Recycled polycarbonate resin composition

Abstract

This invention provides a recycled polycarbonate resin composition that uses recycled polycarbonate resin and has physical properties equivalent to those of unused polycarbonate resin compositions, particularly equivalent optical properties. [Solution] The present invention relates to a recycled polycarbonate resin composition comprising 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2), wherein the resin component contains 0.01 to 0.5 parts by mass of a phosphorus-based antioxidant (B) and 0.1 to 3 parts by mass of a light-diffusing agent (C), and the recovered polycarbonate resin (a2) has a diphenyl carbonate content of 20 ppm or less and a chlorobenzene content of 20 ppm or less.

Description

Technical Field

[0001] The present invention relates to a recycled polycarbonate resin composition.

Background Art

[0002] Polycarbonate resins and the like have mechanical properties, electrical properties, weather resistance, water resistance, chemical resistance, and solvent resistance, and are therefore used in various applications such as electrical and electronic parts, mechanical mechanism parts, and automotive parts.

[0003] In recent years, recycling has been strongly demanded from the perspective of environmental protection. As a method for recovering a thermoplastic resin from a product using a thermoplastic resin, for example, Patent Document 1 discloses that a thermoplastic resin member recovered from equipment parts is pulverized, washed, and then the pulverized material is separated to produce a recycled material. Examples of recycled materials for polycarbonate resins include recycled materials regenerated from optical discs such as CDs, DVDs, and BDs, light guide plates, resin window glasses, and automotive headlamp lenses. However, various additives are contained in the recycled material in various contents, and it has been difficult to obtain a recycled material close to a polycarbonate resin composition that does not use the recycled material only with the recycled material.

[0004] By the way, a light-diffusing molded article made of a resin composition in which a light diffusing agent such as inorganic fine particles or polymer fine particles is blended with a polycarbonate resin is excellent in heat resistance and dimensional stability compared to a light-diffusing molded article made of an acrylic resin. Therefore, it is used in a wide range of fields such as lamp covers, meters, signboards (especially internally illuminated), resin window glasses, light diffusing plates for image reading devices or image display devices (for example, light diffusing plates used in backlight modules of liquid crystal display devices, light diffusing plates used in projection-type display screens such as projector TVs, etc.), light diffusing films (for example, high-permeability light diffusing films used for improving the brightness of liquid crystal display devices, etc.). In such applications, the use of recycled materials has also been demanded.

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a recycled polycarbonate resin composition that uses recycled polycarbonate resin and has physical properties equivalent to those of an unused polycarbonate resin composition, particularly equivalent optical properties.

Means for Solving the Problems

[0007] As a result of intensive studies to solve such problems, the present inventors have found that by mixing a recovered polycarbonate resin having a diphenyl carbonate content of 20 ppm or less and a chlorobenzene content of 20 ppm or less with an unused polycarbonate resin, a recycled polycarbonate resin composition having physical properties equivalent to those of an unused polycarbonate resin composition, particularly equivalent optical properties, can be obtained even when a light diffusing agent is contained, and thus the present invention has been completed.

[0008] That is, the present invention (1) contains 0.01 to 0.5 parts by mass of a phosphorus-based antioxidant (B) and 0.1 to 3 parts by mass of a light diffusing agent (C) with respect to 100 parts by mass of a resin component composed of 1 to 90% by mass of an unused polycarbonate resin (a1) and 99 to 10% by mass of a recovered polycarbonate resin (a2), and the diphenyl carbonate content of the recovered polycarbonate resin (a2) is 20 ppm or less and the chlorobenzene content is 20 ppm or less, and is a recycled polycarbonate resin composition.

[0009] The present invention (2) is the recycled polycarbonate resin composition according to the present invention (1), wherein the light diffusing agent (C) is a silicone-based light diffusing agent, an acrylic-based light diffusing agent, or inorganic fine particles.

[0010] The present invention (3) is a recycled polycarbonate resin composition according to the present invention (1) or (2), wherein the content of the unused polycarbonate resin (a1) is 10 to 80% by mass and the content of the recovered polycarbonate resin (a2) is 90 to 20% by mass.

[0011] The present invention (4) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (3), wherein the viscosity-average molecular weight of the recovered polycarbonate resin (a2) is 17,000 to 28,000.

[0012] The present invention (5) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (4), wherein the recovered polycarbonate resin (a2) has a tris(2,4-di-t-butylphenyl) phosphate content of 20 ppm or less and a 2,4-di-t-butylphenol content of 50 ppm or less.

[0013] The present invention (6) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (5), wherein the recovered polycarbonate resin (a2) contains at least one ultraviolet absorber selected from benzotriazole-based, benzophenone-based, and triazine-based ultraviolet absorbers in a concentration of 2,000 ppm or less.

[0014] The present invention (7) is that the recovered polycarbonate resin (a2) is measured under the conditions of a laser wavelength of 532 nm, exposure time of 1.0 second, number of exposures of 4, and laser output of 1.6 mW, and in the Raman spectrum obtained, the value is 2000 cm⁻¹. -1 This is a recycled polycarbonate resin composition according to any one of the present invention (1) to (6), which is a recovered polycarbonate resin having a strength of 1000 cps or less.

