JPH0977967A - Polycarbonate resin composition and disklike rotating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarbonate resin composition useful for a disklike rotating member satisfying the requirements particularly for a high level of accuracy of surface deflection, rigidity, heat resistance and press fitting strength. SOLUTION: This resin composition is obtained by blending 100 pts.wt. resin composition consisting of 50-90wt.% polycarbonate resin having a viscosity- average molecular weight of 14,000 to 23,000 and 50-10wt.% reinforcing filler of which glass flakes account for at least 70wt.% with 0.1-1.5 pts.wt. polyethylene wax and/or a 1-alkene polymer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polycarbonate resin composition. More specifically, the present invention relates to a polycarbonate resin composition which is useful for a disk-shaped rotating member and has excellent surface runout accuracy, rigidity, heat resistance, and press-fit strength.

[0002]

2. Description of the Related Art Members such as pulleys, gears, turntables, rotating hubs, drum flanges, etc., in which a shaft such as a motor shaft is inserted in the central portion of the member and which rotates about the shaft (hereinafter, these members are rotated in a disk shape). Members) are widely used as internal mechanical parts such as electric appliances, information devices, and robots. Metals have been mainly used for the disk-shaped rotary member, but nowadays products made of a resin composition are predominant because of the problem of high cost due to its production efficiency. However, in fields where more precise functions are required, metal members are still used. Specifically, for example, Nikkei Mechanical 1994, 4,
No. 4 discloses that, in a high-speed reading device called a 4 × speed for a CD-ROM reading device, a steel cut material is used for its turntable. Further, this reference introduces that surface wobbling accuracy is very important as a characteristic of the turntable. The surface runout accuracy means how much the outermost peripheral part is vertically swung when the disc is attached to the shaft once, and when the wobbling is large, a read error may occur due to uneven rotation, for example, on a turntable. Therefore, a problem such as insufficient reproduction of information occurs. Generally, the characteristics required of the disk-shaped rotating member include rigidity, heat resistance, press-fitting strength, etc. in addition to surface runout accuracy. Rigidity is necessary to maintain the shape of the disk-shaped rotary member itself, and if the rigidity is low, problems such as resonance phenomenon due to rotation and smooth transmission of motion will occur. Regarding heat resistance, in many cases, the disk-shaped rotating member is used in the vicinity of a heating element such as a motor, and therefore resistance to the heat is required. Also,
As for the press-fitting strength, a shaft member such as a motor shaft is often directly press-fitted into the disk-shaped rotary member, and therefore, resistance that deformation or cracking does not occur during the press-fitting is required. As the disc-shaped rotating member made of a resin composition, a resin composition in which a metal filler, glass fiber and carbon fiber are mixed with polystyrene resin (Japanese Patent Laid-Open No. 63-142051),
It has been proposed that a composition in which a polyamide resin is highly filled with soft ferrite (Japanese Patent Laid-Open No. 2-127465) is suitable for turntable applications. However, the former resin composition does not sufficiently satisfy high level runout accuracy and heat resistance, and the latter resin composition has problems in terms of press-fit strength, productivity and cost. As described above, a disk-shaped rotary member made of a resin composition satisfying a high level of surface runout accuracy, rigidity, heat resistance and press-fit strength has not been obtained so far.

On the other hand, polycarbonate resin such as 2,2
-The polycarbonate resin obtained by reacting bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) with a carbonate precursor is widely used as an engineering plastic because it has excellent dimensional stability, impact resistance, heat resistance, and the like. And it is used in large quantities. However, it is not applied to the disk-shaped rotary member that requires the above-described high level surface runout accuracy, rigidity, heat resistance, and press-fit strength.

[0004]

DISCLOSURE OF THE INVENTION The present invention is to provide a polycarbonate resin composition which is useful for a disk-shaped rotary member which particularly satisfies high level runout accuracy, rigidity, heat resistance and press-fit strength. .

