Vibration-damping property-imparting material, thermoplastic resin composition, and molded article

Abstract

This vibration-damping property-imparting material comprises a polymer (B) that includes: a polymer (b1) having a glass transition temperature of -10°C to 30°C; and a polymer (b2) different from the polymer (b1). In the polymer (B), the degree of swelling of THF-insoluble matter is 900% or more as measured by the following method. <Method for measuring degree of swelling> The polymer (B) is immersed in tetrahydrofuran (THF) for 24 hours. Thereafter, insoluble matter separated through a centrifugal separation operation is vacuum-dried, and the weight (weight b) thereof is measured.　The obtained THF-insoluble matter is immersed in THF for 24 hours again. Thereafter, the weight (weight c) of the sample swollen with the THF is measured, and the degree of swelling of the THF-insoluble matter is determined by the following formula.　Degree of swelling (%) = c / b×100

Description

Vibration-damping material, thermoplastic resin composition and molded article

[0001] The present invention relates to a vibration-damping material that can be incorporated into a thermoplastic resin composition to provide a molded article having excellent mechanical properties such as flowability, impact resistance, heat resistance, and rigidity, as well as excellent molded appearance, and also having high vibration-damping properties, i.e., high vibration damping (high logarithmic damping rate) and high resonance suppression effect (low vibration transmissibility). The present invention also relates to a thermoplastic resin composition containing the vibration-damping material, and a molded article obtained by molding the thermoplastic resin composition.

[0002] Thermoplastic resins, such as styrene-based resins typified by ABS resins and alloy materials composed of styrene-based resins and other thermoplastic resins, have excellent mechanical, physical, and electrical properties. For this reason, these thermoplastic resins are widely used in the electrical and electronic fields, office automation and home appliances, vehicles, and sanitary appliances. In recent years, the trend toward lighter and smaller products has led to thinner-walled molded products. To address this, increasing the molding temperature and injection speed when obtaining molded products by injection molding or other methods has become necessary. These molding conditions are harsh for thermoplastic resins. Furthermore, when molding using large molding machines, resin retention is likely to occur within the machine cylinder. As a result, molding defects such as jetting due to resin degradation and thermal decomposition, as well as thermal discoloration, occur. Furthermore, the resulting molded products have problems such as poor performance and surface appearance.

[0003] Adding various heat stability improvers to thermoplastic resin compositions has been confirmed to improve the heat stability to some extent, but this has the drawback of increasing costs.

[0004] On the other hand, in recent years, people have come to prefer a healthier and more comfortable living environment, and technologies such as vibration control, vibration isolation, and noise reduction have become more important than ever before. In particular, there is a demand for reduced noise and vibration in the fields of vehicles, home appliances, office automation, and various other fields. For example, there is a demand for materials that reduce the vibration of radiator fans in automobiles, motors in home appliances, and optical discs in office automation.

[0005] Conventionally, vibration-proof and vibration-damping materials have been made by sandwiching a resin or rubber material between two metal plates. However, with the recent trend toward lighter and smaller devices, it has become difficult to design products with such structures. For this reason, there is a demand for materials that form the structures to have high vibration-damping performance.

[0006] However, in general, materials with high rigidity that can be used to form structures have low vibration damping properties, and conversely, materials with high vibration damping properties have low rigidity, which is a trade-off. For this reason, it has been difficult to use resin compositions with vibration damping properties as they are as constituent materials for structures.

[0007] As a means to overcome this, Patent Document 1 proposes a combination of a copolymer having a glass transition temperature of 0°C or higher, which is made of an acrylic acid ester monomer and / or a methacrylic acid ester monomer and another comonomer, with a thermoplastic resin. Patent Document 2 proposes blending a rubber-like polymer having a specific core-shell structure with a styrene-based resin. However, neither Patent Document 1 nor Patent Document 2 provides a molded article that has excellent moldability and surface appearance while maintaining vibration damping properties.

[0008] Patent Document 3 proposes a thermoplastic resin composition comprising a (meth)acrylic acid ester copolymer (a) and another copolymer (b), which has a loss tangent (Tan δ) peak within a specific temperature range that is different from the Tg peak of each polymer constituting the composition. This thermoplastic resin composition exhibits improvements in moldability and surface appearance. However, Patent Document 3 does not provide sufficient vibration damping properties.

[0009] Patent Documents 4 to 6 propose that resin compositions with excellent vibration-damping properties be obtained by blending an elastomeric block polymer having a specific Tan δ with a rubber-reinforced resin. However, the resin compositions of Patent Documents 4 to 6 not only lack sufficient vibration-damping properties, but also suffer from poor molded appearance due to problems such as surface peeling, in which the surface of the molded article becomes layered and, in some cases, lifts or peels off. For these reasons, these compositions are not suitable for practical use as molded articles.

[0010] In Patent Documents 1 to 6 and other patent documents, there are many proposals that consider vibration damping as a vibration-damping performance. However, no proposals have been made so far regarding the unpleasant elements of vibration, such as "rattle" and "chatter," that is, abnormal noise, i.e., resonance. In other words, practical vibration-damping materials cannot be obtained by studying only vibration damping in the past.

[0011] JP 6-41443, JP 11-349785, JP 2000-212373, JP 2001-158841, JP 3-45646, JP 8-3249

[0012] The present invention aims to provide a vibration-damping material that can be blended with a thermoplastic resin composition to provide a molded article that has excellent mechanical properties such as flowability, impact resistance, heat resistance, and rigidity, as well as excellent molded appearance, and that has high vibration-damping properties, i.e., high vibration damping (high logarithmic damping rate) and a high resonance suppression effect (low vibration transmissibility); a thermoplastic resin composition containing this vibration-damping material; and a molded article obtained by molding this thermoplastic resin composition.

[0013] The present inventors have found that a vibration-damping material comprising a polymer (B) having a specific polymer (b1) and a polymer (b2) can solve the above-mentioned problems, and have thus completed the present invention.

[0014] That is, the present invention is summarized as follows.

[0015] [1] A vibration-damping material comprising a polymer (B) having a polymer (b1) having a glass transition temperature of -10°C to 30°C and a polymer (b2) different from the polymer (b1), wherein the polymer (B) has a swelling degree of 900% or more in a THF-insoluble portion measured by the following method. <Method for measuring swelling degree> Polymer (B) is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble portion separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble portion is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble portion is calculated by the following formula: Swelling degree (%) = c / b x 100

[0016] [2] The vibration-damping material according to [1], wherein the polymer (b1) exhibits a peak temperature (peak value) of the primary dispersion of Tan δ measured by the following method, which is 3°C to 45°C, and the peak intensity of the peak value is 1.900 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press at a set temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C

[0017] [3] The vibration-damping material according to [2], wherein the polymer (b1) has a temperature (peak temperature) showing a peak value of the primary dispersion of Tan δ measured by the Tan δ measurement method of 3°C to 45°C, and a peak intensity which is the peak value is 1.950 or more.

[0018] [4] The vibration-damping material according to any one of [1] to [3], wherein the polymer (B) has a swelling degree of the THF-insoluble matter measured by the swelling degree measurement method of 1000% or more.

[0019] [5] The vibration-damping material according to any one of [1] to [4], wherein the polymer (b1) contains a structural unit derived from an acrylic acid ester compound and a structural unit derived from a methacrylic acid ester compound.

[0020] [6] The vibration-damping material according to any one of [1] to [5], wherein the polymer (b2) contains one or more structural units selected from the group consisting of structural units derived from methacrylic acid ester compounds, structural units derived from aromatic vinyl compounds, and structural units derived from vinyl cyanide compounds.

[0021] [7] The vibration-damping material according to any one of [1] to [6], wherein the polymer (b2) is bonded to at least a part of the polymer (b1).

[0022] [8] A thermoplastic resin composition comprising a resin component (A) containing a thermoplastic resin and a vibration-damping agent, wherein the thermoplastic resin composition has at least one glass transition temperature between -10°C and 30°C, and the thermoplastic resin composition has a vibration transmissibility (primary mode) of 19 times or less, as measured by the following method. <Vibration Transmissibility (primary mode)> A test piece measuring 13 mm x 125 mm x 3 mm is molded using the thermoplastic resin composition, and a 5 mm diameter hole is drilled on one side of the test piece, centered at a position 7 mm from the end, and the test piece is fixed to a vibrator with an M5 bolt. The vibration transmissibility (primary mode) of the vibration point (fixed side of the test piece) when the vibrator is vibrated with a sweep signal having a frequency of 10 Hz to 4000 Hz is measured. ２ ] and the acceleration a1 [m / sec ２ ] is measured, and the vibration transmissibility is calculated as the value at the resonance point (first mode) using the following formula: Vibration transmissibility [times] = a1 / a0

[0023] [9] The thermoplastic resin composition according to [8], wherein the swelling degree of the THF-insoluble matter measured by the following method is 900% or more. <Method for measuring swelling degree> The thermoplastic resin composition is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble matter separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble matter is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble matter is calculated by the following formula: Swelling degree (%) = c / b × 100

[0024]

[10] The thermoplastic resin composition according to [8] or [9], wherein the vibration-damping agent contains a polymer (b1) having a temperature (peak temperature) showing a peak value of the primary dispersion of Tan δ measured by the following method, between 3°C and 45°C, and a peak intensity of 1.900 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press at a set temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments), Mode: Tension, Frequency: 1 Hz, Heating rate: 5°C / min, Measurement temperature: -60 to +60°C

[0025]

[11] The vibration-damping material comprises a polymer (B) having: a polymer (b1) comprising structural units derived from an acrylic acid ester compound and structural units derived from a methacrylic acid ester compound, and having a glass transition temperature of -10°C to 30°C; and a polymer (b2) comprising one or more structural units selected from the group consisting of structural units derived from a methacrylic acid ester compound, structural units derived from an aromatic vinyl compound, and structural units derived from a vinyl cyanide compound, wherein the temperature (peak temperature) showing the peak value of the primary dispersion of Tan δ for the polymer (b1) measured by the following method (peak temperature) is 3°C to 45°C, and the peak intensity (peak value) is 1.950 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample of 36 mm in length and 10 mm in width is cut out from the sheet. Using the following dynamic viscoelasticity measuring device, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tensile jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak strength: Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C

[0026]

[12] The thermoplastic resin composition according to

[11] , wherein the polymer (B) has a swelling degree of 1000% or more in the THF-insoluble matter measured by the following method. <Method for measuring swelling degree> Polymer (B) is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble matter separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble matter is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble matter is calculated by the following formula: Swelling degree (%) = c / b × 100

[0027]

[13] The vibration-damping material according to

[11] or

[12] , wherein the polymer (b2) is bonded to at least a part of the polymer (b1).

[0028]

[14] The thermoplastic resin composition according to any one of [8] to

[13] , wherein the thermoplastic resin comprises an acrylic resin.

[0029]

[15] The thermoplastic resin composition according to any one of [8] to

[14] , wherein the thermoplastic resin comprises one or more selected from the group consisting of styrene-based resins, polybutylene terephthalate-based resins, polyamide-based resins, and polycarbonate-based resins.

[0030]

[16] The thermoplastic resin composition according to any one of [8] to

[15] , comprising 90 to 10 parts by weight of the resin component (A) and 10 to 90 parts by mass of the vibration-damping agent, so as to make a total of 100 parts by mass.

[0031]

[17] A molded article obtained by molding the thermoplastic resin composition according to any one of [8] to

[16] .

[0032] The vibration-damping additive of the present invention can provide a thermoplastic resin composition that can realize a molded article having excellent mechanical properties such as fluidity, impact resistance, heat resistance, and rigidity, as well as molded appearance, and also has high vibration-damping properties, i.e., high vibration damping properties (high logarithmic damping rate) and a high resonance-suppressing effect (low vibration transmissibility).The present invention also makes it possible to provide, using this thermoplastic resin composition, a molded article having excellent mechanical properties such as impact resistance, heat resistance, and rigidity, as well as molded appearance, and also has high vibration-damping properties, i.e., high vibration damping properties (high logarithmic damping rate) and a high resonance-suppressing effect (low vibration transmissibility).

[0033]

[0023] In other words, the vibration-damping agent comprising the specific polymer (B) according to the present invention not only provides vibration-damping properties but also effectively maintains the mechanical properties of the resulting molded article and provides a good molded appearance. By blending such a vibration-damping agent of the present invention with a resin component (A) containing a thermoplastic resin, it is possible to obtain a thermoplastic resin composition that is capable of providing a molded article having excellent mechanical properties such as fluidity, impact resistance, heat resistance, and rigidity, as well as molded appearance, and also having high vibration-damping properties, i.e., high vibration damping (high logarithmic damping rate) and a high resonance suppression effect (low vibration transmissibility).