[0015] The present invention (8) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (7), wherein the content of diphenyl carbonate in the composition is 10 ppm or less and the content of chlorobenzene is 2 ppm or less.

[0016] The present invention (9) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (8), wherein the content of diphenyl carbonate in the composition is 5 ppm or less.

[0017] The present invention (10) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (9), wherein the tris(2,4-di-t-butylphenyl) phosphate content in the composition is 10 ppm or less and the 2,4-di-t-butylphenol content is 20 ppm or less.

[0018] The present invention (11) is a recycled polycarbonate resin composition according to any one of the present inventions (1) to (10), wherein the content of at least one ultraviolet absorber selected from benzotriazole-based, benzophenone-based, and triazine-based ultraviolet absorbers in the composition is 5,000 ppm or less.

[0019] The present invention (12) further comprises the following formula: RO-(X'-O) m (Y'-O) n -R (In the formula, R independently represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X' represents a linear alkylene group or a branched alkylene group having 2 to 4 carbon atoms, Y' represents a linear alkylene group or a branched alkylene group having 2 to 5 carbon atoms, X' and Y' may be the same or different, m and n each represent 3 to 60, and m+n is 6 to 120.) This is a recycled polycarbonate resin composition according to any one of the present invention (1) to (11), containing 1.0 part by mass or less of a polyalkylene glycol derivative represented by .

[0020] The present invention (13) relates to a polyalkylene glycol derivative of the following formula: HO-(CH2CH2CH2CH2O) m (CH(CH3)CH2O) n -H (In the formula, m and n each independently represent values ​​from 3 to 60, and m+n represents values ​​from 8 to 90.) This is a recycled polycarbonate resin composition according to the present invention (12), comprising a polyalkylene glycol derivative represented by [formula].

[0021] The present invention (14) is a recycled polycarbonate resin composition in which the difference in total light transmittance before and after a reliability test in which an injection-molded piece with a thickness of 1 mm is held in an autoclave at 120°C and 100% RH for 48 hours is 3.0% or less. [Effects of the Invention]

[0022] The recycled polycarbonate resin composition of the present invention contains a diphenyl carbonate content of 20 ppm or less and a chlorobenzene content of 20 ppm or less, along with a recovered polycarbonate resin and unused polycarbonate resin. Therefore, even though recycled polycarbonate resin is used, and even if a light diffusing agent is included, it is possible to provide a recycled polycarbonate resin composition that has optical properties equivalent to those of a resin composition using unused polycarbonate resin. [Modes for carrying out the invention]

[0023] The embodiments are described in detail below. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art. The inventors provide the following explanation so that those skilled in the art can fully understand the present invention, and do not intend to limit the subject matter described in the claims.

[0024] The recycled polycarbonate resin composition of the present invention contains, per 100 parts by mass of a resin component consisting of 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2), 0.01 to 0.5 parts by mass of a phosphorus-based antioxidant (B) and 0.1 to 3 parts by mass of a light-diffusing agent (C), wherein the diphenyl carbonate content of the recovered polycarbonate resin (a2) is 20 ppm or less, and the chlorobenzene content is 20 ppm or less.

[0025] The unused polycarbonate resin (a1) used in this invention refers to a resin that has been pelletized after polymerization and has not been processed into various molded articles. The unused polycarbonate resin (a1) is a polymer obtained by the phosgene method, which involves reacting various dihydroxydiaryl compounds with phosgene, or by the transesterification method, which involves reacting dihydroxydiaryl compounds with carbonate esters such as diphenyl carbonate. A typical example is polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A).

[0026] Examples of dihydroxydiaryl compounds include bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-tertiary butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, and bis(hydroxyaryl)alkanes, as well as 1,1-bis(4-hydroxyphenyl) Examples include bis(hydroxyaryl)cycloalkanes such as roxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane, dihydroxydiaryl ethers such as 4,4′-dihydroxydiphenyl ether and 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, dihydroxydiaryl sulfides such as 4,4′-dihydroxydiphenyl sulfide, dihydroxydiaryl sulfoxides such as 4,4′-dihydroxydiphenyl sulfoxide and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide, and dihydroxydiaryl sulfones such as 4,4′-dihydroxydiphenyl sulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone.

[0027] These can be used individually or in combination of two or more, but other substances such as piperazine, dipiperidyl hydroquinone, resorcinol, and 4,4′-dihydroxydiphenyl may also be used in combination.

[0028] Furthermore, the above-mentioned dihydroxyaryl compounds may be mixed with trivalent or higher phenol compounds as shown below. Examples of trivalent or higher phenol compounds include phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 2,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, and 2,2-bis-[4,4-(4,4′-dihydroxydiphenyl)-cyclohexyl]-propane.

