Resin composition, method for producing same, and molded body

Abstract

There has been a need for a resin composition that enables a molded body, which is obtained by molding the resin composition, or the like to have excellent properties. In addition, it has not been easy to reliably and easily produce a resin composition, which enables the achievement of a molded body having excellent properties, by a conventional production method.　The above-mentioned problem is solved by a resin composition which contains an oligomer that includes a first constituent unit (A) derived from a monomer represented by general formula (1), and a polycarbonate resin that includes a second constituent unit (B) derived from a monomer represented by any one of general formulae (2a) to (2c), wherein the molecular weight (Mw) of the oligomer is 500-20,000. The details of general formulae (1) and (2a) to (2c) are as shown in the description of the present application.

Description

Resin composition, its manufacturing method and molded article

[0001] The present invention relates to a resin composition, a method for producing a resin composition, a molded article molded from a resin composition, and the like, and in particular to a resin composition containing a predetermined oligomer and a resin.

[0002] Resin compositions have been used in a variety of applications. Resin compositions are often mixtures of several types of resins, oligomers, etc., and known examples of resin compositions include those used for optical applications (see, for example, Patent Document 1).

[0003] Patent document 1: WO2010 / 010703 publication

[0004] Conventional resin compositions have not always been able to easily produce molded articles with excellent appearance. Furthermore, when conventional resin compositions are used for optical applications, the resulting optical components often lack satisfactory properties, such as a large retardation. Therefore, there is a need for resin compositions that can produce molded articles with excellent properties, primarily after molding.

[0005] Furthermore, even with conventional methods for producing resin compositions, it has not been easy to reliably and simply produce resin compositions that can achieve excellent properties, primarily in molded articles, as described above.

[0006] The present invention includes, for example, the following: [1] A resin composition comprising an oligomer including a first structural unit (A) derived from a monomer represented by the following general formula (1), and a polycarbonate resin including a second structural unit (B) derived from a monomer represented by any one of the following general formulae (2a) to (2c), wherein the molecular weight (Mw) of the oligomer is 500 to 20,000. (In formula (1), R ａ and R ｂare each independently hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms, each of which may have a substituent; r and s are each independently an integer of 0 to 4; X is represented by formula (3); (In formula (3), R8 and R9 each independently represent hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 12 carbon atoms, each of which may have a substituent, or R8 and R9 combine to represent a group that forms a carbocycle having 5 to 20 carbon atoms or a heterocycle having 5 to 12 elements, and R 10 and R 11 each independently represents hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms, each of which may have a substituent; R 12 are each independently an alkylene group having 1 to 9 carbon atoms which may have a substituent, c represents an integer of 0 to 20, and d represents an integer of 1 to 500. (In general formulas (2a) to (2c), R ｃ and R ｄare each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent, each Y is independently a fluorene group which may have a substituent, A and B each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent, p and q each independently represent an integer of 0 to 4, and a and b each independently represent an integer of 0 to 10. [2] The resin composition according to [1] above, wherein the molecular weight (Mw) of the oligomer is 1,000 to 10,000. [3] The resin composition according to the above [1] or [2], for example, the above [1], wherein the molecular weight (Mw) of the polycarbonate resin is 20,000 to 300,000. [4] In the general formula (1) representing the monomer that generates the first structural unit (A), R ａ and R ｂare each independently hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms, each of which may have a substituent; and r and s are each independently 0 or 1. [5] The resin composition of any of [1] to [4], for example, the resin composition of [1] above, in which the monomer that produces the second structural unit (B) is represented by general formula (2a). [6] The resin composition of any of [1] to [5], for example, the resin composition of [1] above, in which the content of the oligomer is 0.5 to 18 mass% based on the total mass of the resin composition. [7] The resin composition of any of [1] to [6], for example, the resin composition of [1] above, in which the mass ratio of the polycarbonate resin to the oligomer is 80:20 to 99:1. [8] The resin composition according to [7] above, wherein the mass ratio of the polycarbonate resin to the oligomer is 90:10 to 95:5. [9] The resin composition according to any one of [1] to [8], for example, the resin composition according to [1] above, wherein the resin composition contains any one of a polycarbonate oligomer, a polyester oligomer, and a polyester carbonate oligomer having the first structural unit (A).

[10] The resin composition according to any one of [1] to [9], for example, the resin composition according to [1] above, wherein the resin composition further contains any one of a polyester resin and a polyester carbonate resin having the second structural unit (B).

[11] The resin composition according to any one of [1] to

[10] , for example, the resin composition according to [1] above, wherein the average retardation of the resin composition is 40 nm or less.

[0007]

[12] A method for producing a resin composition according to any one of [1] to

[11] above, for example, the method according to the method according to the method according to the method according to the method according to the method according to the method according to the method above, wherein the polycarbonate resin and the oligomer are mixed at 270°C or higher and melt-extruded.

[13] The method according to the method according to the method above, wherein the screw rotation speed in the cylinder where the melt-extrusion is performed is 200 rpm or higher.

[14] The method according to the method according to the method above, for example, the method according to the method according to the method above, wherein the polycarbonate resin and the oligomer are continuously fed into the cylinder using a rotary feeder.

[0008]

[15] An optical material comprising any one of the above [1] to

[11] , for example, the resin composition described in [1] above.

[16] A molded article molded using any one of the above [1] to

[11] , for example, the resin composition described in [1] above.

[17] The molded article described in

[16] above, which is a lens having an average retardation of 40 nm or less.

[0009] According to the present invention, it is possible to realize a resin composition that can be used to produce a molded article having excellent appearance and good properties, such as a lens with suppressed retardation. The present invention also provides a production method that can reliably produce such a useful resin composition using a simple method.

[0010] 1 is a graph showing the relationship between the molecular weight of the oligomer in the resin composition and the phase difference value (nm) of the molded lens in an example and a comparative example in which the oligomer content is 7.4% by mass. 2 is a graph showing the relationship between the content (mass%) of the oligomer in the resin composition and the phase difference value (nm) of the molded lens in an example and a comparative example in which the weight average molecular weight (Mw) of the oligomer is 4,500.

