WO2014084327A1

WO2014084327A1 - Polycarbonate resin, polycarbonate resin composition and molded article

Info

Publication number: WO2014084327A1
Application number: PCT/JP2013/082110
Authority: WO
Inventors: 貴紀大和田; 菅　浩一; ユミ中山
Original assignee: 出光興産株式会社
Priority date: 2012-11-30
Filing date: 2013-11-28
Publication date: 2014-06-05
Also published as: JP2014108981A; JP6163297B2; TW201428023A; TWI600678B; CN104812796B; CN104812796A

Abstract

A polycarbonate resin wherein a relation between the melt tension [MT (g)] at 280^°C and melt volume rate [MVR (cm³/10 min)] at 280^°C satisfies the requirements represented by formulae (1) to (3), and a polycarbonate resin composition and a molded article containing the same. Formula (1): MT≥(15.4/MVR)-1.3 Formula (2): MT≤(57.4/MVR)-1.3 Formula (3): MT≥1

Description

Polycarbonate resin, polycarbonate resin composition and molded product

The present invention is a polycarbonate resin and a polycarbonate resin that do not require an additive such as PTFE that causes opacity because the melt tension is improved and the drip resistance is excellent while maintaining molding fluidity even in a high shear region. The present invention relates to a composition and a molded article.

Generally, a polycarbonate resin produced from bisphenol A or the like is used in a wide range of applications because of its excellent transparency, heat resistance, and mechanical properties. However, when the polycarbonate resin is used for blow molding, extrusion molding, vacuum molding, and the like, the melt tension is usually low, so that the molded product has uneven thickness or drawdown, which is satisfactory. There is a disadvantage that a molded product cannot be obtained.
On the other hand, it is known to use polytetrafluoroethylene (PTFE) having fibril forming ability to suppress drip and impart flame retardancy, but PTFE is molded with poor compatibility with polycarbonate resin. Causes the product to become opaque.
Therefore, as a method for improving the melt tension to impart drip resistance without using PTFE and to improve the properties such as transparency, flame retardancy and molding fluidity, a polycarbonate resin may contain a branched structure. It is being considered.

For example, in Patent Document 1, an aromatic polycarbonate resin having a branched structure with a branching ratio exceeding 1.1 mol% and not more than 1.5 mol% in order to obtain a resin composition having excellent transparency and flame retardancy. An aromatic polycarbonate resin composition containing a flame retardant is disclosed, and specific examples using trivalent phenol as a branching agent are shown.
Patent Document 2 discloses a low branching agent content of 0.05 to 0.5 mol% in order to solve the problem of moldability degradation caused by uneven thickness and melt viscosity at the time of molding by drawdown. It is disclosed that a branched polycarbonate resin satisfying a relationship in which x and melt tension y are expressed by a specific formula, and a specific example using trivalent phenol as a branching agent is shown.
Further, as Patent Document 3, in order to improve thermal stability, moldability, and drawdown property, a low branching agent content x of 0.1 to 0.7 mol% and a melt tension y are expressed by a specific formula. It is disclosed that a branched polycarbonate resin having a N content in the resin of 0 to 20 ppm and a Cl content of 0 to 200 ppm is used, and trivalent phenol is used as a branching agent. Specific examples were given.
In Patent Document 4, a tetraphenol compound represented by a specific formula is used as a branching agent with respect to 1 mol of dihydric phenol in order to obtain a material having good transparency and moldability and high wear resistance. In other words, it is disclosed that a branched polycarbonate resin having a specific viscosity in the range of 0.20 to 2.0 is used.
Further, as Patent Document 5, in order to give a molded article having improved moldability and improved appearance and color tone in blow molding or the like, a specific tetrahydric phenol is used as a branching agent, and the branching agent content is 0.01. A branched polycarbonate resin having a low intrinsic viscosity [η] of 0.5 to 0.6 (dl / g) and substantially no cross-linked structure is disclosed.

JP 2011-105862 A Japanese Patent No. 3693462 JP 2005-126477 A JP 2001-261808 A Japanese Patent No. 4473446

However, even if a trifunctional branching agent or a tetrafunctional branching agent is used as the branching agent, a polycarbonate resin having excellent molding fluidity in a high shear region has not been obtained.
Accordingly, the present invention provides a polycarbonate resin and a polycarbonate resin composition excellent in drip resistance without adding PTFE or the like while maintaining molding fluidity even in a high shear region, and a molded product produced from these. With the goal.

As a result of intensive studies, the present inventors have determined that a polycarbonate resin satisfying a specific relational expression between melt tension and melt flowability, or a tetrafunctional or higher functional branching agent content and a viscosity average molecular weight within a specific range. Thus, it has been found that the above problems can be solved.
That is, this invention relates to the following polycarbonate resin, a polycarbonate resin composition, and a molded article.

1. A melt tension MT [g] at 280 ° C., the relationship between the melt flow MVR [cm ^3/10 min] at 280 ° C. has the following formula (1) to (3) Polycarbonate resin satisfying.
Formula (1): MT ≧ (15.4 / MVR) −1.3
Formula (2): MT ≦ (57.4 / MVR) −1.3
Formula (3): MT ≧ 1
2. 2. The polycarbonate resin according to 1 above, comprising a polycarbonate resin having a branched structure.
3. 2. The polycarbonate resin according to 1 above, comprising a polycarbonate resin having a branched structure and a linear polycarbonate resin.
4). A polycarbonate resin having a tetrafunctional or higher functional branching agent content of 0.5 to 2.0 mol% and a viscosity average molecular weight of 18,000 to 28,000.
5. 5. A polycarbonate resin composition comprising the polycarbonate resin according to any one of 1 to 4 and an additive.
6). 6. The polycarbonate resin composition as described in 5 above, wherein the additive is a flame retardant.
7). 5. A molded article obtained by molding the polycarbonate resin according to any one of 1 to 4 above or the polycarbonate resin composition according to 5 or 6 above.
8). 8. The molded product according to 7 above, which is blow molded.