[0034] Hereinafter, an embodiment of the present invention will be described in detail.

[0035] In the present invention, "(co)polymerization" means homopolymerization and / or copolymerization. "(Meth)acrylic" means acrylic and / or methacrylic. "(Meth)acrylate" means acrylate and / or methacrylate. "Structural unit" means a structural portion contained in a polymer and derived from a compound (monomer) before polymerization. The content ratio of structural units derived from each compound in a polymer corresponds to the content ratio of the compound in the raw material monomer mixture used to produce the polymer.

[0036] [Vibration-Damping Material] The vibration-damping material of the present invention is a material comprising a polymer (B) (hereinafter, sometimes referred to as "polymer (B) of the present invention") having a polymer (b1) (hereinafter, sometimes referred to as "polymer (b1) of the present invention") having a glass transition temperature of -10°C to 30°C, and a polymer (b2) (hereinafter, sometimes referred to as "polymer (b2) of the present invention") different from polymer (b1, characterized in that the swelling degree of the THF-insoluble matter of polymer (B) measured by the following method is 900% or more. <Method for Measuring Swelling Degree> Polymer (B) is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble matter separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble matter is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble matter is calculated by the following formula: Swelling degree (%) = c / b × 100

[0037] The polymer (B) of the present invention preferably has a swelling degree of the THF-insoluble matter measured by the above-mentioned swelling degree measuring method of 1000% or more.

[0038] The polymer (b1) of the present invention preferably has a temperature (peak temperature) at which the primary dispersion peak value of Tan δ measured by the following method is 3°C to 45°C, and the peak intensity, which is the peak value, is 1.900 or more, particularly 1.950 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C

[0039] The polymer (b1) of the present invention preferably contains a structural unit derived from an acrylic acid ester compound and a structural unit derived from a methacrylic acid ester compound.

[0040] The polymer (b2) of the present invention preferably contains one or more structural units selected from the group consisting of structural units derived from methacrylic acid ester compounds, structural units derived from aromatic vinyl compounds, and structural units derived from vinyl cyanide compounds.

[0041] That is, the polymer (B) of the present invention is preferably a polymer (B) (hereinafter sometimes referred to as "polymer (B) of one embodiment of the present invention") having: a polymer (b1) comprising structural units derived from an acrylic acid ester compound (hereinafter sometimes simply referred to as "acrylic acid ester units") and structural units derived from a methacrylic acid ester compound (hereinafter sometimes simply referred to as "methacrylic acid ester units") and having a glass transition temperature of -10°C to 30°C; and a polymer (b2) comprising one or more structural units selected from the group consisting of structural units derived from a methacrylic acid ester compound (methacrylic acid ester units), structural units derived from an aromatic vinyl compound (hereinafter sometimes simply referred to as "aromatic vinyl units"), and structural units derived from a vinyl cyanide compound (hereinafter sometimes simply referred to as "vinyl cyanide units").

[0042] In the polymer (B) of the present invention, it is preferable that the polymer (b2) of the present invention is bonded to at least a part of the polymer (b1).

[0043] [Mechanism] Vibration can be reduced in the room temperature region by having the glass transition temperature of the polymer (b1) contained in the polymer (B) of the present invention be −10° C. to 30° C. Furthermore, when the temperature (peak temperature) at which the primary dispersion of Tan δ measured for this polymer (b1) shows a peak value is 3° C. to 45° C., and the peak intensity as the peak value is 1.900 or more, particularly 1.950 or more, a more excellent vibration reduction effect and low vibration transmissibility can be obtained.

[0044] In particular, when the polymer (b1) contained in the polymer (B) of one embodiment of the present invention contains an acrylic acid ester unit and a methacrylic acid ester unit, vibration can be effectively reduced. This is thought to be due to the fact that the structural unit of a polar monomer, such as methyl methacrylate, converts vibration into heat. Furthermore, when the glass transition temperature of the polymer (b1) containing an acrylic acid ester unit and a methacrylic acid ester unit is -10°C to 30°C, vibration can be reduced in the room temperature region. Furthermore, when the temperature (peak temperature) showing the peak value of the primary dispersion of Tan δ measured for this polymer (b1) is 3°C to 45°C, and the peak intensity, which is the peak value, is 1.900 or more, particularly 1.950 or more, a better vibration reduction effect and low vibration transmissibility can be obtained.

[0045] Furthermore, by containing the polymer (b2) containing the specific structural unit, mechanical properties such as impact resistance can be exhibited.

[0046] Furthermore, when the swelling degree of the THF-insoluble portion of the polymer (B) of the present invention, measured by the swelling degree measurement method, is 900% or more, particularly 1000% or more, a significantly excellent vibration-reducing effect can be obtained. That is, when the swelling degree of the polymer (B) of the present invention, which is composed of the polymer (b1) and the polymer (b2) of the present invention, is 900% or more, it indicates that the molecular weight between crosslinking points of the polymer (b1) contained in the polymer (B) of the present invention is large and the polymer (b1) easily swells. The ease with which the polymer (b1) swells results in little inhibition of molecular chain motion due to crosslinking, and a significantly excellent vibration-reducing effect can be achieved.

[0047] [Polymer (B)] The polymer (B) of the present invention is a vibration-damping material comprising a polymer (B) having a polymer (b1) having a glass transition temperature of −10° C. to 30° C. and a polymer (b2) different from the polymer (b1), and as long as the degree of swelling of the polymer (B) measured by the above-mentioned method is 900% or more, there are no particular restrictions on the structural units of either the polymer (b1) or the polymer (b2), and there are also no particular restrictions on the form in which the polymer (b1) and the polymer (b2) are present.

[0048] [Relationship between polymer (b1) and polymer (b2)] The form of existence of polymer (b1) and polymer (b2) in polymer (B) of the present invention is not particularly limited, but it is effective for improving impact resistance and is preferable that at least a portion of polymer (b1) corresponding to the rubber portion is bonded to polymer (b2) corresponding to the resin portion by graft polymerization or the like to form a graft copolymer. In other words, in polymer (B) of the present invention, it is preferable that at least a portion of polymer (b2) is bonded to at least a portion of polymer (b1) by graft copolymerization or the like. Therefore, polymer (B) of the present invention is preferably composed of at least a graft copolymer in which at least a portion of polymer (b2) is grafted to at least a portion of polymer (b1), and a (co)polymer constituting polymer (b2) that is not grafted to polymer (b1). Polymer (B) of the present invention may further contain polymer (b1) to which polymer (b2) is not grafted, and further other components such as additives.

[0049] [Polymer (b1)] <Structural Unit> The structural unit of the polymer (b1) of the present invention is not particularly limited as long as it has a glass transition temperature of −10° C. to 30° C. However, in view of high vibration damping properties, ease of adjusting the glass transition point, etc., the polymer (b1) of the present invention is preferably a polymer (b1) comprising an acrylic acid ester unit and a methacrylic acid ester unit (hereinafter, sometimes referred to as “polymer (b1) of one embodiment of the present invention”).

[0050] When the polymer (b1) contains acrylic acid ester units and methacrylic acid ester units, the content ratio of the acrylic acid ester units and the methacrylic acid ester units contained in the polymer (b1) is adjusted in this ratio from the viewpoints of adjusting the glass transition temperature and the vibration reducing effect.

[0051] From this viewpoint, the content of acrylic acid ester units is preferably 41 to 70 parts by mass and the content of methacrylic acid ester units is preferably 59 to 30 parts by mass, and more preferably 46 to 60 parts by mass and 54 to 40 parts by mass of methacrylic acid ester units, per 100 parts by mass of the total of acrylic acid ester units and methacrylic acid ester units contained in polymer (b1) of one embodiment of the present invention.

[0052] The polymer (b1) according to one embodiment of the present invention may contain structural units other than acrylate units and methacrylate units, provided that the object of the present invention is not impaired. Examples of such structural units include structural units derived from a crosslinking agent, which will be described later.

[0053] When the polymer (b1) of one embodiment of the present invention contains a structural unit derived from a crosslinking agent, the appearance, such as gloss, is improved. However, if the content of the structural unit derived from the crosslinking agent is too high, the swelling degree of the resulting polymer (B) decreases, and the effect as a vibration-damping agent is impaired. For this reason, when the polymer (b1) of one embodiment of the present invention contains a structural unit derived from a crosslinking agent, the content thereof is preferably 0.4 parts by mass or less, particularly 0.10 to 0.25 parts by mass, per 100 parts by mass of the polymer (b1).

[0054] The polymer (b1) of one embodiment of the present invention may contain structural units derived from vinyl compounds other than acrylate units and methacrylate units, and examples of such vinyl compounds include the aromatic vinyl compounds and vinyl cyanide compounds exemplified in the description of the rubber-reinforced styrene thermoplastic resin described below. However, from the viewpoint of more effectively obtaining the above-mentioned effects due to the polymer (b1) containing acrylate units and methacrylate units, when the polymer (b1) of one embodiment of the present invention contains structural units derived from other vinyl compounds, the content ratio thereof is preferably 20 parts by mass or less, particularly 0 to 10 parts by mass, per 100 parts by mass of the polymer (b1).

[0055] As the acrylic acid ester compound constituting the acrylic acid ester unit, an acrylic acid ester compound having an alkyl group having 1 to 8 carbon atoms is preferred. Among these, ethyl acrylate, n-butyl acrylate, and n-ethylhexyl acrylate are preferred, and n-butyl acrylate is more preferred, because they provide excellent impact resistance to the thermoplastic resin composition containing the resulting polymer (B). These acrylic acid alkyl ester compounds may be used alone or in combination of two or more.

[0056] As the methacrylic acid ester compound constituting the methacrylic acid ester unit, a methacrylic acid ester compound in which the alkyl group has 1 to 8 carbon atoms is preferred. Among them, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate are preferred, and methyl methacrylate is more preferred, because they provide an excellent vibration-reducing effect to the thermoplastic resin composition containing the resulting polymer (B). These methacrylic acid ester compounds may be used alone or in combination of two or more.

[0057] Examples of crosslinking agents include allyl (meth)acrylate, butylene di(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, polyester di(meth)acrylate, polyurethane di(meth)acrylate, polybutadiene di(meth)acrylate, divinylbenzene, trivinylbenzene, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, diallyl dimethylammonium chloride, polyglycerin poly(meth)acrylate, etc. These may be used alone or in combination of two or more.

[0058] <Method for Producing Polymer (b1)> The polymer (b1) of one embodiment of the present invention can be produced according to a conventional method using a monomer mixture containing an acrylic acid ester compound, a methacrylic acid ester compound, and optionally a crosslinking agent and other vinyl compounds, so as to achieve the above-described preferred ratio of each structural unit.

[0059] The method for producing the polymer (b1) according to one embodiment of the present invention is not particularly limited, but examples thereof include a method of emulsion polymerization of a monomer mixture containing an acrylic acid ester compound, a methacrylic acid ester compound, and optionally a crosslinking agent and another vinyl compound.

[0060] An example of a method for producing polymer (b1) according to one embodiment of the present invention by emulsion polymerization is a method in which an acrylic acid ester compound, a methacrylic acid ester compound, and optionally a crosslinking agent and other vinyl compounds (hereinafter, these may be referred to as a "raw material monomer mixture") and a radical initiator are added to an aqueous solvent, and copolymerized in the presence of an emulsifier. The radical initiator, raw material monomer mixture, and crosslinking agent may be added all at once, in portions, or continuously.

[0061] The emulsifier may be any of known emulsifiers, which may be used alone or in combination of two or more thereof, such as carboxylic acid-based emulsifiers exemplified by alkali metal salts of oleic acid, palmitic acid, stearic acid, and rosin acid, and alkali metal salts of alkenyl succinic acid; and anionic emulsifiers selected from alkyl sulfates, sodium alkylbenzene sulfonates, sodium alkyl sulfosuccinates, and sodium polyoxyethylene nonylphenyl ether sulfates.

[0062] The amount of emulsifier added is preferably 0.01 to 3.0 parts by mass, more preferably 0.05 to 2.0 parts by mass, per 100 parts by mass of the total raw material monomer mixture, from the viewpoint of controlling the particle size of the polymer (b1).

[0063] The initiator used in the production of polymer (b1) according to one embodiment of the present invention is a radical polymerization initiator for radical polymerization, and the type thereof is not particularly limited. Examples of radical polymerization initiators include azo polymerization initiators, photopolymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that combine organic peroxides with transition metals and reducing agents. Among these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that can initiate polymerization by heating are preferred. These may be used alone or in combination of two or more.

[0064] Examples of the azo polymerization initiator include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl 2,2'-azobis( 2-methylpropionate), dimethyl 1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(2,4,4-trimethylpentane), and the like.

