Pellets made from a polycarbonate resin composition and molded articles formed therefrom

Abstract

The present invention provides pellets made from a polycarbonate resin composition containing recycled carbon fibers with excellent extrudeability and conductivity, and molded articles formed therefrom. [Solution] A pellet made of a polycarbonate resin composition containing (A) 100 parts by weight of polycarbonate resin (component A) and (B) 10 to 70 parts by weight of recycled carbon fiber (component B), which is a fired composite of epoxy resin and carbon fiber, and the amount of residue derived from epoxy resin measured by the method specified in this document is 0.05 to 0.28 parts by weight per 1 part by weight, wherein the surface resistivity of a molded product with a thickness of 2 mm measured according to JIS K7194 is 1.0 × 10 9 A pellet characterized by having a coefficient of Ω / □ or less, and a number-average fiber length of recycled carbon fibers in the pellet being 100 to 500 μm.

Description

[Technical Field]

[0001] The present invention relates to pellets made from a polycarbonate resin composition containing recycled carbon fibers and molded articles formed therefrom. [Background technology]

[0002] Carbon fiber reinforced plastics (CRPs) are carbon fibers impregnated with epoxy resin. Due to their high strength and conductivity, they are used in aircraft and a wide range of applications. However, carbon fiber production is known to emit large amounts of carbon dioxide. Therefore, in response to recent environmental concerns, research is underway to develop environmentally friendly materials using recycled carbon fibers recovered from CRPs. However, while calcination is used to separate carbon fibers from CRPs, the remaining residue adheres to the carbon fibers, leading to a decrease in mechanical properties and surface conductivity during compounding. (See Patent Document 1) Furthermore, the amount of recycled carbon fiber needed to achieve the desired properties increases, resulting in higher costs. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2022 / 124332 [Overview of the project] [Problems that the invention aims to solve]

[0004] The object of the present invention is to provide pellets made from a polycarbonate resin composition containing recycled carbon fibers that have excellent extrudeability and conductivity, and molded articles formed therefrom. [Means for solving the problem]

[0005] As a result of intensive studies to solve such problems, the present inventors have found that by adding specific recycled carbon fibers to a polycarbonate resin, pellets made of a polycarbonate resin composition excellent in extrusion properties and conductivity can be provided, and thus have reached the present invention.

[0006] That is, the present invention is as follows. 1. A pellet made of a polycarbonate resin composition containing 10 to 70 parts by weight of (B) recycled carbon fibers (component B), which is a fired product of a composite of an epoxy resin and carbon fibers and has a residue amount measured by the method defined in the text derived from the epoxy resin of 0.05 to 0.28 parts by weight per 1 part by weight, based on 100 parts by weight of (A) polycarbonate resin (component A), wherein the surface resistivity of a molded product having a thickness of 2 mm measured according to JIS K7194 is 1.0×10 9 Ω / □ or less, and the number average fiber length of the recycled carbon fibers in the pellet is 100 to 500 μm. 2. The pellet according to item 1 above, characterized by containing 0.1 to 5 parts by weight of (C) a compound containing a reactive functional group (component C) with respect to 100 parts by weight of component A. 3. The pellet according to item 1 or 2 above, characterized in that component C is at least one selected from the group consisting of an epoxy resin and a phenoxy resin. 4. A molded product formed from the pellet according to item 1 or 2 above. 5. The molded product according to item 4 above, characterized in that the average adhesion area of the residue derived from the epoxy resin measured by the method defined in the text of the recycled carbon fibers is 2.5 μm 2 or less per one recycled carbon fiber.

[0007] Hereinafter, the present invention will be specifically described.

[0008] <Component A: Polycarbonate resin> The polycarbonate resin used as component A in this invention is obtained by reacting a divalent phenol with a carbonate precursor. Examples of reaction methods include interfacial polymerization, molten transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds.

[0009] Typical examples of divalent phenols used here include hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, and 4,4'-(p-phenyl Examples include bis(4-hydroxyphenyl)diphenol, 4,4'-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ester, bis(4-hydroxy-3-methylphenyl)sulfide, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. Preferred divalent phenols are bis(4-hydroxyphenyl)alkanes, among which bisphenol A is particularly preferred and widely used in terms of impact resistance.

[0010] In this invention, in addition to bisphenol A type polycarbonate resin, which is a general-purpose polycarbonate resin, it is possible to use special polycarbonate resins produced using other divalent phenols as component A-1. For example, polycarbonate resins (homopolymers or copolymers) using 4,4'-(m-phenylenediisopropylidene)diphenol (hereinafter sometimes abbreviated as "BPM"), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "Bis-TMC"), 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (hereinafter sometimes abbreviated as "BCF") as some or all of the divalent phenol components are suitable for applications where dimensional changes due to water absorption and morphological stability are particularly demanding. It is preferable that these divalent phenols other than BPA be used in an amount of 5 mol% or more, particularly 10 mol% or more, of the total divalent phenol components constituting the polycarbonate resin. In particular, when high rigidity and better hydrolysis resistance are required, it is especially preferable that component A constituting the resin composition be one of the following copolymer polycarbonate resins (1) to (3). (1) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPM is 20 to 80 mol% (more preferably 40 to 75 mol%, even more preferably 45 to 65 mol%) and BCF is 20 to 80 mol% (more preferably 25 to 60 mol%, even more preferably 35 to 55 mol%). (2) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPA is 10 to 95 mol% (more preferably 50 to 90 mol%, even more preferably 60 to 85 mol%) and BCF is 5 to 90 mol% (more preferably 10 to 50 mol%, even more preferably 15 to 40 mol%). (3) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPM is 20 to 80 mol% (more preferably 40 to 75 mol%, even more preferably 45 to 65 mol%) and Bis-TMC is 20 to 80 mol% (more preferably 25 to 60 mol%, even more preferably 35 to 55 mol%).