According to the present invention, a polycarbonate resin that does not require PTFE or the like that causes opacity is included because the melt tension is improved and the drip resistance is excellent while maintaining molding fluidity even in a high shear region, and the like. A polycarbonate resin composition can be provided.
Moreover, the said polycarbonate resin and the polycarbonate resin composition containing this are especially suitable for blow molding from the said characteristic, The molded article which shape | molded the said polycarbonate resin and the polycarbonate resin composition containing this can be provided.

Is a graph showing relationship (MT) × (1 / MVR ) and melt tension MT [g] and the melt flowability MVR [cm ^3/10 min] in Examples and Comparative Examples.

[Physical properties of polycarbonate resin]
(Melting tension MT and melt flowability MVR)
Polycarbonate resins of the present invention (hereinafter sometimes abbreviated as "PC resin".) Has a melt tension MT [g] at 280 ° C., the relationship between the melt flowability MVR at 280 ℃ [cm ^3/10 min] However, the following expressions (1) to (3) are satisfied.
Formula (1): MT ≧ (15.4 / MVR) −1.3
Formula (2): MT ≦ (57.4 / MVR) −1.3
Formula (3): MT ≧ 1

By satisfying the formulas (1) to (3) in the present invention, the melt tension is improved and excellent drip resistance can be ensured while maintaining the molding fluidity as compared with the existing PC resin.
When the formula (1) is not satisfied, that is, when MT <(15.4 / MVR) −1.3, the excellent drip resistance achieved by the present invention cannot be exhibited, and the formula (2) is not satisfied. In this case, that is, when MT> (57.14 / MVR) -1.3, good fluidity cannot be exhibited in a high shear force region. Further, poor separation occurs at the time of polymerization, which is also a problem in production. Further, when the formula (3) is not satisfied, that is, when MT <1, sufficient drip resistance cannot be ensured, and the end portion of the molded product is waved or the thickness varies.

Furthermore, the relationship between MT and MVR is
From the viewpoint of drip resistance, preferably, MT ≧ (20.6 / MVR) −2.1, MT ≦ (57.4 / MVR) −1.3, MT ≧ 1,
More preferably, from the viewpoint of drip resistance and fluidity during molding, MT ≧ (20.6 / MVR) −2.1, MT ≦ (57.4 / MVR) −1.3, MT ≧ 1, 1 / MVR ≦ 0.3, and
More preferably, from the viewpoint of drip resistance and fluidity during molding, MT ≧ (20.6 / MVR) −2.1, MT ≦ (57.4 / MVR) −1.3, MT ≧ 1, 1 / MVR ≦ 0.25 is satisfied.

The melt tension MT [g] is a value obtained by measurement at 280 ° C., orifice diameter L / D = 8 / 2.095 mm, extrusion speed 10 mm / min, take-up speed 3.1 m / min. Furthermore, the melt flowability MVR [cm ^3/10 min] is, 280 ° C., a melt flow volume per unit time measured under a load 2.16 kg.

In order to satisfy the above formulas (1) to (3), the melt tension MT and the melt fluidity MVR of the PC resin can be achieved by adjusting the branching agent content and viscosity average molecular weight of the PC resin described later. . For example, in order to increase the melt tension MT, it can be adjusted by increasing the branching agent content described later, and the melt fluidity MVR can be adjusted by the viscosity average molecular weight of the PC resin.

(Branching agent content)
The PC resin of the present invention is preferably a PC resin having a branched structure in order to exhibit good melt tension and satisfy the above formulas (1) to (3).
In order to have a branched structure, a PC resin may be produced using a branching agent. From the viewpoint of improving the melt tension while maintaining good fluidity in a high shear force region, a branching agent having four or more functional groups is used. Further, the content of the tetrafunctional or higher functional branching agent in the PC resin is preferably 0.5 to 2.0 mol%, and more preferably 0.5 to 1.5 mol%.
If the branching agent content is 0.5 mol% or more, sufficient melt tension can be imparted to the PC resin, and if it is 2.0 mol% or less, there is no possibility that the polymer is crosslinked and gelled. In addition, it has good impact resistance, and further, the surface of the molded product is not cloudy and has excellent transparency.

In the present invention, the content of the branching agent refers to a constitutional unit derived from a dihydric phenol used as a raw material, a constitutional unit derived from a terminal terminator, and a tetrafunctional or higher functional branching agent, which is contained in the entire PC resin. Mol% of structural units derived from a tetrafunctional or higher functional branching agent relative to the total number of moles of units, that is, a tetrafunctional or higher functional branching agent content (mol%) = [a structural unit derived from a tetrafunctional or higher functional branching agent (mol). / [Constituent unit derived from dihydric phenol (mol) + constituent unit derived from terminal terminator (mol) + constituent unit derived from tetrafunctional or higher branching agent (mol)]] × 100.
Each of the structural units (mol) can be measured by ¹ H-NMR.

Further, as described above, the PC resin of the present invention preferably has a branched structure in order to satisfy the formulas (1) to (3). As the PC resin having the branched structure, a PC resin having a branched structure is used. PC resin which consists only of PC resin which consists of PC resin which has a branched structure, and linear PC resin may be sufficient. From the viewpoint of having superior flame retardancy, it is preferable to use 30 to 100% by mass of a PC resin having a branched structure, and more preferably one type of PC resin having a branched structure that does not contain a linear PC resin. Or it is PC resin which consists of 2 or more types.
When blending a plurality of PC resins to make the PC resin of the present invention, it is sufficient that the PC resin as a whole satisfies the formulas (1) to (3), and the branching agent content is also included in the PC resin as a whole. It is sufficient that the branching agent content is within the preferred range. The method of blending may be blended after each PC resin to be blended is produced, and may be blended when each PC resin is in a molten state, and is not particularly limited.