[0065] Examples of inorganic peroxides include potassium persulfate, sodium persulfate, ammonium persulfate, and hydrogen peroxide.

[0066] Examples of organic peroxides include peroxyester compounds. Specific examples of organic peroxides include α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. ester, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy 2-hexylhexanoate, t-butylperoxy 2-hexylhexanoate, t-butylperoxy isobutyrate, t-hexylperoxy isopropyl monocarbonate, t-butylperoxy maleic acid, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxy methyl urate, 2,5-dimethyl-2,5-bis(m-toluoylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoyl benzoate, t-butylperoxybenzoate, bis(t-butylperoxy)isophthalate, 1,1-bis(t-hexyl 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclododecane, 2,2-bis(t-butylperoxy)butane, n-butyl 4,4-bis(t-butylperoxy)valerate, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, α,Examples of such peroxides include α'-bis(t-butylperoxide)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, dilauroyl peroxide, diisononanoyl peroxide, t-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, dimethylbis(t-butylperoxy)-3-hexyne, bis(t-butylperoxyisopropyl)benzene, bis(t-butylperoxy)trimethylcyclohexane, butyl-bis(t-butylperoxy)valerate, t-butyl 2-ethylhexaneperoxyate, dibenzoyl peroxide, paramenthane hydroperoxide, and t-butyl peroxybenzoate.

[0067] The redox initiator is preferably a combination of an organic peroxide, ferrous sulfate, a chelating agent, and a reducing agent, such as a combination of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextrose, or a combination of t-butyl hydroperoxide, sodium formaldehyde sulfoxylate (Rongalit), ferrous sulfate, and disodium ethylenediaminetetraacetate.

[0068] The amount of initiator added is usually 5 parts by mass or less, preferably 3 parts by mass or less, for example, 0.001 to 3 parts by mass, per 100 parts by mass of the total raw material monomer mixture.

[0069] The emulsion polymerization is usually carried out at 40 to 100° C. for about 30 to 600 minutes.

[0070] <Glass Transition Temperature of Polymer (b1)> The glass transition temperature of the polymer (b1) of the present invention is characterized by being within the range of -10°C to +30°C. If the glass transition temperature is lower than -10°C or higher than 30°C, an excellent vibration-reducing effect cannot be obtained. From the viewpoint of achieving an excellent vibration-reducing effect, the glass transition temperature of the polymer (b1) is preferably -5°C to +25°C, particularly preferably 0°C to +20°C, more preferably +5°C to +20°C, and most preferably in the range of more than +5°C but not more than +20°C.

[0071] To produce a polymer (b1) having a glass transition temperature within the above range, for example, the ratio of acrylic acid ester to methacrylic acid ester in the polymer (b1) of one embodiment of the present invention may be adjusted.

[0072] The glass transition temperature of the polymer (b1) is measured by the method described in the Examples section below.

[0073] <Tan δ of Polymer (b1)> For the polymer (b1) of the present invention, the temperature at which the primary dispersion peak value of Tan δ measured by the following method (peak temperature) is 3°C to 45°C is preferably 1.900 or more, and the peak intensity, which is the peak value, is 1.900 or more. <Method for Measuring Tan δ> Polymer (b1) is used to form a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C

[0074] When the peak temperature of the polymer (b1) is 3° C. to 45° C., the vibration reducing effect is excellent. From this viewpoint, the peak temperature of the polymer (b1) is more preferably 12° C. to 39° C., particularly preferably 17° C. to 35° C.

[0075] Furthermore, if the peak intensity of the polymer (b1) is 1.900 or more, vibration is more effectively reduced. From this viewpoint, the peak intensity of the polymer (b1) is more preferably 1.950 or more, further preferably 2.000 or more, and particularly preferably 2.025 or more. The upper limit of the peak intensity is not particularly limited, but is usually 3 or less.

[0076] To produce a polymer (b1) that satisfies such a Tan δ peak temperature and peak intensity, it is necessary to select an optimum monomer constituting the polymer (b1) and adjust the amount of the crosslinking agent.

[0077] <Volume average particle diameter of polymer (b1)> The shape of the polymer (b1) of the present invention is not particularly limited, but a particulate shape is preferred from the viewpoint of uniformly dispersing the vibration-damping effect. The volume average particle diameter of the particulate polymer (b1) of the present invention is not particularly limited, but from the viewpoint of the above-mentioned dispersibility, it is preferably in the range of 30 to 500 nm, more preferably in the range of 50 to 400 nm, and even more preferably in the range of 80 to 300 nm.

[0078] Here, the volume average particle size of the polymer (b1) of the present invention can be measured by an optical method before mixing or reaction with the polymer (b2). Alternatively, after mixing or reaction, or in the case of a thermoplastic resin composition containing the polymer (B) of the present invention further containing the polymer (b1), the polymer (b1) can be dyed with a dye and then photographed using a transmission electron microscope (TEM), and the resulting image can be subjected to image analysis and measurement. Specifically, the volume average particle size of the polymer (b1) is measured by the method described in the Examples section below.

[0079] To produce a polymer (b1) having a volume average particle size within the above range, the type and amount of emulsifier used may be adjusted when producing the polymer (b1).

[0080] [Polymer (b2)] <Structural Unit> There are no particular limitations on the structural units that constitute the polymer (b2) of the present invention, but the polymer (b1) of the present invention is preferably a polymer (b2) (hereinafter, sometimes referred to as "polymer (b2) of one embodiment of the present invention") that includes one or more structural units selected from the group consisting of structural units derived from methacrylic acid ester compounds (methacrylic acid ester units), structural units derived from aromatic vinyl compounds (aromatic vinyl units), and structural units derived from vinyl cyanide compounds (vinyl cyanide units).

[0081] Examples of combinations of structural units contained in the polymer (b2) according to one embodiment of the present invention include, but are not limited to, the following 1) to 5): 1) a methacrylate unit alone; 2) a methacrylate unit and an aromatic vinyl unit; 3) a methacrylate unit and a vinyl cyanide unit; 4) an aromatic vinyl unit and a vinyl cyanide unit; and 5) a methacrylate unit, an aromatic vinyl unit and a vinyl cyanide unit.

[0082] Among these, 4) those having aromatic vinyl units and vinyl cyanide units, and 5) those having methacrylic acid ester units, aromatic vinyl units, and vinyl cyanide units are preferred in terms of achieving both vibration-reducing effect and physical properties.

[0083] In the case of the combination 2) above, from the viewpoint of vibration-reducing effect, it is preferable that the content of the methacrylic acid ester units be 95 to 60 parts by mass and the content of the aromatic vinyl units be 5 to 40 parts by mass per 100 parts by mass of the total of the methacrylic acid ester units and the aromatic vinyl units. In the case of the combination 3) above, it is preferable that the content of the methacrylic acid ester units be 95 to 60 parts by mass and the content of the vinyl cyanide units be 5 to 40 parts by mass per 100 parts by mass of the total of the methacrylic acid ester units and the vinyl cyanide units. In the case of the combination 4) above, it is preferable that the content of the aromatic vinyl units be 95 to 60 parts by mass and the content of the vinyl cyanide units be 5 to 40 parts by mass per 100 parts by mass of the total of the aromatic vinyl units and the vinyl cyanide units. In the case of the combination of 5) above, it is preferable from the viewpoint of vibration reduction effect and impact resistance that the content of the methacrylic acid ester units be 60 to 80 parts by mass, the content of the aromatic vinyl units be 35 to 15 parts by mass, and the content of the vinyl cyanide units be 25 to 5 parts by mass, relative to 100 parts by mass of the total of the methacrylic acid ester units, aromatic vinyl units, and vinyl cyanide units.

[0084] The polymer (b2) according to one embodiment of the present invention may contain structural units derived from vinyl compounds other than aromatic vinyl units, vinyl cyanide units, and alkyl methacrylate units, provided that the object of the present invention is not impaired. However, in order to more effectively obtain the effects of including aromatic vinyl units, vinyl cyanide units, and alkyl methacrylate units, the content of structural units derived from other vinyl compounds per 100 parts by mass of the polymer (b2) is preferably 20 parts by mass or less, particularly 0 to 10 parts by mass.

[0085] Examples of aromatic vinyl compounds constituting the aromatic vinyl units of polymer (b2) according to one embodiment of the present invention include styrene, α-methylstyrene, o-, m-, or p-methylstyrene, vinylxylene, p-t-butylstyrene, and ethylstyrene. Among these, styrene is preferred from the viewpoint of enhancing the impact resistance of the resulting molded article. These aromatic vinyl compounds may be used alone or in combination of two or more.

[0086] Examples of vinyl cyanide compounds constituting the vinyl cyanide unit of polymer (b2) according to one embodiment of the present invention include acrylonitrile and methacrylonitrile. Among these, acrylonitrile is preferred from the viewpoint of improving the impact resistance of the resulting molded article. These vinyl cyanide compounds may be used alone or in combination of two or more.

[0087] As the methacrylic acid ester compound constituting the alkyl methacrylate unit of polymer (b2) according to one embodiment of the present invention, a methacrylic acid ester compound in which the alkyl group has 1 to 8 carbon atoms is preferred. Among these, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate are preferred, with methyl methacrylate being more preferred, as they provide an excellent vibration-reducing effect to the thermoplastic resin composition containing the resulting polymer (B). These methacrylic acid ester compounds may be used alone or in combination of two or more.

[0088] Examples of other vinyl compounds constituting the other vinyl compound units include vinyl compounds other than aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds used in the production of the rubber-reinforced styrene-based thermoplastic resin (A1) described below.

[0089] <Method for Producing Polymer (b2)> The polymer (b2) of one embodiment of the present invention can be produced by carrying out polymerization, preferably in the presence of the polymer (b1), using a raw material monomer mixture containing one or more of an aromatic vinyl compound, a vinyl cyanide compound, and a methacrylic acid ester compound, and other vinyl compounds used as needed, in the same manner as in the method for polymerizing the vinyl monomer (a1) into the rubbery polymer (g) in the rubber-reinforced styrenic thermoplastic resin described below.

[0090] [Polymer (B)] <Content ratio of polymer (b1) and polymer (b2)> The polymer (B) of the present invention, particularly the polymer (B) of one embodiment of the present invention suitable as the polymer (B) of the present invention, is produced by polymerizing one or more of the aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds constituting the polymer (b2) of one embodiment of the present invention, and other vinyl compounds used as needed, in the presence of the polymer (b1) of one embodiment of the present invention. This method makes it possible to obtain a polymer (B), which is a graft copolymer in which at least a portion of the polymer (b2) is graft copolymerized onto at least a portion of the polymer (b1). The polymer (B) of the present invention may contain a polymer (b2) that is not graft polymerized onto the polymer (b1), or a polymer (b1) to which the polymer (b2) is not graft polymerized.

[0091] The preferred content ratios of polymer (b1) and polymer (b2) in polymer (B) of the present invention are as follows. That is, if the content ratio of polymer (b1) is too high, although vibration-damping properties will be improved, other mechanical properties may deteriorate or manufacturing difficulties may occur. Conversely, if the content ratio of polymer (b1) is too low, when mixed with resin component (A) described below as a vibration-damping additive, sufficient effects in terms of vibration-damping properties, etc. may not be exhibited. From this perspective, the ratio of polymer (b1) and polymer (b2) contained in polymer (B) of the present invention is preferably 30 to 80 parts by mass of polymer (b1) to 70 to 20 parts by mass of polymer (b2) (where the total of polymer (b1) and polymer (b2) is 100 parts by mass), more preferably 40 to 70 parts by mass of polymer (b1) to 60 to 30 parts by mass of polymer (b2).

[0092] <Swelling degree of THF-insoluble fraction> The swelling degree of the THF-insoluble fraction of the polymer (B) of the present invention (hereinafter sometimes simply referred to as "swelling degree") measured by the following method is 900% or more. <Method for measuring swelling degree> After immersing the polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble fraction separated by centrifugation is vacuum dried and its weight (weight b) is measured. The obtained THF-insoluble fraction is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble fraction is calculated by the following formula: Swelling degree (%) = c / b × 100

[0093] The swelling degree of the polymer (B) of the present invention, which is composed of the polymer (b1) and the polymer (b2), is 900% or more, as described above, indicates that the molecular weight between crosslinking points of the polymer (b1) contained in the polymer (B) of the present invention is large and the polymer (b1) easily swells. The fact that the polymer (b1) easily swells means that the inhibition of molecular chain motion due to crosslinking is small, and the polymer (b1) exhibits a significantly excellent vibration-reducing effect.

