Impact sound reducing material and thermoplastic resin composition

Abstract

A strike sound reducing material comprising a (meth) acrylic acid ester polymer (B) having: a polymer (b1) having a structural unit derived from an acrylic acid ester compound and a structural unit derived from a methacrylic acid ester compound and having a glass transition temperature of-15 DEG C to + 5 DEG C; and a polymer (b2) that contains one or more elements selected from the group consisting of a structural unit derived from a methacrylic acid ester compound, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from a vinyl cyanide compound, and that is characterized in that the temperature (peak temperature), which represents the peak value of the main dispersion of tan [delta], measured with respect to the polymer (b1) is-5 DEG C to + 20 DEG C; the peak intensity, which is the peak value, is 2.055 or more.

Description

Technical Field

[0001] The present invention relates to a noise reduction material for impact sound that is blended into a thermoplastic resin composition and can provide a molded product having excellent mechanical properties such as surface gloss, impact resistance, and rigidity and suppressing the generation of impact sound. Further, the present invention relates to a thermoplastic resin composition containing the noise reduction material for impact sound. Background Art

[0002] Rubber-reinforced resins such as ABS resin are widely used as molding materials for vehicle parts such as automotive interior parts due to their excellent mechanical properties, heat resistance, and moldability.

[0003] When molding vehicle parts using resin, not only is it required to satisfy mechanical strength above a certain level, but also, from the perspective of the habitability of the vehicle interior, it is required to reduce the noise generated by the parts and improve the quietness of the vehicle.

[0004] Conventionally, the following solution has been adopted: an automotive interior part is molded from a rubber-reinforced resin using an ethylene·α-olefin rubbery polymer as a rubber component, thereby preventing the generation of squeaking sounds due to contact between parts while maintaining mechanical strength at a certain level (Patent Document 1). However, in Patent Document 1, it is not possible to suppress noise such as impact sound called "rattle".

[0005] There is a literature proposing that by blending an elastomeric block polymer into a flame-retardant rubber-reinforced resin and making the loss coefficient at the second resonance frequency at 25°C be 0.02 or more, vibration can be suppressed and a flame-retardant resin composition having excellent vibration damping properties can be obtained (Patent Documents 2 to 4). However, Patent Documents 2 to 4 do not conduct any research on suppressing noise such as impact sound.

[0006] As a thermoplastic resin composition for a molded product that solves this problem and can provide suppression of the generation of impact sound, preferably maintaining the gloss of the molded product well, and more preferably suppressing the generation of squeaking sounds, the present applicant has proposed a thermoplastic resin composition composed of at least a rubber-reinforced styrenic thermoplastic resin (A1), wherein the rubber-reinforced styrenic thermoplastic resin (A1) contains a specific thermoplastic elastomer that functions as a noise reduction material for impact sound as a rubbery part, and the loss coefficient (η) of the thermoplastic resin composition in the frequency range of 20 Hz to 12,400 Hz shows a specific value or more (Patent Document 5).

[0007] In addition, in order to improve the appearance of the molded product such as color rendering and gloss and the impact resistance of the surface while maintaining the effect of reducing the impact sound in the patent document 5, the present applicant has proposed a thermoplastic resin composition in which a hydrogenated copolymer is blended as a material for reducing the impact sound. The hydrogenated copolymer is obtained by hydrogenating a copolymer composed of a block portion (I) and a random portion (II). The block portion (I) is mainly composed of structural units derived from aromatic vinyl compounds, and the random portion (II) is mainly composed of structural units derived from aromatic vinyl compounds and butadiene. When the total amount of the copolymer is 100% by mass, the content of the structural units derived from aromatic vinyl compounds in the block portion (I) and the random portion (II) is 55% by mass to 80% by mass, and it has a main dispersion peak of tanδ at 0°C or higher (Patent Document 6).

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-112812

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 2001-158841

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 3-45646

[0013] Patent Document 4: Japanese Patent Application Laid-Open No. 8-3249

[0014] Patent Document 5: Japanese Patent Application Laid-Open No. 2020-139028

[0015] Patent Document 6: Japanese Patent Application Laid-Open No. 2022-143324 Summary of the Invention

[0016] Problems to be Solved by the Invention

[0017] The thermoplastic resin composition of Patent Document 6 is not fully satisfactory in terms of mechanical properties such as impact resistance, and further improvement is desired for widespread use.