(Viscosity average molecular weight)
The viscosity average molecular weight (Mv) of the PC resin of the present invention is preferably 18,000 to 28,000, and more preferably 20,000 to 25,000.
A viscosity average molecular weight of 18,000 or more is preferable because drip resistance is sufficient and good flame retardancy can be exhibited. Further, if the viscosity average molecular weight is 28,000 or less, the MVR of the PC resin becomes too low, so that there is no possibility of causing a problem during molding.
In the present invention, the viscosity average molecular weight (Mv) is obtained by measuring the viscosity of a methylene chloride solution at 20 ° C. using an Ubbelohde viscometer, obtaining the intrinsic viscosity [η] from this, and calculating by the following equation. .
[η] = 1.23 × 10 ⁻⁵ Mv ^0.83

The present invention also provides a PC resin having a tetrafunctional or higher functional branching agent content of 0.5 to 2.0 mol% and a viscosity average molecular weight of 18,000 to 28,000.
When the tetrafunctional or higher functional branching agent content and the viscosity average molecular weight are within the above ranges, a PC resin having excellent drip resistance can be obtained. In the PC resin having a branching agent content of 4 or more functionalities and a viscosity average molecular weight within the above ranges, if the branching agent content is outside the range of 0.5 to 2.0 mol%, sufficient melt tension is imparted to the PC resin. It cannot be imparted, and good fluidity cannot be maintained in a high shear force region. Moreover, there exists a possibility that a polymer may bridge | crosslink and gelatinize and impact resistance and transparency may fall. The branching agent content is preferably 0.5 to 1.5 mol%. On the other hand, if the viscosity average molecular weight is outside the range of 18,000 to 28,000, drip resistance becomes insufficient and molding becomes difficult. The viscosity average molecular weight is preferably 20,000 to 25,000.
The tetrafunctional or higher functional branching agent content and the viscosity average molecular weight here are synonymous with those described in the PC resin in which the above MT and MVR satisfy the formulas (1) to (3).

Further, the PC resin having a tetrafunctional or higher functional branching agent content and a viscosity average molecular weight within the above ranges may be a PC resin composed only of a PC resin having a branched structure. PC resin which consists of a shape-like PC resin may be sufficient. Preferably, it is a PC resin composed of one or more kinds of PC resins having a branched structure without containing a linear PC resin.
Further, the PC resin having the above-described tetrafunctional or higher functional branching agent content and viscosity average molecular weight within the above ranges preferably satisfies the formulas (1) to (3) showing the relationship between MT and MVR described above. The preferred embodiment of the relationship with MVR is the same as described above.

[Raw material of polycarbonate resin]
The PC resin of the present invention may be an aromatic PC resin or an aliphatic PC resin, but is preferably an aromatic PC resin from the viewpoint of impact resistance and heat resistance. The aromatic PC resin in the present invention can be produced preferably using a branching agent, a dihydric phenol and a terminal terminator. Moreover, although the manufacturing method is not specifically limited, For example, it can manufacture by the interfacial polymerization method which makes bivalent phenol and a carbonate precursor react directly.
As an industrial method for producing a PC resin having a branched structure by an interfacial polymerization method, for example, an organic solvent is added to an alkaline aqueous solution of a dihydric phenol, and a carbonate precursor such as phosgene is blown into the organic solvent, thereby reactive chloroformate. A polycarbonate oligomer having a group is produced, and at the same time or sequentially with the production of the polycarbonate oligomer, a polycarbonate oligomer, a branching agent, a dihydric phenol and a terminal terminator are subjected to a condensation reaction in the presence of a polymerization catalyst and an aqueous alkali solution. A method of proceeding (polymerization reaction) is employed. In addition, the manufacturing method of PC resin of this invention is not limited to the said interfacial polymerization method.

(Branching agent)
In the present invention, as described above, it is preferable to use a tetrafunctional or higher functional branching agent from the viewpoint of improving the melt tension while maintaining good fluidity in a high shear force region.
Examples of the tetrafunctional or higher functional branching agent include phloroglucide, pyromellitic acid, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, α, α, α ′, α′-tetrakis (4-hydroxyphenyl). ) -P-xylene, α, α, α ′, α′-tetrakis (2-methyl-4-hydroxyphenyl) -p-xylene, α, α, α ′, α′-tetrakis (2,5-dimethyl-) 4-hydroxyphenyl) -p-xylene, α, α, α ', α'-tetrakis (2,6-dimethyl-4-hydroxyphenyl) -p-xylene, α, α'-dimethyl-α, α, α ', Α'-tetrakis (4-hydroxyphenyl) -p-xylene, α, α'-dimethyl-α, α, α', α'-tetrakis (3-methyl-4-hydroxyphenyl) -m-xylene, Bis [4,4-bis (4-hydroxyphenyl) Cyclohexane], bis [4,4-bis (4-hydroxy-3-methylphenyl) cyclohexane], bis [4,4-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane], bis [4,4 -Bis (4-hydroxyphenyl) cyclohexyl] methane, bis [4,4-bis (4-hydroxy-3-methylphenyl) cyclohexyl] methane, bis [4,4-bis (3,5-dimethyl-4-hydroxy) Phenyl) cyclohexyl] methane, 1,1-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] ethane, 1,1-bis [4,4-bis (4-hydroxy-3-methylphenyl) cyclohexyl] Ethane, 1,1-bis [4,4-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexyl] ethane, 2 2-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] propane, 2,2-bis [4,4-bis (4-hydroxy-3-methylphenyl) cyclohexyl] propane, 2,2-bis [ 4,4-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexyl] propane, 2,2-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] butane, 2,2-bis [4 4-bis (4-hydroxy-3-methylphenyl) cyclohexyl] butane, 2,2-bis [4,4-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexyl] butane, 1,1-bis [ 4,4-bis (4-hydroxyphenyl) cyclohexyl] cyclohexane, 1,1-bis [4,4-bis (4-hydroxy-3-methylphenyl) Cyclohexyl] cyclohexane, 1,1-bis [4,4-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexyl] cyclohexane, 1,1-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] -1-phenylethane, 1,1-bis [4,4-bis (4-hydroxy-3-methylphenyl) cyclohexyl] -1-phenylethane, 1,1-bis [4,4-bis (3,5 -Dimethyl-4-hydroxyphenyl) cyclohexyl] -1-phenylethane, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,2-bis (2 , 4-dihydroxyphenyl) propane, 2,2-bis (3,5-dihydroxyphenyl) propane, and the like.