[0029] The viscosity-average molecular weight of unused polycarbonate resin (a1) is not particularly limited, but is usually 18,000 to 25,000 for reasons of moldability and strength. When manufacturing such polycarbonate resin, molecular weight adjusters, catalysts, etc., can be used as needed.

[0030] The recovered polycarbonate resin (a2) used in this invention is recovered from molded articles of polycarbonate resin compositions. Examples of molded articles include those formed by various molding methods such as injection molding, compression molding, extrusion molding, blow molding, and calendering. More specific applications of the molded articles include headlamps, front covers for pachinko machines, silicon wafer cases, transport containers, polycarbonate sheets, and ballpoint pens. Among these, polycarbonate resin compositions recovered from silicon wafer cases and polycarbonate sheets are preferred. These recovered polycarbonate resin compositions can also be used by mixing multiple recovered polycarbonate resin compositions.

[0031] The diphenyl carbonate content in the recovered polycarbonate resin (a2) is 20 ppm or less, but preferably 15 ppm or less. If it exceeds 20 ppm, the decomposition of the polycarbonate resin composition is accelerated in reliability tests, and transparency is impaired. Furthermore, the chlorobenzene content in the recovered polycarbonate resin (a2) is 20 ppm or less, but more preferably 15 ppm or less, and even more preferably 2 ppm or less. If these contents exceed 20 ppm, the decomposition of the polycarbonate resin composition is accelerated in reliability tests, and transparency is impaired.

[0032] The tris(2,4-di-t-butylphenyl) phosphate content in the recovered polycarbonate resin (a2) is preferably 20 ppm or less, and more preferably 10 ppm or less. Furthermore, the 2,4-di-t-butylphenol content is preferably 50 ppm or less, and more preferably 40 ppm or less.

[0033] The content of at least one UV absorber selected from benzotriazole-based, benzophenone-based, and triazine-based UV absorbers in the recovered polycarbonate resin (a2) is preferably 2,000 ppm or less, and more preferably 1,000 ppm or less.

[0034] Examples of benzotriazole-based UV absorbers include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol], and 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzo Examples include riazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), and 2,2'-p-phenylenebis(1,3-benzoxazine-4-one). For example, TINUVIN 329 and TINUVIN 234 from BASF, RIASORB UV-234 from Rianlon Corporation, and LA-31 from ADEKA are commercially available.

[0035] Examples of benzophenone-based UV absorbers include 2,4-dihydroxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone.

[0036] Examples of triazine-based UV absorbers include 2,4-diphenyl-6-(2-hydroxyphenyl-4-hexyloxyphenyl)1,3,5-triazine, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol, and 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]phenol, for example, TINUVIN 1577 from BASF is commercially available.

[0037] The phosphorus-based antioxidant content in the recovered polycarbonate resin (a2) is preferably 5,000 ppm or less, and more preferably 2,000 ppm or less. Examples of phosphorus-based antioxidants are those described later. The lower limit of the phosphorus-based antioxidant content is preferably 100 ppm or more, and more preferably 300 ppm or more.

[0038] Examples of phosphorus-based antioxidants include phosphite ester compounds having the following phosphite ester structure. [ka]

[0039] Examples of phosphorus-based antioxidants include phosphite compounds represented by the following formula (11), phosphite compounds represented by the following formula (12), phosphite compounds represented by the following formula (13), and phosphite compounds represented by the following formula (14).

[0040] Equation (11): [ka] (In the formula, R 1 (where 'a' represents an alkyl group with 1 to 20 carbon atoms, and 'a' represents an integer from 0 to 3.)

[0041] In the above equation (11), R 1is an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms.

[0042] Examples of the compound represented by the formula (11) include triphenyl phosphite, tricresyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, trisnonylphenyl phosphite, and the like. Among these, tris(2,4-di-t-butylphenyl) phosphite is particularly preferred. Examples of commercially available products include Irgafos 168 manufactured by BASF (where "Irgafos" is a registered trademark of BASF SE).

[0043] Formula (12): [Chemical formula] (In the formula, R 2 , R 3 , R 5 and R 6 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group. R 4 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. X represents a single bond, a sulfur atom, or a group represented by the formula: -CHR 7 -(where R 7 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms). A represents an alkylene group having 1 to 8 carbon atoms or a group represented by the formula: *-COR 8 -(where R 8 represents a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond on the oxygen side). Y and Z, one of which represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms).)

[0044] In the formula (12), R 2 , R 3 , R5 and R 6 Each of these independently represents a hydrogen atom, a C1-C8 alkyl group, a C5-C8 cycloalkyl group, a C6-C12 alkylcycloalkyl group, a C7-C12 aralkyl group, or a phenyl group.

[0045] Examples of C1-C8 alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, t-pentyl, i-octyl, t-octyl, and 2-ethylhexyl groups. Examples of C5-C8 cycloalkyl groups include cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of C6-C12 alkylcycloalkyl groups include 1-methylcyclopentyl, 1-methylcyclohexyl, and 1-methyl-4-i-propylcyclohexyl groups. Examples of C7-C12 aralkyl groups include benzyl, α-methylbenzyl, and α,α-dimethylbenzyl groups.