[0011] These special polycarbonate resins may be used individually or mixed in appropriate combinations of two or more types. They can also be mixed with commonly used bisphenol A type polycarbonate resins. The manufacturing methods and properties of these special polycarbonate resins are described in detail in, for example, Japanese Patent Publication No. 6-172508, Japanese Patent Publication No. 8-27370, Japanese Patent Publication No. 2001-55435, and Japanese Patent Publication No. 2002-117580.

[0012] Furthermore, among the various polycarbonate resins mentioned above, those whose copolymerization composition and other properties have been adjusted to bring the water absorption rate and Tg (glass transition temperature) within the following ranges exhibit excellent hydrolysis resistance of the polymer itself, as well as significantly superior low warping after molding. Therefore, they are particularly suitable for fields requiring morphological stability. (i) A polycarbonate resin having a water absorption rate of 0.05 to 0.15%, preferably 0.06 to 0.13%, and a Tg of 120 to 180°C, or (ii) A polycarbonate resin having a Tg of 160 to 250°C, preferably 170 to 230°C, and a water absorption rate of 0.10 to 0.30%, preferably 0.13 to 0.30%, more preferably 0.14 to 0.27%.

[0013] Here, the water absorption rate of the polycarbonate resin was measured using a disc-shaped test piece with a diameter of 45 mm and a thickness of 3.0 mm, after immersion in water at 23°C for 24 hours in accordance with ISO 62-1980. The glass transition temperature (Tg) was determined by differential scanning calorimeter (DSC) measurement in accordance with JIS K7121.

[0014] Carbonyl halides, diester carbonates, or haloformates are used as carbonate precursors, specifically including phosgene, diphenyl carbonate, or dihaloformates of divalent phenols.

[0015] When producing a polycarbonate resin by interfacial polymerization of the divalent phenol and the carbonate precursor, a catalyst, an end-terminating agent, an antioxidant to prevent oxidation of the divalent phenol, etc., may be used as needed. The polycarbonate resin of the present invention also includes a branched polycarbonate resin copolymerized with a trifunctional or polyfunctional aromatic compound, a polyester carbonate resin copolymerized with an aromatic or aliphatic (including alicyclic) bifunctional carboxylic acid, a copolymerized polycarbonate resin copolymerized with a bifunctional alcohol (including alicyclic), and a polyester carbonate resin copolymerized with both such bifunctional carboxylic acid and bifunctional alcohol. Furthermore, a mixture of two or more of the obtained polycarbonate resins may also be used.

[0016] Branched polycarbonate resins can impart properties such as drip prevention to the polycarbonate resin composition of the present invention. Examples of trifunctional or polyfunctional aromatic compounds used in such branched polycarbonate resins include phloroglucin, phloroglucides, or 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2, 2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, and 4-{4-[1,1-bis(4- Examples include trisphenols such as hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, or trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid and their acid chlorides, among which 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.

[0017] In branched polycarbonate resins, the structural units derived from polyfunctional aromatic compounds are preferably 0.01 to 1 mol%, more preferably 0.05 to 0.9 mol%, and even more preferably 0.05 to 0.8 mol%, of the total 100 mol% of structural units derived from divalent phenols and those derived from such polyfunctional aromatic compounds. Furthermore, especially in the case of melt transesterification, branched structural units may be generated as a side reaction, but the amount of such branched structural units is also preferably 0.001 to 1 mol%, more preferably 0.005 to 0.9 mol%, and even more preferably 0.01 to 0.8 mol%, of the total 100 mol% of structural units derived from divalent phenols. 1It can be calculated by 1H-NMR measurement.

[0018] Among aliphatic difunctional carboxylic acids, α,ω-dicarboxylic acids are preferred. Examples of aliphatic difunctional carboxylic acids include linear saturated aliphatic dicarboxylic acids such as sebacic acid (decanediic acid), dodecanediic acid, tetradecanediic acid, octadecanediic acid, and eicosanedioic acid, as well as alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. As for difunctional alcohols, alicyclic diols are more preferred, with examples including cyclohexanedimethanol, cyclohexanediol, and tricyclodecanedimethanol.

[0019] The reaction methods used in the present invention for producing polycarbonate resin, such as interfacial polymerization, molten transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds, are well-known methods described in various literatures and patent publications.

[0020] In producing the polycarbonate resin composition of the present invention, the viscosity-average molecular weight of the polycarbonate resin is preferably 12,500 to 32,000, more preferably 16,000 to 28,000, and even more preferably 18,000 to 26,000. Polycarbonate resins with a viscosity-average molecular weight of less than 12,500 may not yield good mechanical properties. On the other hand, resin compositions obtained from polycarbonate resins with a viscosity-average molecular weight exceeding 32,000 may have poor moldability.

