JPH0881620A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE: To obtain a polycarbonate resin composition useful as an OA(office automation) device, etc., having excellent flame retardance and thermal stability and fluidity, comprising a polycarbonate polyorgansiloxane copolymer, a polycarbonate resin and a specific polytetrafluoroethylene. CONSTITUTION: This composition comprises (A) a polycarbonate polyorganosiloxane copolymer, (B) a polycarbonate resin and (C) a polytetrafluoroethylene having fibril forming ability and >=500,000 average molecular weight in the ratio of 5-100wt.% of the component A based on the components (A+t), 95-0wt.% of the component B based on the components (A+B) and 0.05-1.0 pt.wt. of the component C based on the 100 pts.wt. of the components (A+B).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polycarbonate resin composition. More specifically, it relates to a polycarbonate resin composition having excellent thermal stability, fluidity and flame retardancy.

[0002]

2. Description of the Related Art Polycarbonate resins have 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 and electronic equipment fields, and automobile fields. Among these fields of application, there are fields in which flame retardancy is required, mainly in the fields of office automation equipment and electric / electronic equipment. Polycarbonate resin has a high oxygen index among various thermoplastic resins and is generally said to have self-extinguishing property. However, the level of flame retardancy required in the field of OA equipment and electric / electronic equipment is generally UL9.
In order to impart flame retardancy as high as V-0 level in the 4 standards, it is usually performed by adding a flame retardant and a flame retardant auxiliary.

On the other hand, it is generally known that a polycarbonate-polyorganosiloxane copolymer or a mixture of a polycarbonate-polyorganosiloxane copolymer and a polycarbonate resin exhibits higher flame retardancy than the polycarbonate resin. However, the flame-retardant performance of the polycarbonate-polyorganosiloxane copolymer alone is also insufficient, and therefore compositions containing various flame-retardants have been disclosed. (For example, JP-A-63-289059, JP-A-1-210462, and JP-A-3-200.
862, JP-A-4-202465, etc.).
However, the technique disclosed herein has a drawback that when the polycarbonate-based resin is highly fluidized, melt dripping occurs during combustion. In addition, a system to which a flame retardant and a bromine compound are added generally has a defect of poor thermal stability.

[0004]

Therefore, the present inventors have
In view of the above situation, the inventors have conducted intensive studies to develop a polycarbonate resin composition which has excellent thermal stability and can be highly fluidized. As a result, a polycarbonate-polyorganosiloxane copolymer or a mixture of a polycarbonate-polyorganosiloxane copolymer and a polycarbonate resin is
The composition has a polyorganosiloxane moiety content of 0.1 to 2.
It was found that the maximum oxygen index was developed at 0% by weight,
Furthermore, it has been found that when polytetrafluoroethylene is used in combination, melt dripping at the time of combustion can be prevented, and a polycarbonate resin composition having desired properties can be obtained. The present invention has been completed based on such findings. That is, the present invention provides (A) a polycarbonate-polyorganosiloxane copolymer, (B) a polycarbonate resin, and (C) an average molecular weight of 500,000 having fibril-forming ability.
Consisting of 0 or more polytetrafluoroethylene, (A)
The component is 5 to 100% by weight of the total amount of the components (A) and (B), the component (B) is 95 to 0% by weight of the total amount of the components (A) and (B) in the component (A). The ratio of the polyorganosiloxane part of is 0.1 to 0.1 of the total amount of the components (A) and (B).
A polycarbonate resin composition, wherein the content of the component (C) is 0.05 to 1.0 parts by weight based on 100 parts by weight of the total of the components (A) and (B). .

First, as the component (A) constituting the resin composition of the present invention, there are various polycarbonate-polyorganosiloxane copolymers (hereinafter abbreviated as PC-PDMS copolymers), but it is preferable. Is the general formula (1)

[0006]

Embedded image

[Wherein R ¹ and R ² are each a halogen atom (eg, chlorine, fluorine, iodine) or an alkyl group having 1 to 8 carbon atoms (eg, methyl group, ethyl group, propyl group, isopropyl group, Various butyl groups (n-butyl group, isobutyl group, sec-butyl group, tert-butyl group), various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups). m and n are 0 respectively
An integer of from 4 to 4, when m is 2 to 4, R ¹ may be the same or different, and when n is 2 to 4, R ² may be the same or different. May be.
Z is an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms (for example, methylene group, ethylene group, propylene group, butylene group, penterylene group, hexylene group, ethylidene group, isopropylidene group, etc.) , A cycloalkylene group having 5 to 15 carbon atoms or a cycloalkylidene group having 5 to 15 carbon atoms (for example, a cyclopentylene group, a cyclohexylene group, a cyclopentylidene group, a cyclohexylidene group, etc.), or -SO
_2- , -SO-, -S-, -O-, -CO- bond or formula (2) or formula (2 ')