[0094] From the viewpoint of vibration reduction effect, the swelling degree of the polymer (B) of the present invention is preferably 1000% or more, more preferably 1200% or more. On the other hand, there is no particular upper limit to the swelling degree of the polymer (B) of the present invention, but in order to improve the appearance, the swelling degree of the polymer (B) of the present invention is preferably 1200 to 3000%.

[0095] To produce polymer (B) that satisfies such a swelling degree, a crosslinking agent may be omitted in the production of polymer (b1), or even if a crosslinking agent is used, the amount of the crosslinking agent may be set to 0.65 parts by mass or less, particularly 0 to 0.55 parts by mass, per 100 parts by mass of polymer (b1), thereby reducing the crosslinked structure in polymer (b1).

[0096] <Gel content> The gel content of the polymer (B) of the present invention is preferably 90% or less, particularly 88% or less. If the gel content is 90% or less, the vibration reducing effect is excellent. On the other hand, from the viewpoint of appearance such as gloss, the gel content is preferably 75% or more.

[0097] To produce a polymer (B) having such a gel content, the amount of the crosslinking agent used in producing the polymer (b1) may be adjusted.

[0098] The gel content of the polymer (B) is measured by the method described in the Examples section below.

[0099] <Molecular Weight of Acetonitrile-Soluble Fraction> The weight average molecular weight of the acetonitrile-soluble fraction of the polymer (B) of the present invention (hereinafter sometimes referred to as "molecular weight of the acetonitrile-soluble fraction") is preferably 50,000 to 80,000, particularly 55,000 to 70,000. When the molecular weight of the acetonitrile-soluble fraction of the polymer (B) is within the above range, the polymer has excellent impact resistance.

[0100] To produce polymer (B) having such a molecular weight of the acetonitrile-soluble portion, the amount of chain transfer agent used in producing polymer (b2) may be adjusted.

[0101] The molecular weight of the acetonitrile-soluble portion of the polymer (B) is measured by the method described in the Examples section below.

[0102] <Graft ratio> The graft ratio of the polymer (B) of the present invention is preferably 35 to 120%, particularly 40 to 80%. When the graft ratio is equal to or higher than the lower limit, the impact resistance is excellent. On the other hand, when the graft ratio is equal to or lower than the upper limit, sufficient fluidity can be ensured for injection molding.

[0103] To produce polymer (B) having such a graft ratio, the amounts of the polymerization initiator and chain transfer agent used during the production of polymer (b2) may be adjusted.

[0104] The graft ratio of the polymer (B) is measured by the method described in the Examples section below.

[0105] [Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention is a thermoplastic resin composition comprising a resin component (A) containing a thermoplastic resin and a vibration-damping agent, wherein the thermoplastic resin composition has at least one glass transition temperature between -10°C and 30°C, and the thermoplastic resin composition has a vibration transmissibility (primary mode) of 19 times or less, as measured by the following method. <Vibration Transmissibility (primary mode)> A test piece measuring 13 mm x 125 mm x 3 mm is molded using the thermoplastic resin composition, and a 5 mm diameter hole is drilled on one side of the test piece at a position 7 mm from the end, and the test piece is fixed to a vibrator with an M5 bolt. The vibration of the vibration point (fixed side of the test piece) when the vibrator is vibrated with a sweep signal having a frequency of 10 Hz to 4000 Hz is measured. ２ ] and the acceleration a1 [m / sec ２ ] is measured, and the vibration transmissibility is calculated as the value at the resonance point (first mode) using the following formula: Vibration transmissibility [times] = a1 / a0

[0106] [Physical Properties of Thermoplastic Resin Composition] <Glass Transition Temperature> The thermoplastic resin composition of the present invention is characterized by having at least one glass transition temperature in the range of −10 to 30° C. Hereinafter, the glass transition temperature that the thermoplastic resin composition of the present invention has in the range of −10 to 30° C. may be referred to as the “specific glass transition temperature.”

[0107] A thermoplastic resin composition having a specific glass transition temperature in the range of −10° C. to 30° C. has an excellent vibration-reducing effect. From the viewpoint of the vibration-reducing effect, the specific glass transition temperature of the thermoplastic resin composition of the present invention is preferably in the range of −5° C. to +25° C., more preferably in the range of 0° C. to +20° C., even more preferably in the range of +5° C. to +20° C., and still more preferably in the range of more than +5° C. but not more than +20° C.

[0108] As long as the thermoplastic resin composition of the present invention has at least one glass transition temperature in the range of −10° C. to +30° C., it may have another glass transition temperature in a temperature range other than the range of −10° C. to +30° C.

[0109] The specific glass transition temperature of the thermoplastic resin composition of the present invention corresponds to, for example, the glass transition temperature of the polymer (B) of the present invention as a vibration-damping property imparting material preferably used in the thermoplastic resin composition of the present invention, more specifically, the glass transition temperature of the polymer (b1) of the present invention in the polymer (B) of the present invention.

[0110] <Vibration Transmissibility (Primary Mode)> The thermoplastic resin composition of the present invention exhibits an excellent vibration-reducing effect, with a vibration transmissibility (primary mode) measured by the above-described method being 19 or less. From the viewpoint of vibration-reducing effect, this vibration transmissibility is preferably 18 or less, more preferably 15 or less, even more preferably 12 or less, and particularly preferably 10 or less.

[0111] More specifically, the vibration transmissibility of the thermoplastic resin composition is measured by the method described in the Examples section below.

[0112] <Logarithmic decrement δ> From the viewpoint of reducing vibration, the thermoplastic resin composition of the present invention preferably has a logarithmic decrement δ of 0.20 or more, and more preferably 0.25 or more, when measured by the method described in the Examples section below.

[0113] From the viewpoint of vibration-damping properties, the thermoplastic resin composition of the present invention preferably uses the acrylic resin (A3) described below as the resin component (A). In this case, a thermoplastic resin composition obtained by mixing the vibration-damping agent of the present invention and the acrylic resin (A3) in a mass ratio of vibration-damping agent:acrylic resin (A3) ranging from 20:80 to 85:15 exhibits good vibration-damping properties, with a logarithmic attenuation factor δ of 0.40 to 0.78 and a vibration transmissibility (first mode) of 11.5 to 7.1.

[0114] <Swelling degree of THF-insoluble fraction> The thermoplastic resin composition of the present invention preferably has a swelling degree of 900% or more, measured by the following method. <Method for measuring swelling degree> A thermoplastic resin composition is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble fraction separated by centrifugation is vacuum dried and its weight (weight b) is measured. The obtained THF-insoluble fraction is again immersed in THF for 24 hours, and the weight of the sample swollen with THF (weight c) is measured, and the swelling degree of the THF-insoluble fraction is calculated by the following formula: Swelling degree (%) = c / b × 100

[0115] The swelling degree of the THF-insoluble matter in the thermoplastic resin composition of the present invention is preferably 900% or more, more preferably 1000% or more, and even more preferably 1200% or more, in order to achieve a vibration-reducing effect. There is no particular upper limit to the swelling degree of the thermoplastic resin composition, but in order to improve the appearance, it is preferably 1200 to 3000%.

[0116] When the vibration-damping agent contained in the thermoplastic resin composition of the present invention is the polymer (B) of the present invention, which is preferably used as a vibration-damping agent, the swelling degree of the THF-insoluble matter in the thermoplastic resin composition of the present invention is usually determined by the swelling degree measurement method described above, based on the swelling degree of the polymer (B). Therefore, in the examples shown below, the swelling degree of the thermoplastic resin composition itself is not measured, but the swelling degree of the polymer (B) contained in the thermoplastic resin composition can be considered to be the swelling degree of the thermoplastic resin composition.

[0117] <Aromatic Vinyl Compound Units> The thermoplastic resin composition of the present invention preferably contains structural units derived from the resin component (A) and / or the vibration-damping additive and derived from an aromatic vinyl compound (hereinafter, sometimes referred to as "aromatic vinyl compound units"). The content of the aromatic vinyl compound units in the thermoplastic resin composition of the present invention is preferably 0.5 to 80 mass%, more preferably 1.0 to 70 mass%, and even more preferably 1.5 to 60 mass%. When the content of the aromatic vinyl compound units in the thermoplastic resin composition of the present invention is equal to or greater than the above-mentioned lower limit, excellent moldability is achieved. Furthermore, when the content of the aromatic vinyl compound units in the thermoplastic resin composition of the present invention is equal to or greater than the above-mentioned lower limit, uniform dispersion of the vibration-damping additive is achieved, resulting in stable vibration-damping properties. On the other hand, when the content of the aromatic vinyl compound units in the thermoplastic resin composition of the present invention is equal to or less than the above-mentioned upper limit, excellent impact resistance is achieved.

[0118] The content of the aromatic vinyl compound unit in the thermoplastic resin composition can be determined by infrared spectroscopy (IR), pyrolysis chromatography, or a combination of these. Alternatively, it can be calculated by adding up the proportions of the aromatic vinyl compound unit contained in the resin component (A) and the vibration-damping agent used in the production of the thermoplastic resin composition and the amounts charged as raw materials for production.

[0119] [Vibration-damping agent] The vibration-damping agent contained in the thermoplastic resin composition of the present invention preferably contains a polymer (b1) having a temperature (peak temperature) showing a peak value of the primary dispersion of Tan δ measured by the method described above in the description of the polymer (b1) of the present invention, of 3°C to 45°C, and a peak intensity as the peak value of 1.900 or more.

[0120] Furthermore, the vibration-damping property imparting material contained in the thermoplastic resin composition of the present invention is preferably a vibration-damping property imparting material comprising a polymer (B) having: a polymer (b1) which comprises structural units derived from an acrylic acid ester compound and structural units derived from a methacrylic acid ester compound and has a glass transition temperature of −10° C. to 30° C.; and a polymer (b2) which contains one or more structural units selected from the group consisting of structural units derived from a methacrylic acid ester compound, structural units derived from an aromatic vinyl compound, and structural units derived from a vinyl cyanide compound; and the polymer (b1) has a peak temperature of 3° C. to 45° C. and a peak intensity, which is the peak value, of 1.950 or more.

[0121] The swelling degree of the THF-insoluble portion of the polymer (B) is preferably 1000% or more, and the polymer (b2) is preferably bonded to at least a part of the polymer (b1).

[0122] That is, the vibration-damping agent contained in the thermoplastic resin composition of the present invention is preferably the vibration-damping agent of the present invention described above, that is, the polymer (B) of the present invention.

[0123] [Content ratio of resin component (A) and vibration-damping agent] The thermoplastic resin composition of the present invention may contain only one or more of the polymer (B) of the present invention as the vibration-damping agent. The resin component (A) may also contain only one or more of the various thermoplastic resins described below.

[0124] The thermoplastic resin composition of the present invention preferably contains 90 to 10 parts by mass of resin component (A) and 10 to 90 parts by mass of a vibration-damping additive, totaling 100 parts by mass. When the content of resin component (A) is equal to or less than the upper limit and the content of the vibration-damping additive is equal to or greater than the lower limit, the vibration-reducing effect is excellent. On the other hand, when the content of resin component (A) is equal to or greater than the lower limit and the content of the vibration-damping additive is equal to or less than the upper limit, the inherent properties of resin component (A) are fully exhibited. The thermoplastic resin composition of the present invention more preferably contains 80 to 20 parts by mass of resin component (A) and 20 to 80 parts by mass of the vibration-damping additive, per 100 parts by mass of the total of resin component (A) and the vibration-damping additive. The preferred mixing ratios for each thermoplastic resin as resin component (A) will be described later.

[0125] [Resin Component (A)] The thermoplastic resin composition of the present invention contains a thermoplastic resin as the resin component (A).

[0126] Examples of the thermoplastic resin contained as the resin component (A) in the thermoplastic resin composition of the present invention include styrene-based resins, acrylic-based resins, polycarbonate-based resins such as aromatic polycarbonate resins, polyester-based resins such as polybutylene terephthalate resins, polyolefin-based resins, vinyl chloride-based resins, polyamide-based resins, polyacetal-based resins, polyphenylene ether-based resins, and polyarylene sulfide-based resins.

[0127] Examples of the styrene-based resin include rubber-reinforced styrene-based resins (A1) containing rubber polymers such as butadiene rubber, butyl acrylate rubber, and ethylene-propylene rubber, and styrene-based resins (A2) that do not contain rubber polymers such as acrylonitrile-styrene copolymers.

[0128] These thermoplastic resins can be used alone or in combination of two or more.

[0129] Among these thermoplastic resins, it is preferable to contain a styrene-based resin (A2) from the viewpoints of moldability, appearance, rigidity, and heat resistance. Furthermore, it is preferable to contain a rubber-reinforced styrene-based thermoplastic resin (A1) from the viewpoint of impact resistance. Furthermore, it is preferable to contain an acrylic resin (A3) from the viewpoint of high vibration damping properties. The resin component (A) according to the present invention does not include the polymer (B) of the present invention, which is the vibration damping agent described above.