[0046] The aforementioned R 2 , R 3 and R 5 Each of these is preferably an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an alkylcycloalkyl group having 6 to 12 carbon atoms. In particular, R 2 and R 5 Each of these is preferably independently a t-alkyl group such as a t-butyl group, a t-pentyl group, or a t-octyl group, a cyclohexyl group, or a 1-methylcyclohexyl group. In particular, R 3 The group is preferably a C1-C5 alkyl group such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, or t-pentyl group, and is more preferably a methyl group, t-butyl group, or t-pentyl group.

[0047] The aforementioned R 6It is preferably a hydrogen atom, a C1-C8 alkyl group, or a C5-C8 cycloalkyl group, and more preferably a hydrogen atom, a C1-C5 alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group, or a t-pentyl group.

[0048] In equation (12), R 4 R represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of alkyl groups having 1 to 8 carbon atoms include the aforementioned R. 2 , R 3 , R 5 and R 6 Examples of alkyl groups are given in the explanation. In particular, R 4 It is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0049] In formula (12), X is a single bond, a sulfur atom, or a compound of formula :-CHR 7 This indicates a group represented by -. Here, the formula is -CHR 7 -R inside 7 R represents a hydrogen atom, a C1-C8 alkyl group, or a C5-C8 cycloalkyl group. Examples of C1-C8 alkyl groups and C5-C8 cycloalkyl groups are, for example, the R group. 2 , R 3 , R 5 and R 6 Examples of alkyl and cycloalkyl groups are given in the description. In particular, X is preferably a single bond, a methylene group, or a methylene group substituted with a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, etc., and is more preferably a single bond.

[0050] In formula (12), A is an alkylene group having 1 to 8 carbon atoms or formula:*-COR 8This indicates a group represented by -. Examples of alkylene groups having 1 to 8 carbon atoms include methylene, ethylene, propylene, butylene, pentamethylene, hexamethylene, octamethylene, and 2,2-dimethyl-1,3-propylene, with propylene being preferred. Also, formula: *-COR 8 -R in 8 R represents a single bond or an alkylene group having 1 to 8 carbon atoms. 8 Examples of alkylene groups having 1 to 8 carbon atoms that exhibit this property include the alkylene groups exemplified in the explanation of A above. 8 It is preferably a single bond or an ethylene group. Also, formula: *-COR 8 The asterisk (*) in the - indicates the oxygen-side bond, showing that the carbonyl group is bonded to the oxygen atom of the phosphite group.

[0051] In formula (12), Y and Z represent either a hydroxyl group, a carbon-1 to carbon-8 alkoxy group, or a carbon-7 to carbon-12 aralkyloxy group, and either a hydrogen atom or a carbon-1 to carbon-8 alkyl group. Examples of carbon-1 to carbon-8 alkoxy groups include methoxy, ethoxy, propoxy, t-butoxy, and pentyloxy groups. Examples of carbon-7 to carbon-12 aralkyloxy groups include benzyloxy, α-methylbenzyloxy, and α,α-dimethylbenzyloxy groups. Examples of carbon-1 to carbon-8 alkyl groups include the aforementioned R. 2 , R 3 , R 5 and R 6 Examples of alkyl groups are given in the explanation.

[0052] Examples of compounds represented by formula (12) include 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosfepine, 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenzo[d,f][1,3,2]dioxaphosfepine, Examples include 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphosine and 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphosine. Among these, 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxaphosphine is particularly preferred when the resulting aromatic polycarbonate resin composition is used in fields where optical properties are required. A commercially available example is Sumirizer GP ("Sumirizer" is a registered trademark) manufactured by Sumitomo Chemical Co., Ltd.

[0053] Equation (13): [ka] (In the formula, R 9 and R 10 Each of the following independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and each of the following independently represents an integer from 0 to 3.

[0054] Examples of compounds represented by formula (13) include bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane. Commercially available products include ADEKA Stab PEP-36 ("ADEKA Stab" is a registered trademark) manufactured by ADEKA Corporation.

[0055] Equation (14): [ka]

[0056] (In the formula, R 11 ~R 18 Each of these independently represents an alkyl or alkenyl group having 1 to 3 carbon atoms. 11 and R 12 , R 13 and R 14 , R 15 and R 16 , R 17 and R 18 These elements may be joined together to form a ring. 19 ~R 22 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. d to g are each independently integers from 0 to 5. 1 ~X 4 Each of these independently represents a single bond or a carbon atom. 1 ~X 4 If it is a single bond, R 11 ~R 22 Of these, the functional group attached to the single bond in question is excluded from general formula (14).

[0057] A specific example of the compound represented by formula (14) is bis(2,4-dicumylphenyl)pentaerythritol diphosphite. A commercially available example is "Doverphos® S-9228" manufactured by Dover Chemical.

