JP2002294041A - Damping resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damping resin composition having both excellent damping properties and rigidity, and further to provide a molded product of the composition. SOLUTION: This damping resin composition comprises (A) a liquid crystal polymer and (B) a thermoplastic resin, and satisfies the relation between a loss factor η at 1,000 Hz frequency and a flexural modulus E represented by the formula (I): η×E (GPa)>=0.07 (GPa) (I).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vibration damping resin composition, a molded article using the same, and a molded article for a scanning optical device.

[0002]

2. Description of the Related Art Synthetic resins have been widely used as molding materials for various electric and electronic products. In some cases, it is required to have both the property of damping vibration) and the rigidity (property of an object expressed by flexural modulus or the like that resists load deformation). A flexible material has excellent damping properties but is inferior in rigidity, and a hard material shows the opposite property. It is difficult to develop a damping material, and conventionally, for example, a vibration damping material having a laminated structure of a metal and a resin is known.

[0003] However, such a vibration damping material having a laminated structure involves a laminating step, which complicates the manufacturing process, and also involves a problem of weight increase due to the inclusion of metal. Therefore, only a synthetic resin without metal is used. There is a need for a material having a high level of vibration damping and rigidity.

Further, a laser printer, a facsimile machine, a copying machine, a display device, and a scanning optical device incorporated in a liquid crystal projector have been developed (JP-A-5-341219, 9-1338).
No. 86, etc.), a resin material constituting an optical box used in these devices is required to have high vibration damping property and rigidity.

An object of the present invention is to provide a vibration-damping resin composition capable of obtaining a molded article having a high level of vibration-damping property and rigidity, a molded article using the same, and a molded article for a scanning optical device. And

[0006]

The present invention provides, as a means for solving the above-mentioned problems, a liquid crystal polymer (A) and a thermoplastic resin (B), wherein a loss coefficient η and a flexural modulus E at a frequency of 1000 Hz are as follows. Provided is a vibration damping resin composition satisfying the relationship represented by the formula (I).

Η × E (GPa) ≧ 0.07 (GPa) (I) The loss coefficient η was measured by the central support specific normal vibration method (the details of the measurement method are described in Examples, FIGS. 1 and 2). 2), and the flexural modulus E (GPa) was measured according to the ISO178 standard.

Further, the present invention provides, as another means for solving the problem, a molded article and a molded article for an optical device using the above-mentioned vibration damping resin composition.

According to another aspect of the present invention, there is provided a molded article comprising the vibration-damping resin composition according to any one of claims 1 to 8, wherein the vibration-damping or optical-axis deviation is measured. Provided is a molded article for a scanning optical device which has the following requirements (a) and / or (b) specified by a sex test.

(A): The maximum distance d of the optical axis blur is 2 mm or less.

(B): The optical axis deviation d ₁ after annealing the molded body at 80 ° C. for 1 hour is 2 mm or less.

The vibration damping test for measuring the optical axis blur or the optical axis shift was performed using the measuring apparatus shown in FIGS. 3 and 4, and the details of the test method will be described in Examples.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid crystal polymer (A) used in the present invention includes aromatic-aliphatic polyester, wholly aromatic polyester, aromatic polyazomethylene, polyimide ester and the like. Compounds that exhibit a molten form are selected.

Examples of the aromatic-aliphatic polyester include a copolymer of polyethylene terephthalate and benzoic acid. Examples of the completely aromatic polyester include a copolymer of parahydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; a copolymer of parahydroxybenzoic acid, terephthalic acid and 6-hydroxy-2-naphthol. Examples of the aromatic polyazomethylene include poly (nitrilo-2-methyl-1,4-phenylenenitroethylidene). Examples of the polyimide polyester include a copolymer of 2,6-naphthalenedicarboxylic acid, terephthalic acid and 4 (4-hydroxyphthalimide) phenol, and a copolymer of diphenol and 4- (4-hydroxyphthalimide) benzoic acid. Can be The determination that these copolymers are liquid crystal polymers is made by confirming that the liquid crystal polymers show optical anisotropy in a molten state. For example, a test piece adjusted to a thickness of 1 mm or less is placed on a heating stage of a deflection microscope, and placed under a nitrogen atmosphere.
Heat at a heating rate of ° C / min. In this state, it can be easily confirmed by making the deflector of the deflection microscope orthogonal and observing it at a magnification of 40 times or 100 times. In such a method, the temperature at which these copolymers transition to the liquid crystal phase can be measured at the same time, and the transition temperature is determined by differential scanning calorimetry (D
SC).