[0130] When the thermoplastic resin composition of the present invention contains, as the resin component (A), a thermoplastic resin other than the rubber-reinforced styrene-based thermoplastic resin (A1), the styrene-based resin (A2), and the acrylic-based resin (A3), the content thereof is preferably 50% by mass or less, particularly 30% by mass or less, based on 100% by mass of the resin component (A) containing the rubber-reinforced styrene-based thermoplastic resin (A1), the styrene-based resin (A2), the acrylic-based resin (A3), and other resins.

[0131] <Rubber-reinforced styrene-based thermoplastic resin (A1)> The rubber-reinforced styrene-based thermoplastic resin (A1) contains a rubber polymer portion and a vinyl copolymer portion. The rubber-reinforced styrene-based thermoplastic resin (A1) can be produced by polymerizing a vinyl monomer (a1) such as an aromatic vinyl compound in the presence of a rubber polymer (g).

[0132] Examples of the rubbery polymer (g) include conjugated diene rubbers such as polybutadiene, polyisoprene, butadiene-styrene copolymer, and butadiene-acrylonitrile copolymer; olefin rubbery polymers such as ethylene-α-olefin rubbery polymers such as ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-butene-1 copolymer, and ethylene-butene-1-non-conjugated diene copolymer; acrylic rubber; silicone rubber; polyurethane rubber; silicone-acrylic IPN rubber; natural rubber; conjugated diene block copolymer; and hydrogenated conjugated diene block copolymer.

[0133] Among these, rubbery polymers (g) containing butadiene, such as conjugated diene rubbers such as polybutadiene, butadiene-styrene copolymers, and butadiene-acrylonitrile copolymers, are preferred for indoor applications requiring not only vibration damping but also impact resistance. Among these, rubber-reinforced styrene-based thermoplastic resins (A1) obtained by polymerizing a vinyl monomer (a1) containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of a butadiene-based rubbery polymer are preferred because they are also effective in improving impact resistance. That is, the rubber-reinforced styrene-based thermoplastic resin (A1) is preferably a rubber-reinforced styrene-based thermoplastic resin (A1) containing a rubbery polymer portion made of butadiene rubber and a vinyl-based copolymer portion containing structural units derived from an aromatic vinyl compound and structural units derived from a vinyl cyanide compound.

[0134] Furthermore, in outdoor applications such as automotive exterior parts and residential exterior parts, where not only vibration damping but also weather resistance is required, preferred rubber polymers (g) are ethylene-α-olefin rubbers, acrylic rubbers, silicone rubbers, and silicone-acrylic composite rubbers. Among these, ethylene-α-olefin rubbers, silicone rubbers, and silicone-acrylic composite rubbers are preferred because they are also effective in improving impact resistance. Particularly preferred are rubber-reinforced styrenic thermoplastic resins (A1) obtained by polymerizing a vinyl monomer (a1) containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of these rubber polymers (g). That is, the rubber-reinforced styrenic thermoplastic resin (A1) is preferably a rubber-reinforced styrenic thermoplastic resin (A1) containing a rubbery polymer portion composed of an ethylene-α-olefin rubber, silicone rubber, or silicone-acrylic composite rubber, and a vinyl copolymer portion containing structural units derived from an aromatic vinyl compound and structural units derived from a vinyl cyanide compound.

[0135] Examples of the aromatic vinyl compound used herein include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, hydroxystyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, fluorostyrene, p-t-butylstyrene, ethylstyrene, vinylnaphthalene, divinylbenzene, 1,1-diphenylstyrene, N,N-diethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, and vinylpyridine, with styrene and α-methylstyrene being preferred, and styrene being particularly preferred. These compounds may be used alone or in combination of two or more.

[0136] Examples of other vinyl monomers copolymerizable with aromatic vinyl compounds include vinyl cyanide compounds, (meth)acrylic acid ester compounds, maleimide compounds, and various other functional group-containing unsaturated compounds. These other vinyl monomers can be used alone or in combination of two or more.

[0137] Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile. These can be used alone or in combination of two or more. The use of a vinyl cyanide compound imparts chemical resistance. The amount of the vinyl cyanide compound used is usually 0 to 60% by mass, preferably 5 to 50% by mass, based on the total amount of vinyl monomer (a1).

[0138] Examples of (meth)acrylic acid ester compounds include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. These compounds can be used alone or in combination of two or more. The use of a (meth)acrylic acid ester compound improves surface hardness. The amount of the (meth)acrylic acid ester compound used is usually 0 to 80 mass% as a proportion of the total amount of vinyl monomer (a1).

[0139] Examples of maleimide compounds include maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, and N-benzylmaleimide. These can be used alone or in combination of two or more. To introduce maleimide units, maleic anhydride may be copolymerized and then imidized. The use of a maleimide compound imparts heat resistance. The amount of the maleimide compound used is typically 1 to 60% by mass relative to the total amount of vinyl monomer (a1).

[0140] The rubber-reinforced styrene-based thermoplastic resin (A1) can be produced by a known polymerization method, such as emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, or a polymerization method combining these.

[0141] The rubber-reinforced styrene-based thermoplastic resin (A1) may be used alone or in combination of two or more types having different copolymer compositions, physical properties, etc.

[0142] <Styrenic Resin (A2)> The styrene-based resin (A2) is a (co)polymer obtained by polymerizing an aromatic vinyl compound or an aromatic vinyl compound with another vinyl monomer (a2) copolymerizable with the aromatic vinyl compound. The styrene-based resin (A2) does not include the rubbery polymer (g) described in the description of the rubber-reinforced styrene-based thermoplastic resin (A1). That is, the vinyl monomer (a2) may be an aromatic vinyl compound alone or a mixture of an aromatic vinyl compound and another vinyl monomer copolymerizable with the aromatic vinyl compound. The aromatic vinyl compound and the other vinyl monomer copolymerizable with the aromatic vinyl compound used here can be any of the vinyl monomers (a1) described above for the rubber-reinforced styrene-based thermoplastic resin (A1). The vinyl monomer (a2) may be the same as or different from the vinyl monomer (a1).

[0143] The content of monomers other than aromatic vinyl compounds in the vinyl monomer (a2) is usually 80% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less, when the total amount of the vinyl monomer (a2) is 100% by mass.

[0144] Preferred styrene-based resins (A2) include styrene homopolymers, styrene-acrylonitrile copolymers, α-methylstyrene-acrylonitrile copolymers, α-methylstyrene-styrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-methyl methacrylate copolymers, α-methylstyrene-methyl methacrylate copolymers, α-methylstyrene-acrylonitrile-methyl methacrylate copolymers, styrene-maleimide compound copolymers, and copolymers of these with the above-mentioned functional group-containing unsaturated compounds.

[0145] The styrene-based resin (A2) can be produced by a known polymerization method such as emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, or a combination thereof.

[0146] The styrene-based resin (A2) may be used alone or in combination of two or more types having different copolymerization compositions, physical properties, etc.

[0147] <Acrylic Resin (A3)> The acrylic resin (A3) can be obtained by polymerizing a vinyl monomer containing a (meth)acrylic acid ester monomer or a vinyl monomer mixture thereof by a known method. The vinyl monomer mixture contains a (meth)acrylic acid ester monomer as an essential component and may contain up to 40 mass% of other vinyl monomers shown below as necessary.

[0148] Examples of the (meth)acrylic acid ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, phenyl (meth)acrylate, etc. These can be used alone or in combination of two or more.

[0149] Examples of vinyl monomers other than (meth)acrylic acid ester monomers include aromatic vinyl monomers, vinyl cyanide monomers, maleimide monomers, (meth)acrylic acid, etc. As the aromatic vinyl monomers and vinyl cyanide monomers, the same monomers as those contained in the vinyl monomer (a1) can be used, and one type can be used alone or two or more types can be used in combination.

[0150] Examples of maleimide monomers include N-alkylmaleimides (N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-i-propylmaleimide, N-n-butylmaleimide, N-i-butylmaleimide, N-t-butylmaleimide, etc.), N-cycloalkylmaleimides (N-cyclohexylmaleimide, etc.), and N-arylmaleimides (N-phenylmaleimide, N-alkyl-substituted phenylmaleimide, N-chlorophenylmaleimide, etc.). These can be used alone or in combination of two or more.

[0151] Among the acrylic resins (A3), specific examples of copolymer resins of methyl methacrylate and methyl acrylate include commercially available products such as "Parapet G" manufactured by Kuraray Co., Ltd., and "Acrypet VH" and "Acrypet MD" manufactured by Mitsubishi Chemical Corporation. Specific examples of polyacrylic resins containing both (meth)acrylic acid ester-based monomer units and maleimide-based monomer units include commercially available products such as "Parapet SH-N" manufactured by Kuraray Co., Ltd., and "Polyimilex PML203" manufactured by Nippon Shokubai Co., Ltd.

[0152] These acrylic resins (A3) may be used alone or in combination of two or more.

[0153] <Aromatic Polycarbonate Resin> Any aromatic polycarbonate resin obtained by a known polymerization method can be used, such as an interfacial polycondensation method between a dihydroxyaryl compound and phosgene, or an ester exchange reaction (melt polycondensation) between a dihydroxyaryl compound and a carbonate compound such as diphenyl carbonate.

[0154] Examples of the dihydroxyaryl compounds include bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3-t-butylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxyphenyl ether, 4,4'-dihydroxyphenyl sulfide, 4,4'-dihydroxyphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, hydroquinone, resorcinol, etc. Further examples include hydroxyaryloxy-terminated polyorganosiloxanes (see, for example, U.S. Pat. No. 3,419,634). These may be used alone or in combination of two or more. Of these, 2,2-bis(4-hydroxyphenylpropane (bisphenol A) is preferred.

[0155] The viscosity average molecular weight of the aromatic polycarbonate resin is preferably 12,000 to 40,000, more preferably 15,000 to 35,000, and particularly preferably 18,000 to 30,000. A higher molecular weight increases the mechanical strength of the resulting molded article, but decreases the fluidity, tending to result in a poor appearance of the molded article. Two or more aromatic polycarbonate resins with different molecular weights can also be used as the aromatic polycarbonate resin.

[0156] Here, the viscosity average molecular weight of an aromatic polycarbonate resin can usually be calculated by inserting the specific viscosity (ηsp) measured at 20°C and a concentration of 0.7 g / 100 ml (methylene chloride) using methylene chloride as a solvent into the following formula (iii): Viscosity average molecular weight = (η) × 8130 １．２０５ (iii) Here, [η] = [(ηsp × 1.12 + 1) １／２ −1) / 0.56C, where C indicates concentration.

[0157] <Polybutylene terephthalate-based resin> Polybutylene terephthalate-based resins are typically resins obtained by polycondensation reaction of terephthalic acid and / or its derivatives with 1,4-butanediol and / or its derivatives. As long as the object of the present invention is not impaired, polybutylene terephthalate-based resins copolymerized with other dicarboxylic acids and / or their derivatives, glycols, etc. may also be used.

[0158] Examples of copolymerizable dicarboxylic acids include isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stilbene dicarboxylic acid, 4,4-biphenyl dicarboxylic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, bisbenzoic acid, bis(p-carboxyphenyl)methane, anthracene dicarboxylic acid, 4,4-diphenyl ether dicarboxylic acid, 4,4-diphenoxyethane dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexane dicarboxylic acid, and 1,4-cyclohexane dicarboxylic acid, as well as derivatives thereof. These copolymerizable dicarboxylic acids and / or derivatives thereof may be appropriately selected from the above examples and used alone or in combination of two or more.

[0159] On the other hand, examples of copolymerizable glycols include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, trans- or cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, decamethylene glycol, cyclohexanediol, p-xylenediol, bisphenol A, tetrabromobisphenol A, tetrabromobisphenol A-bis(2-hydroxyethyl ether), etc. These copolymerizable glycols may be appropriately selected from the examples given above and used alone or in combination of two or more.

[0160] The polybutylene terephthalate resin used in the present invention preferably has an intrinsic viscosity of 0.7 to 1.50 dL / g, from the viewpoint of ensuring the flowability and moldability of the thermoplastic resin composition of the present invention and the impact resistance of the molded article of the present invention molded using this thermoplastic resin composition. Here, the intrinsic viscosity of the polybutylene terephthalate resin is a value measured at 30°C in a mixed solution of tetrachloroethane and phenol in a 1:1 (mass ratio).

[0161] The thermoplastic resin composition of the present invention, which uses a polybutylene terephthalate resin, has good chemical resistance, electrical insulation, and abrasion resistance. Therefore, this thermoplastic resin composition can be used for plastic gears, cooling fans for personal computers, etc. Furthermore, by further mixing fillers such as glass fiber and carbon fiber, it can also be used for cooling fan housings, etc.