[0058] Phosphorus-based antioxidants can also include, for example, [1,1'-biphenyl]-4,4'-diylbis[bis(2,4-di-t-butylphenoxy)phosphine]. Commercially available examples include Irgaphos P-EPQ (trade name) from BASF and HOSTANOX P-EPQ (trade name) from Clariant Chemicals.

[0059] The content of non-phosphorus antioxidants in the recovered polycarbonate resin (a2) is preferably 5,000 ppm or less, and more preferably 2,000 ppm or less. Examples of non-phosphorus antioxidants include phenolic antioxidants such as dibutylhydroxytoluene, butylhydroxytoluene, and 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol.

[0060] The lubricant content in the recovered polycarbonate resin (a2) is preferably 10,000 ppm or less, and more preferably 8,000 ppm or less. Examples of lubricants include glycerin monostearate and pentaerythritol tetrastearate.

[0061] The melt volume rate (MVR) of the recovered polycarbonate resin (a2) is preferably 3 to 30, and more preferably 10 to 20. Here, the MVR is measured in accordance with ISO 1133 under conditions of 300°C and a load of 1.2 kg using a melt flow indexer.

[0062] The viscosity-average molecular weight of the recovered polycarbonate resin (a2) is not particularly limited, but is preferably 17,000 to 28,000, and more preferably 18,000 to 25,000, from the viewpoint of moldability and strength.

[0063] Among the recovered polycarbonate resin (a2), the Raman spectrum obtained by measurement under the conditions of a laser light wavelength of 532 nm, exposure time of 1.0 second, number of exposures of 4, and laser output of 1.6 mW showed a value of 2000 cm⁻¹. -1A recycled polycarbonate resin with a strength of 1000 cps or less is preferred. A strength of 900 cps or less is more preferred, 800 cps or less is even more preferred, and 700 cps or less is particularly preferred. 1000cm -1 Beyond a certain point, the optical properties of the recycled polycarbonate resin composition tend to deteriorate.

[0064] The content of unused polycarbonate resin (a1) is 1 to 90% by mass, preferably 10 to 80% by mass, and more preferably 20 to 70% by mass, out of 100% by mass of the total of unused polycarbonate resin (a1) and recovered polycarbonate resin (a2). On the other hand, the content of recovered polycarbonate resin (a2) is 99 to 10% by mass, preferably 90 to 20% by mass, and more preferably 80 to 30% by mass.

[0065] The content of diphenyl carbonate in the recycled polycarbonate resin composition of the present invention is 20 ppm or less, preferably 10 ppm or less, and more preferably 5 ppm or less. The content of chlorobenzene is 20 ppm or less, preferably 2 ppm or less, and more preferably 1 ppm or less.

[0066] The tris(2,4-di-t-butylphenyl) phosphate content in the composition is preferably 20 ppm or less, more preferably 10 ppm or less, and even more preferably 5 ppm or less. The 2,4-di-t-butylphenol content is preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 20 ppm or less.

[0067] The content of at least one UV absorber selected from benzotriazole, benzophenone, and triazine UV absorbers in the composition is preferably 5,000 ppm or less, and more preferably 3,000 ppm or less. A content exceeding 5,000 ppm is undesirable because it degrades the hue. Although some UV absorbers may remain in the recovered polycarbonate resin, this content is preferably 2,000 ppm or less.

[0068] The content of phosphorus-based antioxidant (B) in the composition is 0.01 to 0.5 parts by mass (100 to 5,000 ppm) per 100 parts by mass of resin component consisting of 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2). The content is preferably 0.01 to 0.1 parts by mass (100 to 1,000 ppm), and more preferably 0.01 to 0.05 parts by mass (100 to 500 ppm). The content of non-phosphorus-based antioxidant in the composition is preferably 1,000 ppm or less, and more preferably 500 ppm or less. The content of lubricant in the composition is preferably 10,000 ppm or less, and more preferably 8,000 ppm or less.

[0069] The light diffusing agent is not particularly limited as long as it can scatter light within the polycarbonate resin composition, but from the viewpoint of light diffusing, a spherical shape is preferred, and the closer the shape is to a perfect sphere, the more preferred. Specifically, examples include organic diffusing agents such as silicone-based light diffusing agents, acrylic-based light diffusing agents, silicone rubber-like elastic bodies, polymethylsilcethoxane, acrylic-based, styrene-based, polyester-based, polyolefin-based, urethane-based, nylon-based, methacrylate-styrene-based, fluorine-based, norbornene-based, and silicone-based, as well as inorganic fine particles such as calcium carbonate, titanium dioxide, silica, talc, and barium sulfate. Among these, silicone-based light diffusing agents, acrylic-based light diffusing agents, and inorganic fine particles are preferred, and silicone-based light diffusing agents and acrylic-based light diffusing agents are more preferred. Examples of silicone-based light diffusing agents include TSR9000 from Momentive, SL-200M from Lotte Chemical, KL-200M and KL-100M from ASP, and SI-020 and SI-045 from Aica Kogyo Co., Ltd. Examples of acrylic light diffusing agents include Gantzpearl GM-0449S, GM-0449S-2, GM-0403S, and GM-0205S manufactured by Aica Kogyo Co., Ltd., and Chemisnow KMR-3TA manufactured by Soken Chemical Co., Ltd.