[0018] An object of the present invention is to provide a material for reducing impact sound that can provide a molded product with suppressed generation of impact sound and excellent mechanical properties such as impact resistance when blended into a thermoplastic resin composition, and a thermoplastic resin composition containing the material for reducing impact sound.

[0019] Means for Solving the Problems

[0020] The present inventors have found that a material for reducing impact sound composed of a specific (meth)acrylate polymer can solve the above problems.

[0021] The gist of the present invention is as follows.

[0022] [1] An impact sound reducing material, wherein the impact sound reducing material is composed of a (meth)acrylate polymer (B), and the (meth)acrylate polymer (B) has:

[0023] A polymer (b1) which has a structural unit derived from an acrylate compound and a structural unit derived from a methacrylate compound, and a glass transition temperature of -15°C to +5°C; and

[0024] A polymer (b2) which contains one or more selected from the group consisting of a structural unit derived from a methacrylate compound, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from a cyanated vinyl compound,

[0025] The impact sound reducing material is characterized in that

[0026] For the above polymer (b1), the temperature (peak temperature) representing the peak of the main dispersion of tanδ measured by the following method is -5°C to +20°C, and the peak intensity as the peak is 2.055 or more.

[0027] <Measurement method of Tanδ>

[0028] Using the polymer (b1), a sheet with a thickness of 1.0 mm to 1.1 mm is hot-pressed at a set temperature of 150°C, and a measurement sample is prepared by cutting out a length of 36 mm × width of 10 mm from the sheet.

[0029] Using the following dynamic viscoelasticity measurement device, both ends of 8 mm each of the long side of the measurement sample are fixed with a tensile jig, and tanδ is measured under the following conditions to obtain the peak temperature and peak intensity.

[0030] Measurement device: Dynamic viscoelasticity measurement device ("DMA850" manufactured by TA Instruments)

[0031] Mode: Tensile

[0032] Frequency: 1 Hz

[0033] Temperature increase rate: 5°C / minute

[0034] Measurement temperature: -60°C to +60°C

[0035] [2] The impact sound reducing material according to [1], wherein the swelling degree of the THF-insoluble component of the (meth)acrylate polymer (B) measured by the following method is 1000% or more.

[0036] <Measurement method of swelling degree>

[0037] After impregnating the (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble components separated by centrifugation were dried under vacuum, and the weight (weight b) was measured.

[0038] After impregnating the obtained THF-insoluble components in THF again for 24 hours, the weight of the sample swollen with THF (weight c) was measured, and the swelling degree of the THF-insoluble components was determined by the following formula.

[0039] Swelling degree (%) = c / b × 100

[0040] [3] A thermoplastic resin composition, comprising: a resin component (A) containing a rubber-reinforced styrene-based thermoplastic resin (A1); and the impact sound reduction material according to [1] or [2].

[0041] [4] The thermoplastic resin composition according to [3], comprising 95 to 70 parts by mass of the above resin component (A) and 5 to 30 parts by mass of the above impact sound reduction material (wherein the total of the resin component (A) and the impact sound reduction material is 100 parts by mass).

[0042] Effects of the Invention

[0043] According to the present invention, it is possible to provide a thermoplastic resin molded article that suppresses the generation of impact sound and has excellent mechanical properties such as impact resistance and rigidity.

[0044] The impact sound reduction material composed of the specific (meth)acrylate polymer (B) of the present invention can not only effectively suppress impact sound, but also effectively function to maintain the mechanical properties of the obtained molded article. By blending the impact sound reduction material of the present invention into the resin component (A) containing the rubber-reinforced styrene-based thermoplastic resin (A1), it is possible to not only suppress impact sound but also suppress squeaking sound.

[0045] In the molded article obtained from the thermoplastic resin composition of the present invention, the (meth)acrylate polymer (B) that functions as an impact sound reduction material also functions as a constituent component of the thermoplastic resin composition. Therefore, it not only has acoustic properties in which impact sound and squeaking sound are suppressed, but also has excellent mechanical strengths such as impact resistance and rigidity.

[0046] Therefore, according to the present invention, an article with low impact sound and high impact resistance is provided.

[0047] In particular, by forming at least the contact portion of an article having at least two components that intermittently come into contact with each other due to vibration or the like from the thermoplastic resin composition of the present invention, it is possible to provide an article in which impact sound and squeaking sound are suppressed while sufficiently maintaining mechanical strength, achieving sound insulation or noise reduction.