[0008]

Embedded image

The bond represented by ] The polycarbonate part which has the repeating unit of the structure represented by these, and general formula (3)

[0010]

[Chemical 3]

[Wherein R ³ , R ⁴ and R ⁵ are each a hydrogen atom or an alkyl group having 1 to 5 carbon atoms (eg, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, etc.). Or a phenyl group, and p and q are each an integer of 0 or 1 or more. ] It consists of the polyorganosiloxane part which has a repeating unit of the structure represented by this. Here, the degree of polymerization of the polycarbonate part is 3 to
100 is preferable, and the degree of polymerization of the polyorganosiloxane part is preferably 2 to 500.

The above PC-PDMS copolymer comprises a polycarbonate part having a repeating unit represented by the general formula (1) and a polyorganosiloxane part having a repeating unit represented by the general formula (3). A block copolymer having a viscosity average molecular weight of 10,000 to 40,000.
0, preferably 12,000 to 35,000.
Such a PC-PDMS copolymer is, for example, a polycarbonate oligomer (hereinafter abbreviated as PC oligomer) that constitutes a preliminarily manufactured polycarbonate part.
A polyorganosiloxane having a reactive group at the end which constitutes the polyorganosiloxane part (for example, polydimethylsiloxane (PDMS), polydialkylsiloxane such as polydiethylsiloxane, or polymethylphenylsiloxane) is mixed with methylene chloride, chlorobenzene,
It can be produced by dissolving in a solvent such as chloroform, adding an aqueous sodium hydroxide solution of bisphenol, and using an interfacial polycondensation reaction using triethylamine, trimethylbenzylammonium chloride or the like as a catalyst. A PC-PDMS copolymer produced by the method described in JP-B-44-30105 or the method described in JP-B-45-20510 can also be used.

Here, the PC oligomer having the repeating unit represented by the general formula (1) can be prepared by the general formula (in the solvent method, that is, in the presence of a known acid acceptor and molecular weight modifier in a solvent such as methylene chloride. 4)

[0014]

[Chemical 4]

Reacting a dihydric phenol represented by the formula (wherein R ¹ , R ² , Z, m and n are the same as above) with a carbonate precursor such as phosgene or a carbonate compound. Can be easily manufactured by. That is, for example, by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of a known acid acceptor or a molecular weight regulator, or by reacting dihydric phenol with diphenyl carbonate. It is produced by a transesterification reaction with another carbonate precursor.

There are various dihydric phenols represented by the general formula (4), and 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferable. As dihydric phenols other than bisphenol A, bis (4-hydroxyphenyl) alkanes other than bisphenol A; 1,1- (4-hydroxyphenyl) methane; 1,1- (4-hydroxyphenyl)
Ethane; 4,4'-dihydroxydiphenyl; bis (4
-Hydroxyphenyl) cycloalkane; bis (4-hydroxyphenyl) oxide; bis (4-hydroxyphenyl) sulfide; bis (4-hydroxyphenyl)
Sulfone; bis (4-hydroxyphenyl) sulfoxide; bis (4-hydroxyphenyl) ether; bis (4-hydroxyphenyl) ketone and the like.
In addition to these, examples of the dihydric phenol include hydroquinone. These dihydric phenols may be used alone or in combination of two or more.

Examples of the carbonic acid ester compound include diaryl carbonate such as diphenyl carbonate and dialkyl carbonate such as dimethyl carbonate and diethyl carbonate. As the molecular weight regulator, those usually used for polymerization of polycarbonate may be used, and various types may be used. Specifically, as the monohydric phenol, for example, phenol, p-
Cresol, p-tert-butylphenol, p-tert-
Examples include octylphenol, p-cumylphenol, nonylphenol and the like. In the present invention, PC-P
The PC oligomer used for the production of the DMS copolymer may be a homopolymer using one kind of the above dihydric phenol or a copolymer using two or more kinds. Further, it may be a thermoplastic random branched polycarbonate obtained by using a polyfunctional aromatic compound in combination with the dihydric phenol.