[0070] The amount of light diffusing agent in the composition is 0.1 to 3 parts by mass per 100 parts by mass of resin components consisting of 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2), but 0.2 to 2 parts by mass is preferred, and 0.3 to 1.5 parts by mass is more preferred. If the amount is less than 0.1 parts by mass, the light will not be scattered sufficiently and the effect of preventing visibility of the light source will be poor, and if it exceeds 3 parts by mass, the transmittance may decrease significantly.

[0071] The recycled polycarbonate resin composition of the present invention is given by the following formula: RO-(X'-O) m (Y'-O) n -R (In the formula, R independently represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X' represents a linear alkylene group or a branched alkylene group having 2 to 4 carbon atoms, Y' represents a linear alkylene group or a branched alkylene group having 2 to 5 carbon atoms, X' and Y' may be the same or different, m and n each represent 3 to 60, and m+n is 6 to 120.) It is preferable to contain a polyalkylene glycol derivative represented by the following formula: HO-(CH2CH2CH2CH2O) m (CH(CH3)CH2O) n -H (In the formula, m and n each independently represent a value between 3 and 60, and m+n represents a value between 8 and 90.) A polyalkylene glycol derivative represented by is preferred.

[0072] The content of the polyalkylene glycol derivative in the composition is preferably 1.0 part by mass or less, and more preferably 0.7 parts by mass or less, per 100 parts by mass of the resin component consisting of 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2). The lower limit is not particularly limited, but 0.1 parts by mass or more is preferred.

[0073] The recycled polycarbonate resin composition of the present invention may contain additives other than those mentioned above, such as heat stabilizers, colorants, mold release agents, softeners, antistatic agents, impact modifiers, ultraviolet absorbers, pigments, fluorescent whitening agents, fillers, and flow modifiers, to the extent that they do not impair the effects.

[0074] Examples of fillers include carbon black, glass fiber, and mica.

[0075] The recycled polycarbonate resin composition of the present invention is characterized in that the difference in total light transmittance before and after a reliability test in which an injection-molded piece with a thickness of 1 mm is held in an autoclave at 120°C and 100% RH for 48 hours is 3.0% or less. A difference in total light transmittance of 2.0% or less is more preferable.

[0076] The melt volume rate (MVR) of the recycled polycarbonate resin composition of the present invention is preferably 3 to 30, and more preferably 10 to 20. Here, the MVR is measured in accordance with ISO 1133 under conditions of 300°C and a load of 1.2 kg using a melt flow indexer.

[0077] The recycled polycarbonate resin composition of the present invention uses recycled polycarbonate resin and can provide a recycled polycarbonate resin composition having physical properties equivalent to those of a unused polycarbonate resin composition. Therefore, it can be suitably applied to electrical and electronic components, automotive parts, or mechanical components. [Examples]

[0078] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" and "%" are based on mass.

[0079] The following ingredients were used: Unused polycarbonate resin: SD Polycarbonate 200-13, manufactured by Sumika Polycarbonate Co., Ltd., viscosity-average molecular weight 21,500 Recycled polycarbonate resin; PCR-A (recovered PCR from wafer case), viscosity-average molecular weight 19,300 PCR-B composition (60% recovered PC from wafer cases and 40% recovered PC from sheets), viscosity-average molecular weight 20,200 PCR-C (PC recovered from sheet), viscosity-average molecular weight 22,100 PCR-D (PC recovered from transport container), viscosity-average molecular weight 20,100 PCR-E (recovered PC from pachinko machines), viscosity-average molecular weight 20,600 PCR-F (PC recovered from headlights), viscosity-average molecular weight 19,300 PCR-G (PC recovered from headlights), viscosity-average molecular weight 21,200

[0080] <Analysis of recovered polycarbonate resin> The antioxidants were analyzed as follows: First, polycarbonate resin was dissolved in dichloromethane, methanol was added dropwise to reprecipitate the polymer components, filtered, and the filtrate was placed in a 100 ml round-bottom flask. Then, the filtrate in the round-bottom flask was evaporated to dryness using a rotary evaporator, and 20 ml of methanol was added to prepare the measurement solution. The content of various antioxidants was determined by analyzing this solution using high-performance liquid chromatography.

[0081] The ultraviolet absorber was analyzed as follows: Polycarbonate resin was dissolved in dichloromethane, and the absorbance of this solution at 340 nm to 350 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer to determine the content of the ultraviolet absorber.