[0048] The "vibration damping property" in previous studies relates to vibrations continuously generated in an object when the object is continuously subjected to vibrations. In contrast, the "impact sound" relates to vibrations instantaneously generated when another object collides with the object.

[0049] The time for absorbing and dispersing energy for both is completely different.

[0050] In order to suppress the impact sound, it is necessary to set the speed of absorbing and dispersing energy to an extremely instantaneous time.

[0051] The "vibration damping property" takes the vibration noise generated by continuous vibrations as a problem. In contrast, the "impact sound" takes the sound generated by an instantaneous impact as a problem. In this regard, the two are different. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a perspective view showing a test piece for sound pressure measurement in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0053] Hereinafter, embodiments of the present invention will be described in detail.

[0054] In the present invention, "(co)polymerization" means homopolymerization and / or copolymerization. "(Meth)acrylic acid" means acrylic acid and / or methacrylic acid. "(Meth)acrylate" means acrylate and / or methacrylate.

[0055] A "structural unit" means a structural part derived from a compound (monomer, i.e., monomer) before polymerization contained in a polymer. The content ratio of the structural units of each compound from the polymer corresponds to the content ratio of the compound in the raw material monomer mixture used in the production of the polymer.

[0056] [Impact Sound Reduction Material]

[0057] The impact sound reducing material of the present invention is characterized in that it is composed of a (meth)acrylate polymer (B) (hereinafter sometimes referred to as the "(meth)acrylate polymer (B) of the present invention"), and the (meth)acrylate polymer (B) has: a polymer (b1) which has a structural unit derived from an acrylate compound (hereinafter sometimes simply referred to as an "acrylate unit") and a structural unit derived from a methacrylate compound (hereinafter sometimes simply referred to as a "methacrylate unit"), and a glass transition temperature of -15°C to +5°C; and a polymer (b2) which contains one or more selected from the group consisting of a structural unit derived from a methacrylate compound (methacrylate unit), a structural unit derived from an aromatic vinyl compound (hereinafter sometimes simply referred to as an "aromatic vinyl unit"), and a structural unit derived from a vinyl cyanide compound (hereinafter sometimes simply referred to as a "vinyl cyanide unit"). For the polymer (b1), the temperature (peak temperature) of the peak representing the main dispersion of tanδ measured by the following method is -5°C to +20°C, and the peak intensity of this peak is 2.055 or more.

[0058] <Measurement method of Tanδ>

[0059] Using the polymer (b1), a sheet with a thickness of 1.0 mm to 1.1 mm is hot-pressed at a set temperature of 150°C, and a measurement sample is prepared by cutting out a length of 36 mm × width of 10 mm from this sheet.

[0060] Using the following dynamic viscoelasticity measurement device, both ends of each 8 mm part of the long side of the measurement sample are fixed with a tensile fixture, and tanδ is measured under the following conditions to obtain the peak temperature and peak intensity.

[0061] Measurement device: Dynamic viscoelasticity measurement device ("DMA850" manufactured by TA Instruments)

[0062] Mode: Tensile

[0063] Frequency: 1 Hz

[0064] Heating rate: 5°C / minute

[0065] Measurement temperature: -60°C to +60°C

[0066] [Mechanism]

[0067] By making the polymer (b1) contained in the (meth)acrylate polymer (B) of the present invention contain an acrylate unit and a methacrylate unit, noise such as impact sound can be suppressed. It is considered that this is because the structural unit of a polar monomer such as methyl methacrylate converts noise such as impact sound into heat.

[0068] In addition, by setting the glass transition temperature of the polymer (b1) containing acrylate units and methacrylate units to -15°C to +5°C, noise such as impact sound can be suppressed in the room temperature range.

[0069] In addition, by setting the temperature (peak temperature) representing the peak of the main dispersion of tanδ measured for the polymer (b1) to -5°C to +20°C and the peak intensity of this peak to 2.055 or more, an excellent impact sound reduction effect can be obtained.

[0070] Furthermore, by having the polymer (b2) containing the above specific structural units, mechanical properties such as impact resistance can be exhibited.

[0071] [Relationship between polymer (b1) and polymer (b2)]

[0072] There is no particular limitation on the mode of existence of the polymer (b1) and the polymer (b2) in the (meth)acrylate-based polymer (B) of the present invention. However, it is preferable and effective for improving impact resistance that the polymer (b2) corresponding to the resin part is bonded to at least a part of the polymer (b1) corresponding to the rubbery part by graft polymerization or the like to form a graft copolymer.