In order to achieve the above object, the present inventor has tried to blend a polycarbonate resin with a reinforcing filler mainly containing glass flakes. However, the disk-shaped rotary member produced by injection molding with such a reinforced polycarbonate resin composition could not achieve sufficient surface runout accuracy. Therefore, as a result of sufficiently investigating and examining the situation where the disk-shaped rotating member made by injection molding from this reinforced polycarbonate resin composition cannot achieve sufficient surface runout accuracy, a polycarbonate resin having a specific molecular weight is used as the polycarbonate resin, and It has been found that when a small amount of a specific olefin-based polymer is further blended with the flakes, a sufficient effect is exhibited, and the present invention has been completed.

Conventionally, a resin composition prepared by blending glass flakes with a polycarbonate resin (Japanese Patent Laid-Open No. 62-10985).
No. 5 gazette) is proposed, but it is merely characterized by the small anisotropy exhibited by glass flakes, and a reinforcing filler mainly composed of glass flakes is added to a polycarbonate resin having a specific molecular weight range. It has been known so far that a polycarbonate resin composition in which a small amount of a specific olefin-based polymer is blended can provide a disk-shaped rotating member satisfying all of the surface runout accuracy, rigidity, heat resistance and press-fit strength. Didn't.

[0007]

According to the present invention, (A) 50 to 90% by weight of a polycarbonate resin having a viscosity average molecular weight of 14,000 to 23,000 and (B) at least 70% by weight.
100 parts by weight of a resin composition consisting of 50 to 10% by weight of a reinforcing filler whose weight% is glass flakes, is added with (C) polyethylene wax and / or 1-alkene polymer.
The present invention relates to a polycarbonate resin composition containing 1 to 1.5 parts by weight.

The polycarbonate resin which is the component (A) used in the present invention is an aromatic polycarbonate resin obtained by reacting a dihydric phenol with a carbonate precursor. Typical examples of the dihydric phenol used here are bisphenol A, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3-) Methylphenyl) propane,
Bis (4-hydroxyphenyl) ether, 4,4'-
Dihydroxydiphenyl, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the like can be mentioned. Preferred dihydric phenols are bis (4-hydroxyphenyl) alkanes, of which bisphenol A is particularly preferred. As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples thereof include phosgene, diphenyl carbonate and dihaloformate of dihydric phenol. In producing a polycarbonate resin by reacting the above dihydric phenol and a carbonate precursor, the dihydric phenol may be used alone or in combination of two or more kinds, and if necessary, a catalyst, a molecular weight modifier, an antioxidant. Etc. may be used. Further, the polycarbonate resin may be a branched polycarbonate resin obtained by copolymerizing a polyfunctional aromatic compound having three or more functional groups, or a mixture of two or more types of polycarbonate resins.

The molecular weight of such a polycarbonate resin is
The viscosity average molecular weight is suitably 14,000 to 23,000, preferably 15,000 to 22,000,
000 to 21,000 is particularly preferable. With a polycarbonate resin having a viscosity average molecular weight of less than 14,000, the surface runout accuracy is good but the press-fit strength is not sufficient. With a polycarbonate resin having a viscosity average molecular weight of more than 23,000, the press-fit strength is conversely sufficient. It is difficult to obtain a disk-shaped rotary member with good surface runout accuracy. The surface runout accuracy and the press-fitting strength are in a contradictory relationship, and the balance can be obtained only within a specific molecular weight range. The viscosity average molecular weight (M) in the present invention is obtained by inserting the specific viscosity (η _sp ) obtained from a solution of 0.7 g of polycarbonate resin dissolved in 100 ml of methylene chloride at 20 ° C. into the following equation. η _sp /C=[η]+0.45×[η] ² C [η] = 1.23 × 10 ⁻⁴ M ^0.83 (where [η] is the intrinsic viscosity and C is the polymer concentration of 0.7. )

The basic means for producing a polycarbonate resin will be briefly described. In the solution method using phosgene as a carbonate precursor, the reaction is usually performed in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used. A catalyst such as a tertiary amine or a quaternary ammonium salt may be used to accelerate the reaction, and a molecular weight regulator may be an end-capping agent such as phenol or an alkyl-substituted phenol such as p-tert-butylphenol. Is preferred. The reaction temperature is usually 0 to 40 ° C., the reaction time is several minutes to 5 hours, and the pH during the reaction is preferably 10 or more.

