JP3129374B2 - Flame retardant polycarbonate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant polycarbonate resin composition. More specifically, the present invention relates to a flame-retardant polycarbonate resin composition capable of preventing dripping of a thin-walled material at the time of burning and improving flame retardancy without impairing the transparency of polycarbonate.

[0002]

2. Description of the Related Art Polycarbonate resins have high mechanical strength (particularly impact resistance),
It has excellent electrical properties and transparency, and is widely used as an engineering plastic in various fields such as OA equipment, electric / electronic equipment, automobile, and construction. Among these fields of use, there are fields that require a high degree of flame retardancy, mainly in the fields of OA equipment and electric / electronic equipment. The polycarbonate resin has a high oxygen index among various thermoplastic resins, and generally has self-extinguishing properties. However, in order to satisfy safety requirements in the field of OA equipment, electric / electronic equipment, and various other uses, there is a strong demand for a resin composition with further improved flame retardancy. There is also a demand for thinner materials,
It is becoming necessary to increase flame retardancy without impairing transparency.

Conventionally, in order to enhance the flame retardancy of an aromatic polycarbonate, for example, Japanese Patent Publication No. 47-40445 discloses a polycarbonate resin composition to which an alkali metal salt or an alkaline earth metal salt of perfluoroalkanesulfonic acid is added. Is disclosed. However, the technique disclosed herein has a drawback in that dripping occurs during combustion and the material immediately below is ignited. Japanese Patent Publication No. 60-38418 discloses a technique for preventing dripping during combustion by mixing an aromatic polycarbonate with an organic alkali metal salt or an alkaline earth metal salt and further adding polytetrafluoroethylene. However, there is a drawback that the transparency which is a characteristic of the aromatic polycarbonate is hindered, and its use is also limited.

[0004]

In view of the above circumstances, the present inventor has sought to prevent the aromatic polycarbonate from impairing its transparency without deteriorating its mechanical properties such as impact resistance and dimensional stability. Intensive research has been conducted to develop a flame-retardant polycarbonate resin composition having transparency, which can prevent dripping of a thin material during burning. As a result, by blending a specific branched polycarbonate with a specific branched polycarbonate or a specific aromatic polycarbonate, and adding an organic alkali (earth) metal salt thereto, it has a desired property of transparency. It has been found that a flame-retardant polycarbonate resin composition can be obtained.
The present invention has been completed based on such findings.

That is, the present invention relates to (A) a compound represented by the general formula (I)

[0006]

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[In the formula, R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^{1 to} R ⁶ are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, respectively. And 10 to 100% by weight of a branched polycarbonate having a branched core structure derived from the compound represented by the following general formula (II):

[0008]

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[In the formula, X is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. When a plurality of Xs are present, they may be the same or different.
And b are each an integer of 1 to 4. And Y
Is a single bond, an alkylene group having 1 to 8 carbon atoms or 2 carbon atoms.
To 8 alkylidene groups, cycloalkylene groups having 5 to 15 carbon atoms or cycloalkylidene groups having 5 to 15 carbon atoms, or —S—, —SO—, —SO ₂ —, —O—, —CO— bonds or a formula (III) or (III ')

[0010]

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[0011] The organic resin (C) is composed of 90 to 0% by weight of an aromatic polycarbonate which is a polymer having a structural unit represented by the following formula (C), based on 100 parts by weight of the total of the components (A) and (B). An alkali metal salt and / or an organic alkaline earth metal salt in an amount of from 0.03 to 1.0 part by weight is blended, and a flame-retardant polycarbonate resin composition having transparency (provided that tetrabromobisphenol A is Comes from
Excludes when blending polycarbonate. ) . First, the branched polycarbonate of the component (A) constituting the resin composition of the present invention is a compound represented by the following general formula (I):

[0012]