[0011] Preferred embodiments of the present invention are described in detail below. <1. Resin Composition> 1-1. Components of the Resin Composition The resin composition of the present invention contains an oligomer and a polycarbonate resin. The oligomer and the polycarbonate resin each have specific structural units, which will be described in detail below. The resin composition may also contain a thermoplastic resin other than the polycarbonate resin. For example, the resin composition may contain a thermoplastic resin such as a polyester carbonate resin or a polyester resin in addition to or instead of the polycarbonate resin.

[0012] The oligomer contained in the resin composition may be any one of a polycarbonate oligomer, a polyester oligomer, and a polyester carbonate oligomer, or a mixture thereof. The oligomer preferably contains at least a polycarbonate oligomer.

[0013] The oligomer, which is a component of the resin composition, contains a first structural unit (A) derived from a monomer that is a diol compound represented by the following general formula (1): In other words, the oligomer contains the first structural unit (A) that is bonded to another structural unit via the O of the hydroxyl group of the diol compound represented by formula (1).

[0014] In formula (1) showing a monomer as a raw material for an oligomer, R ａ and R ｂ are each independently selected from hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and an aralkyl group having 7 to 17 carbon atoms, each of which may have a substituent. ａ and R ｂ are each preferably hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms, each of which may have a substituent; more preferably hydrogen, or an alkyl group having 1 to 6 carbon atoms, each of which may have a substituent; even more preferably hydrogen, or an alkyl group having 1 to 3 carbon atoms, each of which may have a substituent; and particularly preferably hydrogen.

[0015] In formula (1) showing the monomer that is the raw material of the oligomer, r and s are each independently an integer of 0 to 4. r and s are each preferably an integer of 0 to 3, more preferably an integer of 0 to 2, even more preferably an integer of 0 or 1, and particularly preferably 0.

[0016] In formula (1) showing the monomer that is the raw material of the oligomer, X is represented by the following general formula (3). R8 and R9 in formula (3) are each independently any of hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and an aryl group having 6 to 12 carbon atoms, each of which may have a substituent, or R8 and R9 may combine to form a carbocycle having 5 to 20 carbon atoms or a 5- to 12-membered heterocycle. R8 and R9 are preferably hydrogen, an alkyl group having 1 to 3 carbon atoms, or a group which combines with each other to form a carbocycle having 5 to 12 carbon atoms.

[0017] R in formula (3) 10 and R 11 are each independently any one of hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms, each of which may have a substituent. 10 and R 11 is preferably hydrogen or an aryl group having 6 to 8 carbon atoms. 12 are each independently an alkylene group having 1 to 9 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms, and more preferably an alkylene group having 1 or 2 carbon atoms, which may have a substituent.

[0018] In formula (3), c is an integer of 0 to 20, and d is an integer of 1 to 500. c is preferably an integer of 0 to 10, and more preferably an integer of 0 to 3. d is preferably an integer of 1 to 300, and more preferably an integer of 1 to 100.

[0019] The substituents contained in the above-mentioned monomer compound or the first structural unit (A) are each independently selected from halogen, a hydroxyl group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, etc. When an alkyl group, an alkenyl group, or an aryl group is contained as a substituent, the above-mentioned number of carbon atoms is the total number of carbon atoms including the carbon atoms of the substituent.

[0020] Specific examples of the above-mentioned monomer compound that forms the first structural unit (A) include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A; BPA), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4'-biphenyldiol, bis(4-hydroxyphenyl)methane (bisphenol F; BPF), bis(2-hydroxyphenyl)methane, 2,4'-dihydroxydiphenylmethane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenylsulfone, bis(2-hydroxyphenyl)sulfone, bis(4-hydroxy-3-methylphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis( 4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) ketone, 1,1-bis(4-hydroxyphenyl) ethane (bisphenol E; BPE), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP; BPAP), bis(4-hydroxyphenyl) diphenylmethane (bisphenol BP; BPBP), 1,1-bis(4-hydroxy-3-methylphenyl) ethane, bis(4-hydroxy-3-methylphenyl) methane, 2,2-bis(4-hydroxy-3-t-butylphenyl) propane, 2,2-bis(4-hydroxyphenyl) butane (bisphenol B; BPB), 1,1-bis(4-hydroxyphenyl) cyclohexane (bisphenol Z;BPZ), 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cycloundecane, 1,1-bis(4-hydroxyphenyl)cyclododecane (bisphenol CD), 2,2-bis(4-hydroxy-3-allylphenyl)propane, 3,3,5-trimethyl-1,1-bis(4-hydroxyphenyl)cyclohexane, 9,9-bis(4-hydroxy-3-ethylphenyl)fluorene , 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, α,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethyldiphenyl random copolymer siloxane, α,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethylsiloxane, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisphenol, 4,4'-[1,3-phenylenebis(1 -methylethylidene) bisphenol, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane (bisphenol G), 1,1-bis(4-hydroxyphenyl)-2-ethylhexane (bisphenol IOTD), 1,1-bis(4-hydroxyphenyl)-2-methylpropane (bisphenol IBTD), 1,1-bis(4-hydroxyphenyl)-2-methylpentane (bisphenol MIBK), 5,5'-(1-methylethylidene)-bis[1,1'-(bisphenyl)-2-ol]propane (bisphenol PH), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC), 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 1,1-bis(4-hydroxyphenyl)decane, 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane, and the like. These may be used alone or in combination of two or more types.

[0021] More preferred specific examples of the monomer compound include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A; BPA), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4'-biphenyldiol, and bis(4-hydroxyphenyl)methane (bisphenol F; BPF).

[0022] The weight average molecular weight (Mw) of the oligomer is 500 to 20,000, for example, 500 or more, and 20,000 or less, or less than 20,000. The Mw value of the oligomer is preferably 600 to 15,000 or 800 to 18,000, more preferably 700 to 12,000 or 900 to 14,000, even more preferably 800 to 8,000 or 950 to 10,000, and particularly preferably 900 to 4,000, 950 to 6,000, or 1,000 to 5,000.