Further, a compound represented by the following chemical formula (A) may be used as a tetrafunctional or more functional branching agent.

In the above formula (A), R ¹ and R ² represent an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. n is an integer of 1 to 100, preferably an integer of 1 to 50. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group. R ¹ and R ² are each independent and may be the same or different. Among the compounds represented by the above formula (A), tetra (4-hydroxyphenyl-polymethylsiloxane) silicon in which R ¹ and R ² are methyl groups is preferable.

The tetrafunctional or higher functional branching agent may be used alone or in combination of two or more.
Among the above tetrafunctional or higher functional branching agents, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] propane, 2, 2 ′, 4,4′-tetrahydroxybenzophenone, 2,2-bis (2,4-dihydroxyphenyl) propane, 2,2-bis (3,5-dihydroxyphenyl) propane and the above formula (A) It is preferable to use the compound.

In addition, a trifunctional or lower branching agent can be used in combination as long as the effects of the present invention are not impaired. Examples of the trifunctional or lower functional branching agent include 1,1,1-tris (4-hydroxyphenyl) ethane, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropyl Benzene, 1- [α-methyl-α- (4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene, phloroglucin, isatin bis (o-cresol) These may be used alone or in combination of two or more.

(Dihydric phenol)
Examples of the dihydric phenol include 1,1-bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, bis {( 4-hydroxy-3,5-dimethyl) phenyl} methane, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) Phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2-bis {(4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4- Hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane Bis (2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, etc. 4-hydroxyphenyl) alkane; 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3 Bis (4-hydroxyphenyl) cycloalkane such as 3,5-trimethylcyclohexane, hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 9, 9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy -3-methyl) phenyl} fluorene, α, α'-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α'- Bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) sulfide, Examples thereof include bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ketone, 4,4′-dihydroxydiphenyl ether, and 4,4′-dihydroxydiphenyl ester.

Among the above dihydric phenols, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) Butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4 It is preferable to use -methylpentane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, especially 2 , 2-bis (4-hydroxyphenyl) propane [commonly called bisphenol A] is preferably used. The dihydric phenol may be a homopolymer using one of the above dihydric phenols or a copolymer using two or more.

(Carbonate precursor)
Examples of the carbonate precursor include carbonyl halide, carbonyl ester, or haloformate, and specific examples include phosgene, dihaloformate of dihydric phenol, diphenyl carbonate, dimethyl carbonate, and diethyl carbonate. The said carbonate precursor may be used individually by 1 type, and may use 2 or more types together.

(Terminal stopper)
Examples of the terminator include phenol, o-cresol, m-cresol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, p-nonylphenol, bromophenol, tribromophenol. , Docosylphenol, tetracosylphenol, hexacosylphenol, octacosylphenol, triacontylphenol, dotriacontylphenol, tetratriacontylphenol, and the like. In addition, monoterpenes of polyterpenes represented by the following chemical formulas (B) and (C) (in formulas (B) and (C), p represents an integer of 0 to 4) may be used as a terminal terminator. . The said terminal terminator may be used individually by 1 type, and may use 2 or more types together.
Among the above terminators, it is preferable to use p-tert-butylphenol and p-cumylphenol.

(catalyst)
As the catalyst, a phase transfer catalyst is suitable. For example, a tertiary amine or a salt thereof, a quaternary ammonium salt, a quaternary phosphonium salt, or the like can be preferably used.
Examples of the tertiary amine include triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, dimethylaniline and the like, and examples of the tertiary amine salt include hydrochlorides and bromic acid of these tertiary amines. Examples include salts. Examples of the quaternary ammonium salt include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, and tetrabutylammonium bromide. Examples thereof include butylphosphonium chloride and tetrabutylphosphonium bromide. The said catalyst may be used individually by 1 type, and may use 2 or more types together.
Among the above catalysts, tertiary amines are preferable, and triethylamine is particularly preferable.

(Organic solvent)
An inert organic solvent is suitable as the organic solvent, and for example, chlorinated hydrocarbons, toluene, acetophenone, and the like can be preferably used.
Examples of the chlorinated hydrocarbon include dichloromethane (methylene chloride), trichloromethane, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, Examples include 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, chlorobenzene and the like. The said organic solvent may be used individually by 1 type, and may use 2 or more types together. Among the organic solvents, methylene chloride is particularly preferable.

(Alkaline aqueous solution)
What is necessary is just to use what an alkali source is a hydroxide of an alkali metal as aqueous alkali solution. Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide and the like. Of the alkali metal hydroxides, sodium hydroxide and potassium hydroxide are preferred.

[Polycarbonate resin composition]
Moreover, this invention provides the polycarbonate resin composition containing the polycarbonate resin and additive which were mentioned above.
As the additive, it is preferable to use a flame retardant in order to ensure excellent flame retardancy even if the molded product is thinner.

(Flame retardants)
Examples of the flame retardant include organic metal salt flame retardants such as organic alkali metal salts and organic alkaline earth metal salts, silicone flame retardants, phosphorus flame retardants, and phosphazene flame retardants. Among these, it is preferable to use organic metal salt flame retardants of organic alkali metal salts and organic alkaline earth metal salts, silicone flame retardants, and phosphorus flame retardants. A flame retardant may be used individually by 1 type and may use 2 or more types together.
The content of the flame retardant is preferably 0.005 to 12 parts by mass, more preferably 0.01 to 10 parts by mass, and further preferably 0.15 to 9 parts by mass with respect to 100 parts by mass of the polycarbonate resin. It is. If the content of the flame retardant is 0.005 parts by mass or more, sufficient flame retardancy can be obtained, and if it is 12 parts by mass or less, sufficient mechanical properties can be obtained.

