Resin pellet group

Abstract

To provide a resin pellet group excellent in injection moldability while reducing production trouble in a pellet transfer process, further capable of suppressing generation of foreign material after molding.SOLUTION: The present invention provides a resin pellet group including a pellet group and a fine powder group. The pellet group includes a polycarbonate resin and has a particle size that remains on a sieve with a mesh opening of 1.7 mm. The fine powder group includes a polycarbonate resin and has a particle size that passes through a sieve with a mesh opening of 1.7 mm. The polycarbonate resin includes structural units derived from a dihydroxy compound represented by Formula (1). The content of the fine powder relative to 100 pts.wt. of the pellet group is 5 ppm to 4000 ppm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a group of resin pellets comprising polycarbonate resin. [Background technology]

[0002] Polycarbonate resins have excellent transparency, heat resistance, mechanical strength, etc., and are therefore widely used as so-called engineering plastics in fields such as optical recording media, optical components such as lenses, electrical and electronic components, automotive parts, etc. Polycarbonate resins generally contain bisphenols as monomer components.

[0003] Polycarbonate resins are generally produced using raw materials derived from petroleum resources. In recent years, concerns about the depletion of petroleum resources have led to a demand for the production of polycarbonate resins using raw materials obtained from biomass resources. Furthermore, concerns about global warming due to increased and accumulated carbon dioxide emissions leading to climate change and other issues have led to a demand for the development of polycarbonates made from plant-derived monomers, which would enable the realization of carbon neutrality.

[0004] Under these circumstances, a method for producing polycarbonate resin using isosorbide, a dihydroxy compound (anhydrosugar alcohol) obtained from biomass resources, as a monomer component has been proposed. Furthermore, polycarbonate resins obtained from isosorbide are known to be useful as optical materials because of their excellent optical properties.

[0005] Polycarbonate resin is typically provided as resin pellets, and polycarbonate resin products are produced by molding the resin pellets into shapes suitable for various applications. Patent Document 1 proposes a polycarbonate molding material for optical disk substrates, in which pellets made of polycarbonate resin obtained from bisphenols coexist with pellet fine powder. Patent Document 1 describes that such molding material can shorten the pellet plasticization time and improve the molding cycle. Patent Document 2 also proposes a package of polycarbonate resin pellets obtained using isosorbide as a monomer component. Patent Document 2 states that such a package minimizes the generation of fine powder during transportation, providing polycarbonate resin pellets that can be molded (produced) into films and the like with little foreign matter. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-71510 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-216807 Summary of the Invention [Problem to be solved by the invention]

[0007] Polycarbonate resins obtained from bisphenols have low rigidity, resulting in fine pellets. Therefore, for example, when pellets are transported from a tank to a molding machine by suction using an autoloader, the lightweight fine particles are sucked up and clog the filter installed in the autoloader, reducing the autoloader's transport function (specifically, its suction function). This can result in poor pellet supply to the molding machine, causing production problems with molded products.

[0008] On the other hand, in the case of polycarbonate resin pellets obtained using isosorbide as a monomer component, if the amount of fine powder is minimized as in Patent Document 2, there is a risk that the screw will make noise during injection molding or that the stability of the metering time during injection molding will be insufficient.

[0009] The present invention has been made in view of the above background, and aims to provide a group of resin pellets that have excellent injection moldability while reducing production problems during the pellet transport process, and that can further suppress the generation of foreign matter after molding. [Means for solving the problem]

[0010] That is, the present invention has the following aspects. [1] A group of resin pellets containing a polycarbonate resin and having a particle size remaining on a sieve with a mesh size of 1.7 mm, and a group of fine powder containing the polycarbonate resin and having a particle size passing through a sieve with a mesh size of 1.7 mm, The polycarbonate resin contains a structural unit derived from a dihydroxy compound represented by formula (1), A group of resin pellets, wherein the content of the fine powder group relative to 100 parts by weight of the group of pellets is 5 ppm to 4000 ppm.

[0011] [ka]

[0012] [2] The group of resin pellets according to [1], wherein the polycarbonate resin has a pencil hardness of HB or higher. [3] The group of resin pellets according to [1] or [2], wherein the polycarbonate resin contains 20 to 95 mass % of structural units derived from the dihydroxy compound represented by the formula (1). [4] The group of resin pellets according to any one of [1] to [3], wherein the polycarbonate resin further contains structural units derived from an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound.

[0013] [5] The group of resin pellets according to any one of [1] to [4], wherein the polycarbonate resin further contains a structural unit represented by the following formula (2) and / or the following formula (3):

[0014] [ka]

[0015] [ka]

[0016] [6] The group of resin pellets according to any one of [1] to [5], wherein the polycarbonate resin further contains a structural unit represented by the following formula (4) and / or the following formula (5):

[0017] [ka]

[0018] However, in the above formula (4), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring.

[0019] [ka]

[0020] However, in the above formula (5), R 1 ~R 3 each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R 4 ~R 9 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring. [Effects of the Invention]

[0021] The resin pellets can reduce production problems that occur during the pellet transport process, and have excellent injection moldability, making it possible to suppress the generation of foreign matter after molding. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes embodiments of the present invention in detail. However, the following description of the configuration is merely an example (i.e., a representative example) of an embodiment of the present invention, and the present invention is not limited to the following content as long as it does not depart from the gist of the present invention. In this specification, the term "repeating structural unit" refers to a structural unit in which the same structure appears repeatedly in a resin and which constitutes the resin by linking together. For example, in the case of a polycarbonate resin, the term "repeating structural unit" also refers to a carbonyl group. Furthermore, the term "structural unit" refers to a partial structure that constitutes a resin, and refers to a specific partial structure contained in a repeating structural unit. For example, it refers to a partial structure sandwiched between adjacent linking groups in a resin, or a partial structure sandwiched between a polymerizable reactive group present at the terminal of a polymer and a linking group adjacent to the polymerizable reactive group. More specifically, in the case of a polycarbonate resin, a carbonyl group is the linking group, and a partial structure sandwiched between adjacent carbonyl groups is referred to as a structural unit. Furthermore, when the term "~" is used in this specification, it is used to include the numerical or physical values ​​written before and after it. Furthermore, numerical values ​​or physical values ​​described as upper and lower limits are intended to include those values. Furthermore, "parts by weight" and "parts by mass," "% by weight" and "% by mass" are essentially synonymous.

[0023] The resin pellets of the present disclosure include a group of pellets containing polycarbonate resin and a group of fine powders. The resin pellets are used for molding such as injection molding and extrusion molding. The pellets refer to a sufficient amount (i.e., a large number) of pellets that can be molded.

[0024] [Polycarbonate resin] The polycarbonate resin contains at least a structural unit derived from a dihydroxy compound represented by formula (1).

[0025] [ka]

[0026] Examples of the dihydroxy compound represented by formula (1) (hereinafter referred to as "compound (1)") include isosorbide, isomannide, and isoidet, which are stereoisomers. These may be used alone or in combination of two or more. Among these, isosorbide, which is obtained by dehydration condensation of sorbitol, which is produced from various starches that are abundant and easily available as plant-derived resources, is most preferred in terms of availability and ease of production, moldability, and the properties of the resulting molded products (e.g., heat resistance, impact resistance, carbon neutrality). Hereinafter, the structural unit derived from compound (1) will be referred to as "structural unit (a)" and the polycarbonate resin containing at least structural unit (a) will be referred to as "ISB-based PC resin."