[0023] 1-3. Polycarbonate Resin (Thermoplastic Resin) The resin composition contains a polycarbonate resin having the second structural unit (B). The resin composition may further contain either a polyester resin or a polyester carbonate resin having the second structural unit (B), or may contain a thermoplastic resin other than a polycarbonate resin that has the second structural unit (B).

[0024] The thermoplastic resin, such as a polycarbonate resin, which is a component of the resin composition, contains a second structural unit (B) derived from a monomer that is a fluorene-based compound represented by at least one of the following general formulas (2a) to (2c): In other words, the polycarbonate resin contains the second structural unit (B) that is bonded to another structural unit via the O of the hydroxyl group of a diol compound represented by any one of formulas (2a) to (2c).

[0025] In the general formulae (2a) to (2c), R ｃ and R ｄare each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent.

[0026] R in general formulas (2a) to (2c) ｃ and R ｄ are preferably each independently selected from a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent, and more preferably are each independently selected from a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ｃ and R ｄ is more preferably selected from a hydrogen atom and an aryl group having 6 to 20 carbon atoms which may have a substituent.

[0027] In general formulas (2a) to (2c), Y each independently represents a fluorene group which may have a substituent. In general formulas (2a) to (2c), A and B each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent, preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent, and more preferably an alkylene group having 1 or 2 carbon atoms which may have a substituent. In general formulas (2a) to (2c), p and q each independently represent an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably 0 or 1. Furthermore, in general formulas (2a) to (2c), a and b each independently represent an integer of 0 to 10, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and particularly preferably 0 or 1.

[0028] R in general formulas (2a) to (2c) ｃ and R ｄAmong the options, the number of carbon atoms in the alkyl group having 1 to 20 carbon atoms, which may have a substituent, and the alkoxy group having 1 to 20 carbon atoms, which may have a substituent, is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3, or 1. ｃ and R ｄ Among the options, the number of carbon atoms in the cycloalkyl group having 5 to 20 carbon atoms, which may have a substituent, and the number of carbon atoms in the cycloalkoxy group having 5 to 20 carbon atoms, which may have a substituent, are preferably 5 to 10, more preferably 6 to 8, and even more preferably 6 or 7. ｃ and R ｄ Among the options above, the number of carbon atoms in the aryl group having 6 to 20 carbon atoms, which may have a substituent, is preferably 6 to 12, more preferably 6 to 10, and even more preferably 6 to 8, or 6.

[0029] The resin composition contains a thermoplastic resin such as a polycarbonate resin represented by any one of formulas (2a) to (2c), and preferably contains at least a polycarbonate resin having a structural unit represented by formula (2a).

[0030] Examples of the substituents that can be contained in the structural unit (B) formed by the fluorene compounds of the above formulas (2a) to (2c) include halogen atoms, hydroxy groups, carboxy groups, cyano groups, C1 to C10 amide groups, C1 to C10 alkyl groups, C5 to C10 cycloalkyl groups, C1 to C10 alkoxy groups, C5 to C10 cycloalkyloxy groups, C2 to C10 alkyloxycarbonyl groups, C5 to C10 cycloalkyloxycarbonyl groups, C7 to C15 aryloxycarbonyl groups, C2 to C10 alkylcarbonyloxy groups, C5 to C10 cycloalkylcarbonyloxy groups, C7 to C15 arylcarbonyloxy groups, C2 to C10 hydroxyalkylcarbonyl groups, glycidyloxycarbonyl groups, etc. The carbon numbers for the fluorene compounds of the general formulas (2a) to (2c) include the number of carbon atoms of the substituents.

[0031] Specific examples of the above-mentioned fluorene-based diol compound that forms the second structural unit (B) include 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF), 9,9-bis(6-(2-hydroxyethoxy)naphthalen-2-yl)fluorene (BNEF), 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenylfluorene (BPPEF)), etc. These fluorene-based diol compounds may be used alone, or two or more types may be used in combination to form the structural unit (B).

[0032] The weight average molecular weight (Mw) of the thermoplastic resin such as a polycarbonate resin is 20,000 to 300,000, for example, 20,000 or more, or more than 20,000, and 300,000 or less, or less than 300,000. The Mw value of the thermoplastic resin such as a polycarbonate resin is preferably 22,000 to 200,000 or 24,000 to 250,000, more preferably 23,000 to 100,000 or 25,000 to 120,000, even more preferably 24,000 to 60,000 or 26,000 to 80,000, and particularly preferably 27,000 to 40,000, 28,000 to 50,000, or 30,000 to 38,000.

[0033] 1-4. Secondary Components The resin composition may contain components other than the oligomer and thermoplastic resin. For example, at least one additive selected from antioxidants, mold release agents, etc. The resin composition preferably contains either an antioxidant or a mold release agent, or both. In the resin composition, the content of secondary components such as additives other than the oligomer and resin, based on the total weight, is preferably 20% by weight or less, more preferably 15% by weight or less or 10% by weight or less, even more preferably 7% by weight or less or 5% by weight or less, and particularly preferably 3% by weight or less or 2% by weight or less. Specific examples of additives contained in the resin composition include the following.

[0034] Antioxidant Examples of the antioxidant include phenol-based antioxidants, hindered phenol-based antioxidants, bisphenol-based antioxidants, and polyphenol-based antioxidants.

[0035] Specifically, 2,6-di-tert-butyl-4-methylphenol, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 4,4'-butylidenebis-(3-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert t-butyl-4-hydroxy-5-methylphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N' -hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxa hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, and the like.

[0036] The antioxidant is added in an amount of preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, relative to 100 parts by mass of the resin composition. The resin composition may contain one type of antioxidant, or two or more types. When two or more types of antioxidants are contained, the total amount thereof is preferably within the above range.