[0021] In this invention, the viscosity-average molecular weight is first calculated using the following formula: the specific viscosity (η SP The viscosity of the solution was determined using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20°C. Specific viscosity (η SP ) = (t-t0) / t0 [t0 is the number of seconds for the methylene chloride to fall, and t is the number of seconds for the sample solution to fall.] The specific viscosity (η) SPCalculate the viscosity-average molecular weight M from the following formula. η SP / c = [η] + 0.45 × [η] 2 c (where [η] is the intrinsic viscosity) [η] = 1.23×10 -4 M 0.83 c = 0.7 Furthermore, the viscosity-average molecular weight of the polycarbonate resin in the polycarbonate resin composition of the present invention is calculated as follows. That is, the composition is mixed with 20 to 30 times its weight of methylene chloride to dissolve the soluble components in the composition. Such soluble components are collected by filtration through celite. Then, the solvent in the resulting solution is removed. The solid after solvent removal is thoroughly dried to obtain a solid of the component dissolved in methylene chloride. From a solution obtained by dissolving 0.7 g of such solid in 100 ml of methylene chloride, the specific viscosity at 20°C is determined in the same manner as above, and the viscosity-average molecular weight M is calculated from the specific viscosity in the same manner as above.

[0022] It is also possible to use a polycarbonate-polydiorganosiloxane copolymer resin as the polycarbonate resin of the present invention. The polycarbonate-polydiorganosiloxane copolymer resin is preferably a copolymer resin prepared by copolymerizing a divalent phenol represented by the following general formula (1) and a hydroxyaryl-terminated polydiorganosiloxane represented by the following general formula (3).

[0023]

Chemical formula

[0024] [In the above general formula (1), R 1 and R 2Each of the following groups independently represents a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group. If there are multiple groups, they may be the same or different. e and f are integers from 1 to 4, and W is at least one group selected from the group consisting of a single bond or a group represented by the general formula (2) below.

[0025] [ka]

[0026] [In the above general formula (2), R 11 ,R 12 ,R 13 ,R 14 ,R 15 ,R 16 ,R 17 and R 18 Each of these independently represents a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms, R 19 and R 20 Each of these independently represents a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group. If there are multiple groups, they may be the same or different. g is an integer from 1 to 10, and h is an integer from 4 to 7.

[0027] [ka]

[0028] [In the above general formula (3), R 3 , R 4 , R 5 , R 6 , R 7 and R 8 Each of these is independently a hydrogen atom, a C1-C12 alkyl group, or a C6-C12 substituted or unsubstituted aryl group, R 9 and R 10 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group with 1 to 10 carbon atoms, and an alkoxy group with 1 to 10 carbon atoms, where p is a natural number, q is 0 or a natural number, and p+q is a natural number between 10 and 300. X is a divalent aliphatic group with 2 to 8 carbon atoms.

[0029] Examples of divalent phenols (I) represented by general formula (1) include 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)propane, 2,2- Bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, bis(4-H 1,1-bis(4-hydroxyphenyl)fluorene, 2,2-diphenylmethane, 3,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'- Dimethyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,Examples include 4-bis(4-hydroxyphenyl)cyclohexane, 1,3-bis(4-hydroxyphenyl)cyclohexane, 4,8-bis(4-hydroxyphenyl)tricyclo[5.2.1.02,6]decane, 4,4'-(1,3-adamantanediyl)diphenol, and 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane.

[0030] Among these, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene are preferred, with 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene being particularly preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane, which has excellent strength and good durability, is the most suitable. These may be used individually or in combination of two or more.

[0031] As the hydroxyaryl-terminated polydiorganosiloxane represented by the above general formula (3), the following compounds are preferably used, for example. [ka]

[0032] Hydroxyaryl-terminated polydiorganosiloxanes (II) can be easily produced by hydrosiliculation reaction of olefinic unsaturated carbon-carbon bonded phenols, preferably vinylphenol, 2-allylphenol, isopropenylphenol, and 2-methoxy-4-allylphenol, to the ends of a polysiloxane chain having a predetermined degree of polymerization. Among these, (2-allylphenol)-terminated polydiorganosiloxanes and (2-methoxy-4-allylphenol)-terminated polydiorganosiloxanes are preferred, and (2-allylphenol)-terminated polydimethylsiloxanes and (2-methoxy-4-allylphenol)-terminated polydimethylsiloxanes are particularly preferred. Hydroxyaryl-terminated polydiorganosiloxanes (II) preferably have a molecular weight distribution (Mw / Mn) of 3 or less. Furthermore, in order to exhibit excellent low outgassing and low-temperature impact resistance during high-temperature molding, such a molecular weight distribution (Mw / Mn) is more preferably 2.5 or less, and even more preferably 2 or less. If the upper limit of this suitable range is exceeded, the amount of outgassing during high-temperature molding increases, and the low-temperature impact resistance may be poor.

[0033] Furthermore, to achieve high impact resistance, the degree of diorganosiloxane polymerization (p+q) of the hydroxyaryl-terminated polydiorganosiloxane(II) is appropriately set to 10-300. This degree of diorganosiloxane polymerization (p+q) is preferably 10-200, more preferably 12-150, and even more preferably 14-100. Below the lower limit of this preferred range, the impact resistance characteristic of polycarbonate-polydiorganosiloxane copolymers is not effectively exhibited, and above the upper limit of this preferred range, appearance defects appear.

[0034] The polydiorganosiloxane content in the total weight of the polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.1 to 50% by weight. More preferably, the polydiorganosiloxane content is 0.5 to 30% by weight, and even more preferably 1 to 20% by weight. Above the lower limit of this preferred range, excellent impact resistance and flame retardancy are obtained, and below the upper limit of this preferred range, a stable appearance less affected by molding conditions is easily obtained. The degree of polydiorganosiloxane polymerization and polydiorganosiloxane content are: 1 It can be calculated by 1H-NMR measurement.