[0027] The ISB-based PC resin is preferably a copolymer polycarbonate resin containing structural units other than the structural unit (a). From the viewpoint of achieving a good balance of various physical properties for use as a molding material, the lower limit of the content of the structural unit (a) in the ISB-based PC resin is preferably 20% by mass or more, and the upper limit is preferably 95% by mass or less. In this specification, structural units other than the structural unit (a) constituting the ISB-based PC resin are appropriately referred to as "structural unit (b)."

[0028] The structural unit (b) is preferably a structural unit derived from a dihydroxy compound other than the compound (1), but may also be a structural unit derived from a compound other than a dihydroxy compound. Suitable dihydroxy compounds forming the structural unit (b) include aliphatic hydrocarbon dihydroxy compounds, alicyclic hydrocarbon dihydroxy compounds, ether-containing dihydroxy compounds, and acetal ring-containing dihydroxy compounds.

[0029] Examples of aliphatic hydrocarbon dihydroxy compounds include the following dihydroxy compounds: straight-chain aliphatic dihydroxy compounds such as ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; and branched-chain aliphatic dihydroxy compounds such as 1,3-butanediol, 1,2-butanediol, neopentyl glycol, and hexylene glycol.

[0030] Examples of dihydroxy compounds of alicyclic hydrocarbons include the following dihydroxy compounds: dihydroxy compounds which are primary alcohols of alicyclic hydrocarbons, exemplified by 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decalindimethanol, 1,5-decalindimethanol, 2,3-decalindimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantanedimethanol, and dihydroxy compounds derived from terpene compounds such as limonene; and dihydroxy compounds which are secondary or tertiary alcohols of alicyclic hydrocarbons, exemplified by 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

[0031] Examples of the ether-containing dihydroxy compound include oxyalkylene glycols, such as diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, and polypropylene glycol.

[0032] Examples of dihydroxy compounds containing an acetal ring include spiroglycol (also known as 3,9-bis(1,1-dimethyl-2-hydroxyethyl-2,4,8,10-tetraoxaspiro[5,5]undecane) and dioxane glycol (also known as 2-(1,1-dimethyl-2-hydroxyethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane).

[0033] Among the dihydroxy compounds exemplified above, 1,4-cyclohexanedimethanol and tricyclodecane dimethanol are preferred as dihydroxy compounds forming structural unit (b). By using 1,4-cyclohexanedimethanol or tricyclodecane dimethanol, a high molecular weight ISB-based PC resin can be easily obtained due to the favorable polymerization reactivity of 1,4-cyclohexanedimethanol or tricyclodecane dimethanol. The structural unit (b) derived from 1,4-cyclohexanedimethanol is represented by the following formula (2), and the structural unit (b) derived from tricyclodecane dimethanol is represented by the following formula (3).

[0034] [ka]

[0035] [ka]

[0036] The content of the structural unit (b) in the ISB-based PC resin is preferably 5% by mass or more and 80% by mass or less, based on the total weight of the ISB-based PC resin. The ISB-based PC resin contains the structural unit (a) and may further contain a structural unit (c) composed of a structural unit represented by the following formula (4) and / or a structural unit represented by the following formula (5). Hereinafter, this structural unit may be referred to as an "oligofluorene structural unit."

[0037] [ka]

[0038] [ka]

[0039] In formulas (4) and (5), R 1 ~R 3 R each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms. 4 ~R 9 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group, provided that R 4 ~R 9 may be the same or different, and R 4 ~R 9 At least two adjacent groups among these may be bonded to each other to form a ring. From the viewpoint that the fluorene rings in the polymer are likely to be oriented perpendicular to the main chain direction and that stronger reverse wavelength dispersion is exhibited, it is preferable that the ISB-based PC resin contains a structural unit represented by formula (5).

[0040] R 1 and R 2As R, for example, the following alkylene groups can be used. Specific examples include linear alkylene groups such as methylene, ethylene, n-propylene, and n-butylene; and branched alkylene groups such as methylmethylene, dimethylmethylene, ethylmethylene, propylmethylene, (1-methylethyl)methylene, 1-methylethylene, 2-methylethylene, 1-ethylethylene, 2-ethylethylene, 1-methylpropylene, 2-methylpropylene, 1,1-dimethylethylene, 2,2-dimethylpropylene, and 3-methylpropylene. 1 and R 2 The positions of the branched chains in R are indicated by numbers assigned so that the carbon on the fluorene ring side is at position 1. From the viewpoint that the fluorene rings in the polymer tend to be oriented perpendicular to the main chain direction and exhibit stronger reverse wavelength dispersion, 1 and R 2 is preferably an ethylene group.

[0041] R 3 As R, for example, the following alkylene groups can be used. Specific examples include linear alkylene groups such as methylene, ethylene, n-propylene, and n-butylene; and branched alkylene groups such as methylmethylene, dimethylmethylene, ethylmethylene, propylmethylene, (1-methylethyl)methylene, 1-methylethylene, 2-methylethylene, 1-ethylethylene, 2-ethylethylene, 1-methylpropylene, 2-methylpropylene, 1,1-dimethylethylene, 2,2-dimethylpropylene, and 3-methylpropylene. 3 The alkylene group preferably has 1 to 2 carbon atoms on the main chain, and more preferably has 1 carbon atom. When the number of carbon atoms on the main chain is too large, R 1 and R 2 As in the case of (1), the fixation of the fluorene rings is weakened, which may result in a decrease in the wavelength dependence of the reverse dispersion, an increase in the photoelastic coefficient, a decrease in heat resistance, etc. On the other hand, the fewer the number of carbon atoms on the main chain, the better the optical properties and heat resistance, but if the 9-positions of two fluorene rings are directly connected, the thermal stability may be deteriorated.

[0042] R 1 ~R 3 Examples of the substituent in include a halogen atom (specifically, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom); an alkoxy group having 1 to 10 carbon atoms such as a methoxy group or an ethoxy group; an acyl group having 1 to 10 carbon atoms such as an acetyl group or a benzoyl group; an acylamino group having 1 to 10 carbon atoms such as an acetamido group or a benzoylamido group; a nitro group; a cyano group; and an aryl group having 6 to 10 carbon atoms such as a phenyl group or a naphthyl group. One to three hydrogen atoms in the aryl group may be substituted with the above-mentioned halogen atom, alkoxy group, acyl group, acylamino group, nitro group, cyano group, etc.

[0043] R 4 ~R 9 The substituted or unsubstituted alkyl group in may be, for example, the following alkyl groups. Specific examples include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, and n-decyl; branched alkyl groups such as isopropyl, 2-methylpropyl, 2,2-dimethylpropyl, and 2-ethylhexyl; and cyclic alkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, and cyclooctyl. The number of carbon atoms in the alkyl group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, making it easier to obtain the desired optical properties derived from the fluorene rings. Examples of substituents for the alkyl group include R 1 ~R 3 Examples of the substituents include those described above for the group.

[0044] R 4 ~R 9As the substituted or unsubstituted aryl group in the above, for example, the following aryl groups can be used. Specific examples include aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl; and heteroaryl groups such as 2-pyridyl, 2-thienyl, and 2-furyl. The number of carbon atoms in the aryl group is preferably 8 or less, and more preferably 7 or less. When the number of carbon atoms is within this range, steric hindrance between the fluorene rings is unlikely to occur, making it easier to obtain the desired optical properties derived from the fluorene rings. As the substituent of the aryl group, R 1 ~R 3 Examples of the substituents include those described above for the group.