[0037] Mold Release Agents Examples of mold release agents include carboxylic acid esters, polysiloxane compounds, and paraffin wax (polyolefin-based). Specific examples include at least one compound selected from the group consisting of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number-average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils. Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic mono-, di-, or tri-carboxylic acids. Aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, with saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms being even more preferred. Specific examples of aliphatic carboxylic acids include palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetraacontanoic acid, montanic acid, glutaric acid, adipic acid, and azelaic acid. The same aliphatic carboxylic acids as those described above can be used as the aliphatic carboxylic acids in the esters of aliphatic carboxylic acids and alcohols. On the other hand, examples of alcohols include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric or polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, aliphatic compounds also include alicyclic compounds. Specific examples of alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, etc. The above-mentioned ester compounds may contain aliphatic carboxylic acids and / or alcohols as impurities, or may be a mixture of multiple compounds.Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture primarily composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate. Aliphatic hydrocarbons having a number-average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Aliphatic hydrocarbons also include alicyclic hydrocarbons. These hydrocarbon compounds may also be partially oxidized. Among these, paraffin wax, polyethylene wax, or partially oxidized polyethylene wax are preferred, with paraffin wax and polyethylene wax being more preferred. The number average molecular weight is preferably 200 to 5000. These aliphatic hydrocarbons may be a single substance or a mixture of substances with various constituent components and molecular weights, as long as the main component is within the above range. Examples of polysiloxane-based silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone. Two or more of these may be used in combination.

[0038] The addition ratio of the release agent is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 2 parts by mass or less, more preferably 1 part by mass or less, relative to 100 parts by mass of the resin composition. Only one type of release agent may be used, or two or more types may be used. When two or more types are used, it is preferable that the total amount is within the above range.

[0039] 1-5. Component Ratios of Resin Composition In the resin composition, the content of the oligomer based on the total mass of the resin composition is preferably 0.5 to 18 mass%. The content of the oligomer in the resin composition is more preferably 1.0 to 15 mass% or 2.0 to 16 mass%, even more preferably 3.0 to 12 mass% or 4.0 to 14 mass%, and particularly preferably 5.0 to 10 mass% or 6.0 to 12 mass%.

[0040] In the resin composition, the mass ratio of the thermoplastic resin such as a polycarbonate resin to the oligomer (for example, the mass ratio of BPEF-PC:BPA-Olig) is preferably 80:20 to 99:1, more preferably 85:15 to 98:2, even more preferably 88:12 to 96:4, and particularly preferably 90:10 to 95:5.

[0041] In the resin composition, the total content of the oligomer and the resin is preferably 80% by weight or more, more preferably 85% by weight or more or 90% by weight or more, even more preferably 93% by weight or more or 95% by weight or more, and particularly preferably 97% by weight or more or 98% by weight or more, based on the total weight. The resin composition may also be formed substantially only from the oligomer and the resin.

[0042] 1-6. Properties of Resin Composition The glass transition temperature (Tg) of the resin composition according to JIS K7121-1987 is preferably 100 to 200°C, more preferably 110 to 180°C, even more preferably 120 to 160°C, and particularly preferably 130 to 150°C.

[0043] The average retardation value of the resin composition is preferably 40 nm or less, more preferably 30 nm or less or 24 nm or less, further preferably 20 nm or less or 16 nm or less, and particularly preferably 14 nm or less or 12 nm or less. Note that, although a method for measuring the average retardation value of a lens which is a molded product will be described later, the average retardation value of a resin composition can also be measured by the same measurement method.

[0044] 2. Method for Producing Resin Compositions 2-1. Production Processes for Oligomers and Thermoplastic Resins Oligomers and thermoplastic resins such as polycarbonate resins are produced by the following methods. Oligomers and polycarbonate resins can be produced, for example, by reacting a raw material compound, such as a bisphenol or a fluorenediol, from which the first or second structural unit (A) or (B) is derived, with a carbonate ester-forming compound. Known methods can be employed, such as the direct reaction of a bisphenol or a fluorenediol with phosgene (phosgene method), or the transesterification of a bisphenol or a fluorenediol with a bisarylcarbonate (transesterification method).

[0045] In the phosgene method, for example, bisphenols or fluorenediols that derive the structural unit (A) or (B) are reacted with phosgene in the presence of an acid binder and a solvent. Examples of the acid binder include pyridine and alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and examples of the solvent include methylene chloride and chloroform. Furthermore, to promote the condensation polymerization reaction, it is preferable to use a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt such as benzyltriethylammonium chloride.

[0046] Furthermore, the degree of polymerization, i.e., molecular weight, of the resulting oligomer and thermoplastic resin can be controlled by adjusting the type and amount of compounds, such as monohydric phenols, that induce terminal structures. In addition to monohydric phenols, it is also possible to induce terminal structures using monohydric phenols such as p-t-butylphenol, p-cumylphenol, and long-chain alkyl-substituted phenols. If desired, small amounts of antioxidants such as sodium sulfite and hydrosulfite, or branching agents such as phloroglucin and isatin bisphenol, may be added. The reaction is typically carried out at a temperature ranging from 0 to 150°C, preferably from 5 to 40°C. The reaction time varies depending on the reaction temperature, but is typically 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. It is also desirable to maintain the pH of the reaction system at 10 or higher during the reaction.

[0047] On the other hand, in the transesterification method, for example, a bisphenol or fluorene-based diol that derives the structural unit (A) or (B), a compound such as a monohydric phenol that derives a terminal structure, and a bisaryl carbonate are mixed and reacted at high temperature under reduced pressure. Examples of bisaryl carbonates include bisaryl carbonates such as diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Two or more of these compounds can also be used in combination. The polymerization reaction using the transesterification method is typically carried out at a temperature in the range of 150 to 350°C, preferably 200 to 300°C, and the final degree of vacuum is preferably 1 mmHg or less. It is preferable to adjust the reaction conditions in this way and distill off phenols derived from the bisaryl carbonate and excess unreacted bisaryl carbonate from the system during the transesterification reaction. The reaction time varies depending on the reaction temperature, the degree of reduced pressure, etc., but is usually about 1 to 24 hours. The reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon, and, if desired, the reaction may be carried out in the presence of a small amount of a molecular weight modifier other than the compound such as a monohydric phenol that induces a terminal structure, or by adding an antioxidant or a branching agent.