<Organic metal salt flame retardant>
The organometallic salt flame retardant is preferably an organic alkali metal salt or an organic alkaline earth metal salt.
Examples of organic alkali metal salts and organic alkaline earth metal salts include various kinds of organic alkali metal salts and organic alkaline earth metal salts of organic acids or organic acid esters having at least one carbon atom. it can.
Here, the organic acid or the organic acid ester is, for example, an organic sulfonic acid, an organic carboxylic acid, or the like. The alkali metal is lithium, sodium, potassium, cesium or the like, and the alkaline earth metal is magnesium, calcium, strontium, barium or the like. Among these, sodium and potassium salts are preferably used. The salt of the organic acid may be substituted with a halogen such as fluorine, chlorine or bromine. An organic alkali metal salt and an organic alkaline earth metal salt may be used individually by 1 type, and may use 2 or more types together.

Among the various organic alkali metal salts and organic alkaline earth metal salts, for example, in the case of organic sulfonic acid, alkali metal salts and alkaline earth metals of perfluoroalkanesulfonic acid represented by the following general formula (I) A salt is preferably used.
(C _e F _{2e + 1} SO ₃ ) _f M (I)
In the formula, e represents an integer of 1 to 10, M represents an alkaline metal such as lithium, sodium, potassium or cesium, or an alkaline earth metal such as magnesium, calcium, strontium or barium, and f represents the valence of M. Show.
As these compounds, for example, those described in Japanese Patent Publication No. 47-40445 correspond to this.

In the general formula (I), examples of the perfluoroalkanesulfonic acid include perfluoromethanesulfonic acid, perfluoroethanesulfonic acid, perfluoropropanesulfonic acid, perfluorobutanesulfonic acid, perfluoromethylbutanesulfonic acid, Fluorohexanesulfonic acid, perfluoroheptanesulfonic acid, perfluorooctanesulfonic acid and the like can be mentioned. In particular, these potassium salts are preferably used.

Examples of alkali metal salts and alkaline earth metal salts of organic sulfonic acids other than the above general formula (I) include 2,5-dichlorobenzenesulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, diphenylsulfone-3- Examples thereof include alkali metal salts and alkaline earth metal salts of organic sulfonic acids such as sulfonic acid, diphenylsulfone-3,3′-disulfonic acid and naphthalenetrisulfonic acid.

Examples of the organic carboxylic acid include perfluoroformic acid, perfluoromethanecarboxylic acid, perfluoroethanecarboxylic acid, perfluoropropanecarboxylic acid, perfluorobutanecarboxylic acid, perfluoromethylbutanecarboxylic acid, perfluorohexanecarboxylic acid. Perfluoroheptanecarboxylic acid, perfluorooctanecarboxylic acid, and the like, and alkali metal salts and alkaline earth metal salts of these organic carboxylic acids can be used.

Next, examples of the organic alkali metal salt and the organic alkaline earth metal salt include polystyrene sulfonic acid alkali metal salts and alkaline earth metal salts. For example, sulfonate group-containing compounds represented by the following general formula (II): Aromatic vinyl resins can be used.

In the above formula (II), Z ¹ represents a sulfonate group, Z ² represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. g is an integer of 1 to 5. h represents a mole fraction, and 0 <h ≦ 1.
Here, the sulfonate group is an alkali metal salt and / or alkaline earth metal salt of sulfonic acid, and examples of the metal include sodium, potassium, lithium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium and the like. It is done.
In the formula, Z ² is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrogen atom or a methyl group. Further, g is an integer of 1 to 5, and h has a relationship of 0 <h ≦ 1. That is, the sulfonate group (Z ¹ ) may be a fully substituted or partially substituted aromatic ring.

In order to further enhance the flame retardancy effect of the polycarbonate resin composition of the present invention, the substitution ratio of the sulfonate group is determined in consideration of the content of the sulfonate group-containing aromatic vinyl resin, and is generally Is used with 10 to 100% substitution.
In addition, in the alkali metal salt and alkaline earth metal salt of polystyrene sulfonic acid, the sulfonate group-containing aromatic vinyl resin is not limited to the polystyrene resin of the above general formula (II), but a styrene monomer It may be a copolymer with other monomer copolymerizable with.

Here, as a method for producing a sulfonate group-containing aromatic vinyl resin, (1) the above aromatic vinyl monomer having a sulfonic acid group or the like, or another monomer copolymerizable therewith (2) Aromatic vinyl polymer, copolymer of aromatic vinyl monomer and other copolymerizable monomer, or mixed polymer thereof is sulfone. And neutralizing with an alkali metal compound and / or an alkaline earth metal compound.
For example, in the above method (2), a polystyrene sulfone oxide is produced by adding a mixed solution of concentrated sulfuric acid and acetic anhydride to a 1,2-dichloroethane solution of polystyrene resin, heating and reacting for several hours. Then, polystyrene sulfonate potassium salt or sodium salt can be obtained by neutralizing with sulfonic acid group and equimolar amount of potassium hydroxide or sodium hydroxide.
The weight average molecular weight of the sulfonate group-containing aromatic vinyl resin used in the present invention is about 1,000 to 300,000, preferably about 2,000 to 200,000. The weight average molecular weight can be measured by the GPC method.

<Silicone flame retardant>
Examples of the silicone flame retardant include silicone oil and silicone resin, and also include silicone compounds having a functional group.
The silicone compound having a functional group includes various compounds. Examples thereof include (poly) organosiloxanes having a functional group, and the skeleton thereof has a basic structure represented by the following general formula (III). It is a polymer and copolymer having
R ³ aR ⁴ bSiO _{(4-ab) / 2} (III)
In the above formula (III), R ³ represents a functional group-containing group, R ⁴ represents a hydrocarbon group having 1 to 12 carbon atoms, and 0 <a ≦ 3, 0 ≦ b <3, and 0 <a + b ≦ 3.
Examples of the functional group include an alkoxy group, aryloxy, polyoxyalkylene group, hydrogen atom, hydroxyl group, carboxyl group, cyanol group, amino group, mercapto group, and epoxy group.
As these functional groups, a silicone compound having a plurality of functional groups and a silicone compound having different functional groups can be used in combination. The silicone compound having this functional group has a functional group (R ³ ) / hydrocarbon group (R ⁴ ) of usually about 0.1 to 3, preferably about 0.3 to 2. These silicone compounds are liquids, powders and the like, but those having good dispersibility in melt kneading are preferred. For example, a liquid having a viscosity of about 10 to 500,000 cst (centistokes) at room temperature can be exemplified. When the silicone compound has a functional group, even if the silicone compound is in a liquid state, it is characterized by being uniformly dispersed in the composition and being less likely to bleed during molding or on the surface of the molded product.