[0045] R 4 ~R 9 As the substituted or unsubstituted acyl group in the above, for example, the following acyl groups can be used. Specific examples include aliphatic acyl groups such as formyl, acetyl, propionyl, 2-methylpropionyl, 2,2-dimethylpropionyl, and 2-ethylhexanoyl; and aromatic acyl groups such as benzoyl, 1-naphthylcarbonyl, 2-naphthylcarbonyl, and 2-furylcarbonyl. The number of carbon atoms in the acyl group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between the fluorene rings is unlikely to occur, making it easy to obtain the desired optical properties derived from the fluorene rings. As the substituent of the acyl group, R 1 ~R 3 Examples of the substituents include those described above for the group.

[0046] R 4 ~R 9As the substituted or unsubstituted alkoxy group or aryloxy group in the above, for example, the following can be used. Specific examples include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group, a trifluoromethoxy group, and a phenoxy group. The number of carbon atoms in the alkoxy group or aryloxy group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between the fluorene rings is unlikely to occur, making it easier to obtain the desired optical properties derived from the fluorene ring. As the substituent of the alkoxy group or aryloxy group, R 1 ~R 3 Examples of the substituents include those described above for the group.

[0047] R 4 ~R 9 The substituted or unsubstituted amino group in the formula (I) can be, for example, the following amino groups. Specific examples include amino groups; aliphatic amino groups such as N-methylamino, N,N-dimethylamino, N-ethylamino, N,N-diethylamino, N,N-methylethylamino, N-propylamino, N,N-dipropylamino, N-isopropylamino, and N,N-diisopropylamino; aromatic amino groups such as N-phenylamino and N,N-diphenylamino; acylamino groups such as formamide, acetamide, decanoylamide, benzoylamide, and chloroacetamide; and alkoxycarbonylamino groups such as benzyloxycarbonylamino and tert-butyloxycarbonylamino. The amino group is preferably an N,N-dimethylamino, N-ethylamino, or N,N-diethylamino group, with an N,N-dimethylamino group being more preferred. In this case, the amino group does not have a highly acidic proton and has a small molecular weight, so the fluorene ratio can be increased, thereby improving thermal stability and reducing the amount of monomers containing oligofluorene structural units used.

[0048] R 4 ~R 9The following can be used as the substituted or unsubstituted vinyl or ethynyl group in the above formula (1). Specific examples include vinyl, 2-methylvinyl, 2,2-dimethylvinyl, 2-phenylvinyl, 2-acetylvinyl, ethynyl, methylethynyl, tert-butylethynyl, phenylethynyl, acetylethynyl, and trimethylsilylethynyl groups. The vinyl or ethynyl group preferably has four or fewer carbon atoms. When the carbon number is within this range, steric hindrance between fluorene rings is unlikely to occur, making it easier to obtain desired optical properties derived from the fluorene rings. Furthermore, the longer the conjugated system of the fluorene ring, the easier it is to obtain stronger reverse dispersion wavelength dependency.

[0049] R 4 ~R 9As the sulfur atom having a substituent in the above, for example, the following sulfur-containing groups can be used. arylsulfonyl groups such as a phenylsulfonyl group and a p-tolylsulfonyl group; alkylsulfonyl groups such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, and an isopropylsulfinyl group; arylsulfinyl groups such as a phenylsulfinyl group and a p-tolylsulfinyl group; alkylthio groups such as a methylthio group and an ethylthio group; arylthio groups such as a phenylthio group and a p-tolylthio group; alkoxysulfonyl groups such as a methoxysulfonyl group and an ethoxysulfonyl group; aryloxysulfonyl groups such as a phenoxysulfonyl group; an aminosulfonyl group; alkylsulfonyl groups such as an N-methylaminosulfonyl group, an N-ethylaminosulfonyl group, an N-tert-butylaminosulfonyl group, an N,N-dimethylaminosulfonyl group, and an N,N-diethylaminosulfonyl group; and arylaminosulfonyl groups such as an N-phenylaminosulfonyl group and an N,N-diphenylaminosulfonyl group. The sulfo group may form a salt with lithium, sodium, potassium, magnesium, ammonium, etc. As the sulfur-containing group, a methylsulfinyl group, an ethylsulfinyl group, or a phenylsulfinyl group is preferred, and a methylsulfinyl group is more preferred. In this case, the sulfur-containing group does not have a proton with high acidity and has a small molecular weight, so the fluorene ratio can be increased. Therefore, in addition to improving thermal stability, the amount of monomers having oligofluorene structural units used can be reduced.

[0050] R 4 ~R 9 As the silicon atom having a substituent in the above, for example, the following silyl groups can be used. Specific examples include trialkylsilyl groups such as trimethylsilyl and triethylsilyl; and trialkoxysilyl groups such as trimethoxysilyl and triethoxysilyl. Trialkylsilyl groups are preferred because they are superior in stability and ease of handling.

[0051] Also, R 4 ~R 9 In the formula (I), examples of the halogen atom that can be used include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, it is preferable to use a fluorine atom, a chlorine atom, or a bromine atom, and more preferably a chlorine atom or a bromine atom, from the viewpoints that they are relatively easy to introduce and have an electron-withdrawing property that tends to increase the reactivity of the 9-position of the fluorene.

[0052] R 4 ~R 9 Specific examples of the ring formed by bonding at least two adjacent groups include the substituted fluorene structures shown in the following group [I]. In the following group [I], the wavy line indicates the position from the 9-position of the fluorene structure to the R 1 and R 2 Or R 2 and R 3 This indicates that the bond leading to

[0053] [ka]

[0054] From the viewpoints of being able to adjust the wavelength dispersion of the ISB-based PC resin to the desired range and improving mechanical properties, the content of the structural unit (c) relative to the total amount (100% by mass) of all structural units and linking groups constituting the ISB-based PC resin is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more. Furthermore, from the viewpoints of reducing the photoelastic coefficient of the ISB-based PC resin and improving the retardation expression, and further, being able to reduce the proportion of the structural unit (c) in the resin, broadening the scope of molecular design and facilitating improvements when modifications of the resin are required, the content of the structural unit (c) is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. The linking group is specifically a carbonate group or ester group present at the end of each structural unit. The content of the structural unit (c) is the total content of the structural unit represented by formula (4) and the structural unit represented by formula (5). If only one of the structural units is contained, the content of the other is 0.

[0055] The method for adjusting the ratio of oligofluorene structural unit in resin can be, for example, copolymerizing the monomer having oligofluorene structural unit with other monomer, or blending the resin containing oligofluorene structural unit with other resin.The method for copolymerizing the monomer having oligofluorene structural unit with other monomer is preferred, because it can precisely control the content of oligofluorene structural unit, obtain high transparency, and obtain uniform properties on the entire surface of the film.

[0056] For the ISB-based PC resin, a dihydroxy compound containing a heterocyclic structure other than the structural unit (a) can be, for example, a structural unit (d) derived from dioxane glycol represented by the following formula (7) or spiro glycol represented by the following formula (8).

[0057] [ka]

[0058] [ka]

[0059] The structural unit (d) is preferably a structural unit derived from the compound of the above formula (8). A specific structural unit is preferably a structural unit represented by the following formula (9).

[0060] [ka]

[0061] From the viewpoint of being able to adjust the balance of physical properties such as heat resistance and optical properties without significantly impairing the excellent properties of the ISB-based PC resin, the content of structural unit (d) relative to 100% by mass (the total amount of all structural units and linking groups constituting the ISB-based PC resin) is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more. From the same viewpoint, the content of structural unit (d) is preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less.

[0062] <Carbonate diester> The linking group of the structural unit contained in the ISB-based PC resin is introduced by polymerizing a carbonate diester represented by the following formula (10).

[0063] [ka]

[0064] In formula (10), R 18 and R 19 are each an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent, and R 18 and R 19 may be the same or different.