[0162] Specific examples of polybutylene terephthalate resins include commercially available products such as "NovaDuran" manufactured by Mitsubishi Chemical Corporation and "Duranex" manufactured by Polyplastics Co., Ltd.

[0163] These polybutylene terephthalate resins may be used alone or in combination of two or more.

[0164] <Polyamide-based resin> Examples of polyamide-based resins include polyamides obtained from diamines and dicarboxylic acids. Here, examples of diamines include aliphatic, alicyclic, and aromatic diamines such as ethylenediamine, diaminobutane, hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 1,3- and 1,4-bis(aminomethyl)cyclohexane, bis(p-aminocyclohexyl)methane, metaxylylenediamine, and paraxylylenediamine. These can be used alone or in combination of two or more.

[0165] Examples of dicarboxylic acids include aliphatic, alicyclic, and aromatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid. These may be used alone or in combination of two or more.

[0166] Examples of polyamide-based resins that may be used include polyamides obtained by ring-opening polymerization of lactams such as ξ-caprolactam and ω-dodecalactam; polyamides obtained from 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid; copolymer polyamides thereof; mixed polyamides thereof; and polyamide elastomers having polyamide as a hard segment and polyether as a soft segment. Among these, polycaproamide (nylon 6), polyundecaneamide (nylon 11), polydodecaamide (nylon 12), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), and copolymers thereof are preferred because they are produced industrially at low cost and in large quantities. Examples of copolymers include nylon 6 / 66, nylon 6 / 610, nylon 6 / 12, nylon 66 / 12, and nylon 6 / 66 / 610 / 12. The polyamide resin may be a mixture of these. As the polyamide resin, bis(p-aminocyclohexyl)methane / terephthalic acid / isophthalic acid polyamide is also preferred.

[0167] These polyamide resins may be used alone or in combination of two or more.

[0168] The thermoplastic resin composition of the present invention using a polyamide-based resin has excellent chemical resistance, impact resistance, and abrasion resistance. Therefore, this thermoplastic resin composition can be used for plastic gears and cooling fans. Furthermore, by further mixing fillers such as glass fiber and carbon fiber, it can also be used for cooling fan housings. Furthermore, when reinforced with carbon fiber (CFRTP: carbon fiber reinforced thermoplastic plastics / thermoplastic CFRP: carbon fiber reinforced thermoplastics), it can also be used as a metal replacement or for housings for devices to prevent malfunctions related to robots.

[0169] <Suitable Mixing Ratio of Resin Component (A) and Vibration-Dampening Material> When emphasis is placed particularly on improving vibration-damping properties in the thermoplastic resin composition of the present invention, it is preferable to use an acrylic resin (A3) as the resin component (A). In this case, the mixing ratio of the vibration-damping material and the acrylic resin (A3) is preferably 10 to 90 mass% of the vibration-damping material and 90 to 10 mass% of the acrylic resin (A3), with the total of these being 100 mass%.

[0170] In the thermoplastic resin composition of the present invention, when emphasis is placed on physical properties such as vibration-damping property and heat resistance, it is preferable to use a styrene-based resin (A2) as the resin component (A). In this case, the mixing ratio of the vibration-damping material and the styrene-based resin (A2) is preferably 20 to 80 mass% of the vibration-damping material and 80 to 20 mass% of the styrene-based resin (A2), with the total being 100 mass%.

[0171] In the thermoplastic resin composition of the present invention, when emphasis is placed on improving vibration-damping properties and impact resistance, it is preferable to use a styrene-based resin (A2) and a rubber-reinforced styrene-based thermoplastic resin (A1) as the resin component (A). In this case, the mixing ratio of the vibration-damping agent to the styrene-based resin (A2) and the rubber-reinforced styrene-based thermoplastic resin (A1) is preferably 20 to 70 mass% of the vibration-damping agent, 60 to 10 mass% of the styrene-based resin (A2), and 60 to 20 mass% of the rubber-reinforced styrene-based thermoplastic resin (A1), based on a total of 100 mass%.

[0172] [Other Components] The thermoplastic resin composition of the present invention may contain other components in addition to the resin component (A) and the vibration-damping agent, provided that the object of the present invention is not impaired. Examples of other components include the following.

[0173] <Slidability-imparting agent> The thermoplastic resin composition of the present invention may contain a sliding property-imparting agent. The sliding property-imparting agent imparts sliding property to the thermoplastic resin composition. This not only facilitates the assembly of an article made from a molded product obtained from the thermoplastic resin composition of the present invention, but also has the effect of suppressing the generation of abnormal noises such as creaking sounds from the article made from such a molded product during use.

[0174] Representative examples of the sliding property imparting agent include low molecular weight polyethylene oxide, ultra-high molecular weight polyethylene, polytetrafluoroethylene, low molecular weight (for example, number average molecular weight of 10,000 or less) polyolefin wax, silicone oil, and the like, as described in JP 2011-137066 A.

[0175] The polyolefin wax is preferably a polyethylene wax or the like having a melting point of 0 to 120° C. Furthermore, when a polyolefin wax having such a melting point or other additives having a melting point of 0 to 120° C. are added to the thermoplastic resin composition of the present invention, the effect of suppressing the generation of abnormal noises such as creaking can be obtained even if the rubber portion of the rubber-reinforced styrene-based thermoplastic resin (A1) does not have a melting point (Tm).

[0176] These agents for imparting sliding properties may be used alone or in combination of two or more.

[0177] When a sliding property imparting agent is blended into the thermoplastic resin composition of the present invention, the blending amount thereof is preferably 0.1 to 10 parts by mass per 100 parts by mass of the rubber-reinforced styrene-based thermoplastic resin (A1), or 0.2 to 5 parts by mass per 100 parts by mass of the resin component (A).

[0178] <Other Additives> Examples of other additives that can be incorporated into the thermoplastic resin composition of the present invention include heat aging inhibitors, antioxidants, ultraviolet absorbers, weathering agents, fillers such as glass fiber and carbon fiber, antistatic agents, flame retardants, antifogging agents, lubricants, antibacterial agents, mildew inhibitors, tackifiers, plasticizers, colorants, graphite, carbon black, carbon nanotubes, and pigments (including pigments imparted with functionality such as infrared absorption and reflection). These may be used alone or in combination of two or more. The amount of these other additives incorporated is typically 0.1 to 30 parts by mass per 100 parts by mass of resin component (A).

[0179] [Method for Producing Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention can be produced by mixing the components in a predetermined blending ratio using a tumbler mixer, Henschel mixer, or the like, and then melt-kneading under appropriate conditions using a kneader such as a single-screw extruder, twin-screw extruder, Banbury mixer, kneader, roll, or feeder ruder. A preferred kneader is a twin-screw extruder. When kneading the components, the components may be kneaded all at once or in multiple stages or in separate blends. After kneading using a Banbury mixer, kneader, or the like, the mixture can also be pelletized using an extruder. The melt-kneading temperature is usually 180 to 300°C, preferably 190 to 280°C.

[0180] [Molded Article] The molded article of the present invention can be obtained by molding the thermoplastic resin composition of the present invention by extrusion molding such as injection molding, sheet extrusion, and profile extrusion molding, vacuum molding, pressure molding, compression molding, calendar molding, foam molding, blow molding, inflation molding, or the like.

[0181] The thermoplastic resin composition of the present invention can also be used as a material for forming a coating layer on a substrate made of other resins or metals.

[0182] In this case, examples of other resins that can be used as constituent materials for the substrate on which a coating layer made of the thermoplastic resin composition of the present invention is formed include rubber-modified thermoplastic resins such as ABS resin and high-impact polystyrene resin (HIPS), and thermosetting resins such as phenolic resin and melamine resin.

[0183] The molded article of the present invention can be used in a variety of applications, including various industrial applications. For example, the molded article of the present invention is suitable for use in vehicle interior and exterior parts such as engine peripheral parts, trunk floor panels, tire covers, floor boxes, glove boxes, parts around gasoline filler caps, wheel caps, door mirrors, and pillars; building materials and parts such as wall materials and window frames; tableware; toys; home appliance parts such as vacuum cleaner housings, television housings, and air conditioner housings; interior materials; marine components; electrical equipment housings such as communication device housings, laptop computer housings, mobile terminal housings, and liquid crystal projector housings; and road materials such as sound-absorbing and sound-proofing panels for roads.

[0184] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples. In the following, "parts" and "%" are by mass unless otherwise specified.

[0185] [Raw Materials] In the following Examples and Comparative Examples, resin components produced by the following methods and the following commercially available products were used as raw materials for producing thermoplastic resin compositions.

[0186] [Rubber-Reinforced Styrenic Thermoplastic Resin (A1)] <Production of (A1-1)> 280 parts of water and 60 parts (solids equivalent) of polybutadiene latex having a volume average particle size of 0.26 μm and a gel content of 90% as a diene rubber polymer, 0.3 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, and 0.01 parts of disodium ethylenediaminetetraacetate were charged into a polymerization vessel equipped with a stirrer. After deoxygenation, the mixture was heated to 60°C with stirring in a nitrogen stream. Thereafter, a monomer mixture consisting of 10 parts of acrylonitrile, 30 parts of styrene, 0.2 parts of t-dodecyl mercaptan, and 0.3 parts of cumene hydroperoxide was continuously added dropwise at 60°C over 5 hours. After completion of the dropwise addition, the polymerization temperature was raised to 65°C, and stirring was continued for 1 hour. The polymerization was then terminated to obtain a graft copolymer latex. The polymerization conversion was 98%. Then, 0.2 parts of 2,2'-methylene-bis(4-ethylene-6-t-butylphenol) was added to the obtained latex, and calcium chloride was added to coagulate the mixture, followed by washing, filtration and drying to obtain a powdery ABS resin (A1-1). The graft ratio of the obtained ABS resin (A1-1) was 40%, and the intrinsic viscosity [η] of the acetone soluble matter was 0.38 dl / g.

[0187] <Production of (A1-2)> Monomer mixture (II) was prepared by mixing 30.4 parts of styrene, 9.6 parts of acrylonitrile, and 0.05 parts of t-butyl mercaptan. A glass reactor was charged with 60 parts of polybutyl acrylate rubber polymer latex (based on solids), 12 parts of water, and 0.36 parts of sodium dodecylbenzenesulfonate, and the mixture was heated to 70°C under a nitrogen stream while stirring. When the temperature reached 70°C, 52% by mass of an aqueous solution (hereinafter abbreviated as "RED aqueous solution (I)") prepared by dissolving 0.003 parts of ethylenediaminetetraacetic acid tetrasodium dihydrate, 0.001 parts of ferrous sulfate heptahydrate, and 0.05 parts of sodium formaldehyde sulfoxylate in 2 parts of water was charged into the reactor. Immediately after this charging, the entire amount of the monomer mixture (II) and 0.06 parts of t-butyl hydroperoxide were continuously added over 2 hours and 30 minutes to carry out polymerization. 150 minutes after the start of polymerization, the remaining 48 mass% of the RED aqueous solution (I) and 0.03 parts of t-butyl hydroperoxide were charged into the reactor, and the mixture was maintained at the same temperature for 60 minutes, after which the polymerization was terminated to obtain a graft copolymer latex. This graft copolymer latex was coagulated, washed with water, and dried to obtain a powdery graft copolymer (A1-2). The gel content, swelling degree, graft ratio, and molecular weight of the acetonitrile-soluble portion of the obtained graft copolymer (A1-2) were measured. The results are shown in Table 2A.

[0188] [Styrene-based resin (A2)] <(A2-1)> As the AS resin (A2-1), an acrylonitrile-styrene copolymer was used, which had a ratio of acrylonitrile units of 27% and a ratio of styrene units of 73%, respectively, an intrinsic viscosity [η] (in methyl ethyl ketone, 30°C) of 0.47 dl / g, and a glass transition temperature (Tg) of 103°C.