[0048] Alternatively, oligomers or polycarbonate resins may be produced by melt polycondensation using a catalyst and a bisphenol compound or fluorene-based diol raw material that derives the structural unit (A) or (B), while removing by-products through a transesterification reaction under heating at atmospheric or reduced pressure. The melt polycondensation reaction is generally carried out in two or more stages. Specifically, the first stage is carried out at a temperature of 120 to 220°C, preferably 160 to 200°C, for 0.1 to 5 hours, preferably 0.5 to 3 hours, at a pressure of atmospheric to 200 Torr. The temperature is then gradually increased to a final temperature of 230 to 260°C over 1 to 3 hours, while the pressure is gradually reduced to a final pressure of 1 Torr or less, to continue the reaction. Finally, the polycondensation reaction is carried out at a temperature of 230 to 260°C under a reduced pressure of 1 Torr or less, and the pressure is restored with nitrogen to terminate the reaction when a predetermined viscosity is reached. The reaction time at 1 Torr or less is, for example, 0.1 to 2 hours, and the total reaction time is, for example, 1 to 6 hours, usually 2 to 5 hours.

[0049] Among thermoplastic resins and oligomers, thermoplastic resins in particular may contain impurities such as alcoholic compounds such as phenolic compounds that may be generated as by-products during production, or diol components or carbonate diesters that remain unreacted. The impurities, such as alcoholic compounds such as phenolic compounds and carbonate diesters, may cause a decrease in strength or the generation of odor when molded into a molded article, so it is preferable that the content of these impurities is as small as possible.

[0050] The content of residual phenolic compounds in the thermoplastic resin is preferably 3,000 ppm by mass or less, more preferably 1,000 ppm by mass or less, and particularly preferably 300 ppm by mass or less, based on 100% by mass of the thermoplastic resin. The content of residual diol components in the thermoplastic resin is preferably 1,000 ppm by mass or less, more preferably 100 ppm by mass or less, and particularly preferably 10 ppm by mass or less, based on 100% by mass of the thermoplastic resin. Furthermore, the content of residual carbonate diesters in the thermoplastic resin is preferably 1,000 ppm by mass or less, more preferably 100 ppm by mass or less, and particularly preferably 10 ppm by mass or less, based on 100% by mass of the thermoplastic resin. In particular, it is preferable that the contents of compounds such as phenol and t-butylphenol are low, and it is preferable that the contents of these compounds are within the above ranges.

[0051] The content of phenolic compounds remaining in a thermoplastic resin can be measured by a method of analyzing phenolic compounds extracted from the thermoplastic resin using gas chromatography. The content of alcoholic compounds remaining in a thermoplastic resin can also be measured by a method of analyzing alcoholic compounds extracted from the thermoplastic resin using gas chromatography. The content of diol components and carbonate diesters remaining in a thermoplastic resin can also be measured by a method of extracting these compounds from the thermoplastic resin and analyzing them using gas chromatography.

[0052] The contents of by-produced alcohol compounds such as phenolic compounds, diol components, and carbonate diesters may be reduced to an undetectable level, but from the viewpoint of productivity, they may be contained in small amounts within a range that does not impair the effects. Furthermore, small amounts can improve the plasticity of the thermoplastic resin when it is melted.

[0053] The content of each of the phenolic compound, diol component, or carbonate diester remaining in the thermoplastic resin may be, for example, 0.01 ppm by mass or more, 0.1 ppm by mass or more, or 1 ppm by mass or more, relative to 100% by mass of the thermoplastic resin. The content of the alcoholic compound remaining in the thermoplastic resin may be, for example, 0.01 ppm by mass or more, 0.1 ppm by mass or more, or 1 ppm by mass or more, relative to 100% by mass of the thermoplastic resin.

[0054] The contents of by-produced alcohol compounds such as phenolic compounds, diol components, and carbonate diesters in the thermoplastic resin can be adjusted to fall within the above ranges by appropriately adjusting the polycondensation conditions and apparatus settings, and can also be adjusted by the conditions of the extrusion step after polycondensation.

[0055] For example, the amount of remaining by-produced alcohol-based compounds such as phenol-based compounds is related to the type of carbonate diester used in the polymerization of the thermoplastic resin, the polymerization reaction temperature, the polymerization pressure, etc. By adjusting these factors, the amount of remaining by-produced alcohol-based compounds such as phenol-based compounds can be reduced.

[0056] For example, when a thermoplastic resin is produced using a dialkyl carbonate such as diethyl carbonate, the molecular weight is difficult to increase, resulting in a low-molecular-weight thermoplastic resin, and the content of by-product alkyl alcohol compounds tends to be high. Such alkyl alcohols are highly volatile, and if they remain in the thermoplastic resin, the moldability of the resin tends to deteriorate. Furthermore, if a large amount of by-product alcohol compounds such as phenolic compounds remain, odor problems may occur during resin molding, or the cleavage reaction of the resin skeleton may progress during compounding, resulting in a decrease in molecular weight. Therefore, it is preferable that the content of by-product alcohol compounds remaining in the obtained thermoplastic resin is 3000 ppm by mass or less relative to the thermoplastic resin (100% by mass). The content of the remaining alcohol compounds is preferably 3000 ppm by mass or less, more preferably 1000 ppm by mass or less, and particularly preferably 300 ppm by mass or less relative to 100% by mass of the thermoplastic resin.