[0065] R 18 and R 19 is preferably a substituted or unsubstituted aromatic hydrocarbon group, more preferably an unsubstituted aromatic hydrocarbon group. Examples of the substituent on the aliphatic hydrocarbon group include an ester group, an ether group, an amide group, and a halogen atom, and examples of the substituent on the aromatic hydrocarbon group include alkyl groups such as a methyl group and an ethyl group.

[0066] Examples of the carbonic acid diester represented by the above formula (10) include diphenyl carbonate (hereinafter sometimes abbreviated as DPC), substituted diphenyl carbonates such as ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate, with diphenyl carbonate and substituted diphenyl carbonate being preferred, and diphenyl carbonate being particularly preferred.

[0067] The carbonate diester may contain impurities such as chloride ions, and these impurities may inhibit the polymerization reaction or deteriorate the hue of the resulting resin. Therefore, it is preferable to use a diester that has been purified by distillation or the like, as necessary.

[0068] The pencil hardness of polycarbonate resin is preferably HB or higher, which improves the scratch resistance of extrusion-molded products such as sheets and films, and injection-molded products.

[0069] [Resin pellet group] Pellets containing ISB-based PC resin are typically produced as follows. Specifically, ISB-based PC resin is molten in an extruder, mixed with optional additives, and extruded through a die as several strands. The strands are then cooled and solidified in a cooling water bath and cut using the clearance between regularly spaced blades known as strand cutters and a roller. The pellets thus obtained are elliptical cylindrical, and the length of the pellet is the distance between the cut sections, which corresponds to the height of the elliptical cylinder. The pellet length is determined by the spacing between the blades, which are located at regular intervals. However, depending on the strand thickness and the cutter mechanism, the pellet length can be nonuniform and typically exhibits a certain distribution. Furthermore, the pellet diameter is determined by the resin output rate from the extruder and the pelletizer rotation speed. However, variations in the diameter can occur due to inconsistent output rate or unstable temperatures in the strand cooling bath.

[0070] To ensure the quality and precision of the molded product obtained after molding, it is preferable to use pellets with lengths and diameters that fall within as narrow a distribution range as possible. Various methods can be considered for producing pellets with a relatively narrow length distribution. For example, the size of the die hole can be adjusted in relation to the resin flow rate through the die to make the strand thickness uniform, or the distance between the roller and the cutter can be shortened to prevent fluctuations in the cut length. Other methods for achieving a uniform diameter include, for example, increasing the cylinder temperature to ensure a uniform extrusion rate from the extruder or strictly controlling the temperature of the strand cooling tank. The length and diameter of the pellets are measured using a vernier caliper, and the average values ​​are determined from measurements taken at preferably 150 or more points (number of pellets).

[0071] When producing pellets of ISB-based PC resin using the above method, fine particles that are significantly smaller than the pellets are usually generated depending on the cutting speed and the condition of the cutter blade. This fine powder is no different from the pellets in terms of molecular weight or additive concentration, but when pellets containing a few percent of this fine powder are used to mold compacts, defects such as silver streaks can occur in the molded products, so traditionally, most of the fine powder has been removed from the pellets.

[0072] In the resin pellet group of the present disclosure, fine powder containing an ISB-based PC resin of a predetermined size or less is present together with pellets containing an ISB-based PC resin, and the content of the fine powder per 100 parts by mass of the pellets is 5 ppm to 4000 ppm. In this case, the plasticization time of the pellets can be stabilized while suppressing the occurrence of defects in the molded body. Furthermore, the fine powder containing the ISB-based PC resin has relatively high rigidity due to the physical properties of the ISB-based resin, and therefore is less likely to clog the filter when the pellets are transported from a tank to a molding machine by suction using an autoloader. Therefore, the resin pellet group of the present disclosure can suppress the occurrence of conveyance problems despite the presence of the fine powder. Specifically, by having the fine powder coexist in an amount of 5 ppm or more per 100 parts by mass of the pellets, the metering time during pellet plasticization can be further shortened at the same screw rotation speed and cylinder temperature. Furthermore, by setting the content of the fine powder to 4000 ppm, the occurrence of defects in the molded body can be suppressed. Furthermore, by keeping the content of the fine powder of a predetermined size within the above range, screw noise during injection molding can be prevented. Also, production problems that occur during the pellet transport process can be reduced.From this viewpoint, the content of fine powder per 100 parts by mass of pellets is preferably 6 ppm to 2500 ppm, and more preferably 8 to 1500 ppm.

[0073] The pellet group has a particle size that allows it to remain on a sieve with 1.7 mm openings. The particle size of the pellet group is not particularly limited as long as it can be used for molding and does not impede the effects of the present invention.

[0074] The fine powder contains ISB-based PC resin and is essentially the same as the pellets except for the particle size. The fine powder group has a particle size that passes through a 1.7 mm sieve. The particle size of the fine powder is preferably that which passes through a 1.4 mm sieve, and more preferably that which passes through a 1 mm sieve. Fine powder group that passes through a 1.7 mm or larger sieve will not stabilize the plasticization time of the pellets. The effect can be achieved by allowing the fine powder group of the specified size to coexist with the pellet group in the specified amount range. The coexistence method is not particularly limited; for example, fine powder of the specified size can be recovered from the pellets and added to achieve the content range, or excess fine powder can be removed. Furthermore, fine powder generated during pelletization or crushed pellets can be used as the fine powder group.

[0075] [Polycarbonate resin manufacturing conditions] Polycarbonate resins can be produced by commonly used polymerization methods. For example, they can be produced by solution polymerization or interfacial polymerization using phosgene or carboxylic acid halides, or melt polymerization, which involves a reaction without using a solvent. Among these production methods, melt polymerization is preferred because it does not use solvents or highly toxic compounds, thereby reducing the environmental impact and also providing excellent productivity.

[0076] If a solvent is used in polymerization, the solvent may remain in the polycarbonate resin, and the plasticizing effect of the solvent lowers the glass transition temperature of the polycarbonate resin, which can cause quality fluctuations during processing steps such as molding and stretching, as described below. Furthermore, halogenated organic solvents such as methylene chloride are often used as solvents, but if halogenated solvents remain in the polycarbonate resin, they can cause corrosion of metal parts when molded articles using this resin are incorporated into electronic devices, etc. Polycarbonate resins obtained by melt polymerization do not contain solvents, which is advantageous for stabilizing processing steps and product quality.

[0077] When producing polycarbonate resin by melt polymerization, a monomer having the structural units described above, a carbonic acid diester, and a polymerization catalyst are mixed and subjected to a transesterification reaction (also called a polycondensation reaction) in a molten state, and the reaction rate is increased while removing elimination components from the system. Toward the end of the polymerization, the reaction is continued under high temperature and high vacuum conditions until the target molecular weight is reached. Once the reaction is complete, the molten polycarbonate resin is withdrawn from the reactor. In this way, polycarbonate resin is obtained.

[0078] In the polycondensation reaction, the reaction rate and the molecular weight of the resulting polycarbonate resin can be controlled by strictly adjusting the molar ratio of all dihydroxy compounds to all diester compounds used in the reaction. In the case of polycarbonate resin, the molar ratio of carbonate diester to all dihydroxy compounds is preferably adjusted to 0.90 to 1.10, more preferably 0.96 to 1.08, and particularly preferably 0.98 to 1.06. In the case of polyestercarbonate resin, the molar ratio of the total amount of carbonate diester and all diester compounds to all dihydroxy compounds is preferably adjusted to 0.90 to 1.10, more preferably 0.96 to 1.08, and particularly preferably 0.98 to 1.06.