<Phosphorus flame retardant>
As the phosphorus flame retardant, a phosphorus flame retardant containing no halogen is preferable. If halogen is contained, harmful gases may be generated during molding, mold corrosion may occur, and harmful substances may be discharged during incineration of molded products, which is not preferable from the viewpoint of environmental pollution and safety.
Examples of the phosphorus-based flame retardant containing no halogen include a halogen-free organic phosphorus-based flame retardant. As the organic phosphorus flame retardant, any organic compound having a phosphorus atom and not containing a halogen can be used without particular limitation. Of these, phosphate ester compounds having at least one ester oxygen atom directly bonded to a phosphorus atom are preferably used. Examples of halogen-free phosphorus flame retardants other than organic phosphorus compounds include red phosphorus.
There is no restriction | limiting in particular as a phosphate ester compound, For example, it is a phosphate ester compound represented with the following general formula (IV).

In the formula, R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or an organic group, X represents a divalent or higher valent organic group, s is 0 or 1, and t is It is an integer of 1 or more, and r represents an integer of 0 or more.
In the above formula (IV), the organic group is an alkyl group, a cycloalkyl group, an aryl group or the like, which may or may not be substituted. Examples of the substituent when substituted include an alkyl group, an alkoxy group, an aryl group, an aryloxy group, and an arylthio group. Further, an arylalkoxyalkyl group that is a combination of these substituents, or an arylsulfonylaryl group that is a combination of these substituents bonded by an oxygen atom, nitrogen atom, sulfur atom, or the like is used as a substituent. Etc.

In the formula (IV), the divalent or higher organic group X means a divalent or higher valent group formed by removing one or more hydrogen atoms bonded to a carbon atom from the above organic group. For example, it is derived from an alkylene group, a (substituted) phenylene group, or a bisphenol that is a polynuclear phenol. Preferable examples include bisphenol A, hydroquinone, resorcinol, diphenylmethane, dihydroxydiphenyl and dihydroxynaphthalene.

The phosphate ester compound may be a monomer, dimer, oligomer, polymer or a mixture thereof. Specifically, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, tri (2-ethylhexyl) phosphate, diisopropyl Phenyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, trinaphthyl phosphate, bisphenol A bisphosphate, hydroquinone bisphosphate, resorcin bisphosphate, resorcinol-diphenyl phosphate, trioxybenzene triphosphate, cresyl diphenyl phosphate, or these Substitutes, condensates, etc. It is below.

(Additives other than flame retardants)
In the polycarbonate resin composition of the present invention, as additives other than the above flame retardants, inorganic fillers, hindered phenols, phosphites and phosphates, antioxidants, benzotriazoles and benzophenones UV stabilizers such as hindered amines, aliphatic carboxylic acid ester and paraffinic external lubricants, coloring agents, flame retardant aids, antistatic agents and the like can be used.

Various materials can be used as the inorganic filler, and specifically, glass materials, carbon fibers, and other inorganic fillers can be used.
First, as the glass material, for example, glass fibers, glass beads, glass flakes, glass powder, and the like can be used. Here, as a glass fiber used, any of an alkali-containing glass, a low alkali glass, and an alkali free glass may be sufficient. The fiber length is about 0.1 to 8 mm, preferably 0.3 to 6 mm, and the fiber diameter is about 0.1 to 30 μm, preferably 0.5 to 25 μm. And the form of this glass fiber does not have a restriction | limiting in particular, For example, various things, such as roving, a milled fiber, a chopped strand, are mentioned. These glass fibers may be used individually by 1 type, and may use 2 or more types together.
The glass material was surface-treated with a silane coupling agent such as aminosilane, epoxysilane, vinylsilane, or methacrylsilane, a chromium complex compound, or a boron compound in order to increase the affinity with the resin. It may be a thing. As such a glass material, for example, commercially available MA-409C (average fiber diameter 13 μm) or TA-409C (average fiber diameter 23 μm) manufactured by Asahi Fiber Glass Co., Ltd. can be suitably used.

Next, the carbon fiber is generally produced by firing using cellulose fiber, acrylic fiber, lignin, petroleum, coal-based pitch or the like as a raw material, and has various flame resistance, carbonaceous, graphite, etc. There are several types. The fiber length of the carbon fiber is about 0.01 to 10 mm, preferably 0.02 to 8 mm, and the fiber diameter is about 1 to 15 μm, preferably 5 to 13 μm. The form of the carbon fiber is not particularly limited, and examples thereof include various types such as roving, milled fiber, chopped strand, and strand. These carbon fibers may be used individually by 1 type, and may use 2 or more types together.
Further, the surface of these carbon fibers may be subjected to a surface treatment with an epoxy resin, a urethane resin or the like in order to increase the affinity with the resin. As such a carbon fiber, for example, Besfight (average fiber diameter: 7 μm) manufactured by Toho Rayon Co., Ltd. can be suitably used as a commercially available product.

Other inorganic fillers include, for example, aluminum fibers, calcium carbonate, magnesium carbonate, dolomite, silica, diatomaceous earth, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, calcium sulfate, magnesium sulfate, calcium sulfite, talc, Clay, mica, asbestos, calcium silicate, montmorillonite, bentonite, carbon black, graphite, iron powder, lead powder, aluminum powder and the like can also be used.