The thermoplastic resin (B) used in the present invention may be one or two selected from polycarbonate resins, polystyrene resins, polyolefin resins, polyamide resins and polyphenylene sulfide resins.
Species or more. As the component (B), a polycarbonate resin alone or a combination of a polycarbonate resin and a polystyrene resin, particularly an ABS resin or an ASA resin is preferable.

Examples of the polycarbonate resin include those obtained by reacting a dihydric phenol with a carbonate precursor by a well-known solution method or melting method.

The dihydric phenol includes 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2 -Screw (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) sulfide, bis (4-hydroxyphenyl)
One or more selected from sulfones and the like are included. Of these, bis (4-hydroxyphenyl) alkane-based ones are preferred, and bisphenol A is particularly preferred.

The carbonate precursor is at least one selected from diallyl carbonates such as diphenyl carbonate, dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, carbonyl halides such as phosgene, and haloformates such as dihaloformate of dihydric phenol.

Although the number average molecular weight of the polycarbonate resin is not particularly limited, it is preferably in the range of about 17000 to 32,000 in order to give a molded article obtained from the composition the mechanical strength required for practical use. preferable.

Examples of the polystyrene resin include polymers of styrene and styrene derivatives such as α-substituted and nuclear-substituted styrene. Further, a copolymer mainly composed of these monomers and a monomer of a vinyl compound such as acrylonitrile, acrylic acid and methacrylic acid and / or a conjugated diene compound such as butadiene and isoprene is also included. For example, polystyrene, impact-resistant polystyrene (HIPS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylonitrile-styrene copolymer (AS resin), styrene-methacrylate copolymer (MS resin), styrene-butadiene A copolymer (SBS resin), an acrylonitrile-styrene-acrylate copolymer (ASA resin), and the like can be given.

Further, the polystyrene resin may include a styrene copolymer in which a carboxyl group-containing unsaturated compound for improving compatibility with the polyamide resin is copolymerized. The styrenic copolymer in which the carboxyl group-containing unsaturated compound is copolymerized is a carboxyl group-containing unsaturated compound and optionally other monomers copolymerizable therewith in the presence of the rubbery polymer. Is a copolymer obtained by polymerizing Specific examples of the components include: 1) In the presence of a rubbery polymer obtained by copolymerizing a carboxyl group-containing unsaturated compound, a monomer containing an aromatic vinyl monomer as an essential component or aromatic vinyl and a carboxyl group-containing unsaturated compound. A graft polymer obtained by polymerizing a monomer containing a saturated compound as an essential component, and 2) a graft polymer containing an aromatic vinyl and a carboxyl group-containing unsaturated compound as essential components in the presence of a rubbery polymer. Graft copolymer obtained by copolymerization of a monomer, 3) a rubber-reinforced polystyrene resin in which a carboxyl group-containing unsaturated compound is not copolymerized, a carboxyl group-containing unsaturated compound, and aromatic vinyl as essential components. 4) A mixture of the above 1) and 2) and a copolymer containing a carboxyl group-containing unsaturated compound and aromatic vinyl as essential components; 5) The above 1) and 2) ), 3), 4) and aromatic vinyl There is a mixture with a copolymer containing as an essential component.

In the above 1) to 5), styrene is preferable as the aromatic vinyl, and acrylonitrile is preferable as the monomer copolymerized with the aromatic vinyl. The content of the carboxyl group-containing unsaturated compound in the polystyrene resin is preferably 0.1 to 8% by weight, more preferably 0.2 to 8% by weight.
~ 7% by weight.

As the polyolefin-based resin, a resin having 2 carbon atoms
And low-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene random copolymer, ethylene-propylene block copolymer. , Polymethylpentene, polybutene-1 or the like, and among them, polypropylene is preferable.