[0073] In other words, in the (meth)acrylate-based polymer (B), it is preferable that at least a part of the polymer (b2) is bonded to at least a part of the polymer (b1) by graft polymerization or the like.

[0074] Therefore, the (meth)acrylate-based polymer (B) is preferably composed of at least a graft copolymer in which at least a part of the polymer (b2) is grafted onto at least a part of the polymer (b1) and a (co)polymer constituting the polymer (b2) that is not graft-polymerized to the polymer (b1). The (meth)acrylate-based polymer (B) may further contain the polymer (b1) that is not grafted with the polymer (b2). The (meth)acrylate-based polymer (B) may further contain other components such as additives.

[0075] [Polymer (b1)]

[0076] [Structural unit]

[0077] The polymer (b1) of the present invention has acrylate units and methacrylate units.

[0078] Regarding the content ratio of the acrylate units and methacrylate units contained in the polymer (b1), from the viewpoint of adjusting the glass transition temperature, it is preferable that there are more acrylate units, and from the viewpoint of the impact sound suppression effect, it is preferable that there are more methacrylate units.

[0079] From such a viewpoint, it is preferable that the content ratio of the acrylate unit in 100 parts by mass in total of the acrylate unit and the methacrylate unit contained in the polymer (b1) is 57 to 72 parts by mass, and the content ratio of the methacrylate unit is 43 to 28 parts by mass. More preferably, the acrylate unit is 61 to 70 parts by mass and the methacrylate unit is 39 to 30 parts by mass.

[0080] The polymer (b1) may contain structural units other than the acrylate unit and the methacrylate unit within the range not impairing the object of the present invention. Examples of such structural units include structural units derived from the crosslinking agent described later.

[0081] By making the polymer (b1) contain the structural unit derived from the crosslinking agent, the appearance such as gloss becomes good. However, if the content ratio of the structural unit derived from the crosslinking agent is large, the swelling degree of the obtained (meth)acrylate polymer (B) becomes small, and the effect as a material for reducing impact sound is impaired.

[0082] Therefore, when the polymer (b1) contains the structural unit derived from the crosslinking agent, its content ratio is preferably 0.4 parts by mass or less, particularly preferably 0.10 to 0.25 parts by mass, in 100 parts by mass of the polymer (b1).

[0083] The polymer (b1) may also contain structural units derived from vinyl compounds other than the acrylate unit and the methacrylate unit. Examples of such vinyl compounds include aromatic vinyl compounds and vinyl cyanide compounds exemplified in the description of the rubber-reinforced styrene-based thermoplastic resin (A1) described later. However, from the viewpoint of more effectively obtaining the above effects brought about by the polymer (b1) containing the acrylate unit and the methacrylate unit, when the polymer (b1) contains structural units derived from other vinyl compounds, its content ratio is preferably 20 parts by mass or less, particularly preferably 0 to 10 parts by mass, in 100 parts by mass of the polymer (b1).

[0084] As the acrylate compound constituting the acrylate unit, an acrylate compound having 1 to 8 carbon atoms in the alkyl group is preferable. Among them, from the aspect that the impact resistance of the thermoplastic resin composition blended with the obtained (meth)acrylate polymer (B) is excellent, ethyl acrylate, n-butyl acrylate, and n-ethylhexyl acrylate are preferable, and n-butyl acrylate is more preferable.

[0085] These alkyl acrylate compounds may be used alone or in combination of two or more.

[0086] As the methacrylate compound constituting the methacrylate unit, a methacrylate compound having 1 to 8 carbon atoms in the alkyl group is preferred. Among them, from the aspect of excellent impact sound reduction effect of the thermoplastic resin composition blended with the (meth)acrylate polymer (B), methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate are preferred, and methyl methacrylate is more preferred.

[0087] These methacrylate compounds can be used alone or in combination of two or more.

[0088] Examples of the crosslinking agent 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-butanediol 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, diallyldimethylammonium chloride, polyglycerol poly(meth)acrylate, etc.

[0089] They can be used alone or in combination of two or more.

[0090] <Method for producing polymer (b1)>

[0091] The polymer (b1) can be produced by a conventional method using a monomer mixture containing an acrylate compound, a methacrylate compound, and a crosslinking agent and other vinyl compounds used as needed in such a manner that the proportions of the above-mentioned preferred structural units are achieved.