[0189] <Production of (A2-2)> A reactor equipped with a stirrer was charged with 250 parts of water, 3 parts of sodium laurate, 0.2 parts of t-dodecyl mercaptan, 0.4 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, 0.01 parts of disodium ethylenediaminetetraacetate, and 0.5 parts of cumene hydroperoxide, and the reactor was deoxygenated. Subsequently, 73 parts of α-methylstyrene were charged in a nitrogen stream at 60°C with stirring. After sufficient emulsification, 17 parts of acrylonitrile, a component other than α-methylstyrene, were continuously added dropwise over 5 hours to carry out copolymerization. The polymerization was terminated when the polymerization conversion rate reached 85.0%. Next, 0.5 parts of cumene hydroperoxide, 0.05 parts of t-dodecyl mercaptan, 0.4 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, and 0.01 parts of disodium ethylenediaminetetraacetate were further charged to the polymerization solution. Thereafter, 2 parts of styrene, 3 parts of acrylonitrile, and 5 parts of methacrylic acid were continuously added dropwise over 0.5 hours while stirring at 60°C in a nitrogen stream, to carry out copolymerization. After completion of the dropwise addition, the mixture was stirred at 60°C for 1.5 hours, and then the polymerization was terminated. The final polymerization conversion was 96.0%. The residual monomer amounts in the reactor, relative to the total amount of monomers used in the polymerization, were 1.4% α-methylstyrene, 0.2% styrene, 1.2% acrylonitrile, and 1.2% methacrylic acid. Thereafter, the mixture was solidified with calcium chloride, and then a styrene-based resin (A2-2) having an intrinsic viscosity [η] of 0.31 dL / g was recovered using a vented extruder "DMG40 mm" (model name) manufactured by Nippon Placon Co., Ltd.

[0190] <Production of (A2-3)> 15 parts of acrylonitrile, 55 parts of styrene, and 30 parts of N-phenylmaleimide were polymerized by known continuous solution polymerization to obtain an acrylonitrile-styrene-N-phenylmaleimide terpolymer. This was designated as styrene-based resin (A2-3). The reduced viscosity of the acetone-soluble portion of the styrene-based resin (A2-3) was 0.60 dL / g.

[0191] [Acrylic Resin (A3)] <(A3-1)> PMMA (Acrypet VH5 (trade name)) manufactured by Mitsubishi Chemical Corporation was used as the acrylic resin (A3-1).

[0192] [Other Resins] As the PC resin (A4-1), an aromatic polycarbonate resin "NOVAREX 7022J (trade name)" manufactured by Mitsubishi Engineering Plastics Corporation was used. As the PBT resin (A4-2), a polybutylene terephthalate resin "DURANEX 2006 (trade name)" manufactured by Polyplastics Co., Ltd. was used. As the PA resin (A4-3), a nylon 6 resin "CM1021 (trade name)" manufactured by Toray Industries, Inc. was used.

[0193] [Vibration-damping material] The vibration-damping materials used were vibration-damping materials (B-1) to (B-15) according to the examples, which were produced by the methods described below, or vibration-damping materials (BX-1) to (BX-4), (BX-6), and (BX-7) according to the comparative examples, as well as the following commercially available vibration-damping materials (BX-8) and (BX-9).

[0194] <Vibration-damping agent (BX-8)> Asahi Kasei's hydrogenated styrene-butadiene copolymer "S1605" (styrene content: 66%, hydrogenation rate: 95%) <Vibration-damping agent (BX-9) Mitsui Chemicals' α-olefin copolymer "EP-1001" with excellent vibration-damping and stress relaxation properties

[0195] [Methods for Measuring Polymers] The methods for evaluating various physical properties and characteristics of polymers in the examples and comparative examples are as follows.

[0196] [Glass transition temperature (Tg)] In accordance with JIS K7121, a DSC curve was measured using a differential scanning calorimeter ("Q200" manufactured by TA Instruments) under the conditions of heating once from -90°C to 50°C (1st run), then cooling to -90°C, and then heating from -90°C to 50°C at 10°C / min (2nd run). The midpoint glass transition temperature of the 2nd run determined from this DSC curve was defined as the glass transition temperature in the present invention.

[0197] [Volume average particle size] The volume average particle size was determined by photon correlation spectroscopy using a "Microtrac Model: 9230UPA" manufactured by Nikkiso Co., Ltd.

[0198] [Tan δ Peak Intensity and Peak Temperature] A sample of polymer (b1) was obtained by coagulating and drying the latex of polymer (b1). The sample was then formed into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and cut into a measurement sample having a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the sample were fixed with a tension jig, and Tan δ was measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60°C to +60°C

[0199] [Swelling degree of THF-insoluble matter] Polymer (B) was immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble matter separated by centrifugation was vacuum-dried and its weight (weight b) was measured. The resulting THF-insoluble matter was again immersed in THF for 24 hours, and the weight of the sample swollen with THF (weight c) was measured, and the swelling degree of the THF-insoluble matter was calculated using the following formula: Swelling degree (%) = c / b × 100 Here, the swelling degree refers to the swelling degree of the graft structure contained in polymer (B). If the graft structure does not have a crosslinked structure, it cannot be obtained as a THF-insoluble matter. If the graft structure does not have a crosslinked structure, it will dissolve in THF, and an accurate swelling degree cannot be determined. For this reason, if the gel content is 1% or less, the swelling degree was determined to be 3000% or more.

[0200] [Gel Content] 1 g of polymer (B) was added to 100 mL of THF, allowed to stand at room temperature for 48 hours, and then filtered through a 100-mesh wire net (mass: W1 gram). The THF-insoluble matter and the wire net obtained were vacuum-dried at 80°C for 6 hours and weighed (mass: W2 grams). W1 and W2 were substituted into the following formula (i) to obtain the gel content. Gel Content = [[W2 (g) - W1 (g)] / 1 (g)] × 100 (i)

[0201] [Grafting Rate] 1 g of polymer (B) was added to 20 mL of acetonitrile and shaken for 2 hours using a shaker. The resulting acetonitrile suspension was centrifuged for 60 minutes using a centrifuge (rotation speed: 32,000 rpm), and a precipitate (acetonitrile-insoluble component) and an acetonitrile solution (acetonitrile-soluble component) were separated and collected. The precipitate (acetonitrile-insoluble component) was dried and its mass (T (g)) was measured, and the grafting rate was calculated using the following formula. In the formula, T is the mass (g) of the acetonitrile-insoluble component of polymer (B). S is the mass (g) of the rubber polymer (b1) contained in 1 g of polymer (B). Grafting rate (mass%) = {(T - S) / S} × 100. However, when polymer (b1) is composed of an aromatic vinyl compound and a conjugated diene, acetone was used instead of acrylonitrile for the measurement.

[0202] [Molecular Weight of Acetonitrile-Soluble Fraction] The acetonitrile-soluble fraction obtained in the above evaluation of the graft ratio was measured by gel permeation chromatography under the following conditions. A calibration curve was prepared using standard polystyrene, and the weight-average molecular weight in terms of polystyrene was calculated from the relationship between the molecular weight and retention time. Apparatus: "HLC-8320GPC EcoSEC" manufactured by Tosoh Corporation Column: "TSK-gel-GMH" manufactured by Tosoh Corporation Solvent: THF Flow rate: 0.8 mL / min Measurement temperature: 23°C

[0203] [Production of (R-1)] A monomer mixture (I) was prepared by mixing 39.26 parts of n-butyl acrylate (hereinafter abbreviated as "BA"), 20.60 parts of methyl methacrylate (hereinafter abbreviated as "MMA"), and 0.14 parts of allyl methacrylate (hereinafter abbreviated as "AMA") as a crosslinking agent. 220 parts of water and 0.1 parts of sodium dodecylbenzenesulfonate as an emulsifier were charged into a 10 L glass reactor equipped with a stirrer, a raw material and auxiliary agent adding device, a thermometer, a heating device, etc., and the internal temperature was raised to 70°C under a nitrogen stream while stirring. When the temperature reached 70°C, 84 mass% of an aqueous solution (hereinafter abbreviated as "RED aqueous solution (II)") prepared by dissolving 0.01 parts of tetrasodium ethylenediaminetetraacetate dihydrate, 0.002 parts of ferrous sulfate heptahydrate, and 0.3 parts of sodium formaldehyde sulfoxylate in 8.5 parts of water was charged into the reactor. Immediately thereafter, 100 parts of the monomer mixture (I) and 0.2 parts of cumene hydroperoxide were continuously added over 3 hours. One hour after the start of the dropwise addition, an aqueous solution prepared by dissolving 1.6 parts of dodecylbenzenesulfonic acid in 20 parts of water was charged into the reactor. Immediately after the completion of the continuous addition of the monomer mixture (I), the remaining 16 mass% of the RED aqueous solution (II) and 0.005 parts of cumene hydroperoxide were charged into the reactor, and the internal temperature of the reactor was maintained at 70°C for an additional 30 minutes. Thereafter, the polymerization reaction was terminated to obtain an acrylic rubber polymer (R-1) latex. The polymerization conversion rate at this time was 97%. The volume average particle diameter of the obtained acrylic rubber polymer (R-1) particles, measured by the method described above, was 150 nm. The acrylic rubber polymer (R-1) latex was dried to obtain a film, and the glass transition temperature (Tg) was measured by the method described above. In addition, the peak intensity and peak temperature of Tan δ were measured by the method described above. The results are shown in Table 1A.

[0204] [Production of (R-4)] A 100-liter stainless steel autoclave equipped with a stirrer and a thermometer was charged with 145 parts of ion-exchanged water, 1.0 part of disproportionated potassium rosinate, 1.0 part of potassium oleate, 0.4 parts of sodium formaldehyde sulfoxylate dihydrate, 0.1 parts of anhydrous sodium sulfate, 0.3 parts of tertiary dodecyl mercaptan, 0.5 parts of diisopropylbenzene hydroperoxide, 11.2 parts of 1,3-butadiene (hereinafter abbreviated as "BD"), and 16.8 parts of styrene (hereinafter abbreviated as "ST"), and the internal temperature was raised to 50°C. Subsequently, an aqueous solution consisting of 0.5 parts of sodium pyrophosphate, 0.005 parts of ferrous sulfate heptahydrate, and 5 parts of water was added to initiate polymerization. At a polymerization temperature of 57°C, a mixture consisting of 28.8 parts of 1,3-butadiene and 43.2 parts of styrene was added dropwise using a pressure pump. Next, when the polymerization conversion reached 40%, 0.3 parts of normal dodecyl mercaptan was added and the polymerization was continued. After 8 hours, the remaining 1,3-butadiene was removed to obtain a butadiene polymer latex (R-4) having a solid content of 40.2%, a polymerization conversion of 97%, and a volume average particle size of 70 nm. The measurement results of the volume average particle size, Tg, peak intensity of Tan δ, and peak temperature of the butadiene polymer latex (R-4) are shown in Table 1A.

[0205] [Production of (R-2), (R-3), (R-5) to (R-13), and (RX-1) to (RX-4), (RX-6), and (RX-7)] Acrylic rubber polymers (R-2), (R-3), (R-5) to (R-13), and (RX-1) to (RX-4), (RX-6), and (RX-7) were produced in the same manner as (R-1), except for the formulations shown in Tables 1A and 1B. The volume average particle diameter, Tg, Tan δ peak intensity, and peak temperature measurements of these acrylic rubber polymers are shown in Tables 1A and 1B. Table 1B also lists the Tg, Tan δ peak intensity, and peak temperature measured for the vibration-damping additive (BX-8) and the vibration-damping additive (BX-9), as well as the Tg, Tan δ peak intensity, and peak temperature of (RX-8) and (RX-9), respectively.

[0206] [Production of (B-1)] Monomer mixture (II) was prepared by mixing 8.4 parts of ST, 2.8 parts of acrylonitrile (hereinafter abbreviated as "AN"), 28.8 parts of MMA, and 0.05 parts of t-butyl mercaptan. 40 parts of the acrylic rubber polymer (R-1) latex (solids content), 12 parts of water, and 0.36 parts of sodium dodecylbenzenesulfonate were charged into the glass reactor used in the production of the acrylic rubber polymer (R-1) latex, and the mixture was heated to 70°C under a nitrogen stream while stirring. When the temperature reached 70°C, 52% by mass of an aqueous solution (RED aqueous solution (I)) prepared by dissolving 0.003 parts of tetrasodium ethylenediaminetetraacetate dihydrate, 0.001 parts of ferrous sulfate heptahydrate, and 0.05 parts of sodium formaldehyde sulfoxylate in 2 parts of water was charged into the reactor. Immediately after this charging, the entire amount of the monomer mixture (II) and 0.06 parts of t-butyl hydroperoxide were continuously added over 2 hours and 30 minutes to carry out polymerization. 150 minutes after the start of polymerization, the remaining 48% by mass of the RED aqueous solution (I) and 0.03 parts of t-butyl hydroperoxide were charged into the reactor. The mixture was maintained at the same temperature for 60 minutes, after which the polymerization was terminated to obtain a graft copolymer (B-1) latex. This graft copolymer (B-1) latex was coagulated, washed with water, and dried to obtain a powdery graft copolymer (B-1). The gel content, swelling degree, graft ratio, and molecular weight of the acetonitrile-soluble portion of the resulting graft copolymer (B-1) were measured. The results are shown in Table 2A.