[0079] If the molar ratio deviates significantly from the upper or lower limit, it becomes impossible to produce a resin with the desired molecular weight. Furthermore, if the molar ratio is too low, the number of hydroxyl terminal groups in the produced resin increases, which may result in a deterioration in the thermal stability of the resin. Furthermore, a large amount of unreacted dihydroxy compound remains in the polycarbonate resin, which may cause contamination of the molding machine in the subsequent molding process or a poor appearance of the molded product. On the other hand, if the molar ratio is too high, the rate of the transesterification reaction may decrease under the same conditions, or the amount of residual carbonate diester or diester compound in the produced polycarbonate resin may increase, and these remaining low-molecular-weight components may similarly cause problems in the molding process.

[0080] The melt polymerization method is usually carried out in two or more multi-stage processes. The polycondensation reaction may be carried out in two or more stages using one polymerization reactor with conditions sequentially changed, or in two or more stages using two or more reactors with conditions changed for each stage. From the viewpoint of production efficiency, however, it is carried out using two or more, preferably three or more, reactors. The polycondensation reaction may be carried out in a batch system, a continuous system, or a combination of a batch system and a continuous system, but from the viewpoint of production efficiency and stability of quality, a continuous system is preferred.

[0081] In polycondensation reactions, it is important to properly control the balance between temperature and pressure in the reaction system. If either the temperature or pressure is changed too quickly, unreacted monomers may be distilled out of the reaction system. As a result, the molar ratio of dihydroxy compounds to diester compounds may change, and a polycarbonate resin with the desired molecular weight may not be obtained. Furthermore, the polymerization rate of the polycondensation reaction is controlled by the balance between the hydroxyl group terminals and the ester group terminals or carbonate group terminals. Therefore, particularly when polymerization is carried out in a continuous system, if the balance of the terminal groups fluctuates due to the distillation of unreacted monomers, it becomes difficult to control the polymerization rate at a constant rate, and there is a risk of significant fluctuation in the molecular weight of the resulting polycarbonate resin. Since the molecular weight of a polycarbonate resin correlates with its melt viscosity, there is a risk that when the resulting polycarbonate resin is molded, the melt viscosity will fluctuate, leading to problems such as the inability to obtain molded products of uniform dimensions.

[0082] Furthermore, if unreacted monomers are distilled out, not only the balance of the terminal groups but also the copolymerization composition of the polycarbonate resin may deviate from the desired composition, which may affect the mechanical properties and optical properties. In a retardation film, the wavelength dispersion of the retardation is controlled by the ratio of the fluorene-based monomer to other copolymerization components in the polycarbonate resin, so if the ratio is disrupted during polymerization, the designed optical properties may not be obtained.

[0083] Hereinafter, the melt polycondensation reaction process will be described by dividing it into a stage in which a monomer is consumed to produce an oligomer, and a stage in which polymerization is allowed to proceed up to a desired molecular weight to produce a polymer. Specifically, the following conditions can be adopted as reaction conditions for the first-stage reaction. That is, the internal temperature of the polymerization reactor is set within a range of usually 130°C or higher, preferably 150°C or higher, more preferably 170°C or higher, and usually 250°C or lower, preferably 240°C or lower, more preferably 230°C or lower. The pressure of the polymerization reactor is set within a range of usually 70 kPa or lower (hereinafter, pressure refers to absolute pressure), preferably 50 kPa or lower, more preferably 30 kPa or lower, and usually 1 kPa or higher, preferably 3 kPa or higher, more preferably 5 kPa or higher. The reaction time is set within a range of usually 0.1 hour or higher, preferably 0.5 hour or higher, and usually 10 hours or lower, preferably 5 hours or lower, more preferably 3 hours or lower.

[0084] The first-stage reaction is carried out while distilling off the monohydroxy compound derived from the diester compound produced. For example, when diphenyl carbonate is used as the carbonate diester, the monohydroxy compound distilled off in the first-stage reaction is phenol. In the first-stage reaction, lowering the reaction pressure accelerates the polymerization reaction, but also increases the amount of unreacted monomer distilled off. To simultaneously suppress the distillation of unreacted monomer and accelerate the reaction by reducing pressure, it is effective to use a reactor equipped with a reflux condenser. It is particularly effective to use a reflux condenser in the early stages of the reaction when there is a large amount of unreacted monomer.

[0085] In the second-stage reaction, the pressure of the reaction system is gradually reduced from the pressure in the first stage, and the monohydroxy compound subsequently generated is removed from the reaction system, ultimately reducing the pressure of the reaction system to 5 kPa or less, preferably 3 kPa or less, and more preferably 1 kPa or less. The internal temperature is set within a range of usually 210°C or higher, preferably 220°C or higher, and usually 270°C or less, preferably 260°C or less. The reaction time is set within a range of usually 0.1 hours or higher, preferably 0.5 hours or higher, more preferably 1 hour or higher, and usually 10 hours or less, preferably 5 hours or less, and more preferably 3 hours or less. To suppress coloration and thermal degradation and obtain a polycarbonate resin with good hue and thermal stability, the maximum internal temperature throughout all reaction stages should be set to 270°C or less, preferably 265°C or less, and more preferably 260°C or less.

[0086] The transesterification catalyst (hereinafter sometimes simply referred to as catalyst or polymerization catalyst) that can be used during polymerization can have a significant effect on the reaction rate and the color tone and thermal stability of the polycarbonate resin obtained by polycondensation. The catalyst used is not limited as long as it can satisfy the transparency, color, heat resistance, thermal stability, and mechanical strength of the produced polycarbonate resin. Examples of the catalyst include metal compounds of Group 1 or 2 of the long periodic table (hereinafter simply referred to as "Group 1" and "Group 2"), basic boron compounds, basic phosphorus compounds, basic ammonium compounds, amine compounds, and other basic compounds. Preferably, at least one metal compound selected from the group consisting of metals of Group 2 of the long periodic table and lithium is used.

[0087] As the Group 1 metal compound, for example, the following compounds can be used, but other Group 1 metal compounds can also be used: sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride, sodium tetraphenylborate, tetraphenylborate potassium tetraphenylborate, lithium tetraphenylborate, cesium tetraphenylborate, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, dicesium hydrogen phosphate, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, dicesium phenylphosphate, alcoholates and phenolates of sodium, potassium, lithium and cesium, and disodium, dipotassium, dilithium and dicesium salts of bisphenol A. Of these, it is preferable to use lithium compounds from the viewpoints of polymerization activity and the hue of the resulting polycarbonate resin.

[0088] The Group 2 metal compound may be, for example, the following compounds, although other Group 2 metal compounds may also be used: calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. Of these, magnesium compounds, calcium compounds, and barium compounds are preferably used, and from the viewpoints of polymerization activity and the hue of the resulting polycarbonate resin, magnesium compounds and / or calcium compounds are more preferably used, and calcium compounds are most preferably used.

[0089] It is possible to use, in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound as an auxiliary compound. However, it is particularly preferable to use at least one metal compound selected from the group consisting of metals of Group 2 of the long form periodic table and lithium. The amount of the polymerization catalyst used is usually 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol, per mole of all dihydroxy compounds used in the polymerization. When at least one metal compound selected from the group consisting of metals of Group 2 of the long periodic table and lithium is used as the polymerization catalyst, particularly when a magnesium compound and / or a calcium compound is used, the metal amount of the polymerization catalyst used is usually 0.1 μmol or more, preferably 0.3 μmol or more, and particularly preferably 0.5 μmol or more, per mole of all dihydroxy compounds. The amount of the polymerization catalyst used is preferably 30 μmol or less, preferably 20 μmol or less, and particularly preferably 10 μmol or less.