The polycarbonate resin composition is a method in which the above-mentioned PC resin and various additives are usually used, for example, a ribbon blender, a Henschel mixer (trade name), a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw. It can be obtained by mixing and kneading by a method using an extruder, a kneader, a multi-screw extruder or the like. The heating temperature at the time of kneading is usually selected in the range of 250 to 300 ° C.

[Molding]
Moreover, this invention provides the molded article which shape | molded the above-mentioned polycarbonate resin or the above-mentioned polycarbonate resin composition. In particular, blow molding is suitable as a molding method from the characteristics of PC resin that melt tension is improved and drip resistance is excellent while maintaining molding fluidity, and a blow molded molded article is provided.

For the polycarbonate resin or the polycarbonate resin composition, various known molding methods such as injection molding, extrusion molding, compression molding, calendar molding, rotational molding and the like can be applied in addition to the above blow molding. By these molding methods, for example, molded articles for various industrial uses such as lighting covers, protective covers for displays, OA equipment, and electrical and electronic fields can be manufactured.

The polycarbonate resin of the present invention has improved melt tension and excellent drip resistance while maintaining molding fluidity. Therefore, the polycarbonate resin and the polycarbonate resin composition containing the polycarbonate resin are opaque in order to obtain drip resistance. No additive such as PTFE is required. Therefore, a molded article excellent in transparency and flame retardancy can be provided by using the polycarbonate resin of the present invention and the polycarbonate resin composition containing the polycarbonate resin.

The following examples further illustrate the present invention, but the present invention is not limited to these examples.

[Physical property measurement method]
(Primary structure)
Viscosity average molecular weight: Mv
Using an Ubbelohde viscometer, the viscosity of a methylene chloride solution at 20 ° C. obtained by determining the intrinsic viscosity [eta], the equation ^{[η] = 1.23 × 10 -5} Mv 0.83, viscosity average molecular weight (Mv) was calculated.
-Branching agent content rate Using the JNM-LA500 by JEOL Co., Ltd., 1H-NMR was measured about the obtained flakes, and the branching agent content rate (mol%) of the branching agent used was computed by the following formula.
Branching agent content (mol%) = [constituent unit derived from branching agent (mol) / [constituent unit derived from dihydric phenol (mol) + constituent unit derived from terminal terminator (mol) + constituent unit derived from branching agent ( mol)]] × 100
(Melting characteristics)
-Melt fluidity: MVR
Yasuda Seiki Co., Ltd., using instrument names MFR meter E Unit, at 280 ° C., load 2.16 kg, was measured melt flowability MVR (cm ^3/10 min).
Melt tension: MT
Made by Toyo Seiki Seisakusho Co., Ltd. Equipment name Capillograph 1C is used, 280 ° C., orifice diameter L / D = 8 / 2.095 mm, extrusion speed 10 mm / min, take-up speed 3.1 m / min, melt tension MT (g) Was measured.

Example 1
(1) Polycarbonate oligomer synthesis process (linear oligomer)
To a 5.6 mass% aqueous sodium hydroxide solution, 2,000 mass ppm of sodium dithionite is added to bisphenol A (hereinafter sometimes abbreviated as BPA) which is dissolved later, and the concentration of bisphenol A is added thereto. Bisphenol A was dissolved to 13.5% by mass to prepare an aqueous sodium hydroxide solution of bisphenol A.
An aqueous sodium hydroxide solution of 40 L / hr of bisphenol A, 15 L / hr of dichloromethane and 4.0 kg / hr of phosgene were continuously passed through a tubular reactor having an inner diameter of 6 mm and a tube length of 30 m. The tubular reactor had a jacket portion, and the temperature of the reaction solution was kept at 40 ° C. or lower by passing cooling water through the jacket.
The reaction solution exiting the tubular reactor was continuously introduced into a 40-liter baffled tank reactor equipped with a receding blade, and bisphenol A aqueous sodium hydroxide solution 2.8 L / hr, 25 mass. The reaction was carried out by adding 0.64 L / hr of 0.07 L / hr of% sodium hydroxide aqueous solution, 17 L / hr of water and 1% by mass triethylamine aqueous solution.
The reaction solution overflowing from the tank reactor was continuously extracted and allowed to stand to separate and remove the aqueous phase, and the dichloromethane phase was collected. The polycarbonate oligomer obtained had a concentration of 324 g / L and a chloroformate group concentration of 0.74 mol / L.

(2) Polycarbonate polymerization step Into a 1 L tank reactor equipped with baffle plates and paddle type stirring blades, 340 mL of oligomer solution, 180 mL of dichloromethane, and 70 μL of triethylamine were charged.
Here, a sodium hydroxide aqueous solution of branching

agent

2,2 ′, 4,4′-tetrahydroxybenzophenone (THBP) (THBP 1.30 g was dissolved in an aqueous solution in which 2.35 g of sodium hydroxide was dissolved in 34 mL of water) was added. The polymerization reaction was carried out for 10 minutes.
Subsequently, a solution obtained by dissolving 4.92 g of p-tert-butylphenol (PTBP) in 30 mL of dichloromethane and an aqueous sodium hydroxide solution of BPA (13.1 g of sodium hydroxide were dissolved in 190 mL of water, 50 mg of sodium dithionite, BPA 25 (2 g dissolved) was added and the polymerization reaction was carried out for 50 minutes.
After adding 200 mL of dichloromethane for dilution, the organic phase was separated into an organic phase containing polycarbonate resin and an aqueous phase containing excess BPA and sodium hydroxide, and the organic phase was isolated. The dichloromethane solution of the obtained polycarbonate resin was sequentially washed with 15% by volume of 0.03 mol / L / sodium hydroxide aqueous solution and 0.2 mol / L hydrochloric acid, and then the electric conduction in the aqueous phase after washing. The washing was repeated with pure water until the degree became 0.05 μS / m or less. The dichloromethane solution of the polycarbonate resin obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 100 ° C. under reduced pressure to obtain a polycarbonate resin.
Table 1 shows the viscosity average molecular weight, branching agent content, melt tension, and melt fluidity of the obtained polycarbonate resin. Further, FIG. 1 shows a relationship (MT) × (1 / MVR) between melt tension and melt fluidity.