[0057] 2-2. Melting and Extrusion Process The resin composition is preferably produced by melting and mixing the oligomer obtained by the above-mentioned process and a thermoplastic resin such as a polycarbonate resin. In the melting process for producing the resin composition, for example, any of the following may be used: a method of mixing solid oligomer and solid polycarbonate resin and kneading them with a kneader; a method of adding solid polycarbonate resin to molten oligomer and kneading them; a method of adding solid oligomer to molten polycarbonate resin and kneading them; or a method of mixing molten oligomer and polycarbonate resin and kneading them. The kneading process may be either continuous or batchwise.

[0058] The method for producing a resin composition preferably includes a melt-extrusion step in which an oligomer and a resin are melted and extruded. In the melt-extrusion step, a continuous extruder is preferably used, and a batch-type extruder such as a Labo Plastomill or a kneader can be used. The step of melting and kneading the oligomer and the resin may be carried out with or without deactivating the catalysts used in the polymerization steps of the oligomer and the resin, respectively. A catalyst deactivator for deactivating the catalyst may be added to the oligomer and the resin before melting and kneading, and then the mixture may be melted and kneaded. Alternatively, the catalyst deactivator may be added to the oligomer and the resin at the start of the kneading step and then kneaded. Additives other than the catalyst deactivator may be added at the same time as the catalyst deactivator or at a different time. The additives other than the catalyst deactivator may be added to the oligomer alone, the resin alone, or a mixture of the oligomer and the resin. The method of adding the catalyst deactivator and other additives is not particularly limited. For example, the catalyst deactivator and other additives may be mixed with or impregnated into the oligomer before the kneading step with the resin, or may be mixed with or impregnated into the resin before the kneading step. The catalyst deactivator and other additives may be dissolved together in an organic solvent, such as alcohols such as methanol and ethanol, acetone, toluene, phenol, or water, or another solvent, and the resulting solution may be mixed with the oligomer or resin and then kneaded. Alternatively, the catalyst deactivator and additive components may be dissolved separately in the same or different solvents, and the resulting solutions may be added to the oligomer or resin and kneaded.

[0059] In the melt extrusion process of the resin composition, for example, an oligomer, a thermoplastic resin, and additives are melt-mixed, and the mixture is then charged into a melt kneading device and kneaded. In the melt kneading process, it is preferable to continuously charge raw materials such as a polycarbonate resin and an oligomer, for example, by using a rotary feeder or the like to continuously charge the raw materials into the cylinder of the kneading device.

[0060] As operating conditions for kneading in the melt kneading apparatus, the rotation speed of the screw provided in the cylinder is preferably 200 rpm or more, more preferably 250 rpm or more, and even more preferably 275 rpm or more, and is adjusted to, for example, 300 rpm. Furthermore, for example, a rotary feeder is preferably used to introduce raw materials into the melt kneading apparatus, and the rotation speed of the rotary feeder is preferably set to 6 to 10 rpm, and is adjusted to, for example, 8 rpm, as a setting condition for introducing raw materials. The heating temperature of the mixture of oligomer, thermoplastic resin, etc. in the melt kneading step is preferably 270°C or more, and is adjusted to, for example, 275°C.

[0061] When only the polycarbonate resin having the second structural unit (B) obtained from the fluorene-based monomer is melt-kneaded, the above-mentioned melt-kneading device may be set under conditions such as a screw rotation speed of 100 rpm, a feeder rotation speed of 15 rpm, and a cylinder temperature of 260° C. However, in the melt-extrusion process using such an alloy of polycarbonate resin and oligomer, poor appearance such as cloudiness is likely to occur, so it is preferable to adjust the melt-kneading conditions so that the temperature inside the device, i.e., the heating temperature of the mixture, is higher, the residence time in the kneading device is longer, and the mixture is under high-shear conditions, compared to the above-mentioned process of melt-kneading only the polycarbonate resin.

[0062] According to the examples described in detail below, a lens having suppressed retardation and low birefringence, without noticeable cloudiness in visual appearance, could be produced by injection molding using a resin composition obtained by adjusting the melt-kneading conditions in this manner.

[0063] In a method for producing a resin composition, a process may be employed in which an oligomer and a resin are dissolved in a solvent, poured into a mold, and then the solvent is evaporated. Examples of solvents that can be used include methylene chloride, chloroform, and cresol. This process allows additives to be dissolved and added simultaneously with the oligomer and resin. Furthermore, when antioxidants, mold release agents, ultraviolet absorbers, flow modifiers, reinforcing agents, nucleating agents, dyes, antistatic agents, antibacterial agents, and the like are added to the resin composition as needed, these additives may be added to either or both of the oligomer and polycarbonate resin before kneading, or may be added simultaneously during blending and kneading, or may be kneaded after mixing.

[0064] <3. Optical Material> The resin composition of the present invention is suitably used as a material for forming an optical component by curing it into a predetermined shape. That is, the resin composition is suitable for use as an optical material. By using the resin composition of the present invention as an optical material, or by adding appropriate additives to the resin composition, an optical component having excellent appearance and favorable properties such as suppressed retardation can be produced.

[0065] <4. Molded Article> The molded article of the present invention is molded from the resin composition described above. That is, the molded article contains the resin composition of the present invention and is molded into a predetermined shape. Such a molded article has good properties, such as reduced surface irregularities, an excellent appearance, and a small retardation.

[0066] For example, in the molded product, the average retardation value measured by the method described below is preferably 40 nm or less, more preferably 30 nm or less or 24 nm or less, even more preferably 20 nm or less or 16 nm or less, and particularly preferably 14 nm or less or 12 nm or less.

[0067] Examples of molded articles include those obtained by processing the resin composition by extrusion molding, blow molding, injection molding, etc., such as extrusion molded articles, hollow molded articles, precision parts, thin injection molded articles, etc. Specific examples of molded articles using the resin composition as an optical material include optical parts such as optical lenses, optical films, liquid crystal displays, light guide plates, various films such as optical disk substrates, and housings for electronic devices such as smartphones.