Next, the polycarbonate resin as the component (B) constituting the polycarbonate resin composition is not particularly limited, but can be easily produced by reacting a dihydric phenol with phosgene or a carbonate compound. That is, for example, by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of a known acid acceptor or a molecular weight regulator, or by reacting dihydric phenol with diphenyl carbonate. It is produced by a transesterification reaction with another carbonate precursor. Here, the dihydric phenol may be the same as or different from the compound represented by the general formula (4). Further, it may be a homopolymer using one kind of the dihydric phenol or a copolymer using two or more kinds. Further, it may be a thermoplastic random branched polycarbonate obtained by using a polyfunctional aromatic compound in combination with the dihydric phenol.

Examples of carbonic acid ester compounds include diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate. As the molecular weight regulator, those generally used for the polymerization of polycarbonate may be used, and various types thereof may be used. Specifically, as the monohydric phenol, for example, phenol, p-
Cresol, p-tert-butylphenol p-tert-
Octylphenol, p-cumylphenol, nonylphenol and the like can be mentioned.

The mixing ratio of the components (A) and (B) is
The component (A) is 5 to 100% by weight, preferably 10 to 100% by weight, based on the total amount of the components (A) and (B).
The component (B) is 95 to 0% by weight, preferably 90 to 0% by weight. When the amount of the component (A) is less than 5% by weight and the amount of the component (B) exceeds 95% by weight, the dispersibility of the polyorganosiloxane is deteriorated and sufficient flame retardancy cannot be obtained. On the other hand, when the component (A) and the component (B) are in a preferable range, a material having good flame retardancy can be obtained. The ratio of the polyorganosiloxane part in the component (A) is 0.1 to 2.0% by weight, preferably 0.5 to 1.% by weight based on the total amount of the components (A) and (B).
It is 5% by weight. Here, if it is less than 0.1% by weight or exceeds 2.0% by weight, a sufficient oxygen index cannot be obtained and the desired flame retardancy is not exhibited. Within the preferred range, a more suitable oxygen index can be obtained, and excellent flame retardancy can be obtained.

The component (C) of the present invention, polytetrafluoroethylene (hereinafter abbreviated as "PTFE"), has an effect of preventing melt dripping, and if it has the ability to form fibrils, it has high flame retardancy. Can be given. It is necessary that the average molecular weight is 50,000 or more, preferably 50,000 to 100,000, and more preferably 1,000,000 to 100,000. Component (C) is a total of 10 components (A) and (B).
0.05 to 1.0 parts by weight, preferably 0.1 to 0 parts by weight
~ 0.5 parts by weight. If this amount exceeds 1.0 parts by weight,
Not only does it have a negative impact on impact resistance and the appearance of molded products,
Strand discharge pulsates during kneading and extrusion, and stable pellet production cannot be performed, which is not preferable. Further, if the amount is less than 0.05 part by weight, a sufficient effect of preventing melt dripping cannot be obtained. Within the preferred range, a suitable melt dripping prevention effect can be obtained, and excellent flame retardancy can be obtained.

The PTFE having fibril-forming ability, which is the component (C) of the resin composition of the present invention, is not particularly limited, but for example, those classified as type 3 by the ASTM standard can be used. Specific examples of this type include Teflon 6-J (trade name, manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.), Polyflon D.
-1 and Polyflon F-103 (trade name, manufactured by Daikin Industries, Ltd.) and the like. In addition to type 3, Algoflon F5 (trade name, manufactured by Montefluos Co., Ltd.), Polyflon MPA FA-100 (trade name, manufactured by Daikin Industries, Ltd.) and the like can be mentioned. You may use these PTFE in combination of 2 or more types. The PTFE having the above-mentioned fibril forming ability is, for example, 1 to 100 in the presence of sodium, potassium or ammonium peroxydisulfide in an aqueous solvent of tetrafluoroethylene.
Temperature 0-200 ° C, preferably 20-1 under psi pressure
It can be obtained by polymerizing at 00 ° C.