In the transesterification reaction (melting method) using a carbonic acid diester as a carbonate precursor, the dihydric phenol in a predetermined ratio is stirred with the carbonic acid diester in the presence of an inert gas while stirring to produce an alcohol or a phenol compound. Is distilled out. The reaction temperature varies depending on the boiling point of the produced alcohol or phenol, and is usually in the range of 120 to 300 ° C. From the initial stage of the reaction, the reaction is completed while reducing the pressure to distill off the produced alcohol or phenols. Further, in order to accelerate the reaction, a catalyst usually used in transesterification reaction can be used. Examples of carbonic acid diesters used in this transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate and the like. Of these, diphenyl carbonate is particularly preferred.

The reinforcing filler used as the component (B) in the present invention is a reinforcing filler mainly composed of glass flakes,
Used as glass flakes alone or as a mixture of glass flakes with other reinforcing fillers. When used as a mixture of glass flakes and other reinforcing fillers, the amount of glass flakes in 100% by weight of the reinforcing filler mixture is 70% by weight.
The above is necessary. If the amount is less than 70% by weight, the surface runout accuracy required for the disk-shaped rotating member becomes insufficient.

The glass flakes used in the present invention are preferably plate-shaped. Furthermore, the average particle size is 10 to 1,0
The average particle size is preferably (a),
When the thickness is (b), the (a) / (b) ratio is 5 to 50.
0 is preferable, 6 to 450 is more preferable, 7 to 400 is particularly preferable. Average particle size is 10
If it is less than μm or the ratio (a) / (b) is less than 5, the rigidity becomes insufficient, and if the average particle size exceeds 1,000 μm or the ratio (a) / (b) exceeds 500, The shaft press-fitting strength of the disk-shaped rotating member is reduced. Here, the average particle size of the glass flakes is calculated as the median size of the weight distribution of the particle sizes determined by the standard sieving method.

As the other reinforcing filler which can be used together with the glass flakes, a fibrous filler is particularly preferable from the viewpoint of improving the press-fit strength and rigidity. Examples of the fibrous filler include glass fibers, carbon fibers, metal fibers, organic fibers such as ceramic fibers typified by alumina fibers and aramid fibers, among others, particularly strength,
Glass fiber and carbon fiber are preferable in terms of price and the like.
As the glass fiber and the carbon fiber, those widely known as a resin reinforcing material are usually used. Average diameter is 5
It is preferably about 20 μm. If it is less than 5 μm, the press-fit strength is improved, but the surface runout accuracy deteriorates.
If it is larger than 0 μm, the press-fit strength and rigidity are likely to be insufficiently improved. The average fiber length is 0.05 to 20 mm.
Are preferred. If it is less than 0.05 mm, the strength and rigidity are apt to be insufficiently improved, and if it exceeds 20 mm, not only the breaking during kneading becomes large but the strength improving effect is small and the adverse effect on handling becomes large, which is not preferable.

Such glass flakes and glass fibers are preferably surface-treated with a silane coupling agent or the like. By this surface treatment, decomposition of the polycarbonate resin can be suppressed and adhesion can be improved. The silane coupling agent referred to here is the following formula

[0016]