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Wherein R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^{1 to} R ⁶ are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, respectively. And a branched nucleus structure derived from the compound represented by the formula: Here, R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. R ^{1 to} R ⁶ are
A hydrogen atom or an alkyl group having 1 to 5 carbon atoms (e.g., methyl, ethyl, n-propyl, n-butyl, n-
A pentyl group), which may be the same or different. Among them, R is preferably a methyl group, and R ^{1 to} R ⁶ are each preferably a hydrogen atom. As the compound represented by the general formula (I), specifically, 1,1,1-tris (4
1,1,1-tris (4-hydroxyphenyl) -ethane; 1,1,1-tris (4-hydroxyphenyl) -propane;
1-tris (2-methyl-4-hydroxyphenyl)-
Methane; 1,1,1-tris (2-methyl-4-hydroxyphenyl) -ethane; 1,1,1-tris (3-methyl-4-hydroxyphenyl) -methane; 1,1,1
-Tris (3-methyl-4-hydroxyphenyl) -ethane; 1,1,1-tris (3,5-dimethyl-4-hydroxyphenyl) -methane; 1,1,1-tris (3,5-dimethyl -4-hydroxyphenyl) -ethane; 1,1,1-tris (3-chloro-4-hydroxyphenyl) -methane and the like. Among these, 1,1,1-tris (4-hydroxyphenyl)-
Alkanes are preferred, and in particular, R is a methyl group, R ^{1 to} R
⁶ is 1,1,1-tris (4
-Hydroxyphenyl) -ethane is preferred. In the present invention, the branched polycarbonate used as the component (A) has, as a branching agent, a branched nucleus structure derived from the compound represented by the above general formula (I). It is represented.

[0014]

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[Wherein, m, n and o are integers;
C indicates a polycarbonate portion. In the above-mentioned branched polycarbonate, for example, when bisphenol A is used as a raw material component, PC represents a repeating unit represented by the following formula.

[0016]

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The branched polycarbonate which is the component (A) preferably has a viscosity average molecular weight of 15,000 to 40,000. Viscosity average molecular weight of 15,000
If it is less than 40, the impact resistance may be reduced.
If it exceeds 000, the moldability may deteriorate. This branched polycarbonate preferably has an acetone-soluble content of 3.5% by weight or less. If the acetone-soluble content exceeds 3.5% by weight, the impact resistance may decrease. Here, the acetone-soluble component means a component that is subjected to Soxhlet extraction from a target branched polycarbonate using acetone as a solvent.

The above-mentioned branched polycarbonate can be produced by various methods. For example, JP-A-3-
No. 182,524, that is, an aromatic dihydric phenol, a branching agent represented by the general formula (I), a polycarbonate oligomer derived from phosgene, an aromatic dihydric phenol and a terminal stopper.
The reaction mixture containing these is reacted while stirring so as to form a turbulent flow, and when the viscosity of the reaction mixture increases, the reaction mixture is efficiently produced by adding an aqueous alkali solution and reacting the reaction mixture as a laminar flow. be able to.

Next, the aromatic polycarbonate (PC) as the component (B) constituting the resin composition of the present invention is a non-branched polycarbonate containing no halogen in the molecular structure, and preferably has the general formula (II) )

[0020]

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Wherein X is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (eg, a methyl group, an ethyl group,
Propyl, n-butyl, isobutyl, amyl,
Isoamyl group, hexyl group, etc.), and when X is plural, they may be the same or different, and a and b are each an integer of 1 to 4. Y is a single bond, an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms (for example, a methylene group,
Ethylene group, propylene group, butylene group, pentylene group, hexylene group, ethylidene group, isopropylidene group, etc., cycloalkylene group having 5 to 15 carbon atoms or cycloalkylidene group having 5 to 15 carbon atoms (for example, cyclopentylene group) , Cyclohexylene, cyclopentylidene, cyclohexylidene, etc.), or -S-, -SO
—, —SO ₂ —, —O—, —CO— bond or the formula (II
I) or (III ')

[0022]

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The bond represented by the following is shown. ] It is a polymer which has a structural unit represented by these. Among them, X is preferably a hydrogen atom, and Y is preferably an ethylene group or a propylene group. This aromatic polycarbonate has the general formula (IV)

[0024]

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Wherein X, Y, a and b are the same as above. Can be easily produced by reacting the dihydric phenol represented by the formula (1) with a phosgene or carbonic acid diester compound. That is, for example,
In a solvent such as methylene chloride, in the presence of a known acid acceptor or molecular weight regulator, by reaction of a dihydric phenol with a carbonate precursor such as phosgene, or a carbonate precursor such as dihydric phenol and diphenyl carbonate It is produced by transesterification reaction with