[0035] In the present invention, only one hydroxyaryl-terminated polydiorganosiloxane(II) may be used, or two or more may be used. Furthermore, to the extent that it does not interfere with the present invention, other comonomers other than the divalent phenol (I) and hydroxyaryl-terminated polydiorganosiloxane (II) may be used in combination in an amount of 10% by weight or less relative to the total weight of the copolymer.

[0036] In the present invention, a mixed solution containing an oligomer having terminal chloroformate groups is prepared in advance by the reaction of divalent phenol(I) and a carbonate ester-forming compound in a mixture of a water-insoluble organic solvent and an alkaline aqueous solution.

[0037] In producing the divalent phenol(I) oligomer, the entire amount of divalent phenol(I) used in the method of the present invention may be converted into an oligomer at once, or a portion of it may be added as a reaction material to the subsequent interfacial polycondensation reaction as a post-added monomer. The post-added monomer is added to expedite the subsequent polycondensation reaction, and it is not necessary to add it if it is not needed. The method of this oligomer formation reaction is not particularly limited, but it is generally preferable to carry it out in a solvent in the presence of an acid binder.

[0038] The proportion of ester-forming compounds used can be adjusted as appropriate, taking into account the stoichiometric ratio (equivalent) of the reaction. Furthermore, when using gaseous ester-forming compounds such as phosgene, a method of blowing them into the reaction system is preferably employed.

[0039] Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, or mixtures thereof. The proportion of acid binder used should be determined appropriately, taking into account the stoichiometric ratio (equivalents) of the reaction, as described above. Specifically, it is preferable to use 2 equivalents or a slightly excess amount of acid binder relative to the number of moles of divalent phenol(I) used to form the oligomer (usually 1 mole corresponds to 2 equivalents).

[0040] As the aforementioned solvent, various reaction-inert solvents, such as those used in the production of known polycarbonate resins, may be used individually or as a mixed solvent. Typical examples include hydrocarbon solvents such as xylene, and halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. Halogenated hydrocarbon solvents such as methylene chloride are particularly preferred.

[0041] There are no particular restrictions on the reaction pressure for oligomer formation; it can be atmospheric pressure, pressurized pressure, or reduced pressure, but it is usually advantageous to carry out the reaction under atmospheric pressure. The reaction temperature is selected from the range of -20 to 50°C, and since polymerization is often exothermic, water cooling or ice cooling is desirable. The reaction time depends on other conditions and cannot be specified in general, but it is usually carried out in 0.2 to 10 hours. The pH range for the oligomer formation reaction is the same as for known interfacial reaction conditions, and the pH is always adjusted to 10 or higher.

[0042] In this invention, a mixed solution containing an oligomer of divalent phenol (I) having terminal chloroformate groups is obtained, and while stirring the mixed solution, a hydroxyaryl-terminated polydiorganosiloxane (II) represented by general formula (3), which has been highly purified to a molecular weight distribution (Mw / Mn) of 3 or less, is added to the divalent phenol (I), and the hydroxyaryl-terminated polydiorganosiloxane (II) and the oligomer are subjected to interfacial polycondensation to obtain a polycarbonate-polydiorganosiloxane copolymer.

[0043] [ka]

[0044] (In the above general formula (3), R 3 , R 4 , R 5 , R 6 , R 7 and R 8 Each of these is independently a hydrogen atom, a C1-C12 alkyl group, or a C6-C12 substituted or unsubstituted aryl group, R 9 and R 10 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group with 1 to 10 carbon atoms, and an alkoxy group with 1 to 10 carbon atoms, where p is a natural number, q is 0 or a natural number, and p+q is a natural number between 10 and 300. X is a divalent aliphatic group with 2 to 8 carbon atoms.

[0045] When carrying out an interfacial polycondensation reaction, an acid binder may be added as appropriate, taking into consideration the stoichiometric ratio (equivalent) of the reaction. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, or mixtures thereof. Specifically, when adding a portion of the hydroxyaryl-terminated polydiorganosiloxane(II) or divalent phenol(I) as described above as a post-added monomer to this reaction step, it is preferable to use 2 equivalents or an excess amount of alkali relative to the total number of moles of the post-added divalent phenol(I) and hydroxyaryl-terminated polydiorganosiloxane(II) (usually 1 mole corresponds to 2 equivalents).

[0046] The polycondensation reaction between the divalent phenol (I) oligomer and the hydroxyaryl-terminated polydiorganosiloxane (II) is carried out by vigorously stirring the above mixture.

[0047] In such polymerization reactions, end-terminating agents or molecular weight modifiers are commonly used. Examples of end-terminating agents include compounds having a monovalent phenolic hydroxyl group, such as ordinary phenols, p-tert-butylphenol, p-cumylphenol, and tribromophenol, as well as long-chain alkylphenols, aliphatic carboxylic acid chlorides, aliphatic carboxylic acids, alkyl hydroxybenzoates, hydroxyphenylalkylates, and alkyl etherphenols. The amount used is in the range of 100 to 0.5 moles, preferably 50 to 2 moles, per 100 moles of all divalent phenolic compounds used, and it is naturally possible to use two or more compounds in combination.

