manufactured by Zeon corporation, japan). The results are shown in tables 1 and 2.

< object 2 >

The water absorption (%) and the water swelling factor (%) were measured using an optical polycarbonate resin with a low abbe number (molecular weight Mw 27,000, EP5000, mitsubishi gas chemical corporation). The results are shown in tables 1 and 2.

[ Table 1]

[ Table 2]

From the results shown in tables 1 and 2, it is understood that the water absorption expansion ratio of the polycarbonate resin with a low abbe number of the object 2 (EP 5000, mitsubishi gas chemical) and the water absorption expansion ratio of the polycarbonate resin of example 1 are close to each other, and the present invention can solve the problem of providing a high abbe number polycarbonate resin with a small difference in water absorption expansion ratio between the polycarbonate resin with a high refractive index and a low abbe number. On the other hand, it is found that the resin having a high Abbe number in comparative example 1 has a very low water absorption expansion ratio, and the above-mentioned object of the present invention cannot be achieved.

< comparative example 2 >

108g (0.75 mol) of dimethyl fumarate, 128g (0.97 mol) of dicyclopentadiene and 300g of p-xylene were charged in an autoclave, and the inside of the system was replaced with nitrogen gas. Then, the internal temperature of the autoclave was raised to 180 ℃ and the reaction was carried out at this temperature for 20 hours with stirring. After the reaction was completed, 6g of activated carbon carrying 10% of palladium was added, the inside of the system was replaced with hydrogen, and then 21MPa of hydrogen was added to the system, followed by reaction at 80 ℃ for 1 hour with stirring. The reaction mixture was distilled under reduced pressure, and then the residue was recrystallized from ethanol, thereby obtaining dimethyl perhydro-1, 4:5, 8-dimethyloldinaphthalenedicarboxylate. A300 mL autoclave was charged with 52g of dimethyl perhydro-1, 4:5, 8-dimethyloldinadicarboxylate, 5g of copper-chromium oxide (N-203-SD, manufactured by Rieko chemical Co., Ltd.), and 100mL of 1, 4-dioxane. Then, the inside of the system was replaced with hydrogen, and then hydrogen was added to the system to conduct a reaction at 200 ℃ for 20 hours under a pressure of 30 MPa. After the reaction was completed, 1, 4-dioxane was removed, and the obtained white powder was recrystallized from ethyl acetate, and as a result, perhydro-1, 4:5, 8-dimethanol naphthalene-2, 3-dimethanol represented by the following structural formula was obtained.

Here, 30.90g (0.139 mol) of the obtained perhydro-1, 4:5, 8-dimethanol naphthalene-2, 3-dimethanol, 29.80g (0.139 mol) of diphenyl carbonate and 0.09mg (1.1. mu. mol) of sodium hydrogencarbonate were charged into a 300mL reactor equipped with a stirrer and a distillation apparatus, and the mixture was heated and stirred at 215 ℃ for 1 hour under a nitrogen atmosphere of 760 Torr. The transesterification reaction was started from 200 ℃ by heating with an oil bath. 5 minutes after the start of the reaction, stirring was started, and after 20 minutes, the pressure was reduced from 760Torr to 200Torr for 10 minutes. While reducing the pressure, the temperature is heated to 210 ℃, after the reaction starts 70 minutes after the temperature to 220 ℃, after 80 minutes after 30 minutes reduced pressure to 150Torr, the temperature to 240 ℃, and reduced pressure to 1Torr, then maintained for 10 minutes, get polycarbonate resin.

The polycarbonate resin obtained was molded into the shape of a test piece of type 1 according to Japanese Industrial Standard K7113, and the tensile yield elongation (tensile rate 2mm/min.) was measured. The polycarbonate resin obtained in comparative example 2 had a tensile elongation at yield of 51%, whereas the polycarbonate resin obtained in example 3 had a tensile elongation at yield of 150%.

Industrial applicability

The present invention can provide an optical lens having an excellent high Abbe number. The optical lens of the present invention can be injection-molded, has high productivity and is inexpensive, and therefore, can be used in fields where expensive high-abbe-number glass lenses have been conventionally used, such as cameras, telescopes, binoculars, and television projectors, and is extremely useful. Further, the difference in water absorption rate between the high abbe number lens and the low abbe number lens is small, and therefore, the present invention is particularly suitable for a small optical lens unit. Further, according to the present invention, it is possible to easily obtain a high abbe number aspherical lens which is difficult to be technically processed in a glass lens by injection molding, and it is extremely useful.

Claims (11)

1. A polycarbonate resin comprising a constituent unit represented by the following general formula (1),

in the general formula (1), R is H, CH₃Or C₂H₅。

2. The polycarbonate resin of claim 1, wherein:

containing-CH in the general formula (1)₂Isomers in which O-group is bonded at 6-position (isomers at 2, 6-position) with-CH in the general formula (1)₂The O-group is bound to a mixture of isomers at the 7-position (isomers at the 2, 7-positions).

3. The polycarbonate resin of claim 2, wherein:

the content ratio of the isomers at the 2, 6-positions to the isomers at the 2, 7-positions is 1.0: 99.0-99.0: 1.0.

4. the polycarbonate resin according to any one of claims 1to 3, wherein:

the polycarbonate resin has a water-swelling rate of 0.01 to 0.5%.

5. The polycarbonate resin according to any one of claims 1to 4, wherein:

the abbe number of the polycarbonate resin is 25 or more.

6. The polycarbonate resin according to any one of claims 1to 5, wherein:

the glass transition temperature of the polycarbonate resin is 110-160 ℃.

7. The polycarbonate resin according to any one of claims 1to 6, wherein:

the weight average molecular weight of the polycarbonate resin is 5,000-50,000.

8. An optical lens obtained by molding the polycarbonate resin according to any one of claims 1to 7.

9. A method for producing a polycarbonate resin, characterized in that:

comprising a step of reacting a diol compound represented by the following general formula (2) with a carbonic acid diester,

in the general formula (2), R is H, CH₃Or C₂H₅。

10. The method for producing a polycarbonate resin according to claim 9, wherein:

the diol compound comprises-CH in the general formula (2)₂Isomers in which OH group is bound at 6 position (isomers at 2,6 position) and-CH in the general formula (2)₂Mixture of isomers with OH groups bound in position 7 (isomers in position 2, 7):

11. the method for producing a polycarbonate resin according to claim 10, wherein:

the content ratio of the isomers at the 2, 6-positions to the isomers at the 2, 7-positions is 1.0: 99.0-99.0: 1.0.