Here, there are various dihydric phenols represented by the general formula (IV). For example, bis (4-hydroxyphenyl) methane; bis (4-hydroxyphenyl) phenylmethane; bis (4-hydroxyphenyl) naphthylmethane; bis (4-hydroxyphenyl)-(4-isopropylphenyl) methane; bis (3 , 5-Dichloro-4-hydroxyphenyl) methane; bis (3,5-dimethyl-4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl)
Ethane; 1-naphthyl-1,1-bis (4-hydroxyphenyl) ethane; 1-phenyl-1,1-bis (4-
1,2-bis (4-hydroxyphenyl) ethane; 2,2-bis (4-hydroxyphenyl) propane [commonly known as bisphenol A];
-Methyl-1,1-bis (4-hydroxyphenyl) propane; 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane; 1-ethyl-1,1-bis (4-hydroxyphenyl) Propane; 2,2-bis (3-methyl-4-hydroxyphenyl) propane;
1,1-bis (4-hydroxyphenyl) butane; 2,
2-bis (4-hydroxyphenyl) butane; 1,4-
Bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) pentane; 4-methyl-
2,2-bis (4-hydroxyphenyl) pentane;
2,2-bis (4-hydroxyphenyl) hexane;
4,4-bis (4-hydroxyphenyl) heptane;
2,2-bis (4-hydroxyphenyl) nonane; 1,
10-bis (4-hydroxyphenyl) decane; 1,1
Dihydroxydiarylalkanes such as -bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane; 1,1-bis (4-hydroxyphenyl)
Cyclohexane; dihydroxydiarylcycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclodecane; bis (4-hydroxyphenyl) sulfone; dihydroxydiarylsulfone such as bis (3,5-dimethyl-4-hydroxyphenyl) sulfone , Bis (4-hydroxyphenyl) ether; dihydroxydiaryl ethers such as bis (3,5-dimethyl-4-hydroxyphenyl) ether, 4,4 ′
-Dihydroxybenzophenone; 3,3 ', 5,5'-
Dihydroxydiaryl ketones such as tetramethyl-4,4'-dihydroxybenzophenone, bis (4-hydroxyphenyl) sulfide; bis (3-methyl-4
Dihydroxydiaryl sulfides such as bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, dihydroxy diaryl sulfoxides such as bis (4-hydroxyphenyl) sulfoxide, and 4,4′-dihydroxy diphenyl Dihydroxydiphenyls such as 9,9-bis (4-
And dihydroxyarylfluorenes such as (hydroxyphenyl) fluorene. Among these, 2,2-bis (4-hydroxyphenyl) propane [commonly known as bisphenol A] is preferable.

Other than the dihydric phenols represented by the general formula (IV), dihydroxybenzenes such as hydroquinone, resorcinol and methylhydroquinone;
Dihydroxynaphthalenes such as 5-dihydroxynaphthalene; 2,6-dihydroxynaphthalene; These dihydric phenols may be used alone or in combination of two or more. Examples of the carbonic acid diester compound include diaryl carbonates such as diphenyl carbonate, dimethyl carbonate, and the like.
And dialkyl carbonates such as diethyl carbonate.

As the molecular weight regulator, those usually used for the polymerization of polycarbonate may be used, and various types may be used. Specifically, examples of the monohydric phenol include phenol, p-cresol, and p-cresol.
tret-butylphenol, p-tret-octylphenol, p-cumylphenol, nonylphenol and the like. Further, the aromatic polycarbonate used in the present invention may be a mixture of two or more aromatic polycarbonates. The aromatic polycarbonate has a viscosity average molecular weight of 1 from the viewpoint of mechanical strength and moldability.
Preferred are those having a molecular weight of from 10,000 to 100,000,
000 to 40,000 are preferred. In some cases, the aromatic polycarbonate of the component (B) may be represented by the general formula (V):

[0029]

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Wherein X, Y, a and b are the same as above. And a polycarbonate unit having a repeating unit having the structure represented by the general formula (VI):

[0031]

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[Wherein R ⁷ , R ⁸ and R ⁹ are each a hydrogen atom and an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, n-butyl, isobutyl, amyl) Group, isoamyl group, hexyl group, etc.) or phenyl group, which may be the same or different. Further, s and t are each an integer of 0 or 1 or more. And a polyorganosiloxane part having a repeating unit having a structure represented by the following formula:
The degree of polymerization of the polyorganosiloxane moiety is preferably 5 or more.