Embedded image

[Where Y is an amino group, an epoxy group,
Boronic acid group, vinyl group, mercapto group, halogen atom, etc.
A group having reactivity or affinity with a resin matrix, R
¹~ R ^FourAre each a single bond or alkylene having 1 to 7 carbon atoms.
Represents a group, an amide bond in the alkylene molecular chain,
Via an ester bond, ether bond or imino bond
May be. X¹~ X^ThreeAre hydrogen atom and halogen atom, respectively.
And an alkoxy group having 1 to 4 carbon atoms
More preferred atoms or groups are preferred. X¹~ X^Threeof
At least two of them are halogen atoms or alkoxy groups
is there. ] A silane compound represented by
Vinyltrichlorosilane, vinyltriethoxysilane,
Vinyltrimethoxysilane, γ-methacryloxypropy
Lutrimethoxysilane, β- (3,4-epoxycyclo)
Hexyl) ethyltrimethoxysilane, γ-glycidoxy
Cypropyltrimethoxysilane, γ-glycidoxy pro
Pyrmethyldiethoxysilane, N-β (aminoethyl)
γ-aminopropyltrimethoxysilane, N-β (ami
Noethyl) γ-aminopropylmethyldiethoxy sila
Γ-aminopropyltriethoxysilane, N-phen
Nyl-γ-aminopropyltrimethoxysilane, γ-me
Lucaptopropyltrimethoxysilane and γ-chlorop
Examples include ropyltrimethoxysilane and the like. More glass
Flake, glass fiber, carbon fiber acrylic resin, Ure
Tan resin, epoxy resin, unsaturated polyester resin, etc.
Granulated or bunched with a binder is preferable because it is easy to handle.
New However, granules obtained by such granulation or focusing
For flakes or bundles, glass flakes as described above
Average particle size range, fiber diameter of glass fiber and carbon fiber,
Fiber length does not apply.

The polyethylene wax and / or 1-alkene polymer used as the component (C) is blended for the purpose of obtaining good surface runout accuracy without impairing rigidity, heat resistance and press-fit strength. As the polyethylene wax, one widely known at present can be used,
Examples thereof include those obtained by polymerizing ethylene under high temperature and high pressure, those obtained by thermally decomposing polyethylene, and those obtained by separating and purifying low molecular weight components from a polyethylene polymer. The molecular weight and the degree of branching are not particularly limited, but the number average molecular weight is preferably about 1,000 to 20,000. Further, a polyethylene wax modified with maleic acid and / or maleic anhydride may be used. 1
As the alkene polymer, a polymer of 1-alkene having 5 to 40 carbon atoms can be used, and further maleic acid and / or
Alternatively, a type in which maleic anhydride is simultaneously copolymerized can also be used. The number average molecular weight is 1,000 to 2 as the molecular weight.
About 10,000 is preferable. When both polyethylene wax and 1-alkene have a molecular weight of less than 1,000, they have an adverse effect on the press-fit strength.
When it exceeds 0, the surface runout accuracy is adversely affected.

The amount of the reinforcing filler mainly composed of the glass flakes (B) is 10 with the total amount of the polycarbonate resin (A) and the reinforcing filler mainly composed of the glass flakes (B) being 100% by weight. ~ 50% by weight, preferably 1
5 to 45% by weight. If it is less than 10% by weight, the rigidity required for the disk-shaped rotating member cannot be secured, and if it is more than 50% by weight, it is difficult to obtain good surface runout accuracy, and it becomes brittle and the press-fit strength is insufficient. become.
The amount of the polyethylene wax and / or 1-alkene polymer used in (C) is 100 parts by weight of a resin composition comprising a polycarbonate resin of (A) and a reinforcing filler mainly of glass flakes of (B). It is 0.1 to 1.5 parts by weight. If the amount of the polyethylene wax and / or 1-alkene polymer (C) is less than 0.1 parts by weight, the surface runout is adversely affected, and if it exceeds 1.5 parts by weight, the press-fit strength is adversely affected. .

In the polycarbonate resin composition of the present invention, a flame retardant such as a halogen-based or phosphoric ester-based flame retardant can be used as long as the object of the present invention is not impaired. Examples of the halogen-based flame retardant include brominated bisphenol carbonate oligomer, brominated bisphenol epoxy resin, brominated bisphenol phenoxy resin, brominated polystyrene and the like. Examples of the phosphoric acid ester flame retardant include trimethyl phosphate,
Triethyl phosphate, tributyl phosphate, trioctyl phosphate, tricresyl phosphate,
Triphenyl phosphate, cresyl diphenyl phosphate, tris (tribromoneopentyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromophenyl) phosphate and the like can be mentioned.
If necessary, polytetrafluoroethylene having a fibrillation-forming ability can be used as a drip preventing agent during combustion. Further, in the polycarbonate resin composition of the present invention, optional additives such as flame retardant aids such as antimony trioxide and sodium antimonate, heat stabilizers such as phosphoric acid ester and phosphorous acid ester, etc. are used within a range not impairing the object of the present invention. , Fluidity modifiers such as polycaprolactone, antioxidants such as hindered phenols, slidability modifiers such as polytetrafluoroethylene and polyethylene, light stabilizers, colorants, lubricants, foaming agents, etc. Depending on its effective expression amount, other fillers such as glass powder, glass beads, mica, talc, calcium carbonate,
Carbon black, metal powder or the like may be blended, and, for example, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polyamide, acrylic resin, aromatic polyester,
A thermoplastic resin such as a phenoxy resin or an epoxy resin, or an elastic body may be blended. Of these, it is particularly preferable to add a heat stabilizer such as a phosphoric acid ester or a phosphorous acid ester for the purpose of improving heat stability.