Examples of the polyamide resin include polyamide resins formed from diamine and dicarboxylic acid and copolymers thereof, specifically, nylon 66, polyhexamethylene sebacamide (nylon 610), polyhexamethylene. Dodecanamide (nylon 6.12), polydodecamethylene dodecanamide (nylon 1212), polymethaxylylene adipamide (nylon MXD6), polytetramethylene adipamide (nylon 46), and mixtures and copolymers thereof Nylon 6/66, Nylon 66 / 6T (6T: polyhexamethylene terephthalamide) having a 6T component of 50 mol% or less, and Nylon 66 / 6I (6I: polyhexamethylene isolate) having a 6I component of 50 mol% or less. Phthalamide), nylon 6T / 6I / 66, nylon 6T / 6I / 61 Copolymer and the like; polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I), poly (2-methyl pentamethylene) terephthalamide (nylon M5
T), copolymers such as poly (2-methylpentamethylene) isophthalamide (nylon M5I), nylon 6T / 6I, nylon 6T / M5T, and copolymer nylon such as amorphous nylon, and amorphous nylon. Examples include polycondensates of terephthalic acid and trimethylhexamethylenediamine.

Further, a ring-opening polymer of a cyclic lactam, a polycondensate of an aminocarboxylic acid and a copolymer comprising these components, specifically, nylon 6, poly-ω-undecanaamide (nylon 11), poly- Aliphatic polyamide resins such as ω-dodecanamide (nylon 12) and copolymers thereof, copolymers with polyamides comprising diamines and dicarboxylic acids, specifically nylon 6T / 6, nylon 6T
/ 11, nylon 6T / 12, nylon 6T / 6I / 1
2, nylon 6T / 6I / 610/12 and the like, and mixtures thereof.

The polyphenylene sulfide resin is represented by the following formula:

[0027]

Embedded image

Having a substantially linear structure containing at least 70 mol% of a repeating unit represented by the formula:
It may be one obtained by copolymerizing another monomer at a ratio less than the above.

The content of the components (A) and (B) in the composition is preferably such that the component (A) is 5 to 50% by weight, more preferably 7 to 45% by weight, and still more preferably 10 to 40% by weight. Wherein the component (B) is preferably 95 to 50% by weight,
More preferably 93 to 55% by weight, even more preferably 90 to 90% by weight.
６０60% by weight.

The composition of the present invention may further contain (C) an inorganic filler. The component (C) mainly contributes to the improvement of the rigidity, and generally does not itself contribute to the improvement of the loss coefficient η. However, in the case of (η × E) represented by the formula (I), the flexural modulus increases due to the incorporation of the component (C), so that the vibration damping property may be improved.

As the component (C), a fiber, flake, plate, whisker, granule, hollow bead or the like generally used as a reinforcing material for a thermoplastic resin is used, and the material of the filler is an inorganic material (glass, glass, etc.). Carbon, silicon-containing compounds (eg, silicon carbide), metals and metal salts (eg, alumina, aluminum borate, tungsten, titanium, copper, potassium titanate, zinc carbonate, etc.), and organic substances (eg, aramid fibers) can be used. . In addition, the surface of the filler may be treated with a silane-based, epoxy-based, acrylic-based, titanate-based coupling agent, or the like, within a range that does not impair the purpose of the invention, in order to improve the adhesion between the resin and the filler. Good.

The content of the component (C) in the composition is as follows:
The amount is preferably 1 to 120 parts by weight, more preferably 5 to 100 parts by weight, and still more preferably 10 to 80 parts by weight, based on 100 parts by weight of the total of component (B) and (B).

The composition of the present invention may further contain a flame retardant. In many cases, a molded article of an optical device is required to have flame retardancy. By adding a flame retardant, a composition having both vibration damping property and flame retardancy can be obtained.

Examples of the flame retardant include hydrated metal flame retardants such as aluminum hydroxide and magnesium hydroxide, bromo flame retardants, chlorine flame retardants, phosphorus flame retardants, and inorganic flame retardants such as antimony trioxide. Among them, phosphorus-based flame retardants are preferred.