[0090] When a polyester carbonate resin is produced using a diester compound as a monomer, a transesterification catalyst such as a titanium compound, a tin compound, a germanium compound, an antimony compound, a zirconium compound, a lead compound, an osmium compound, a zinc compound, or a manganese compound can also be used, with or without being used in combination with the basic compound. The amount of these transesterification catalysts used is typically within a range of 1 μmol to 1 mmol, preferably 5 μmol to 800 μmol, and particularly preferably 10 μmol to 500 μmol, in terms of the metal amount, relative to 1 mol of all dihydroxy compounds used in the reaction.

[0091] If the amount of catalyst is too small, the polymerization rate will be slow, and the polymerization temperature will have to be increased accordingly to obtain a polycarbonate resin with the desired molecular weight. As a result, the color of the resulting polycarbonate resin is likely to deteriorate, and unreacted raw materials may volatilize during polymerization, causing the molar ratio of dihydroxy compound to diester compound to be disrupted, resulting in the desired molecular weight not being achieved. On the other hand, if the amount of polymerization catalyst used is too large, undesirable side reactions may occur, which may result in a deterioration in the color of the resulting polycarbonate resin or in discoloration or decomposition of the polycarbonate resin during molding.

[0092] Among the Group 1 metals, sodium, potassium, and cesium can adversely affect the color of polycarbonate resins if present in large amounts. These metals may be present not only in the catalysts used, but also in raw materials or reactors. Regardless of their origin, the total amount of these metal compounds in the polycarbonate resin is preferably 2 μmol or less, preferably 1 μmol or less, and more preferably 0.5 μmol or less, per mol of the total dihydroxy compounds.

[0093] After polymerization as described above, the polycarbonate resin can usually be cooled and solidified, and then pelletized using a rotary cutter, etc. The pelletization method is not limited, and examples thereof include a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor, cooled and solidified in the form of strands, and pelletized, a method in which the polycarbonate resin is fed in a molten state from the final polymerization reactor to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to pelletize, and a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor, cooled and solidified in the form of strands, once pelletized, and then fed again to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to pelletize.

[0094] Since polycarbonate resins are suitable for optical applications, it is preferable that the polycarbonate resin contains as little foreign matter as possible. Filtration using a filter is preferably performed to remove foreign matter such as discoloration and gel from the polycarbonate resin obtained by melt polycondensation. In particular, it is preferable to melt-extrude the polycarbonate resin using the above-mentioned vented twin-screw extruder and then filter it using a filter to remove residual monomers, by-product phenol, etc. by devolatilization under reduced pressure, and mix in additives such as a heat stabilizer and a mold release agent.

[0095] The filter may be of any known form, such as a candle type, pleated type, or leaf disc type. The aperture of the filter is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less, in terms of a filtration accuracy of 99%. When it is particularly desired to reduce foreign matter, the aperture of the filter is preferably 10 μm or less. However, if the aperture is small, the pressure loss in the filter increases, which may lead to damage to the filter or deterioration of the polycarbonate resin due to shear heat. Therefore, it is preferable to use a filter with a filtration accuracy of 99%. The mesh size of the filter mentioned here is determined in accordance with ISO16889.

[0096] The polycarbonate resin filtered through the filter is discharged from a die head in the form of strands, cooled and solidified, and pelletized using a rotary cutter or the like. However, when the polycarbonate resin is stranded or pelletized in direct contact with the outside air, it is desirable to carry out the stranding or pelletization in a clean room that is preferably Class 7, more preferably Class 6, as defined in JIS B 9920:2002, in order to prevent contamination by foreign matter from the outside air.

[0097] During pelletization, cooling methods such as air cooling and water cooling are preferably used. The air used during air cooling should be one that has been previously purified of foreign matter using a HEPA filter or similar to prevent re-adhesion of foreign matter. When using water cooling, it is desirable to remove metals from the water using an ion exchange resin or similar, and then use water that has been further purified of foreign matter using a water filter. The mesh size of the water filter used is preferably 10 to 0.45 μm, providing a filtration accuracy of 99% removal.

[0098] Fine particles generated during pelletization and pneumatic piping transport can be passed through a fine particle removal device just before the pellet product tank to keep the amount of fine particles constant. Specifically, it is recommended to use a Makino Sangyo Pelletron DeDuster Z-770 and adjust the valve opening so that the negative pressure in the fine particle suction piping is 100 Pa.

[0099] [Additives] The polycarbonate resin may contain commonly used additives such as heat stabilizers, antioxidants, catalyst deactivators, ultraviolet absorbers, light stabilizers, release agents, dyes and pigments, impact modifiers, antistatic agents, lubricants, plasticizers, compatibilizers, nucleating agents, flame retardants, inorganic fillers, and foaming agents, as long as the additives do not impair the object of the present invention.

[0100] (heat stabilizer) If necessary, a heat stabilizer can be blended into the polycarbonate resin to prevent a decrease in molecular weight or deterioration in color during melt processing, etc. Examples of such heat stabilizers include commonly known hindered phenol-based heat stabilizers and / or phosphorus-based heat stabilizers.

[0101] Examples of the hindered phenol compound that can be used include the following compounds: 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5 2,2'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis-(2,4-di-tert-butylphenol), tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the like. Among these, it is preferable to use tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, or 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0102] Examples of phosphorus-based compounds that can be used include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof, as shown below, but phosphorus-based compounds other than these can also be used: triphenyl phosphite, tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, phosphate, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphinate, dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate. These heat stabilizers may be used alone or in combination of two or more.

[0103] Such a heat stabilizer may be added to the reaction liquid during melt polymerization, or may be added to the polycarbonate resin using an extruder and kneaded. When a film is produced by melt extrusion, the heat stabilizer or the like may be added to the extruder to produce a film, or the heat stabilizer or the like may be added in advance to the polycarbonate resin using an extruder and then formed into pellets or the like. The amount of these heat stabilizers added is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, and even more preferably 0.001 parts by mass or more, and is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, based on 100 parts by mass of polycarbonate resin.

[0104] (Catalyst deactivator) Adding an acidic compound to a polycarbonate resin to neutralize and deactivate the catalyst used in the polymerization reaction can improve color tone and thermal stability. The acidic compound used as a catalyst deactivator can be a compound having a carboxylic acid group, a phosphoric acid group, or a sulfonic acid group, or an ester thereof, but it is particularly preferable to use a phosphorus-based compound containing a partial structure represented by the following formula (11) or (12).

[0105] [ka]

[0106] [ka]

[0107] Examples of phosphorus compounds represented by the above formula (11) or (12) include phosphoric acid, phosphorous acid, phosphonic acid, hypophosphorous acid, polyphosphoric acid, phosphonate esters, and acidic phosphate esters. Among the above, phosphorous acid, phosphonic acid, and phosphonate esters are more effective in deactivating the catalyst and inhibiting coloration, with phosphorous acid being particularly preferred. Examples of phosphonic acids include phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, nitrilotris(methylenephosphonic acid), and propylphosphonic anhydride.

[0108] Phosphonate esters include dimethyl phosphonate, diethyl phosphonate, bis(2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, diethyl ethylphosphonate, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl)phosphonate, diethyl vinylphosphonate, and hydroxymethyl Examples thereof include diethyl phosphonate, dimethyl (2-hydroxyethyl)phosphonate, diethyl p-methylbenzylphosphonate, diethyl phosphonoacetic acid, ethyl diethylphosphonoacetate, tert-butyl diethylphosphonoacetate, diethyl (4-chlorobenzyl)phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl phosphonoacetaldehyde diethyl acetal, and diethyl (methylthiomethyl)phosphonate.