For producing the polycarbonate resin composition of the present invention, any method is employed. For example, the polycarbonate resin of (A), the reinforcing filler mainly composed of glass flakes of (B), the polyethylene wax and / or the 1-alkene polymer of (C), and other additives as appropriate, simultaneously or in any order, For example, tumbler, V type blender, Nauter mixer, Banbury mixer,
A method of mixing with a kneading roll or an extruder is appropriately adopted.
The polycarbonate resin composition thus obtained is generally molded by injection molding. In particular, the molding conditions of the disk-shaped rotating member, the gate arrangement, etc. are not limited.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to Examples. The parts in the examples are parts by weight, and the evaluation was made by the following method. (1) Surface runout accuracy [μm]: A disc-shaped rotating member with a diameter of 30 mm and a thickness of 1.5 mm has a hole with a diameter of 2 mm in the center, and a hub with a diameter of 5 mm and a height of 5.5 mm is provided around the hole. The turntable was injection-molded, left for 1 hour in an atmosphere of 23 ° C. and 50% RH, then mounted on a measuring jig, and the amount of surface runout was measured by a test indicator type 513 manufactured by Mitutoyo Corporation. The amount of surface wobbling was determined to be 30 μm or less. (2) Flexural modulus [kgf / cm ² ]: ASTM D-790
Was measured by It is a measure of the rigidity required for the disk-shaped rotating member. (3) Deflection temperature under load [° C]: Measured according to JIS K-7207. It was a measure of the heat resistance required for the disk-shaped rotating member, and passed 120 ° C or higher. (4) Tensile elongation value [%]: Measured according to ASTM D-638. It is a measure of the press-fit strength required for the disk-shaped rotating member. The larger the tensile elongation value, the more resistant to deformation (toughness)
Since it is high, cracking of the hub portion due to press fitting can be suppressed.

[Example 1] Viscosity average molecular weight 15,500
35 parts of polycarbonate resin [Panlite L-1225LL manufactured by Teijin Chemicals Ltd.], viscosity average molecular weight 19,50
35 parts of polycarbonate resin [Panlite L-1225L manufactured by Teijin Chemicals Co., Ltd.], polyethylene wax [High Wax HW405MP manufactured by Mitsui Petrochemical Co., Ltd.]
5 parts, 1 part of carbon black as a colorant and trimethyl phosphate [TMP manufactured by Daihachi Chemical Co., Ltd.] 0.02
After dry blending 2 parts, vented twin-screw extruder with screw diameter 30 mm [TEX 30X manufactured by Nippon Steel Co., Ltd.]
SST] first chute, cylinder temperature 30
Melt and knead at 0 ° C, and the average particle size is 60 with a thickness of 2-6 μm.
0 μm glass flakes [REFG manufactured by Nippon Sheet Glass Co., Ltd.
-101] 30 parts was supplied to the second chute, the entire composition was uniformly kneaded, and then pellets were obtained by strand cutting. The supply of each raw material was adjusted by a measuring instrument [CWF manufactured by Kubota Corporation] so as to have a predetermined blending amount. The viscosity average molecular weight of the obtained pellets was 16,500. The pellets were dried at 120 ° C for 5 hours with a hot air circulation dryer, and then an injection molding machine [S manufactured by Sumitomo Heavy Industries, Ltd. S
G150U], a bending test piece and a tensile test piece were molded at a cylinder temperature of 310 ° C. and a mold temperature of 100 ° C. Further, a turntable for measuring surface runout accuracy was injection-molded with an injection molding machine [80MSP manufactured by Mitsubishi Heavy Industries, Ltd.] at a cylinder temperature of 310 ° C and a mold temperature of 100 ° C. Table 1 shows the evaluation results.