The phosphorus-based flame retardant is not particularly limited as long as it is a compound having a phosphorus atom. Red phosphorus, an organic phosphorus compound such as a phosphoric acid ester, phosphonic acid and its derivatives (including salts), and phosphinic acid and its derivatives Derivatives (including salts), phosphines, phosphine oxides, biphosphines, phosphonium salts, phosphazenes, phosphaphenanthrene derivatives, inorganic phosphates and the like.

The content of the component (D) in the composition is as follows:
The amount is preferably 0.1 to 50 parts by weight, more preferably 1 to 40 parts by weight, and still more preferably 5 to 30 parts by weight, based on 100 parts by weight of the total of component (B) and component (B).

The composition of the present invention may further comprise a stabilizer against heat, light or oxygen (a phenolic compound,
Antioxidants such as phosphorus compounds; UV absorbers such as benzotriazole compounds, benzophenone compounds and phenyl salicylate compounds; heat stabilizers such as hindered amine stabilizers, tin compounds, epoxy compounds, etc.), plasticizers, polydimethyl A slidability improving agent such as siloxane, a lubricant, a release agent, an antistatic agent, a coloring agent, and the like may be added.

In the composition of the present invention, the loss coefficient η and the flexural modulus E at a frequency of 1000 Hz determined by a predetermined measuring method satisfy the relationship represented by the following formula (I).

Η × E (GPa) ≧ 0.07 (GPa) (I) In the present invention, the numerical value represented by the formula (I) is 0.08
5 (GPa) or more, and preferably 0.10 (GPa).
Pa) or more is more preferable.

In the present invention, the loss coefficient η and the flexural modulus E are
Are adjusted so as to satisfy the relationship of the formula (I) according to the level of the vibration damping property and the rigidity required according to the application. For example, in applications where particularly high rigidity is required and the demand for vibration damping is not so high, the flexural modulus E can be increased and the loss coefficient η can be decreased as long as the relationship of the formula (I) is satisfied. On the other hand, in applications where particularly high vibration damping properties are required and rigidity requirements are not so high, it is necessary to increase the loss coefficient η and decrease the flexural modulus E within a range satisfying the relationship of the formula (I). it can.

The molded article of the present invention can be obtained by using the above-mentioned vibration-damping resin composition and applying a known resin molding method. A molding method for obtaining a molded article for a scanning optical device is not particularly limited, and although it depends on the shape of the molded article, an injection molding method or an injection compression molding method can be applied. Since the molded article of the present invention has excellent vibration damping properties,
It is suitable for a scanning optical device incorporated in a laser printer, a facsimile machine, a copying machine, a display device, a camera, and a video camera, and particularly suitable for an optical box which is an outer case of the scanning optical device.

Further, when used as a molded article for a scanning optical device such as an optical box, the following (a) and (b) defined by a vibration damping test for measuring optical axis deviation or optical axis deviation.
It is desirable to have one or both of the above requirements.

(A): The maximum distance d of the optical axis blurring is 2 mm or less, preferably 1.8 mm or less.

(B): The optical axis deviation d ₁ after annealing the molded body at 80 ° C. for 1 hour is 2 mm or less, preferably 1.8.
mm or less.

By having one or both of the requirements (a) and (b) in this way, when used as an optical box for a laser printer, a facsimile, or the like, for example, there is little misalignment in printing and clear Since a high-quality image can be obtained, the optical device is suitable as a high-resolution optical device.

[0046]

The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. Details of each component used in the examples and a measuring method are as follows. 1. Components used (A) Component LCP: Liquid crystal polymer (trade name Vectra A950; manufactured by Polyplastics Co., Ltd.) (B) Component PC: Polycarbonate ABS: ABS resin (C) Component Glass fiber: Trade name ECS-03T-129, Japan 1. Talc manufactured by Denki Glass Co., Ltd .: Micron White 5000S, manufactured by Hayashi Kasei Co., Ltd. (D) Component Flame retardant: FP500, manufactured by Asahi Denka Kogyo Co., Ltd. Measurement method (1) Loss coefficient η Using the test device (conceptual diagram) shown in FIG. 1, measurement was performed by the following method according to the center supported specific vibration method (JIS G0602).