[0068] [Analysis Method] 1) Weight-average molecular weight (Mw) The polystyrene-equivalent molecular weight (Mw) of a polycarbonate resin or polycarbonate resin composition was measured by gel permeation chromatography (GPC) under the following conditions: Measurement conditions: Measuring instrument: HLC-8320GPC manufactured by Tosoh Corporation; Column: Shodex K-G + K-805L x 2 + K-800D; Eluent: Chloroform; Temperature: Column thermostat 40°C; Flow rate: 1.0 ml / min; Concentration: 0.1 wt / vol%; Injection volume: 100 μl; Pretreatment: Filtration through a 0.45 μm filter; Detector: UV refractometer; Standard polystyrene: EasiCal Type PS-1 polystyrene manufactured by GL Sciences Inc.

[0069] 2) Glass transition temperature (Tg) Measured according to JIS K7121-1987 using a differential scanning calorimeter with a heating program of 10°C / min. Differential scanning calorimeter: X-DSC7000 manufactured by Hitachi High-Tech Science Corporation. 3) Retardation of molded lens The polycarbonate resin composition was dried at 120°C for 8 hours and injection molded to obtain a plano-convex lens with a diameter of 50 mm, a central thickness of 6 mm, and a peripheral thickness of 2 mm. Molding conditions: Molding machine: Injection molding machine S-2000i30A (30 tons) manufactured by FANUC Corporation Molding conditions: Cylinder temperature: 270°C Mold temperature: Tg of resin - 15°C The obtained lens test piece was annealed under the following conditions. Annealing conditions: Annealing temperature: Tg of resin - 20°C Annealing time: 24 hours The phase difference of the lens molded product after the annealing treatment was measured using a two-dimensional birefringence measuring device WPA-100 manufactured by Photonic Lattice.

[0070] 4) Appearance Evaluation of Molded Lenses The appearance of plano-convex lens molded articles produced by the method described above in the section 3) Retardation of Molded Lenses was evaluated according to the following criteria: Excellent: No lumpy appearance defects or phase separation on the surface of the molded article Good: Almost no lumpy appearance defects or phase separation on the surface of the molded article Fair: Lumpy appearance defects and phase separation on the surface of the molded article Note that "lumps" refers to tiny swellings or protrusions (blisters) that appear on the surface of the molded article.

[0071] [Synthesis Example 1: Oligomer] (Step 1) 5,000 g of 2,2'-bis(4-hydroxyphenyl)propane (BPA: manufactured by Mitsubishi Chemical Corporation) was added as a raw material to 31 L of a 9 wt% aqueous sodium hydroxide solution, and 6 g of hydrosulfite was further added and dissolved. 20 L of dichloromethane was added to this solution, and while stirring, the solution temperature was set to 20°C, and 3,040 g of phosgene was further blown in over 30 minutes. (Step 2) After the phosgene blowing was completed, 940 g of p-tert-butylphenol (PTBP) dissolved in 5 L of dichloromethane was added, and the mixture was emulsified by vigorously stirring for 7 minutes. 20 ml of triethylamine was then added as a polymerization catalyst, and polymerization was carried out for approximately 30 minutes.

[0072] (Post-process) The polymerization solution was separated into an aqueous layer and an organic layer, and the organic layer was neutralized with phosphoric acid and repeatedly washed with pure water until the pH of the washings reached pH 7.0. The organic solvent was evaporated from this purified polycarbonate resin solution to obtain a powder of BPA oligomer (BPA-Olig). This oligomer powder was dried at 100°C for 24 hours to completely remove the solvent. The molecular weight (Mw) of the obtained BPA oligomer (BPA-Olig) was 4,500.

[0073] [Synthesis Example 2: Oligomer] A BPA oligomer (BPA-Olig) having a molecular weight (Mw) of 1,500 was obtained in the same manner as in Synthesis Example 1, except that the amount of PTBP used was changed to 1,316 g. [Synthesis Example 3: Oligomer] A BPA oligomer (BPA-Olig) having a molecular weight (Mw) of 10,000 was obtained in the same manner as in Synthesis Example 1, except that the amount of PTBP used was changed to 387.1 g. [Synthesis Example 4: Oligomer] A BPA oligomer (BPA-Olig) having a molecular weight (Mw) of 800 was obtained in the same manner as in Synthesis Example 1, except that the amount of PTBP used was changed to 2,193.4 g. Synthesis Example 5: Oligomer A BPA oligomer (BPA-Olig) having a molecular weight (Mw) of 18,000 was obtained in the same manner as in Synthesis Example 1, except that the amount of PTBP used was changed to 205.6 g.

[0074] [Polymerization Example 1: Polycarbonate Resin] 39,455 g (89.97 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF), 19,907 g (92.93 mol) of diphenyl carbonate (DPC), and 1.08 ml (1.08 × 10) of a 0.10 mol / L aqueous sodium hydrogen carbonate solution were used as raw materials. －３ mole, i.e., 1.20 × 10 per mole of the total of dihydroxy compounds －５ (mol) was placed in a 50-liter reactor equipped with a stirrer and distillation device, and heated to 215°C over 1 hour under a nitrogen atmosphere of 760 Torr with stirring. The pressure was then adjusted to 150 Torr over 10 minutes, and the reaction system was maintained at 215°C and 150 Torr for 20 minutes to carry out a transesterification reaction. The reaction system was then heated to 240°C at a rate of 37.5°C / hr and maintained at 240°C and 150 Torr for 10 minutes. The pressure was then adjusted to 120 Torr over 10 minutes, and the reaction system was maintained at 240°C and 120 Torr for 70 minutes. The pressure was then adjusted to 100 Torr over 10 minutes, and the reaction system was maintained at 240°C and 100 Torr for 10 minutes. The pressure was then reduced to 1 Torr or less over 40 minutes, and the polymerization reaction was carried out with stirring under conditions of 240°C and 1 Torr or less for 10 minutes. After the reaction was completed, nitrogen was blown into the reactor to pressurize it, and the produced polycarbonate resin (BPEF-PC) was extracted.