Comparative Example 1 Pellets were prepared in the same manner as in Example 1 except that 0.5 part of polyester wax [E type manufactured by Hoechst Co.] was used instead of 0.5 part of polyethylene wax used in Example 1. The molded articles for measurement were obtained and the evaluation results are shown in Table 1. In addition, the viscosity average molecular weight of the pellet was greatly reduced to 14,500, and as apparent from the table, the tensile elongation value was low and the press-fit strength was poor.

Comparative Example 2 Instead of 30 parts of the glass flakes used in Example 1, 5 parts of glass flakes [REFG-101 manufactured by Nippon Sheet Glass Co., Ltd., thickness 2 to 6 μm, average particle diameter 600 μm] and glass fiber were used. Pellets were obtained in the same manner as in Example 1 except that a mixture of 25 parts of 3PE-455 manufactured by Nitto Boseki Co., Ltd. and a fiber diameter of 13 μm was used, molded articles for measurement were used, and the evaluation results are shown in Table 1. Indicated. As is clear from the table, the amount of surface runout is large.

[Example 2] Viscosity average molecular weight 15,500
Viscosity average molecular weight of 1 without using polycarbonate resin
Pellets were obtained in the same manner as in Example 1 except that 70 parts of 9,500 polycarbonate resin [Panlite L-1225L manufactured by Teijin Kasei Co., Ltd.] was used, each molded article for measurement was molded, and the evaluation results are shown. Shown in 1.

Comparative Example 3 Pellets were obtained in the same manner as in Example 2 except that polyethylene wax was not used, and molded articles for measurement were molded, and the evaluation results are shown in Table 1. As is clear from the table, the amount of surface runout is large.

[Comparative Example 4] Pellets were obtained in the same manner as in Example 2 except that the amount of polyethylene wax used was increased to 2.5 parts, moldings for measurement were molded, and the evaluation results are shown in Table 1. . As is clear from the table, the tensile elongation value is low and the press-fit strength is poor.

[Comparative Example 5] Viscosity average molecular weight 19,500
Polycarbonate resin having a viscosity average molecular weight of 30,000 in place of 70 parts of the polycarbonate resin [Teijin Kasei Co., Ltd.
Pelrite K-1300] was used in the same manner as in Example 2 except that 70 parts of the product was used, and molded articles for measurement were molded, and the evaluation results are shown in Table 1. As is clear from the table, the amount of surface runout is large.

[Comparative Example 6] Viscosity average molecular weight 19,500
In place of 70 parts of the polycarbonate resin, 55% by weight of polyphenylene ether resin [polyphenylene ether manufactured by GEM POLYMER], 35% by weight of rubber-containing polystyrene resin [Topolex 855-51 manufactured by Mitsui Toatsu Chemicals, Inc.] and triphosphate. Phenyl [TP manufactured by Daihachi Chemical Co., Ltd.
P] Pellets were obtained in the same manner as in Example 2 except that 70 parts by weight of a mixture containing 10% by weight of P] was used to mold molded articles for measurement, and the evaluation results are shown in Table 1. As is clear from the table, the deflection temperature under load and the tensile elongation value are low, and the heat resistance and press-fit strength are poor.

[Example 3] Viscosity average molecular weight 15,500
Viscosity average molecular weight of 1 without using polycarbonate resin
60 parts of 9,500 polycarbonate resin [Panlite L-1225L manufactured by Teijin Chemicals Ltd.] was used, and in addition to 30 parts of glass flakes, glass fiber [3 manufactured by Nitto Boseki Co., Ltd.
Pellets were obtained in the same manner as in Example 1 except that PE-455, diameter 13 μm] 10 parts were also used, and molded articles for measurement were molded, and the evaluation results are shown in Table 1.