[0207] [Production of (B-2) to (B-15) and (BX-1) to (BX-4), (BX-6), and (BX-7)] Graft copolymers (B-2) to (B-15), (BX-1) to (BX-4), (BX-6), and (BX-7) were produced in the same manner as for graft copolymer (B-1), except that the acrylic rubber polymers (R-2) to (R-13), (RX-1) to (RX-4), (RX-6), and (RX-7) obtained above were used in the formulations shown in Tables 2A and 2B. The gel content, swelling degree, graft ratio, and molecular weight of the acetonitrile-soluble portion of these graft copolymers were measured and the results are shown in Tables 2A and 2B.

[0208] The acrylic rubber polymers (R-1) to (R-13) correspond to the polymer (b1) of the present invention. The graft copolymers (B-1) to (B-15) correspond to the polymer (B) of the present invention in which the polymer (b2) of the present invention is graft-polymerized onto the polymer (b1) of the present invention.

[0209]

[0210]

[0211]

[0212]

[0213] [Examples 1 to 34, Comparative Examples 1 to 5, 7 to 10] [Production of Thermoplastic Resin Composition] The raw materials shown in Tables 3A to 3F were mixed in the blending ratios shown in the same tables. Then, using a twin-screw extruder (model name "TEX44, Japan Steel Works"), the mixture was melt-kneaded at 250°C and pelletized. The resulting resin compositions were used for the following measurements and evaluations. The results are shown in Tables 3A to 3F. The Charpy impact strength was evaluated for Examples 1, 9, 29, and 32 and Comparative Examples 9 to 10, and the results are shown in Table 4. The materials (F-1) and (F-2) used in Examples 15 to 17 were as follows: (F-1): Glass fiber chopped strand "CSF3PE-331ST" manufactured by Nitto Boseki Co., Ltd. (F-2): Carbon fiber "CFU-HC / HT" manufactured by Nippon Polymer Co., Ltd.

[0214] For the obtained thermoplastic resin compositions, the proportion of aromatic vinyl compound (ST) units in the raw materials used and the content of ST units in the thermoplastic resin compositions calculated from the blending ratio of the raw materials used are as shown in Tables 3A to 3F.

[0215] [Evaluation method] <Logarithmic decay rate δ> A test piece measuring 13 mm x 125 mm x 3 mm was molded, and after fixing one end of the test piece at 17 mm, vibration was applied to the other end so that the initial displacement was 10 mm, and a free vibration waveform was obtained with the horizontal axis representing time and the vertical axis representing displacement. The logarithmic decay rate δ was calculated using the following formula. Vibration data was logged using an FFT analyzer "OR34" manufactured by OROS. Logarithmic decay rate δ = (1 / m) x ln(αn / αn+m) δ: logarithmic decay rate m: period used in calculation αn: nth amplitude value αn+m: amplitude value of the n+mth period counting from the period having the nth amplitude value

[0216] <Vibration Transmissibility (1st Mode)> The vibration transmissibility of the test piece was measured using a vibration exciter "K2007E01" manufactured by The Modal Shop and an FFT analyzer "OR34" manufactured by OROS. A test piece measuring 13 mm x 125 mm x 3 mm was molded, and a 5 mm diameter hole was drilled on one side of the test piece, centered at a position 7 mm from the end, and the test piece was fixed to the vibration exciter with an M5 bolt. The vibration exciter was vibrated with a sweep signal having a frequency of 10 Hz to 4000 Hz, and the acceleration a0 [m / sec] at the vibration point (fixed side of the sample) was measured. ２ ] and the acceleration a1 [m / sec] at the measurement point (opposite side of the sample fixing) ２ ] was measured. The sweep signal refers to a signal that was changed from a low frequency to a high frequency at a constant speed. The vibration transmissibility was calculated using the following formula: Vibration transmissibility [times] = a1 / a0 The vibration transmissibility refers to the value at the resonance point (first mode).

[0217] <MVR> Melt volume flow rate was measured in accordance with ISO 1133 at a temperature of 220°C or 240°C under a load of 10 kg.

[0218] <Charpy Impact Strength> Charpy impact strength (impact direction: edgewise) was measured in accordance with ISO 179 at a test temperature of 23°C.

[0219] <Tensile Yield Stress> Measured in accordance with ISO 527.

[0220] <Flexural modulus (rigidity)> Measured in accordance with ISO178.

[0221] <Deflection temperature under load> Measurement was carried out in accordance with ISO 75 under a load of 1.8 MPa.

[0222] <Rockwell hardness> Measured in accordance with ISO2039.

[0223] <Gloss> 100 parts of pellets of each thermoplastic resin composition and 0.8 parts of carbon black were mixed using a Henschel mixer, and the mixture was fed into an extruder heated to 250°C and kneaded to obtain black pellets. The black pellets were injection molded under conditions of a cylinder temperature of 240°C, a mold temperature of 60°C, and an injection rate of 20 g / sec to obtain a plate-shaped molded product having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm. The reflectance (%) of the surface of the molded product was measured at an incident angle of 60° and a reflection angle of 60° according to ISO 2813 using a gloss meter VG7000 manufactured by Nippon Denshoku Industries Co., Ltd. Higher reflectance indicates better surface appearance.

[0224] <Peeling> Pellets of the thermoplastic resin composition obtained by melt-kneading were injection molded using a J35AD injection molding machine manufactured by Japan Steel Works, Ltd. at a cylinder temperature of 250°C, an injection pressure of 70 MPa, and a mold temperature of 50°C to obtain a molded plate measuring 55 mm x 80 mm x 2.4 mm thick. This molded plate had a film gate measuring 50 mm wide and 1 mm thick on the short side. The gate cut portion was visually observed to determine whether peeling occurred (×) or not (◯).

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232] From the above results, it can be seen that the thermoplastic resin compositions of the examples, which contain a vibration-damping additive made of the polymer (B) of the present invention, are excellent not only in vibration-damping effect but also in resonance-suppressing effect, have good gloss, are free of the peeling phenomenon that has been a problem in the past, and have excellent appearance. On the other hand, the thermoplastic resin compositions of the comparative examples, which use a (meth)acrylic acid ester-based polymer that does not satisfy the requirements of the present invention as a vibration-damping additive, are inferior in both vibration-reducing effect and resonance-suppressing effect. In the comparative examples 9 and 10, which use a conventional thermoplastic elastomer as a vibration-damping additive, the logarithmic decrement of the vibration-damping property is insufficient, and in particular the vibration transmissibility indicating resonance is poor, and the peelability is also poor.

[0233] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the present invention. This application is based on Japanese Patent Application No. 2024-031500, filed on March 1, 2024, and is incorporated by reference in its entirety.

Claims

1. A vibration-damping material comprising a polymer (B) having a polymer (b1) with a glass transition temperature of -10°C to 30°C and a polymer (b2) different from the polymer (b1), wherein the polymer (B) has a swelling degree of 900% or more in the THF-insoluble portion measured by the following method. <Method for measuring swelling degree> After immersing the polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble portion separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble portion is again immersed in THF for 24 hours, and the weight of the sample swollen with THF (weight c) is measured, and the swelling degree of the THF-insoluble portion is calculated by the following formula: Swelling degree (%) = c / b x 100 2. The vibration-damping material according to claim 1, wherein the polymer (b1) exhibits a peak temperature (peak value) of the primary dispersion of Tan δ measured by the following method, which is 3°C to 45°C, and the peak intensity of the peak value is 1.900 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C 3. The vibration-damping material according to claim 2, wherein the polymer (b1) exhibits a peak value of the primary dispersion of Tan δ (peak temperature) measured by the Tan δ measurement method at a temperature of 3°C to 45°C, and the peak intensity of the peak value is 1.950 or more.

4. The vibration-damping material according to claim 1, wherein the swelling degree of the THF-insoluble portion of the polymer (B) measured by the swelling degree measuring method is 1000% or more.

5. The vibration-damping material according to claim 1, wherein the polymer (b1) contains a structural unit derived from an acrylic acid ester compound and a structural unit derived from a methacrylic acid ester compound.

6. The vibration-damping material according to claim 1, wherein the polymer (b2) contains one or more structural units selected from the group consisting of structural units derived from methacrylic acid ester compounds, structural units derived from aromatic vinyl compounds, and structural units derived from vinyl cyanide compounds.

7. The vibration-damping material according to claim 1, wherein the polymer (b2) is bonded to at least a portion of the polymer (b1).

8. A thermoplastic resin composition comprising a resin component (A) containing a thermoplastic resin and a vibration-damping agent, wherein the thermoplastic resin composition has at least one glass transition temperature between -10°C and 30°C, and the vibration transmissibility (primary mode) of the thermoplastic resin composition measured by the following method is 19 times or less. <Vibration Transmissibility (primary mode)> A test piece measuring 13 mm x 125 mm x 3 mm is molded using the thermoplastic resin composition, and a 5 mm diameter hole is drilled on one side of the test piece at a position 7 mm from the edge, and the test piece is fixed to a vibrator with an M5 bolt. The vibration transmissibility (primary mode) of the vibration point (fixed side of the test piece) when the vibrator is vibrated with a sweep signal having a frequency of 10 Hz to 4000 Hz is measured. ２ ] and the acceleration a1 [m / sec ２ ] is measured, and the vibration transmissibility is calculated as the value at the resonance point (first mode) using the following formula: Vibration transmissibility [times] = a1 / a0 9. The thermoplastic resin composition according to claim 8, wherein the swelling degree of the THF-insoluble matter in the thermoplastic resin composition is 900% or more, as measured by the following method. <Method for measuring swelling degree> The thermoplastic resin composition is immersed in tetrahydrofuran (THF) for 24 hours, and the insoluble matter separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The obtained THF-insoluble matter is again immersed in THF for 24 hours, and the weight of the sample swollen with THF (weight c) is measured, and the swelling degree of the THF-insoluble matter is calculated by the following formula: Swelling degree (%) = c / b x 100 10. The thermoplastic resin composition according to claim 8, wherein the vibration-damping agent contains a polymer (b1) having a temperature (peak temperature) showing a peak value of the primary dispersion of Tan δ measured by the following method, between 3°C and 45°C, and a peak intensity of 1.900 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample is cut out from the sheet to a length of 36 mm and a width of 10 mm. Using the dynamic viscoelasticity measuring device described below, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tension jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak intensity. Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C 11. The thermoplastic resin composition according to claim 8, wherein the vibration-damping material comprises a polymer (B) having: a polymer (b1) comprising structural units derived from an acrylic acid ester compound and structural units derived from a methacrylic acid ester compound, and having a glass transition temperature of -10°C to 30°C; and a polymer (b2) comprising one or more structural units selected from the group consisting of structural units derived from a methacrylic acid ester compound, structural units derived from an aromatic vinyl compound, and structural units derived from a vinyl cyanide compound, wherein the temperature (peak temperature) showing the peak value of the primary dispersion of Tan δ measured by the following method for the polymer (b1) is 3°C to 45°C, and the peak intensity of the peak value is 1.950 or more. <Method for Measuring Tan δ> Polymer (b1) is molded into a sheet having a thickness of 1.0 to 1.1 mm using a heat press set at a temperature of 150°C, and a measurement sample of 36 mm in length and 10 mm in width is cut out from the sheet. Using the following dynamic viscoelasticity measuring device, 8 mm portions on both ends of the long side of the measurement sample are fixed with a tensile jig, and Tan δ is measured under the following conditions to determine the peak temperature and peak strength: Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) Mode: Tension Frequency: 1 Hz Heating rate: 5°C / min Measurement temperature: -60 to +60°C 12. The thermoplastic resin composition according to claim 11, wherein the swelling degree of the THF-insoluble portion of the polymer (B) is 1000% or more, as measured by the following method. <Method for measuring swelling degree> After immersing the polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble portion separated by centrifugation is vacuum-dried and its weight (weight b) is measured. The resulting THF-insoluble portion is again immersed in THF for 24 hours, and the weight (weight c) of the sample swollen with THF is measured, and the swelling degree of the THF-insoluble portion is calculated by the following formula: Swelling degree (%) = c / b x 100 13. The vibration-damping material according to claim 11, wherein the polymer (b2) is bonded to at least a portion of the polymer (b1).

14. The thermoplastic resin composition according to claim 8, wherein the thermoplastic resin comprises an acrylic resin.

15. The thermoplastic resin composition according to claim 8, wherein the thermoplastic resin comprises one or more resins selected from the group consisting of styrene-based resins, polybutylene terephthalate-based resins, polyamide-based resins, and polycarbonate-based resins.

16. The thermoplastic resin composition according to claim 8, comprising 90 to 10 parts by weight of said resin component (A) and 10 to 90 parts by weight of said vibration-damping material, totalling 100 parts by weight.

17. A molded article obtained by molding the thermoplastic resin composition according to any one of claims 8 to 16.

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