[0082] The lubricants were analyzed as follows: First, polycarbonate resin was dissolved in dichloromethane, methanol was added dropwise to reprecipitate the polymer components, filtered, and the filtrate was placed in a 100 ml round-bottom flask. Then, the filtrate in the round-bottom flask was evaporated to dryness using a rotary evaporator, and 20 ml of methanol was added to prepare the measurement solution. The content of various lubricants was determined by analyzing this solution using LC / MS.

[0083] The PC impurities, tris(2,4-di-t-butylphenyl) phosphate and 2,4-di-t-butylphenol, were analyzed as follows. First, polycarbonate resin was dissolved in dichloromethane, methanol was added dropwise to reprecipitate the polymer components, filtered, and the filtrate was placed in a 100 ml round-bottom flask. Then, the filtrate in the round-bottom flask was evaporated to dryness using a rotary evaporator, and 10 ml of methanol was added to prepare the measurement solution. The content of tris(2,4-di-t-butylphenyl) phosphate and 2,4-di-t-butylphenol was determined by analyzing this solution by LC / MS.

[0084] The PC impurities, chlorobenzene and diphenyl carbonate, were analyzed as follows: First, polycarbonate resin was dissolved in dichloromethane, and the solution was introduced into a pyrolysis furnace and heated to approximately 200°C. The resulting volatile components were then cooled and collected with liquid nitrogen. Subsequently, these collected components were separated and analyzed by GC / MS to determine the content of chlorobenzene and diphenyl carbonate.

[0085] The results of these analyses are shown in Table 1. Here, ND means that it was not detected. The names of the compounds of each detected component are listed below.

[0086] [Phenol-based antioxidants] BHT: Dibutylhydroxytoluene AO-50 (manufactured by ADEKA Corporation): n-octadecyl-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate

[0087] [Phosphorus-based antioxidants] PEP-36 (manufactured by ADEKA Corporation): Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite P-EPQ (BASF): [1,1'-biphenyl]-4,4-diylbis[bis(2,4-di-tert-butylphenoxy)phosphine] P-168 (BASF): Tris(2,4-di-tert-butylphenyl) phosphite Doverphos S-9228: Bis(2,4-dicumylphenyl)pentaerythritol diphosphite

[0088] [Benzotriazole-based UV absorbers] Tinuvin 329 (BASF): 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-2-phenol RIASORB UV-234 (manufactured by Rianlon Corporation): 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol LA-31 (manufactured by ADEKA Corporation): 2,2'-Methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol]

[0089] [Lubricant] GMS: Glycerin Monostearate (manufactured by Riken Vitamin Co., Ltd.) PETS: Pentaerythritol tetrastearate (manufactured by Emily Oleochemicals Japan Co., Ltd.)

[0090] [Fluorescent whitening agent] Kayalight O (manufactured by Nippon Kayaku Co., Ltd.)

[0091] [PC impurities] Tris(2,4-di-t-butylphenyl) phosphate (Sigma-Aldrich Co., LLC) 2,4-di-t-butylphenol (manufactured by Tokyo Chemical Industry Co., Ltd.) Chlorobenzene (manufactured by Fujifilm Wako Pure Chemical Corporation) Diphenyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0092] [Diffusing agent] Diffuser A: SL-200M (Silicone-based light diffuser, manufactured by LOTTE Chemical Corporation) Diffuser B: GM-0449S (Acrylic light diffuser, manufactured by Aica Kogyo Co., Ltd.)

[0093] [Polyalkylene glycol derivatives] Modified glycol (random copolymer) polycerin DCB-2000 (manufactured by NOF Corporation) consisting of tetramethylene glycol units and propylene glycol units.

[0094] <Melt Volume Rate (MVR)> After drying the recovered polycarbonate resin at 120°C for 4 hours, the melt volume rate (MVR) was measured in accordance with ISO 1133 under conditions of 300°C and a load of 1.2 kg using a melt flow indexer (120-SAS-1, manufactured by Yasuda Seiki Seisakusho Co., Ltd.).

[0095] <2000cm -1 Raman spectral intensity in > Under the conditions of a laser wavelength of 532 nm, exposure time of 1.0 second, number of exposures of 4, and laser output of 1.6 mW, the Raman spectrum was measured by focusing on the surface of the recovered polycarbonate resin pellets and measured at 2000 cm⁻¹. -1 The intensity at [location] was determined. A micro-Raman analyzer (RAMAN touch VIS-ICS-S, manufactured by Nanophoton Inc.) was used to measure the Raman spectrum.

[0096] [Table 1]

[0097] Examples 1-9 and Comparative Examples 1-8 The various components were mixed in a tumbler according to the formulations and ratios shown in Tables 2 and 3. The mixture was then melt-kneaded at a cylinder temperature of 280°C using a 37mm diameter twin-screw extruder (TEM37SS, manufactured by Shibaura Machinery Co., Ltd.) to obtain various pellets. The obtained pellets were used to perform MVR measurements and analyze the content of impurities such as chlorobenzene using the method described above, as well as conducting the reliability tests shown below. The results are shown in Tables 2 and 3.