[0075] [Example 1: Resin Composition] 10 g of a hindered phenol-based antioxidant (AO-60 manufactured by ADEKA Corporation), 3 g of a phosphite-based antioxidant (PEP-36 manufactured by ADEKA Corporation), and 15 g of glycerin monostearate (S-100A manufactured by Riken Vitamin Co., Ltd.) as a mold release agent were added to a mixture of 0.74 kg of the BPA oligomer (BPA-Olig) obtained in Synthesis Example 1 and 9.26 kg of the polycarbonate resin (BPEF-PC) obtained in Polymerization Example 1, and the mixture was fed into a twin-screw extruder (TEM-26SX manufactured by Shibaura Machine Co., Ltd.) via a rotary feeder (rotation speed: 8 rpm). The cylinder temperature of the twin-screw extruder was set to 275°C, and the screw rotation speed was adjusted to 300 rpm, and the raw materials were kneaded and pelletized to obtain a polycarbonate resin composition.

[0076] [Examples 2 to 6 and Reference Example] Polycarbonate resin compositions were obtained in the same manner as in Example 1, except that the BPA oligomer (BPA-Olig) and polycarbonate resin (BPEF-PC) shown in Table 1 were used. In these Examples 1 to 6 and Reference Example, the content of the oligomer was adjusted to 7.4 mass% based on the total mass of the polycarbonate resin composition. [Comparative Example 1] Polycarbonate resin compositions were obtained in the same manner as in Example 1, except that a polycarbonate resin composed of BPA (Iupilon H-4000, manufactured by Mitsubishi Engineering-Plastics Corporation) was used instead of the BPA oligomer (BPA-Olig). In Comparative Example 1, the content of the BPA resin was adjusted to 7.4 mass% based on the total mass of the polycarbonate resin composition. The physical properties of the polycarbonate resin compositions obtained in these Examples, Reference Examples, and Comparative Examples are shown in Table 1 and FIG. 1. In the Reference Example, the melt viscosity of the obtained polycarbonate resin composition was low and it was not possible to pelletize it. However, based on the results of the other Examples, it was considered that if it was used as a raw material for a molded article, good properties such as good retardation would be achieved.

[0077] [Examples 7, 8, Comparative Examples 2 and 3] Polycarbonate resin compositions were obtained in the same manner as in Example 1, except that a BPA oligomer (BPA-Olig) and a polycarbonate resin (BPEF-PC) were used, as shown in Table 2. In Examples 1, 7, 8 and Comparative Example 2, the weight average molecular weight (Mw) of the oligomer contained in the polycarbonate resin composition was 4,500. Furthermore, the polycarbonate resin composition of Comparative Example 3 did not contain any oligomer. The physical properties of the polycarbonate resin compositions obtained in these Examples and Comparative Examples are shown in Table 2 and FIG. 2, along with the physical properties of Example 1.

Claims

1. A resin composition comprising an oligomer containing a first structural unit (A) derived from a monomer represented by the following general formula (1) and a polycarbonate resin containing a second structural unit (B) derived from a monomer represented by any one of the following general formulas (2a) to (2c), wherein the molecular weight (Mw) of the oligomer is 500 to 20,000. (In formula (1), ａ R ｂ and R are each independently hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 20 carbon atoms which may each have a substituent, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms; r and s are each independently an integer of 0 to 4; X is represented by formula (3), 10 R 11 and R 12 are each independently hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms which may each have a substituent, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R is each independently an alkylene group having 1 to 9 carbon atoms which may have a substituent; c represents an integer of 0 to 20; d represents an integer of 1 to 500.) ｃ R ｄ is independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 20 carbon atoms which may have a substituent, a cycloalkoxyl group having 5 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent; Y is independently a fluorene group which may have a substituent; A and B each independently represent an alkylene group having 1 to 5 carbon atoms which may have a substituent; p and q each independently represent an integer of 0 to 4; a and b each independently represent an integer of 0 to 10.) 2. The resin composition according to claim 1, wherein the molecular weight (Mw) of the oligomer is 1,000 to 10,000.

3. The resin composition according to claim 1, wherein the molecular weight (Mw) of the polycarbonate resin is 20,000 to 300,000.

4. In the general formula (1) representing the monomer that generates the first structural unit (A), R ａ and R ｂ are each independently hydrogen, an alkyl group having 1 to 12 carbon atoms which may each have a substituent, or an aryl group having 6 to 10 carbon atoms, and r and s are each independently 0 or 1. The resin composition according to claim 1.

5. The resin composition according to claim 1, wherein the monomer that generates the second structural unit (B) is represented by the general formula (2a).

6. The resin composition according to claim 1, wherein the content of the oligomer based on the total mass of the resin composition is 0.5 to 18% by mass.

7. The resin composition according to claim 1, wherein the mass ratio of the polycarbonate resin to the oligomer is 80:20 to 99:

1.

8. The resin composition according to claim 7, wherein the mass ratio of the polycarbonate resin to the oligomer is 90:10 to 95:

5.

9. The resin composition according to claim 1, wherein the resin composition contains any one of a polycarbonate oligomer, a polyester oligomer, and a polyester carbonate oligomer having the first structural unit (A).

10. The resin composition according to claim 1, wherein the resin composition further contains any one of a polyester resin and a polyester carbonate resin having the second structural unit (B).

11. The resin composition according to claim 1, wherein the average retardation of the resin composition is 40 nm or less.

12. A method for producing the resin composition according to any one of claims 1 to 11, the method comprising mixing and melt-extruding the polycarbonate resin and the oligomer at 270°C or higher.

13. The production method according to claim 12, wherein the screw rotation speed in the cylinder for performing the melt extrusion is 200 rpm or more.

14. The production method according to claim 12, wherein the polycarbonate resin and the oligomer are continuously charged into the cylinder using a rotary feeder.

15. An optical material comprising the resin composition according to any one of claims 1 to 11.

16. A molded article molded using the resin composition according to any one of claims 1 to 11.

17. The molded article according to claim 16, which is a lens having an average retardation of 40 nm or less.

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