[0092] There is no particular limitation on the method for producing the polymer (b1). Examples of the method for producing the polymer (b1) include an emulsion polymerization method of a monomer mixture containing an acrylate compound, a methacrylate compound, and a crosslinking agent and other vinyl compounds used as needed.

[0093] As a method for producing the polymer (b1) by an emulsion polymerization method, a method of adding an acrylate compound, a methacrylate compound, and a crosslinking agent and other vinyl compounds (hereinafter sometimes referred to as "raw material monomer mixture") and a radical initiator to an aqueous solvent and carrying out copolymerization in the presence of an emulsifier can be cited.

[0094] The addition method of the radical initiator, the raw material monomer mixture, and the crosslinking agent can be any one of one-time addition, batch addition, and continuous addition.

[0095] As the emulsifier, carboxylic acid-based emulsifiers such as alkali metal salts of oleic acid, palmitic acid, stearic acid, rosin acid, and alkali metal salts of alkenyl succinic acid can be used; anionic emulsifiers selected from alkyl sulfates, sodium alkylbenzenesulfonates, sodium alkylsulfosuccinates, sodium polyoxyethylene nonylphenyl ether sulfates, etc. can be used; well-known emulsifiers such as these can be used alone or in combination of two or more.

[0096] Relative to a total of 100 parts by mass of the raw material monomer mixture, the addition amount of the emulsifier is preferably 0.01 part by mass to 3.0 parts by mass, more preferably 0.05 part by mass to 2.0 parts by mass, which is preferable from the aspect of controlling the particle diameter of the polymer (b1).

[0097] The initiator used in the production of the polymer (b1) is a radical polymerization initiator for carrying out radical polymerization, and its type is not particularly limited. As the radical polymerization initiator, for example, azo polymerization initiators, photopolymerization initiators, inorganic peroxides, organic peroxides, redox initiators obtained by combining organic peroxides, transition metals, and reducing agents, etc. can be cited. Among them, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that can initiate polymerization by heating are preferred. They can be used alone or in combination of two or more.

[0098] As the azo polymerization initiator, for example, 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), etc. can be cited.

[0099] As the inorganic peroxide, for example, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, etc. can be cited.

[0100] As the organic peroxide, for example, a peroxide ester compound can be cited. As its specific examples, α,α'-bis(neodecanoyl peroxide) diisopropylbenzene, cumyl neodecanoate peroxide, 1,1,3,3-tetramethylbutyl neodecanoate peroxide, 1-cyclohexyl-1-methylethyl neodecanoate peroxide, tert-hexyl neodecanoate peroxide, tert-butyl neodecanoate peroxide, tert-hexyl pivalate peroxide, tert-butyl pivalate peroxide, 1,1,3,3-tetramethylbutyl 2-ethylhexanoate peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoyl peroxide) hexane, 1-cyclohexyl-1-methylethyl 2-ethylhexanoate peroxide, tert-hexyl 2-ethylhexanoate peroxide, tert-butyl 2-ethylhexanoate peroxide, tert-butyl isobutyrate peroxide, tert-hexyl isopropyl monocarbonate peroxide, tert-butyl maleate peroxide, tert-butyl 3,5,5-trimethylhexanoate peroxide, tert-butyl laurate peroxide, 2,5-dimethyl-2,5-bis(m-toluoyl peroxide) hexane, tert-butyl isopropyl monocarbonate peroxide, tert-butyl 2-ethylhexyl monocarbonate peroxide, tert-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis(benzoyl peroxide) hexane, tert-butyl acetate peroxide, tert-butyl m-toluoylbenzoate peroxide, tert-butyl benzoyl peroxide, bis(tert-butyl peroxide) isophthalate, 1,1-bis(tert-hexyl peroxide) 3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexyl peroxide) cyclohexane, 1,1-bis(tert-butyl peroxide) 3,3,5-trimethylcyclohexane, 1,1-bis(tert-butyl peroxide) cyclohexane, 1,1-bis(tert-butyl peroxide) cyclododecane, 2,2-bis(tert-butyl peroxide) butane, n-butyl 4,4-bis(tert-butyl peroxide) valerate, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl) propane, α,α'-bis(tert-butyl peroxide) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane, tert-butyl cumyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, dilauroyl peroxide, diisononanoyl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, dimethyl bis(tert-butyl peroxide)-3-hexyne, bis(tert-butyl peroxide isopropyl) benzene, bis(tert-butyl peroxide) trimethylcyclohexane, butyl bis(tert-butylperoxy) valerate, tert-butyl 2-ethylperoxyhexanoate, benzoyl peroxide, p-menthane hydroperoxide, tert-butyl peroxybenzoate, etc.