The resin composition of the present invention comprises, in addition to the above-mentioned components (A), (B) and (C), if necessary, various inorganic fillers, additives, or other synthetic resins, Elastomers and the like can be blended within a range that does not impair the object of the present invention [these are abbreviated as component (D) below]. First, examples of the inorganic filler to be blended for the purpose of mechanical strength, durability or amount increase of the polycarbonate resin composition include glass fiber (GF), carbon fiber, glass beads, glass flakes, carbon black, calcium sulfate, Examples thereof include calcium carbonate, calcium silicate, titanium oxide, alumina, silica, asbestos, talc, clay, mica, and quartz powder. Also,
Examples of the additives include hindered phenol-based, phosphorus-based (phosphorous ester-based, phosphoric ester-based, etc.) and amine-based antioxidants, such as benzotriazole-based and benzophenone-based UV absorbers, for example, Examples thereof include external lubricants such as aliphatic carboxylic acid ester-based, paraffin-based, silicone oil and polyethylene wax, release agents, antistatic agents, colorants and the like. Other synthetic resins include polyethylene, polypropylene, polystyrene,
AS resin (acrylonitrile-styrene copolymer), A
Examples thereof include BS resins (acrylonitrile-butadiene-styrene copolymer) and polymethylmethacrylate resins. Further, as the elastomer, isobutylene-isoprene rubber, styrene-butadiene rubber,
Examples thereof include ethylene-propylene rubber and acrylic elastomer.

The resin composition of the present invention can be obtained by blending the above-mentioned components (A), (B) and (C) with (D) if necessary and kneading. The compounding and kneading are methods commonly used, 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. Can be done by. The heating temperature for kneading is usually selected in the range of 240 to 320 ° C. The polycarbonate resin composition thus obtained,
Various known molding methods, such as injection molding, blow molding,
Extrusion molding, compression molding, calender molding, rotational molding, etc. can be applied to manufacture molded articles such as chassis of OA equipment or molded articles in the electric and electronic fields.

[0025]

The present invention will be further described in detail with reference to production examples, examples and comparative examples.

Production Example 1 [Production of PC oligomer A] 400 liters of 5% by weight
60 kg of bisphenol A was dissolved in a sodium hydroxide aqueous solution to prepare a sodium hydroxide aqueous solution of bisphenol A. Then, the aqueous sodium hydroxide solution of bisphenol A kept at room temperature was flown at a flow rate of 138 liters / hour, and methylene chloride was flown at a flow rate of 69 liters / hour through an orifice plate through a tubular reactor having an inner diameter of 10 mm and a tube length of 10 m. It was introduced, and phosgene was co-distilled into the mixture and blown at a flow rate of 10.7 kg / hour for continuous reaction for 3 hours. The tubular reactor used here was a double tube, and cooling water was passed through the jacket to keep the discharge temperature of the reaction solution at 25 ° C. The pH of the discharged liquid is 10 to 11
Was adjusted so that The reaction liquid thus obtained was allowed to stand still to separate and remove the aqueous phase, and a methylene chloride phase (220 liters) was collected. To this, 170 liters of methylene chloride was further added and sufficiently stirred. This was designated as PC oligomer A (concentration: 317 g / liter). The degree of polymerization of the PC oligomer A obtained here is 3 to 4
Met.

Production Example 2-1 [Production of Reactive PDMS-A] 1,483 g of octamethylcyclotetrasiloxane, 96 g of 1,1,3,3-tetramethyldisiloxane and 35 g of 86% sulfuric acid were mixed. The mixture was stirred at room temperature for 17 hours. After that, the oil phase is separated and
5 g of sodium hydrogen carbonate was added and stirred for 1 hour. After filtration, vacuum distillation was performed at 150 ° C. and 3 torr to remove low-boiling substances to obtain oil. 60 g of 2-allylphenol and 0.0
To a mixture of 014 g of platinum chloride-platinum as an alcoholate complex, 294 g of the oil obtained above was added.
Added at a temperature of ° C. The mixture was stirred for 3 hours while maintaining the temperature of 90 to 115 ° C. The product was extracted with methylene chloride and washed three times with 80% aqueous methanol to remove excess 2-allylphenol. The product was dried over anhydrous sodium sulphate and evaporated in vacuo to a temperature of 115 ° C. The obtained terminal phenol PDMS is N
According to the measurement of MR, the number of repeating dimethylsilanooxy units was 30.

Production Example 2-2 [Production of Reactive PDMS-B] In Production Example 2-1,
The procedure of Production Example 2-1 was repeated, except that the amount of 1,1,3,3-tetramethyldisiloxane was changed to 18.1 g. In the obtained terminal phenol PDMS, the number of repeating dimethylsilanooxy units was 150 as measured by NMR.