Example 4 In place of 30 parts of the glass flakes used in Example 1, 20 parts of glass flakes [REFG-101 manufactured by Nippon Sheet Glass Co., Ltd., thickness 2 to 6 μm, average particle diameter 600 μm] and glass fiber were used. [Nitto Boseki Co., Ltd. 3PE-455, diameter 13 μm] A mixture of 10 parts is used, and 2 parts of brominated bisphenol A carbonate oligomer [Teijin Kasei Co., Ltd. Fireguard FG-7000] is used as a flame retardant. Pellets were obtained in the same manner as in Example 1 except for the above, and molded articles for measurement were molded, and the evaluation results are shown in Table 1.

The symbols of the components used in Table 1 are shown below. PC-1: Polycarbonate resin having a viscosity average molecular weight of 15,500 [Panlite L-1225L manufactured by Teijin Chemicals Ltd.]
L] PC-2: polycarbonate resin having a viscosity average molecular weight of 19,500 [Panlite L-1225L manufactured by Teijin Chemicals Ltd.] PC-3: polycarbonate resin having a viscosity average molecular weight of 30,000 [Panlite manufactured by Teijin Chemicals Ltd.] K-1300] PPE: polyphenylene ether resin [polyphenylene ether manufactured by GEM POLYMER] 55% by weight, polystyrene resin containing rubber [Topolex 8 manufactured by Mitsui Toatsu Chemicals, Inc.]
55-51] 35% by weight and triphenyl phosphate [TPP manufactured by Daihachi Chemical Co., Ltd.] 10% by weight, 100% by weight in total GFL: glass flake [REFG manufactured by Nippon Sheet Glass Co., Ltd.]
-101, thickness 2 to 6 μm, average particle diameter 600 μm] CS: glass fiber [3PE-455 manufactured by Nitto Boseki Co., Ltd.,
Fiber diameter 13 μm] WAX-1: Polyethylene wax [High wax HW405MP manufactured by Mitsui Petrochemical Co., Ltd.] WAX-2: Polyester wax [E type manufactured by Hoechst] FR: Brominated bisphenol A carbonate oligomer [manufactured by Teijin Chemicals Ltd.] Fireguard FG-7000] CB: Carbon black ST-1: Trimethyl phosphate [TMP manufactured by Daihachi Chemical Co., Ltd.]

[0034]

[Table 1]

[0035]

INDUSTRIAL APPLICABILITY The polycarbonate resin composition of the present invention makes it possible to provide a disk-shaped rotary member that satisfies particularly high levels of surface runout accuracy, rigidity, heat resistance and press-fit strength. It is useful for a turntable of a corresponding CD-ROM reproducing device, and its industrial effect is exceptional.

Claims (4)

[Claims] 1. (A) The viscosity average molecular weight is from 14,000 to
A resin composition 1 comprising 50 to 90% by weight of a polycarbonate resin of 23,000 and (B) 50 to 10% by weight of a reinforcing filler having at least 70% by weight of glass flakes.
A polycarbonate resin composition prepared by blending 100 parts by weight of (C) polyethylene wax and / or 0.1-1.5 parts by weight of a 1-alkene polymer. 2. The glass flakes have an average particle size of 10
2. The polycarbonate resin composition according to claim 1, wherein the ratio (a) / (b) is 5 to 500, where the average particle size is (a) and the thickness is (b). 3. The polycarbonate resin composition according to claim 1, wherein the polyethylene wax and / or 1-alkene polymer (C) has a number average molecular weight of 1,000 to 20,000. 4. (A) The viscosity average molecular weight is 14,000 to
A resin composition 1 comprising 50 to 90% by weight of a polycarbonate resin of 23,000 and (B) 50 to 10% by weight of a reinforcing filler having at least 70% by weight of glass flakes.
A disk-shaped rotating member obtained by molding a polycarbonate resin composition obtained by mixing 0.1 part by weight of (C) polyethylene wax and / or 1-alkene polymer with 100 parts by weight of (C).