As the organic alkali metal salt or alkaline earth metal salt of the component (C) constituting the resin composition of the present invention, there are various ones, but an organic acid or an organic acid having at least one carbon atom. An alkali metal salt or an alkaline earth metal salt of an acid ester. Here, the organic acid or the ester of the organic acid is an organic sulfonic acid, an organic carboxylic acid, an organic phosphoric acid ester, or the like. On the other hand, alkali metals are sodium, potassium, lithium, cesium and the like, and alkaline earth metals are magnesium, calcium, strontium, barium and the like. Accordingly, the alkali (earth) metal salt of an organic acid is an alkali metal salt of an organic sulfonic acid, an organic phosphoric acid ester, or an organic carboxylic acid, or a salt of an alkaline earth metal. Particularly, salts of sodium, potassium and cesium are preferably used. Further, the salt of the organic acid may be substituted with halogen such as fluorine, chlorine and bromine. Among the various organic alkali metal salt or alkaline earth metal salts, for example, in the case of organic sulfonic acid of the general formula _{(VII) (C q F 2q} + 1 SO 3) p M ··· (VII) [wherein Wherein q represents an integer of 1 to 10, M represents an alkali metal such as lithium, sodium, potassium and cesium, or an alkaline earth metal such as magnesium, calcium, strontium and barium, and p represents the valence of M. Show. The alkali metal salt or alkaline earth metal salt of perfluoroalkanesulfonic acid represented by the formula (1) is preferably used. Examples of these compounds include, for example,
The one described in Japanese Patent No. 40445 corresponds to this. In the general formula (VII), examples of the perfluoroalkanesulfonic acid include perfluoromethanesulfonic acid, perfluoroethanesulfonic acid, perfluoropropanesulfonic acid, perfluorobutanesulfonic acid,
Perfluoromethylbutanesulfonic acid, perfluorohexanesulfonic acid, perfluoroheptanesulfonic acid,
Perfluorooctanesulfonic acid and the like can be mentioned, and particularly, potassium salts thereof are preferably used. Others: 2,5-dichlorobenzenesulfonic acid; 2,4,5
-Trichlorobenzenesulfonic acid; diphenylsulfone-3sulfonic acid; diphenylsulfone-3,3'sulfonic acid; and alkali metal salts or alkaline earth metal salts such as naphthalenetrisulfonic acid.

As the organic carboxylic acid, for example,
Perfluoroformic acid, perfluoromethanecarboxylic acid, perfluoroethanecarboxylic acid, perfluoropropanecarboxylic acid, perfluorobutanecarboxylic acid, perfluoromethylbutanecarboxylic acid, perfluorohexanecarboxylic acid, perfluoroheptanecarboxylic acid, perfluorooctane Examples thereof include carboxylic acids and the like, and alkali metal salts or alkaline earth metal salts of these organic carboxylic acids are used. The alkali metal or alkaline earth metal is the same as described above. Further, as the organic phosphate, a compound represented by the general formula (VIII)

[0035]

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[In the formula, R ¹⁰ and R ¹¹ each independently represent a halogen-substituted or unsubstituted alkyl group or aryl group, and R ¹⁰ and R ^{11 are} directly bonded to each other by R ¹¹ or an alkylene group. And a single condensed ring may be formed. And a compound in which a hydrogen atom in the above formula is replaced with an alkali metal or an alkaline earth metal is used. Examples of such an alkali (earth) metal salt of an organic phosphoric acid ester include a phosphoric acid ester alkali (earth) metal salt of di (pt-butylphenol) and a phosphoric acid of di (p-cumylphenol). An acid (alkali) earth metal salt, a brominated phenyl phosphate (alkaline) metal salt and the like are used. The above organic alkali metal salts or alkaline earth metal salts may be used alone or in combination of two or more.