[0098] <Reliability Testing> The obtained recycled polycarbonate resin composition was molded using an injection molding machine (FANUC ROBOSHOT S2000i100A) with a cylinder temperature of 290°C and a mold temperature of 80°C. The resulting molded products were held in an autoclave at 120°C and 100% RH for 48 hours. The total light transmittance (unit: %) was measured using a haze meter HM-150L2N manufactured by Murakami Color Technology Laboratory Co., Ltd. in accordance with JIS K7136, and the difference in total light transmittance was calculated.

[0099] [Table 2]

[0100] [Table 3]

[0101] As shown in Table 2, in the recycled polycarbonate resin compositions of Examples 1 to 9, the chlorobenzene and diphenyl carbonate content of the recovered polycarbonate resin was 20 ppm or less, so even with the inclusion of a light diffusing agent, the Δ total light transmittance before and after the reliability test was 3.0% or less. On the other hand, as shown in Table 3, in the recycled polycarbonate resin compositions of Comparative Examples 1 to 8, the chlorobenzene and diphenyl carbonate content of the recovered polycarbonate resin was 20 ppm or more, so the Δ total light transmittance before and after the reliability test exceeded 3.0%, resulting in poor reliability. [Industrial applicability]

[0102] The recycled polycarbonate resin composition of the present invention, despite utilizing recovered polycarbonate resin, exhibits excellent reliability in reliability tests, is environmentally friendly, and possesses high industrial value.

Claims

1. The resin component consists of 1 to 90% by mass of unused polycarbonate resin (a1) and 99 to 10% by mass of recovered polycarbonate resin (a2), and contains 0.01 to 0.5 parts by mass of phosphorus-based antioxidant (B) and 0.1 to 3 parts by mass of light diffusing agent (C). A recycled polycarbonate resin composition characterized in that the recovered polycarbonate resin (a2) has a diphenyl carbonate content of 20 ppm or less and a chlorobenzene content of 20 ppm or less.

2. The recycled polycarbonate resin composition according to claim 1, wherein the light diffusing agent (C) is a silicone-based light diffusing agent, an acrylic-based light diffusing agent, or inorganic fine particles.

3. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the content of the unused polycarbonate resin (a1) is 10 to 80% by mass, and the content of the recovered polycarbonate resin (a2) is 90 to 20% by mass.

4. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the viscosity-average molecular weight of the recovered polycarbonate resin (a2) is 17,000 to 28,000.

5. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the recovered polycarbonate resin (a2) has a tris(2,4-di-t-butylphenyl) phosphate content of 20 ppm or less and a 2,4-di-t-butylphenol content of 50 ppm or less.

6. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the recovered polycarbonate resin (a2) contains at least one ultraviolet absorber selected from benzotriazole-based, benzophenone-based, and triazine-based ultraviolet absorbers in a concentration of 2,000 ppm or less.

7. The Raman spectrum obtained by measuring the recovered polycarbonate resin (a2) under the conditions of a laser light wavelength of 532 nm, exposure time of 1.0 second, number of exposures of 4, and laser output of 1.6 mW showed a value of 2000 cm⁻¹. －１ The recycled polycarbonate resin composition according to claim 1 or 2, wherein the recovered polycarbonate resin has a strength of 1000 cps or less.

8. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the content of diphenyl carbonate in the composition is 10 ppm or less, and the content of chlorobenzene is 2 ppm or less.

9. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the content of diphenyl carbonate in the composition is 5 ppm or less.

10. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the tris(2,4-di-t-butylphenyl) phosphate content in the composition is 10 ppm or less, and the 2,4-di-t-butylphenol content is 20 ppm or less.

11. The recycled polycarbonate resin composition according to claim 1 or 2, wherein the content of at least one ultraviolet absorber selected from benzotriazole-based, benzophenone-based, and triazine-based ultraviolet absorbers in the composition is 5,000 ppm or less.

12. Furthermore, the following formula: RO-(X'-O) ｍ (Y'-O) ｎ -R (In the formula, R independently represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X' represents a linear alkylene group or a branched alkylene group having 2 to 4 carbon atoms, Y' represents a linear alkylene group or a branched alkylene group having 2 to 5 carbon atoms, X' and Y' may be the same or different, m and n each represent 3 to 60, and m + n is 6 to 120.) A recycled polycarbonate resin composition according to claim 1 or 2, containing 1.0 part by mass or less of a polyalkylene glycol derivative represented by .

13. Polyalkylene glycol derivatives are given by the following formula: HO-(CH) ２ CH ２ CH ２ CH ２ O) ｍ (CH(CH ３ )CH ２ O) ｎ -H (In the formula, m and n each independently represent a range of 3 to 60, and m + n represents a range of 8 to 90.) The recycled polycarbonate resin composition according to claim 12, comprising a polyalkylene glycol derivative represented by .

14. A recycled polycarbonate resin composition in which a 1 mm thick injection-molded piece is held in an autoclave at 120°C and 100% RH for 48 hours, and the difference in total light transmittance before and after this reliability test is 3.0% or less.

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