Production Example 3-1 [Production of PC-PDMS Copolymer A ₁ ] 185 g of the reactive PDMS-A obtained in Production Example 2-1 was converted into methylene chloride 2
It was dissolved in 1 liter and 10 liters of the PC oligomer obtained in Production Example 1 was mixed. There, sodium hydroxide 2
What dissolved 6 g in 1 liter of water and 5.7 cc of triethylamine were added, and it was made to react by stirring at 500 rpm for 1 hour at room temperature. After completion of the reaction, 600 g of bisphenol A dissolved in 5 liter of a 5.2% by weight sodium hydroxide aqueous solution, 8 liter of methylene chloride and 81 g of p-tert-butylphenol were added to the above reaction system,
The mixture was stirred and reacted at 0 rpm at room temperature for 1 hour. After the reaction,
Add 5 liters of methylene chloride, wash with 5 liters of water, wash with 5 liters of 0.01N sodium hydroxide aqueous solution with alkali, wash with 5 liters of 0.1N hydrochloric acid, and wash with 5 liters of water. Finally, methylene chloride was removed to obtain a chip-shaped PC-PDMS copolymer.

Production Example 3-2 [Production of PC-PDMS Copolymer A ₂ ] In Production Example 3-1, 81 g of p-tert-butylphenol was 113 g.
A chip-like PC-PDMS copolymer was obtained in the same manner as in Production Example 3-1 except that the above was changed to.

Production Example 3-3 [Production of PC-PDMS Copolymer A ₃ ] In Production Example 3-1, 185 g of reactive PDMS-A was changed to 42 g,
Chip-like PC-P was prepared in the same manner as in Production Example 3-1 except that 81 g of p-tert-butylphenol was changed to 113 g.
A DMS copolymer was obtained.

Production Example 3-4 [Production of PC-PDMS Copolymer A ₄ ] In Production Example 3-1, the reactive PDMS-A was changed to the reactive PDMS-B, and 81 g of p-tert-butylphenol was changed to 113 g. A chip-shaped PC was manufactured in the same manner as in Production Example 3-1 except that the above was changed.
-PDMS copolymer was obtained.

PC-P obtained in Production Examples 3-1 to 3-4
Each of the DMS copolymers A _{1 to} A ₄ was dried at 120 ° C. for one day and then pelletized by an extruder at 280 ° C. Then, for each physical property, the PDMS chain length, the PDMS content and the viscosity average molecular weight were measured. The measuring method is shown below, and the results are shown in Table 1. (1) PDMS chain length (n: dimethylsilanooxane unit) The peak of the methyl group of dimethylsiloxane seen at ¹ H-NMR at 0.2 ppm and PC- at 2.6 ppm.
It was calculated from the intensity ratio with the methylene group peak of the PDMS bond. (2) Bisphenol A found at 1.7 ppm in PDMS content ¹ H-NMR
Was calculated from the intensity ratio of the peak of the methyl group of isopropyl and the peak of the methyl group of dimethylsiloxane seen at 0.2 ppm. (3) Viscosity average molecular weight (Mv) The viscosity of the methylene chloride solution at 20 ° C. was measured with an Ubbelohde viscometer, and the intrinsic viscosity [η] was calculated from this, and then calculated by the following formula. [Η] = 1.23 × 10 ^-5 Mv ^0.83

[0034]

[Table 1]

Examples 1 to 4 and Comparative Examples 1 to 6 PC-PDMS copolymers A _{1 to} A ₄ obtained in Production Examples 3-1 to _3-4 and commercially available polycarbonate resin, PTF
E, cryolite (Na ₃ AlF ₆ ) which is an alkali metal salt was blended at a blending ratio shown in Table 2, and the temperature was set to 280 by a vented twin-screw extruder [manufactured by Toshiba Machine Co., Ltd., TEM-35B]. The mixture was kneaded at 0 ° C and pelletized. The raw materials used are as follows. (A) Polycarbonate resin B ₁ : Tufflon A2200 [manufactured by Idemitsu Petrochemical Co., Ltd., M
v = 21,000] B ₂ : Tufflon A1500 [manufactured by Idemitsu Petrochemical Co., Ltd., M
v = 15,000] (B) PTFE C ₁ : Algoflon F5 [manufactured by Montefluos Company] capable of forming fibrils C ₂ : Lubron L5 [manufactured by Daikin Industries, Ltd.] not capable of forming fibrils (C) Polydimethylsiloxane D ₁ : SH200 [Toray Dow Corning Silicone Co., Ltd.] (D) Cryolite E ₁ : Na ₃ AlF ₆ [Aldrich Chemical Co., Ltd.]