The resin composition of the present invention comprises the above-mentioned components (A), (B) and (C).
The branched polycarbonate of the component is blended in an amount of 10 to 100% by weight, preferably 30 to 100% by weight, and the aromatic polycarbonate of the component (B) in a proportion of 90 to 0% by weight, preferably 70 to 0% by weight. ) And the component (B), based on 100 parts by weight in total, of the alkali metal salt and / or the alkaline earth metal salt of the organic acid of the component (C), from 0.03 to 1.
0 parts by weight, preferably 0.04 to 0.50 parts by weight, more preferably 0.05 to 0.20 parts by weight. Here, if the amount of the component (A) is less than 10% by weight, the effect of preventing dripping during combustion is undesirably small. And, in the above preferable range, the effect of preventing dripping during combustion can be sufficiently obtained. On the other hand, if the component (C) is less than 0.03 parts by weight, it is difficult to achieve the target flammability (UL94, V-0).
On the other hand, if the content exceeds 1.0 part by weight, no further flammability can be expected for the compounded composition, and conversely, transparency may be impaired, which is not preferable. Then, in the above preferable range, dripping during combustion can be prevented without impairing the transparency, and the combustibility can be sufficiently improved.

The resin composition of the present invention includes the above (A),
In addition to the components (B) and (C), if necessary, as the component (D), as long as the object of the present invention is not impaired, for example,
Various additives or other synthetic resins, elastomers and the like can be compounded. Examples of the above various additives include hindered phenols, phosphites,
Antioxidants such as phosphate esters and amines, ultraviolet absorbers such as benzotriazoles and benzophenones, light stabilizers such as hindered amines, aliphatic carboxylate esters and paraffinic external lubricants, silicone oils and polyethylene Examples include an internal lubricant such as wax, a release agent, an antistatic agent, and a coloring agent. Examples of the above hindered phenolic antioxidants include BHT (2,6-di-tert-butyl-p-cresol), “Irganox 1076” (trade name) and “Irganox 1010” (trade name) manufactured by Ciba-Geigy. ), "Ethyl 330" manufactured by Ethyl
(Trade name) "Sumilyzer GM" manufactured by Sumitomo Chemical Co., Ltd.
(Trade name) and the like are preferably used. Examples of other synthetic resins include, for example, polyester (polyethylene terephthalate, polybutyrene terephthalate, etc.), polyamide, polyethylene, polypropylene, polystyrene, acrylonitrile-styrene copolymer (A
S resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polymethyl methacrylate, and the like. And as the elastomer, for example,
Isobutylene-isoprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, acrylic elastomer, polyester elastomer, polyamide elastomer, MBS which is a core shell type elastomer
(Methyl methacrylate-styrene-butadiene) rubber,
MAS (methyl methacrylate-acrylonitrile-styrene) rubber and the like.

The resin composition of the present invention can be obtained by mixing and kneading the above components (A), (B) and (C) with (D) if necessary. The compounding and kneading may be performed by a commonly used method, for example, a method using a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a co-kneader, a multi-screw extruder, or the like. Can be performed. In addition, the heating temperature at the time of kneading is usually selected in the range of 240 to 300 ° C. The polycarbonate resin composition thus obtained is
Various known molding methods, such as injection molding, blow molding,
By applying extrusion molding, compression molding, calendar molding, rotational molding and the like, it can be used to manufacture various molded products including molded products and building materials in the field of home appliances.

[0040]

EXAMPLES The present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples. In addition, each raw material used in the example and the comparative example is as follows. (A) Branched polycarbonate (branched PC) 1) Branched PC-A: produced in Production Example 1. It was used as a branch PC in Examples 1 to 5. 2) Branched PC-B: produced in Production Example 2. This was used as the branch PC in Example 7. 3) IB 2500 [Non-halogen branched PC manufactured by Idemitsu Petrochemical Co., Ltd.] This was used as the branched PC in Example 6. (B) Aromatic polycarbonate resin (PC) Toughlon A1900 [Idemitsu Petrochemical Co., Ltd., polycarbonate resin from bisphenol A (non-halogen PC), Mv = 19,500] (C) Flame retardant 1) Perfluorobutane sulfone Acid alkali salt Megafax F114 [Dainippon Ink Chemical Co., Ltd., potassium perfluorobutanesulfonate (C ₄ F ₉ SO ₃ K)] 2) Naphthalene trisulfonate Na [Konishi Chemical Co., Ltd.] 3) Sodium dichlorobenzenesulfonate [Konishi Chemical Co., Ltd.
(D) Others 1) Antioxidant [Irgafos 168, manufactured by Nippon Ciba Geigy Co., Ltd.] 2) Lubricant [Likemar S-11A, manufactured by Riken Vitamin Co., Ltd.] 3) UV absorber [Chemisorb 79, Chemipro Chemical ( stock)
Made)