First, the resin compositions of Examples and Comparative Examples were injection-molded under the same conditions to obtain flat test pieces. Next, a mounting screw was adhered to the central portion of one surface of the test piece with an instant adhesive. Thereafter, the test sample was mounted on an impedance head, and was fixed to the impedance head with the above-mentioned mounting screws, so that the sample was mounted on a vibrator.

Next, sweep vibration is applied by a vibrator,
From the output of the impedance head, the transfer function (vibration degree /
(Excitation force) was measured. The transfer function is first excited for about 30 seconds with a swept sine wave having a component of 10 kHz or less, and the approximate natural frequencies are grasped. Next, the vicinity of each natural frequency is analyzed by the zoom analysis function of the Fourier analyzer. It was measured by sweeping with a sine wave.

The transfer function thus measured is processed by a computer, and the loss coefficient η is calculated from the following equation: η = (f ₂ −f ₁ ) / f ₀ using the half width method (see FIG. 2). did.

Using the measurement method described above, the size of the specimen was changed between 1000 to 2000 mm in length, 10 to 20 mm in width, and 2 to 5 mm in thickness.
The loss coefficients at 50 Hz and 1100 ± 50 Hz were determined, and the average value of the two frequencies was 1000 Hz.
At the loss factor.

(2) Flexural modulus E (GPa) Measured according to the ISO178 standard.

(3-1) Vibration Suppression Test (Measurement of Optical Axis Shake) A vibration suppression test was conducted by the following method using the measuring apparatus shown in FIGS. FIG. 3 is a plan view of the apparatus, and FIG.
Is a front view of the device.

First, the measuring device shown in FIGS. 3 and 4 will be described. A mirror support 12 is provided on one end side of the optical base 10 with legs, and a first mirror 14 is fixed to an inner slope of the support. Then, the optical table 10 and the mirror support 1
The test box 16 is placed in contact with the test box 2. The test box 16 was formed by injection molding using the respective compositions of Examples and Comparative Examples, and was 72 mm long and 124 mm wide.
It is a box without a lid having a size of 50 mm, a height of 50 mm, and a thickness of 1.6 mm. The box is placed on the optical bench 10 with the opening face down, and is fixed with an epoxy resin or the like.

The second mirror 1 is provided on the outer upper surface of the test box 16.
8 is fixed, and a motor 20 is provided inside the test box 16.
Is installed in contact with a part of the inner surface. The motor 20 is fixed on the optical bench 10. 22 is a half mirror, 24 is a He-Ne laser oscillator, and 26 is a screen.

Next, a test method using the measuring apparatus shown in FIGS. 3 and 4 will be described. The laser beam (the optical axis is shown by a thick solid line in the drawing) emitted from the He-Ne laser oscillator 24 is changed in direction by the half mirror 22, and then the first mirror 14, the second mirror 18, and the first mirror 14 are changed.
And finally projected on the screen 26. The irradiation point at this time is set as the origin. Here, as shown, the distance between the first mirror 14 and the second mirror 18 is 70 m.
m, the distance between the first mirror 14 and the screen 26 is 1930 m
m.

After that, at 23 ° C., the motor 20 in the test box 16 is started, and while being rotated at 1000 rpm for 15 minutes, a laser beam is irradiated in the same manner as described above and projected on the screen 26. The maximum distance between the laser beam irradiation point (blur point) and the origin at this time was defined as an optical axis blur (d in FIG. 3) and measured. The smaller the maximum distance d is, the smaller the optical axis blurring is, which indicates that the optical axis stability is excellent in a state where vibration is applied.

(3-2) Vibration Suppression Test (Measurement of Optical Axis Displacement after Annealing Process) A test box is set in the same manner as in the above (3-1) Optical axis blur measurement, and the origin of the laser beam irradiation point is set. It was confirmed. Thereafter, a movable thermostat was set, and the test box and the first mirror were put together in the thermostat. Anneal the test box at 80 ° C. for 1 hour, then remove the thermostat, and allow
Left for a minute. The irradiation point of the laser beam was measured, and the distance d ₁ from the origin measured before annealing was defined as the optical axis shift after annealing. The smaller the deviation of the optical axis, the better the optical axis stability due to the thermal history.