[0036]

[Table 2]

[0037]

[Table 3]

The obtained pellets were each dried with hot air at 120 ° C. for 5 hours, and then IS100EN manufactured by Toshiba Machine Co., Ltd.
(Injection molding machine), molding temperature of 280 ℃, 80 ℃
Combustion test bar was made at the mold temperature of Sumitomo Heavy Industries, Ltd.
Made by Sumitomo Nestal N515 / 150, 300
Molding temperature of ℃, mold temperature of 80 ℃, 140mm × 14
A 0 mm × 3.2 mm surface appearance and long-term heat resistance evaluation flat plate was prepared. As the performance evaluation of the obtained pellets and molded products, oxygen index, flame retardancy, surface appearance, long-term heat resistance and flow value were measured. The measuring method is shown below, and the results are shown in Table 3. (1) Oxygen index Measured according to JIS K7201. In the combustion tube where the oxygen / nitrogen ratio was changed, approach ignition from above,
The minimum value of oxygen / nitrogen that burns continuously for 3 minutes or more was determined. (2) Flame retardant UL94 standard. Thickness 1.5mm and 1.0mm. A vertical burn test was conducted according to Underwriters Laboratory Subject 94. (3) Flow value According to JIS K 7201, it was measured at a measurement temperature of 280 ° C. and a load of 160 kg. (4) Surface appearance 140 mm × 140 mm × molded at a molding temperature of 300 ° C.
A 3.2 mm flat plate was visually observed to evaluate the presence or absence of silver. (5) Long-term heat resistance 140 mm x 140 mm x molded at a molding temperature of 300 ° C
A 3.2 mm flat plate was placed on a High Temp. O
After left in ven PHH-200 at 140 ° C for 1000 hours, color tone difference (ΔYI) from the initial (0 hour) molded product
Was measured. YI (yellowness) is JIS K 7105
It was measured according to.

[0039]

[Table 4]

[0040]

[Table 5]

As shown in Table 3, the PDMS content in the PC-PDMS copolymer and the polycarbonate resin was 0.1.
˜2.0% by weight and the content of PTFE in the range of 0.05 to 1.0 parts by weight show high flame retardancy. Moreover, Example 2
4 is also excellent in fluidity. On the other hand, Comparative Examples 1 to 6 do not satisfy any of the requirements of the present invention, so that desired flame retardancy cannot be obtained. Comparative Example 1 has a low oxygen index and a thickness of 1.5 m.
V-2 disqualified for both m and 1.0 mm. Comparative Example 2 is PT
Since it lacks FE, it has no effect of preventing molten dripping,
0 cannot be acquired. Comparative Example 3 is an example in which a polycarbonate resin and polydimethylsiloxane are mixed, but the oxygen index is low and flame retardancy cannot be obtained. It can be seen that the improvement of the oxygen index is observed only when the PC-PDMS copolymer of the example is used. Comparative Examples 4 and 5 are PD
Although the MS contents are out of range, the improvement of the oxygen index is small and the desired flame retardancy cannot be obtained. Comparative Example 6 is an example using PTFE having no fibril forming ability, but melt dripping cannot be prevented and V-0 cannot be obtained.
Comparative Example 7 is an example in which an alkali metal salt was added to Example 3 (see Japanese Patent Application Laid-Open No. 3-200862), but the inorganic metal salt was not compatible with the base polymer at the time of high temperature molding and silver was generated. , Inferior in long-term heat resistance, and changes in color tone are severe.

[0042]

EFFECTS OF THE INVENTION According to the present invention, since a flame retardant and a bromine compound are not contained at all, it is possible to provide a flame retardant polycarbonate resin composition having excellent thermal stability and fluidity. Therefore, the resin composition obtained by the present invention,
For example, it is preferably used in OA equipment and electric / electronic fields.

Claims (2)

[Claims] 1. An average molecular weight of 500,0 having (A) a polycarbonate-polyorganosiloxane copolymer, (B) a polycarbonate resin, and (C) a fibril-forming ability.
Made of polytetrafluoroethylene of 00 or more,
Component (A) is 5 to 1 of the total amount of component (A) and component (B)
00% by weight, the component (B) is 95 to 0% by weight of the total amount of the components (A) and (), and the proportion of the polyorganosiloxane part in the component (A) is the components (A) and (B). Of the total amount of
0.1 to 2.0% by weight, and the component (C) is 0.05 to 1.0 parts by weight based on 100 parts by weight of the total of the components (A) and (B). Composition. 2. The ratio of the polyorganosiloxane part in the component (A) is 0.5 to 1. of the total amount of the component (A) and the component (B).
The polycarbonate resin composition according to claim 1, which is 5% by weight.