[0048] To accelerate the polycondensation reaction, a catalyst such as a tertiary amine like triethylamine or a quaternary ammonium salt may be added. The reaction time for such polymerization is preferably 30 minutes or more, and more preferably 50 minutes or more. Optionally, a small amount of antioxidant such as sodium sulfite or hydrosulfide may be added.

[0049] Branching agents can be used in combination with the above-mentioned divalent phenolic compounds to form branched polycarbonate-polydiorganosiloxanes. Examples of trifunctional or polyfunctional aromatic compounds used in such branched polycarbonate-polydiorganosiloxane copolymer resins include phloroglucin, phloroglucid, or 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2, 2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, and 4-{4-[1 Examples include trisphenols such as 1-bis(4-hydroxyphenyl)ethyl]benzene-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, or trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid and their acid chlorides, among which 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred. The proportion of polyfunctional compounds in the branched polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.001 to 1 mol%, more preferably 0.005 to 0.9 mol%, even more preferably 0.01 to 0.8 mol%, and particularly preferably 0.05 to 0.4 mol%, of the total amount of the polycarbonate-polydiorganosiloxane copolymer resin. 1 It can be calculated by 1H-NMR measurement.

[0050] The reaction pressure can be reduced, atmospheric, or pressurized, but it is usually preferable to use atmospheric pressure or the self-pressure of the reaction system. The reaction temperature is selected from the range of -20 to 50°C, and since polymerization often generates heat, water cooling or ice cooling is desirable. The reaction time varies depending on other conditions such as the reaction temperature and cannot be specified in general terms, but it is usually carried out in 0.5 to 10 hours.

[0051] Depending on the circumstances, the obtained polycarbonate-polydiorganosiloxane copolymer resin may be subjected to appropriate physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking, partial decomposition, etc.) to obtain the desired reduced viscosity [η SP It can also be obtained as a polycarbonate-polydiorganosiloxane copolymer resin of [c].

[0052] The resulting reaction product (crude product) can be recovered as a polycarbonate-polydiorganosiloxane copolymer resin of the desired purity (degree of purification) by various post-treatment methods, such as known separation and purification methods.

[0053] The average size of polydiorganosiloxane domains in polycarbonate-polydiorganosiloxane copolymer resin molded articles is preferably in the range of 1 to 40 nm. More preferably, this average size is 1 to 30 nm, and even more preferably 5 to 25 nm. Below the lower limit of this preferred range, impact resistance and flame retardancy may not be sufficiently exhibited, and above the upper limit of this preferred range, impact resistance may not be stably exhibited.

[0054] The average domain size and normalized dispersion of polydiorganosiloxane domains in the polycarbonate-polydiorganosiloxane copolymer resin molded product of this invention were evaluated by small-angle X-ray scattering (SAXS). Small-angle X-ray scattering is a method for measuring diffuse scattering and diffraction occurring in the small-angle region with a scattering angle (2θ) < 10° or less. In this small-angle X-ray scattering method, if there are regions with different electron densities of about 1 to 100 nm in size in the material, diffuse scattering of X-rays is measured due to the difference in electron density. The particle size of the object to be measured is determined based on this scattering angle and scattering intensity. In the case of polycarbonate-polydiorganosiloxane copolymer resin, which has an aggregated structure in which polydiorganosiloxane domains are dispersed in a polycarbonate polymer matrix, diffuse scattering of X-rays occurs due to the difference in electron density between the polycarbonate matrix and the polydiorganosiloxane domains. The scattering intensity I is measured at each scattering angle (2θ) in the range of less than 10° to obtain a small-angle X-ray scattering profile. Assuming that the polydiorganosiloxane domains are spherical and that there is variability in the particle size distribution, a simulation is performed using commercially available analysis software with a hypothetical particle size and a hypothetical particle size distribution model to determine the average size and particle size distribution (normalized variance) of the polydiorganosiloxane domains. The small-angle X-ray scattering method allows for accurate, simple, and reproducible measurement of the average size and particle size distribution of polydiorganosiloxane domains dispersed in a polycarbonate polymer matrix, which cannot be accurately measured by transmission electron microscopy. The average domain size refers to the numerical average of the individual domain sizes. Normalized variance refers to a parameter that normalizes the spread of the particle size distribution by the average size. Specifically, it is the value obtained by normalizing the variance of the polydiorganosiloxane domain size by the average domain size, and is expressed by the following equation (1).

[0055]

number

[0056] The terms "average domain size" and "normalized dispersion" used in connection with the present invention indicate measured values obtained by measuring the 1.0 mm thick portion of the three-stage plate prepared by the method described in the Examples by such small-angle X-ray scattering method. Also, analysis was performed using an isolated particle model that does not consider inter-particle interaction (inter-particle interference).

[0057] <Component B: Recycled carbon fiber> The recycled carbon fiber in the present invention is a fired product of a composite of an epoxy resin and a carbon fiber, and examples thereof include end materials of intermediate products such as prepregs generated from the manufacturing process of CFRP and carbon fibers recovered from used CFRP. The recycled carbon fiber can be recovered by any method, but it is preferably a method of heating and removing only the matrix resin from CFRP by thermal decomposition.

[0058] The recycled carbon fiber needs to have a residue amount derived from the epoxy resin of 0.05 to 0.28 parts by weight per 1 part by weight, and preferably the residue amount is 0.05 to 0.2 parts by weight, and more preferably 0.05 to 0.1 parts by weight. When the residue amount is less than 0.05 parts by weight, defibration of the recycled carbon fiber occurs, resulting in a significant deterioration in extrusion properties. When it exceeds 0.28 parts by weight, the surface resistivity increases. The measurement of the residue amount was carried out by the method described in the Examples.