Comparative Example 1
(1) Polycarbonate oligomer synthesis process (branched oligomer)
To a 5.6 mass% aqueous sodium hydroxide solution, 2,000 mass ppm of sodium dithionite is added to bisphenol A (hereinafter sometimes abbreviated as BPA) which is dissolved later, and the concentration of bisphenol A is added thereto. Bisphenol A was dissolved to 13.5% by mass to prepare an aqueous sodium hydroxide solution of bisphenol A. In addition, 5,000 mass ppm sodium dithionite was added to a 5.1 mass% aqueous sodium hydroxide solution with respect to the branching

agent

1,1,1-tris (4-hydroxyphenyl) ethane (THPE) that was dissolved later. This was dissolved in a THPE concentration of 11.3% by mass to prepare a THPE aqueous solution of sodium hydroxide.
40 L / hr of sodium hydroxide aqueous solution of bisphenol A, 1.4 L / hr of sodium hydroxide aqueous solution of THPE, 15 L / hr of dichloromethane and 4.0 kg / hr of phosgene were continuously added to a tubular reactor having an inner diameter of 6 mm and a tube length of 30 m. I passed. The tubular reactor had a jacket portion, and the temperature of the reaction solution was kept at 40 ° C. or lower by passing cooling water through the jacket.
The reaction solution exiting the tubular reactor was continuously introduced into a 40-liter baffled tank reactor equipped with a receding blade, and bisphenol A aqueous sodium hydroxide solution 2.8 L / hr, 25 mass. The reaction was carried out by adding 0.64 L / hr of 0.07 L / hr of% sodium hydroxide aqueous solution, 17 L / hr of water and 1% by mass triethylamine aqueous solution.
The reaction solution overflowing from the tank reactor was continuously extracted and allowed to stand to separate and remove the aqueous phase, and the dichloromethane phase was collected. The obtained polycarbonate oligomer had a concentration of 354 g / L and a chloroformate group concentration of 0.70 mol / L.

(2) Polycarbonate polymerization step A 1 L tank reactor equipped with baffle plates and paddle type stirring blades was charged with 310 mL of oligomer solution, 210 mL of dichloromethane, 3.66 g of p-tert-butylphenol (PTBP), and 60 μL of triethylamine.
A sodium hydroxide aqueous solution of BPA (11.3 g of sodium hydroxide dissolved in 165 mL of water and 50 mg of sodium dithionite and 21.8 g of BPA) was added thereto, and a polymerization reaction was carried out for 60 minutes.
After adding 200 mL of dichloromethane for dilution, the organic phase was separated into an organic phase containing polycarbonate resin and an aqueous phase containing excess BPA and sodium hydroxide, and the organic phase was isolated. The obtained polycarbonate resin solution in dichloromethane was washed successively with 15% by volume of 0.03 mol / L · NaOH aqueous solution and 0.2 mol / L hydrochloric acid, and the electric conductivity in the aqueous phase after washing was Washing with pure water was repeated until the concentration became 0.05 μS / m or less. The dichloromethane solution of the polycarbonate resin obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 100 ° C. under reduced pressure to obtain a polycarbonate resin.
Table 1 shows the viscosity average molecular weight, branching agent content, melt tension, and melt fluidity of the obtained polycarbonate resin. Further, FIG. 1 shows a relationship (MT) × (1 / MVR) between melt tension and melt fluidity. Since THPE was continuously charged in the flow reaction system, the amount of branching agent [g] in Table 1 is indicated by “−”.

Examples 2 to 15 and Comparative Examples 3 to 10
In Example 1, it carried out like Example 1 except having changed the branching agent seed | species, the amount of branching agents, and the amount of PTBP according to Table 1, respectively.
Table 1 shows the viscosity average molecular weight, branching agent content, melt tension, and melt fluidity of the obtained polycarbonate resin. Further, FIG. 1 shows a relationship (MT) × (1 / MVR) between melt tension and melt fluidity.

Comparative Example 2
The same operation as in Comparative Example 1 was performed except that the amount of PTBP was changed according to Table 1 in Comparative Example 1.
Table 1 shows the viscosity average molecular weight, branching agent content, melt tension, and melt fluidity of the obtained polycarbonate resin. Further, FIG. 1 shows a relationship (MT) × (1 / MVR) between melt tension and melt fluidity.

The polycarbonate resin of the present invention is excellent in transparency and flame retardancy because the polycarbonate resin and the polycarbonate resin composition containing the polycarbonate resin and the polycarbonate resin composition are excellent in drip resistance because the melt tension is improved while maintaining the molding fluidity. For example, it is suitable for various industrial uses such as lighting covers, protective covers for displays, OA equipment, and electric and electronic fields.

1 MT = (15.4 / MVR) −1.3 straight line 2 MT = (57.14 / MVR) −1.3 straight line 3 MT = (20.6 / MVR) −2.1 straight line

Claims

A melt tension MT [g] at 280 ° C., the relationship between the melt flow MVR [cm 3/10 min] at 280 ° C. has the following formula (1) to (3) Polycarbonate resin satisfying.
Formula (1): MT ≧ (15.4 / MVR) −1.3
Formula (2): MT ≦ (57.4 / MVR) −1.3
Formula (3): MT ≧ 1
The polycarbonate resin according to claim 1, comprising a polycarbonate resin having a branched structure.
The polycarbonate resin according to claim 1, comprising a polycarbonate resin having a branched structure and a linear polycarbonate resin.
Polycarbonate resin having a tetrafunctional or higher functional branching agent content of 0.5 to 2.0 mol% and a viscosity average molecular weight of 18,000 to 28,000.
A polycarbonate resin composition comprising the polycarbonate resin according to any one of claims 1 to 4 and an additive.
The polycarbonate resin composition according to claim 5, wherein the additive is a flame retardant.
A molded product obtained by molding the polycarbonate resin according to any one of claims 1 to 4 or the polycarbonate resin composition according to claim 5 or 6.
The molded product according to claim 7, which is blow-molded.