[0109] Examples of acidic phosphate esters include phosphate diesters such as dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis(butoxyethyl) phosphate, bis(2-ethylhexyl) phosphate, diisotridecyl phosphate, dioleyl phosphate, distearyl phosphate, diphenyl phosphate, and dibenzyl phosphate, or mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

[0110] These may be used alone or in any combination and ratio of two or more. If the amount of the phosphorus-based compound added to the polycarbonate resin is too small, the catalyst deactivation and coloration suppression effects will be insufficient. If the amount is too large, the polycarbonate resin may become colored, especially in durability tests under high temperature and high humidity. The amount of the phosphorus-based compound added may be an amount corresponding to the amount of catalyst used in the polymerization reaction. The amount of phosphorus-based compound added is preferably 0.5 to 5 times the amount of phosphorus atoms per mole of the metal catalyst used in the polymerization reaction, more preferably 0.7 to 4 times the amount of phosphorus atoms per mole of the metal catalyst used in the polymerization reaction, and particularly preferably 0.8 to 3 times the amount of phosphorus atoms per mole of the metal catalyst used in the polymerization reaction.

[0111] (polymer alloy) For the purpose of improving properties such as mechanical properties and solvent resistance, the polycarbonate resin may be kneaded with one or more synthetic resins, rubbers, elastomers, etc., such as aromatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, AS, polylactic acid, polybutylene succinate, etc., to form a polymer alloy.

[0112] The above-mentioned additives and modifiers can be produced by mixing the above-mentioned components with the polycarbonate resin simultaneously or in any order using a mixer such as a tumbler, V-type blender, Nauta mixer, Banbury mixer, kneading roll, or extruder. Among these, kneading using an extruder, particularly a twin-screw extruder, is preferred from the viewpoint of improving dispersibility. [Example]

[0113] Examples of polycarbonate resins are shown below, but the present invention is not limited to the following examples as long as the gist of the invention is not exceeded. [Raw materials used] The abbreviations and manufacturers of the compounds used in the following Production Examples and Examples are as follows:

[0114] <Dihydroxy compounds> ISB: Isosorbide (manufactured by Rocket Fleuret) CHDM: 1,4-cyclohexanedimethanol (SK Chemicals) <Carbonate diester> DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)

[0115] <Catalyst deactivator> Phosphonic acid (Tokyo Chemical Industry Co., Ltd.)

[0116] <Polycarbonate resin: A1> ISB / CHDM=70 / 30 mol% copolymer polycarbonate (structural unit (a) / structural unit (b)=58.8 / 24.9 wt%) It was synthesized according to Production Example 1 described below. <Polycarbonate resin: A2> ISB / CHDM = 90 / 10 mol% copolymer polycarbonate (structural unit (a) / structural unit (b) = 75.5 / 8.1 wt%) It was synthesized according to Production Example 2 described below.

[0117] <Aromatic polycarbonate: A3> As the aromatic polycarbonate, the following commercially available products were used. Aromatic polycarbonate (A3): "S3000" manufactured by Mitsubishi Engineering Plastics Corporation (weight average molecular weight Mw = 22,000) <Polycarbonate resin fine powder: B1> The above A1 and A2 raw materials were sieved through a sieve with 1.7 mm openings, and the fine powder that passed through was collected. <Aromatic polycarbonate resin fine powder: B2> The above A3 raw material was sieved through a sieve with 1.7 mm openings, and the fine powder that passed through was collected.

[0118] <Manufacturing methods for each polycarbonate resin>

[0119] (Production Example 1) Polycarbonate resin: A1 Polycarbonate resin was polymerized using a continuous polymerization system consisting of three vertical stirred reactors, one horizontal stirred reactor, and a twin-screw extruder. ISB, CHDM, and DPC were melted in separate tanks and continuously fed into the first vertical stirred reactor at flow rates of 29.8 kg / hr for ISB, 12.6 kg / hr for CHDM, and 63.1 kg / hr for DPC (molar ratio ISB / CHDM / DPC = 0.700 / 0.300 / 1.010). Simultaneously, an aqueous solution of calcium acetate monohydrate, the polymerization catalyst, was fed into the first vertical stirred reactor at a ratio of 1.5 μmol of calcium acetate monohydrate per mol of total dihydroxy compounds. The internal temperature, internal pressure, and residence time of each reactor were as follows: first vertical stirred reactor: 190°C, 25 kPa, 120 minutes; second vertical stirred reactor: 195°C, 10 kPa, 90 minutes; third vertical stirred reactor: 205°C, 4 kPa, 45 minutes; and fourth horizontal stirred reactor: 220°C, 0.1 to 1.0 kPa, 120 minutes. The internal pressure of the fourth horizontal stirred reactor was finely adjusted during operation so that the reduced viscosity of the resulting polycarbonate resin would be 0.42 dL / g to 0.43 dL / g.

[0120] The polycarbonate resin extracted from the fourth horizontal stirred reactor was fed in its molten state into a vented twin-screw extruder, TEX30α (manufactured by The Japan Steel Works, Ltd.). The extruder had three vacuum vents, through which residual low-molecular-weight components in the resin were removed by volatilization. Phosphonic acid (0.63 wt. ppm relative to the polycarbonate resin) was added as a catalyst deactivator just before the first vent. The polycarbonate resin, still in its molten state after passing through the extruder, was passed through a 10 μm Ultipleat candle filter (manufactured by PALL) to filter out impurities. The polycarbonate resin was then extruded in strand form through a die, cooled with water, solidified, and cut into pellets by a rotary cutter. The resulting pelletized polycarbonate resin (i.e., pellet group) is designated "A1." The pellet group had a particle size that would remain on a 1.7 mm mesh sieve.

[0121] (Production Example 2) Polycarbonate resin: A2 The same procedure as in Production Example 1 was repeated, except that the feed rates of the various raw materials were adjusted to 38.3 kg / hr of ISB, 4.1 kg / hr of CHDM, and 62.9 kg / hr of DPC (molar ratio ISB / CHDM / DPC = 0.900 / 0.100 / 1.000), and the reduced viscosity of the resulting polycarbonate resin was adjusted to 0.435 dL / g to 0.4451 dL / g. The resulting polycarbonate resin is designated "A2." The pellets of polycarbonate resin A2 had a particle size that allowed them to remain on a sieve with 1.7 mm openings, and their median diameter D50 was generally the same as in Production Example 1.

[0122] [Measurement method] The physical properties of each polycarbonate resin constituting the resin composition of the present invention were measured according to the following methods.

[0123] (reduced viscosity) A polycarbonate resin sample was dissolved in methylene chloride to prepare a polycarbonate resin solution with a precise concentration of 0.6 g / dL. Using a Moritomo Rika Kogyo Ubbelohde viscosity tube, measurements were performed at a temperature of 20.0°C ± 0.1°C to measure the solvent transit time t0 and the solution transit time t. The relative viscosity η was calculated using the obtained t0 and t values ​​using the following equation (i). rel The relative viscosity η rel Using the following formula (ii), the specific viscosity η sp asked for. η rel =t / t0(i) η sp =(η-η0) / η0=η rel -1 (ii) Then, the obtained specific viscosity ηsp is divided by the concentration c [g / dL] to obtain the reduced viscosity η sp / c [dL / g] was calculated.