[0059] The number average fiber length in the pellets of the recycled carbon fiber is 100 to 500 μm, preferably 200 to 400 μm, and more preferably 300 to 400 μm. When the number average fiber length is less than 100 μm, the surface resistivity increases. Under normal extrusion conditions, the number average fiber length does not exceed 500 μm. The number average fiber length was measured by the method described in the Examples.

[0060] The fiber diameter of the recycled carbon fiber is not particularly limited, but is preferably 2 to 15 μm, more preferably 3 to 10 μm. Carbon fibers having an average fiber diameter within such a range may be able to exhibit good mechanical properties without impairing the appearance of the molded product.

[0061] Also, it is preferable that at least a part of the B component has an adhesion agent attached thereto. When no adhesion agent is attached, the recycled carbon fiber may be defibrated and the extrudability may be significantly reduced. Examples of the adhesion agent include polyester-based adhesion agents, polyamide-based adhesion agents, and epoxy-based adhesion agents, but an epoxy-based adhesion agent is preferable.

[0062] The adhesion amount of the adhesion agent is preferably 0.5 to 5.0% by weight, more preferably 1.0 to 3.0% by weight. If the adhesion amount of the adhesion agent is less than 0.5% by weight, the productivity or the molding processability may be reduced, and if it exceeds 5.0% by weight, the mold deposit property may deteriorate.

[0063] The 5% weight loss temperature in the thermogravimetric-differential thermal analysis measurement when the temperature of the B component is raised from room temperature at a rate of 5 °C / min in air is preferably 460 °C or higher, preferably 470 °C or higher, and more preferably 475 °C or higher. If the 5% weight loss temperature is less than 460 °C, the generation of mold deposits during injection molding may be significant. The upper limit of the 5% weight loss temperature is not particularly limited, but is preferably 500 °C or lower.

[0064] The content of the B component is 10 to 70 parts by weight, preferably 15 to 70 parts by weight, and more preferably 25 to 70 parts by weight with respect to 100 parts by weight of the A component. If the content is less than 10 parts by weight, the surface resistivity becomes high, and if it exceeds 70 parts by weight, the extrudability deteriorates.

[0065] [[ID=二十]]<C component: Compound containing a reactive functional group>[[ID=二十一]] Examples of compounds containing reactive functional groups include compounds containing reactive groups such as epoxy groups, phenoxy groups, carboxylic acid groups, and acid anhydride groups. The compound acts as an adhesion improver between component A and component B, and is preferably at least one selected from the group consisting of epoxy resins and phenoxy resins.

[0066] Examples of phenoxy resins include those represented by the following general formula (4). [ka] (In the formula, X is at least one group selected from the group consisting of groups represented by the general formula (5) below, Y is a residue of a compound that reacts with a hydrogen atom or a hydroxyl group, and n is an integer of 0 or more.) [ka] (In the formula, Ph represents a phenyl group.)

[0067] Examples of epoxy resins include epoxy resins represented by the following general formula (6). [ka] (In the formula, X and n are the same as in general formula (4).)

[0068] In the above general formula (4), examples of compounds that react with the hydroxyl group include esters, carbonates, compounds having epoxy groups, carboxylic acid anhydrides, acid halides, compounds having isocyanate groups, etc. Among esters, intramolecular esters are particularly preferred, such as caprolactone. In the phenoxy resin represented by the above general formula (4), the compound in which Y is a hydrogen atom can be easily produced from divalent phenols and epichlorohydrin. Furthermore, the compound in which Y is a residue of the compound that reacts with the hydroxyl group can be easily produced by mixing the phenoxy resin produced from divalent phenols and epichlorohydrin with the compound that reacts with the hydroxyl group under heating.

[0069] The epoxy resin represented by the above general formula (6) can be easily produced from divalent phenols and epichlorohydrin. Examples of divalent phenols include 2,2-bis(4-hydroxyphenyl)propane [bisphenol A], 1,1-bis(4-hydroxyphenyl)ethane, or 4,4'-dihydroxybiphenyl.

[0070] Commercially available phenoxy resins and epoxy resins can also be used. Examples of commercially available phenoxy resins (bisphenol A type) include PKHB (manufactured by InChem, Mw=13,700), PKHH (manufactured by InChem, Mw=29,000), PKFE (manufactured by InChem, Mw=36,800), and YP-50 (manufactured by Toto Kasei Co., Ltd., Mw=43,500).

[0071] Furthermore, commercially available epoxy resins (bisphenol A type) include EPICLON HM-101 (manufactured by Dainippon Ink and Chemicals, Inc., Mw=48,000) and jER1256 (manufactured by Mitsubishi Chemical Corporation, Mw=26,600).

[0072] The content of component C is preferably 0.1 to 5 parts by weight, more preferably 2 to 5 parts by weight, and even more preferably 4 to 5 parts by weight, per 100 parts by weight of component A. If the content is less than 0.1 parts by weight, the effect of reducing surface resistivity may not be obtained, and if it exceeds 5 parts by weight, discoloration during molding and a decrease in mechanical properties may occur.