Production Example 1 Production of Branched Polycarbonate A (Branched PC-A)
g of bisphenol A and 1.17 kg of 1,1,1-tris (4-hydroxyphenyl) ethane were dissolved to prepare an aqueous sodium hydroxide solution. Then, the above-mentioned aqueous sodium hydroxide solution kept at room temperature was introduced at a liquid volume of 138 liters / hour and methylene chloride at a liquid volume of 69 liters / hour into a tubular reactor having an inner diameter of 10 mm and a length of 10 m through an orifice plate. Then, phosgene is fed into this
Blowing was performed at a liquid volume of 0.7 kg / hour, and the reaction was continuously performed for 3 hours. The tubular reactor used here was a double tube, and the outlet temperature of the reaction solution was kept at 25 ° C. by passing cooling water through the jacket. Further, the pH of the discharged liquid was adjusted so as to indicate 10 to 11. The reaction solution thus obtained was allowed to stand, and the aqueous phase was separated and removed to obtain a methylene chloride phase (220 liters). Further, 170 liters of methylene chloride was added thereto, and the mixture was sufficiently stirred. Polycarbonate oligomer A (concentration: 317 g / liter) was used. The degree of polymerization of the obtained polycarbonate oligomer was 3 to 4. To 5.61 l of the obtained polycarbonate oligomer, 3.39 l of methylene chloride was added to prepare a solution a. Separately, 173.4 g of sodium hydroxide and 482.9 g of bisphenol A were dissolved in 2.9 liters of water to obtain a solution b. Solutions a and b obtained
And 0.856 g of triethylamine as a catalyst and p-tert-butylphenol 4 as a terminator.
5.5 g was added, and the mixture was stirred in a turbulent state at 600 rpm for 10 minutes. Thereafter, 167 ml of an aqueous sodium hydroxide solution (concentration: 48% by weight) was added, and 200 rpm at room temperature.
For 60 minutes to carry out a reaction. After the reaction,
5 liters of water and 5 liters of methylene chloride are added, and the mixture is separated into a methylene chloride phase and an aqueous phase.
Was washed with an aqueous solution of sodium hydroxide and then washed with 0.1N hydrochloric acid. afterwards,
After washing with water to remove methylene chloride, a branched polycarbonate which is a flake polymer was obtained.

Production Example 2 [Preparation of Branched Polycarbonate Polymer B (Branched PC-B)] 2.280 kg of bisphenol A (BPA) and isatin-bisphenol (0.2 mol% of branching agent with bisphenol A being 100 mol%) 6.34 g) were dissolved in 21 kg of a 6.2% strength sodium hydroxide solution under nitrogen. To 25 kg of methylene chloride was added p-tert-butylphenol 38
g of phosgene was passed through the entire reaction mixture at 25 ° C. for 1 hour with vigorous stirring while maintaining a pH of 13-14. Then, triethylamine 6g
And 400 ml of 45% strength sodium hydroxide were added and the condensation was continued for another hour. The organic phase formed is separated off, washed twice with 2% strength phosphoric acid and then washed with water for 3 times.
Wash once or until the aqueous phase is free of electrolytes. Thereafter, the solvent was removed to obtain a branched polycarbonate which is a flake polymer.

Examples 1 to 7 and Comparative Examples 1 to 3 According to the compounding amounts shown in Table 1, the branched polycarbonate, the aromatic polycarbonate and each of the flame retardants were dried, then dry-blended and supplied to an extruder. And kneaded at a temperature of 280 ° C. to produce pellets. In Example 6, as other components, an antioxidant [0.05 parts by weight to 100 parts by weight of (branched PC + PC)] and a lubricant [0.30
Parts by weight (100 parts by weight of (branched PC + PC)) and an ultraviolet absorber (0.30 parts by weight to 100 parts by weight of (branched PC + PC)). The obtained pellet was dried at 120 ° C. for 12 hours, and then injection molded at a mold temperature of 80 ° C. and a molding temperature of 280 ° C. to produce a test piece. With respect to the test pieces obtained in Examples and Comparative Examples, the oxygen index, the flame retardancy, the number of drops during burning, and the haze were measured as quality evaluations. Table 2 shows the results.