[0124] (Pencil hardness) The polycarbonate resin pellets were dried at 100°C for 5 hours and then injection-molded into flat test pieces (60mm x 60mm x 3mm thick) using an injection molding machine ("J75EII" manufactured by The Japan Steel Works, Ltd.) under conditions of a cylinder set temperature of 280°C, a mold temperature of 80°C, a screw rotation speed of 50 rpm, and an injection speed of 30 mm / s. The pencil hardness of the flat test pieces (60mm x 60mm x 3mm thick) obtained above was measured using a pencil hardness tester under a load of 750g in accordance with ISO-15184.

[0125] (Fine powder measurement method) 2 kg of polycarbonate resin pellets were weighed and placed in a stainless steel sieve with a diameter of 200 mm, a depth of 50 mm, and an opening of 1.7 mm. After sieving for 5 minutes, the weight of the fine powder that passed through the mesh was measured, and the fine powder content in the pellets was expressed in ppm.

[0126] (Screw noise) The polycarbonate resin obtained by the method described above was dried at 100°C for 5 hours, and then an injection molding machine (J75EII manufactured by Japan Steel Works, Ltd.) was used to mold polycarbonate resin plates under the following conditions: cylinder temperatures C1: 205°C / C2: 230°C / C3: 240°C / NH: 240°C, mold temperature 90°C, screw rotation speed 50 rpm, injection pressure dwell time 15 seconds, and cooling time 30 seconds. After 10 consecutive shots, the presence or absence of screw squeal was evaluated during measurement after injection. An unpleasant sound was scored as "x", and otherwise scored as "o".

[0127] (Metric stability) The polycarbonate resin obtained by the method described above was dried at 100°C for 5 hours, and then an injection molding machine (J75EII manufactured by Japan Steel Works, Ltd.) was used to mold a polycarbonate resin plate under the following conditions: cylinder temperature C1: 205°C / C2: 230°C / C3: 240°C / NH: 240°C, mold temperature 90°C, screw rotation speed 50 rpm, injection pressure holding time 15 seconds, and cooling time 30 seconds.In 10 consecutive molding shots, if the measurement time after injection varied by 2 seconds or more, it was marked ``X'', and otherwise it was marked ``O''.

[0128] (film foreign matter) The polycarbonate resin obtained by the method described above was dried at 100°C for 5 hours, and then fed into the extruder of the OCS Gel Counter FSA film inspection line, and a 35±5 μm film was extruded at 250°C. The transmission image of the film was observed with a camera unit equipped with an image processing device of the Gel Counter, and foreign matter of 150 μm or more was counted. The observation was carried out over a 3-millimeter area of ​​a 5-8 cm wide central portion of the film. 2 The range is 1m 2 The number of foreign particles per unit was calculated.

[0129] (Time until pellet transport trouble occurs) In continuous production by injection molding, pellets were supplied to the hopper of an injection molding machine (Japan Steel Works, Ltd., J75EII) at a rate of 20 kg / hr and a conveying distance of 15 m using a Kawata Corporation pellet autoloader AL-0208a, and the time until pellet conveying trouble due to filter clogging occurred was measured.

[0130] [Example 1] The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A1, the content of polycarbonate resin fine powder measured by the above-mentioned method being 10 ppm by weight. The obtained results are shown in Table 1.

[0131] [Example 2] The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A1, the content of polycarbonate resin fine powder measured by the above-mentioned method being 100 ppm by weight. The obtained results are shown in Table 1.

[0132] [Example 3] The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A1, the content of polycarbonate resin fine powder measured by the above-mentioned method being 1000 ppm by weight. The obtained results are shown in Table 1.

[0133] [Comparative Example 1] The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A1, whose content of polycarbonate resin fine powder measured by the above-mentioned method was 0 ppm by weight. In Comparative Example 1, the fine powder was completely removed by suction from the pellets after production. The other conditions were the same as in Example 1. The results obtained are shown in Table 1.

[0134] Comparative Example 2 The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A1, the content of polycarbonate resin fine powder measured by the above-mentioned method being 5000 ppm by weight. The obtained results are shown in Table 1.

[0135] [Example 4] The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A2, the content of polycarbonate resin fine powder measured by the above-mentioned method being 100 ppm by weight. The obtained results are shown in Table 1.

[0136] Comparative Example 3 The above-mentioned various evaluations were carried out using a group of pellets of polycarbonate resin A2, which had a polycarbonate resin fine powder content of 0 ppm by weight as measured by the above-mentioned method. The obtained results are shown in Table 1.

[0137] Comparative Example 4 The above-mentioned various evaluations were carried out using a group of pellets of aromatic polycarbonate resin A3, the content of which was 100 ppm by weight as measured by the above-mentioned method. The obtained results are shown in Table 1.

[0138] [Table 1]

[0139] As can be seen from Table 1, in Examples 1 to 4, which contain a pellet group containing a specific polycarbonate resin and a predetermined amount of fine powder group of a predetermined size, the injection moldability is excellent while reducing production problems during the pellet transport process, and the generation of foreign matter after molding is suppressed.

[0140] In contrast, Comparative Examples 1 and 3 did not contain fine powder, and therefore had poor injection moldability. Furthermore, Comparative Example 2 contained too much fine powder, shortening the time until production problems occurred during the pellet transport process and increasing the amount of foreign matter in the molded body. Comparative Example 4 contained pellets and fine powder of aromatic polycarbonate resin, but did not contain a polycarbonate resin represented by formula (1), such as ISB. In this case, even with the coexistence of fine powder, the time until production problems occurred during the pellet transport process was shortened.

[0141] As described above, it has been found that a group of resin pellets containing a predetermined amount of fine powder of a predetermined size together with a group of pellets containing a polycarbonate resin containing structural units derived from the dihydroxy compound represented by the formula (1) produces fewer foreign objects when molded into a film, has excellent injection moldability, and extends the time until pellet transport problems occur, thereby reducing production problems.

Claims

1. A group of resin pellets including a group of pellets containing a polycarbonate resin and having a particle size that remains on a sieve with an opening of 1.7 mm, and a group of fine powder containing the polycarbonate resin and having a particle size that passes through a sieve with an opening of 1.7 mm, The polycarbonate resin contains a structural unit derived from a dihydroxy compound represented by formula (1), The resin pellet group has a content of the fine powder group of 5 ppm to 4000 ppm relative to 100 parts by weight of the pellet group. 【Chemical 1】

2. The group of resin pellets according to claim 1 , wherein the polycarbonate resin has a pencil hardness of HB or higher.

3. The group of resin pellets according to claim 1 or 2, wherein the polycarbonate resin contains 20 to 95% by mass of structural units derived from the dihydroxy compound represented by formula (1).

4. The group of resin pellets according to claim 1 or 2, wherein the polycarbonate resin further contains structural units derived from an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound.

5. The group of resin pellets according to claim 1 or 2, wherein the polycarbonate resin further contains a structural unit represented by the following formula (2) and / or the following formula (3): 【Chemistry 2】 【Chemistry 3】

6. The group of resin pellets according to claim 1 or 2, wherein the polycarbonate resin further contains a structural unit represented by the following formula (4) and / or the following formula (5): 【Chemistry 4】 (However, in the above formula (4), R １ ~R ３ each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R ４ ~R ９ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R ４ ~R ９ may be the same or different, R ４ ~R ９ At least two adjacent groups among these may be bonded to each other to form a ring.) 【Chemistry 5】 (However, in the above formula (5), R １ ~R ３ each independently represents a direct bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms; R ４ ~R ９ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted vinyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; R ４ ~R ９ may be the same or different, R ４ ~R ９ At least two adjacent groups among these may be bonded to each other to form a ring.)

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