[0073] <Other ingredients> The resin composition of the present invention may contain other thermoplastic resins to the extent that it does not contradict the spirit of the present invention, and may optionally contain additives such as antioxidants, impact modifiers, plasticizers, fillers, flame retardants, colorants, light stabilizers, heat stabilizers, blocking inhibitors, lubricants, dispersants, flow modifiers, and crystal nucleating agents. Other thermoplastic resins include polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate (PBT), polyhexylene terephthalate, polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate, and polyester resins such as copolymerized polyester resins like polyethylene isophthalate / terephthalate copolymer and polybutylene terephthalate / isophthalate copolymer.

[0074] <About pellet manufacturing> The pellets of the present invention can be prepared by melt-kneading a polycarbonate resin composition using an extruder such as a single-screw or twin-screw extruder. Various additives can also be incorporated into the preparation of these pellets.

[0075] <Regarding the manufacturing of molded products> The pellets of the present invention can be used to manufacture various molded products by injection molding. In such injection molding, molded products can be obtained using injection molding methods such as conventional molding methods, as well as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including those using supercritical fluid injection), insert molding, in-mold coating molding, heat-insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high-speed injection molding, depending on the purpose. The advantages of these various molding methods are already widely known. Furthermore, molding can be performed using either a cold runner or a hot runner method. The pellets of the present invention can also be used in the form of various irregularly shaped extruded products, sheets, and films by extrusion molding. For forming sheets and films, methods such as inflation molding, calendering, and casting can also be used. Furthermore, it is possible to mold them as heat-shrinkable tubes by applying specific stretching operations. The pellets of the present invention can also be molded into products by rotational molding or blow molding.

[0076] <Surface resistivity of molded product> The pellets of this invention have a surface resistivity of 1.0 × 10⁻¹⁰ of a molded article with a thickness of 2 mm, as measured according to JIS K7194. 9 The resistivity is less than or equal to Ω / □. The resistivity is 1.0 × 10⁻⁶. 5 It is preferable that the ratio is Ω / □ or less, and 1.0 × 10 3 It is more preferable that the resistivity is Ω / □ or less. 9 If the resistivity exceeds Ω / □, sufficient antistatic properties cannot be obtained. While there is no particular lower limit to this resistivity, it is set to 1.0 × 10⁻⁶ because sparks may occur when charged objects come into contact with it. 0 It is preferable that the ratio is Ω / □ or greater.

[0077] <Average adhesion area of ​​recycled carbon fiber residue in molded products> The average adhesion area of ​​recycled carbon fiber residue in molded articles formed from the pellets of the present invention is 2.5 μm per recycled carbon fiber. 2 Preferably, the following is true: 2.0 μm 2The following is more preferable: 1.5 μm 2 The following is even more preferable: The average surface area of ​​the residue is 2.5 μm². 2 Beyond this limit, the surface resistivity may increase. While there is no particular lower limit to the residue adhesion area, if the surface resistivity is too low, sparks may occur when a charged object comes into contact with it. Therefore, 0.5 μm is recommended. 2 The above is preferable. Note that "area of ​​residue of recycled carbon fibers" refers to the area of ​​residue attached to the cross-section of the recycled carbon fiber to which the residue is attached. The method for measuring the area of ​​residue of recycled carbon fibers attached to the molded product is as described in the examples. [Effects of the Invention]

[0078] The pellets made from the polycarbonate resin composition of the present invention have excellent extrudeability and conductivity, making them useful in applications where conductivity is required, and thus offering significant industrial benefits. [Modes for carrying out the invention]

[0079] The present inventors consider the best possible form of the present invention to be a combination of the preferred ranges of the above requirements, and a representative example is described in the following embodiments. Of course, the present invention is not limited to these forms. [Examples]

[0080] The present invention will be further explained with reference to the following examples, but is not limited thereto. The following items were evaluated: (i) Extrusion Each component, excluding the recycled carbon fiber, was weighed according to the proportions shown in the table, and uniformly mixed using a tumbler. This mixture was then fed into an extruder to produce resin composition pellets. The recycled carbon fiber was fed in through a side feeder. In Comparative Example 5, the recycled carbon fiber was also fed in along with the above mixture. The extruder used was a vented twin-screw extruder manufactured by Japan Steel Works Ltd.: TEX-30XSST (full meshing, co-direction rotation, 2-thread screw). The extrusion conditions were a discharge rate of 20 kg / h, a screw rotation speed of 150 rpm, a vent vacuum of 3 kPa, and an extrusion temperature of 300°C. Extrusion performance was evaluated according to the following criteria. ○: No mis-engagement or strand breakage occurs in the side screws. ×: Poor engagement or strand breakage may occur in the side screws.

[0081] (ii) Conductivity (surface resistivity) The pellets obtained by the method described in "(i) Extrusion" were dried in a hot air dryer at 120°C for 5 hours. Ten shots of a 100mm x 50mm x 1~3mmt three-tier plate were formed using an injection molding machine (Sumitomo Heavy Industries, Ltd.; SE130EV-A), and the surface resistivity of the 2mmt portion was measured. Surface resistivity was measured in accordance with JIS K7194. After conditioning the sample in an atmosphere of 23°C and 50% relative humidity for 24 hours, the surface resistivity was measured under ambient conditions of 23°C and 50% relative humidity and evaluated according to the following criteria. ○: Surface resistivity is 1.0 × 10 9 Ω / □ or less ×: Surface resistivity is 1.0 × 10 9 It exceeds Ω / □.