(4) Flame retardancy Evaluation was performed using a 1/8 inch thick test piece in accordance with the UL94 test method.

Examples 1 to 8 and Comparative Examples 1 to 4 [Compounding ratios shown in Table 1 [Components (A) and (B) are expressed as% by weight. Others are expressed in terms of parts by weight based on 100 parts by weight of the total of components (A) and (B)]. After mixing other than glass fiber using a tumbler, the mixture was melt-kneaded using a twin-screw extruder and pelletized. The cylinder temperature was set to 250 ° C., and the glass fiber was mixed from the side feed in the middle of the extruder to obtain a pellet-shaped vibration-damping resin composition. The above-mentioned measurements (1) to (4) were performed using a molded product obtained by injection molding the obtained pellet at a cylinder temperature of 250 ° C. and a mold temperature of 60 ° C.

[0060]

[Table 1]

[0061]

The molded article obtained from the vibration damping resin composition of the present invention has a high level of vibration damping properties and rigidity.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a device for measuring a loss coefficient η.

FIG. 2 is an explanatory diagram of a method of measuring a loss coefficient η.

FIG. 3 is a plan view of a measuring device used for measuring a vibration damping test.

FIG. 4 is a front view of a measuring device used for measurement of a vibration damping test.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 79/02 C08L 79/02 79/08 79/08 D 101/00 101/00 (72) Inventor Serizawa Hajime Hajime 21-4 Sankeidai, Mishima City, Shizuoka Pref. AD01 AD02 AD05 AE07 AE17 AF12 BB05 BC07 4J002 BB03X BB12X BB15X BB17X BC03X BC04X BC05X BC06X BC07X BC08X BC09X BN12X BN14X BN15X BP01X DA01 BP02X CF16W CF17W CF18W CG01X CG02CL0101 CG01X CG02X DK006 DL006 EW047 EW087 EW127 EW147 EW157 EW177 FA016 FA046 FA066 FA106 FD016 FD030 FD040 FD050 FD060 FD070 FD137

Claims (11)

[Claims] 1. A loss coefficient η at a frequency of 1000 Hz, comprising (A) a liquid crystal polymer and (B) a thermoplastic resin.
And a flexural modulus E satisfying the relationship represented by the following formula (I). η × E (GPa) ≧ 0.07 (GPa) (I) 2. The formula (I) is given by η × E (GPa) ≧ 0.1
The damping resin composition according to claim 1, wherein the viscosity is 0 (GPa). 3. The content of (A) the liquid crystal polymer is from 5 to 50.
The vibration damping resin composition according to claim 1 or 2, wherein the content of the thermoplastic resin (B) is 95 to 50% by weight. 4. The thermoplastic resin according to claim 1, wherein the thermoplastic resin is at least one selected from the group consisting of a polycarbonate resin, a polystyrene resin, a polyolefin resin, a polyamide resin and a polyphenylene sulfide resin.
4. The vibration damping resin composition according to 2 or 3. 5. The vibration damping resin composition according to claim 1, wherein (B) the thermoplastic resin is a polycarbonate resin or a combination of a polycarbonate resin and a polystyrene resin. 6. The vibration damping property according to any one of claims 1 to 5, wherein the inorganic filler (C) is contained in an amount of 1 to 120 parts by weight based on 100 parts by weight of the total of the components (A) and (B). Resin composition. 7. The vibration damper according to claim 1, wherein the flame retardant (D) is contained in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the total of the components (A) and (B). Resin composition. 8. The vibration damping resin composition according to claim 7, wherein (D) the flame retardant is a phosphorus-based flame retardant. 9. A molded article comprising the vibration damping resin composition according to claim 1. 10. A molded article for a scanning optical device, comprising the vibration-damping resin composition according to claim 1. 11. A molded article comprising the vibration damping resin composition according to claim 1, wherein the molded article is a molded article comprising: A molded article for a scanning optical device, which has the requirements of (a) and / or (b). (A): The maximum distance d of the optical axis blur is 2 mm or less. (B): The optical axis deviation d ₁ after annealing the molded body at 80 ° C. for 1 hour is 2 mm or less.