[0044]

[Table 1]

[0045]

[Table 2]

The measurement of the oxygen index, the flame retardancy, the number of drops during combustion, and the haze was performed in the following manner. 1) Oxygen index Measured according to JIS-K-7201. 2) Flame retardancy A vertical combustion test was performed according to UL94 standard 1/16 inch (thickness) Underwriters Laboratory Subject 94. 3) Number of drippings during burning Five UL94 vertical burning tests were evaluated, and the number of fired drops and cotton ignition was determined. 4) Haze Measured according to JIS-K-7105.

As can be seen from Table 2, in Examples 1 to 7, the transparency is inhibited by blending a branched PC containing no halogen in the molecular structure or a PC containing no halogen in the molecular structure. Without dripping at the time of combustion, the flame retardancy by UL94 1/16 inch,
It has passed V-0. On the other hand, when the branched PC and the organic alkali metal salt of Comparative Example 1 were not blended, V
-2out is inferior in flame retardancy. If the amount of the branched PC in Comparative Example 2 is less than 10% by weight, the prevention of dripping is not sufficient. When the amount of the organic alkali metal salt of Comparative Example 3 exceeds 1 part by weight, the transparency is greatly impaired,
The difference from the present invention is remarkable.

[0048]

As described above, according to the polycarbonate resin composition of the present invention, an organic alkali metal salt and / or an alkaline earth metal salt are added to a specific branched polycarbonate, or the branched polycarbonate and a specific aromatic polycarbonate. By blending, it is possible to prevent dripping at the time of burning without impairing transparency, and to improve flame retardancy. Therefore, the polycarbonate resin composition of the present invention can be used for molding various molded articles, for example, flame-retardant products such as OA equipment, electric / electronic fields, and building materials.

Claims (5)

(57) [Claims] (A) General formula (I) [Wherein, R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^{1 to} R ⁶ are each a hydrogen atom or 1 to 5 carbon atoms.
5 represents an alkyl group. A branched polycarbonate having a branched core structure derived from the compound represented by the formula
100% by weight and (B) the general formula (II) [In the formula, X is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. When a plurality of Xs are present, they may be the same or different, and a and b are Each is an integer of 1 to 4. And Y is a single bond, an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms or a cycloalkylidene group having 5 to 15 carbon atoms, or -S- , -S
O—, —SO ₂ —, —O—, —CO— bond or formula (III) or (III ′) The bond represented by is shown. (C) an organic alkali metal comprising 90 to 0% by weight of an aromatic polycarbonate which is a polymer having a structural unit represented by the following formula (A) and component (B): salts and / or flame-retardant polycarbonate resin composition having transparency, characterized in that by blending the 0.03 to 1.0 parts by weight of the organic alkaline earth metal salt (however, tetrabromobisphenol a
Except when blending polycarbonate derived from
Good. ) . 2. The component (A) wherein the branched core structure of the branched polycarbonate is derived from 1,1,1-tris (4-hydroxyphenyl) -alkanes. The flame-retardant polycarbonate resin composition according to the above. 3. The method according to claim 2, wherein the 1,1,1-tris (4-hydroxyphenyl) -alkane is 1,1,1-tris (4-hydroxyphenyl) -ethane. Flame retardant polycarbonate resin composition. 4. (C) an organic alkali metal salt and / or an organic alkaline earth metal salt is represented by the following general formula _{(C q F 2q + 1 SO} 3) p M [wherein, q is an integer from 1 to 10 And M represents an alkali metal or an alkaline earth metal, and p represents the valence of M. The flame-retardant polycarbonate resin composition according to claim 1, which is an alkali metal salt or an alkaline earth metal salt of perfluoroalkanesulfonic acid represented by the formula: 5. An organic alkali metal salt of component (C) and / or
5. The flame-retardant polycarbonate resin composition according to claim 1, wherein the composition comprises 0.04 to 0.50 parts by weight of an organic alkaline earth metal salt. 6.