[0082] (iii) Amount of recycled carbon fiber residue The amount of residue was determined by heating 10 mg of recycled carbon fiber using a thermogravimetric-differential thermal analyzer and measuring the weight loss using the following method. Specifically, the recycled carbon fiber was heated to 600°C in a nitrogen gas atmosphere, then cooled to 300°C and held for 20 minutes. After that, it was heated from 300°C to 900°C in an air atmosphere, and the weight loss of the recycled carbon fiber at around 600°C was measured.

[0083] (iv) Recycled carbon fiber length in molded product Using pellets prepared by the method described in "(i) Extrusion," dumbbell pieces conforming to ISO 527-2 were created using a ROBOSHOT (α-S100iA) injection molding machine manufactured by FANUC Corporation, under conditions of cylinder temperature 300°C and mold temperature 100°C. Several grams were taken from the molded dumbbell pieces, dissolved in chloroform, and the contained carbon fibers were filtered and separated. The separated carbon fibers were suspended in water, and the suspension was imaged using an SC-2micro manufactured by JASCO International Corporation, and measured by image analysis. The sample size was 5000 fibers, and fibers smaller than 40 μm were excluded by filtering before measurement.

[0084] (v) Area of ​​residue of recycled carbon fibers attached to molded product First, using polycarbonate resin composition pellets containing recycled carbon fibers with residue attached, as used in the examples, dumbbell pieces conforming to ISO 527-2 were prepared under the conditions described in "(iv) Recycled carbon fiber length in molded product" (hereinafter referred to as "residue-attached dumbbell pieces"). Next, dumbbell pieces conforming to ISO 527-2 were molded under the same conditions using polycarbonate resin composition pellets with the same composition as the above-mentioned polycarbonate resin composition pellets containing recycled carbon fibers without residue attached, which were prepared by firing the recycled carbon fibers with the residue attached. Next, the central portion of the residue-attached dumbbell piece was cut perpendicular to the flow direction, and the cross-section was photographed using a scanning electron microscope at a magnification of 1000x. Image analysis was performed on the image to determine the total area (μm²) of the cross-sectional area of ​​1000 recycled carbon fibers with residue attached. 2 Next, using a dumbbell piece without residue attached, the total cross-sectional area (μm²) of 1000 recycled carbon fibers without residue attached was calculated. 2 The residue adhesion area (μm²) per recycled carbon fiber in the molded product was calculated using the following formula. 2 The number of books was calculated. [Residue adhesion area per recycled carbon fiber in molded product (μm²)] 2 / number of fibers) = [(Total cross-sectional area of ​​recycled carbon fibers with 1000 residue fibers attached) - (Total cross-sectional area of ​​recycled carbon fibers without 1000 residue fibers attached)] / 1000

[0085] [Examples 1-15, Comparative Examples 1-5] The evaluation results are shown in Tables 1 and 2. The symbols used in Tables 1 and 2 represent the following components. The explanations follow the symbols in the tables below.

[0086] (Component A: Polycarbonate resin) A-1: Aromatic polycarbonate resin (polycarbonate resin powder with a viscosity-average molecular weight of 22,400, manufactured by conventional methods from bisphenol A and phosgene; manufactured by Teijin Limited, product name: Panlite L-1225WP) (Component B: Recycled carbon fiber) B-1: Residue-attached recycled carbon fiber (manufactured by Carbon Fiber Recycle Co., Ltd.: T8S103CD0R (product name)), epoxy-based sizing agent (attachment amount: 2% by weight), residue amount: 0.18 parts by weight per 1 part by weight B-2: Recycled carbon fiber prepared by firing CFRP. Residue amount: 0.25 parts by weight per 1 part by weight B-3: Recycled carbon fiber prepared by firing CFRP. Residue amount: 0.05 parts by weight per 1 part by weight B-4 (Comparative Example): Recycled carbon fiber prepared by calcining component B-1, residue amount: 0.02 parts by weight per 1 part by weight B-5 (Comparative Example): Recycled carbon fiber prepared by firing CFRP. Residue amount: 0.30 parts by weight per 1 part by weight (Component C: Compound containing reactive group) C-1: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER-1256 (product name), weight-average molecular weight 50,000) C-2: Bisphenol A type phenoxy resin (manufactured by Gabriel Phenoxies, trade name PKHH, weight-average molecular weight 52,000)

[0087] [Table 1]

[0088] Table 2

Claims

1. A pellet made of a polycarbonate resin composition containing 10 to 70 parts by weight of recycled carbon fiber (component B), which is a fired composite of epoxy resin and carbon fiber, and in which the amount of residue derived from epoxy resin, as measured by the method specified in this document, is 0.05 to 0.28 parts by weight per 1 part by weight, per 100 parts by weight of polycarbonate resin (component A), wherein the surface resistivity of a molded product with a thickness of 2 mm, as measured according to JIS K7194, is 1.0 × 10⁻⁶ ９ A pellet characterized by having a coefficient of Ω / □ or less, and a number-average fiber length of recycled carbon fibers in the pellet being 100 to 500 μm.

2. The pellet according to claim 1, characterized in that it contains 0.1 to 5 parts by weight of a compound containing a reactive functional group (component C) per 100 parts by weight of component A.

3. The pellet according to claim 1 or 2, characterized in that component C is at least one selected from the group consisting of epoxy resins and phenoxy resins.

4. A molded article formed from the pellets described in claim 1 or 2.

5. The average adhesion area of ​​epoxy resin-derived residue, measured using the method specified in the text for recycled carbon fibers, was 2.5 μm per recycled carbon fiber. ２ The molded article according to feature 4, which is as follows:

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