[0101] As the redox initiator, an initiator obtained by combining an organic peroxide with ferrous sulfate, a chelating agent, and a reducing agent is preferably used. For example, an initiator composed of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextran, or an initiator obtained by combining tert-butyl hydroperoxide, sodium formaldehyde sulfoxylate (rongalite), ferrous sulfate, and disodium ethylenediaminetetraacetate can be cited.

[0102] With respect to a total of 100 parts by mass of the raw material monomer mixture, the addition amount of the initiator is usually 5 parts by mass or less, preferably 3 parts by mass or less, and for example, is 0.001 part by mass to 3 parts by mass.

[0103] The emulsion polymerization is usually carried out at 40°C to 100°C for about 30 minutes to 600 minutes.

[0104] <Glass transition temperature of polymer (b1)>

[0105] The glass transition temperature of the polymer (b1) of the present invention is characterized in that it is in the range of -15°C to +5°C. Even if the glass transition temperature is less than -15°C or exceeds +5°C, an excellent impact sound reduction effect cannot be obtained. From the aspect of excellent impact sound reduction effect, the glass transition temperature of the polymer (b1) is preferably -10°C to 0°C, and particularly preferably -7°C to 0°C.

[0106] In order to produce the polymer (b1) having a glass transition temperature within the above range, the ratio of acrylate to methacrylate can be adjusted.

[0107] The glass transition temperature of the polymer (b1) is measured by the method described in the items of the following examples.

[0108] <Tanδ of polymer (b1)>

[0109] For the polymer (b1) of the present invention, the temperature (peak temperature) representing the peak of the main dispersion of tanδ measured by the following method is -5°C to +20°C, and the peak intensity as this peak is 2.055 or more.

[0110] <Measurement method of Tanδ>

[0111] Using the polymer (b1), a sheet having a thickness of 1.0 mm to 1.1 mm is formed by hot pressing at a set temperature of 150°C, and a measurement sample is produced by cutting out a length of 36 mm × width of 10 mm from this sheet.

[0112] Using the following dynamic viscoelasticity measurement device, both ends of 8 mm each of the long side of the measurement sample are fixed with a stretching jig, and tanδ is measured under the following conditions, and the peak temperature and the peak intensity are obtained.

[0113] Measurement device: Dynamic viscoelasticity measurement device ("DMA850" manufactured by TA Instruments)

[0114] Mode: Tensile

[0115] Frequency: 1 Hz

[0116] Temperature increase rate: 5°C / minute

[0117] Measuring temperature: -60°C to +60°C

[0118] If the peak temperature of the polymer (b1) is -5°C to +20°C, the effect of reducing the impact sound is excellent. From this aspect, the peak temperature of the polymer (b1) is preferably 0 to +20°C, particularly preferably 0 to +15°C.

[0119] If the peak intensity of the polymer (b1) is 2.055 or more, the impact sound can be more effectively suppressed. From this aspect, the peak intensity of the polymer (b1) is more preferably 2.07 or more, particularly preferably 2.09 or more. There is no particular limitation on the upper limit of the peak intensity, and it is usually 3 or less.

[0120] In order to produce the polymer (b1) that satisfies the peak temperature and peak intensity of such tanδ, it is only necessary to select the optimal monomers constituting the polymer (b1) and adjust the amount of the crosslinking agent.

[0121] [Polymer (b2)]

[0122] [Structural unit]

[0123] The polymer (b2) is a polymer (b2) containing one or more selected from the group consisting of a structural unit derived from a methacrylate compound (methacrylate unit), a structural unit derived from an aromatic vinyl compound (aromatic vinyl unit), and a structural unit derived from a cyanated vinyl compound (cyanated vinyl unit).

[0124] As a combination example of the structural units contained in the polymer (b2), the following 1) to 5) can be cited, but it is not limited to the following examples at all.

[0125] 1) Methacrylate unit alone

[0126] 2) Methacrylate unit and aromatic vinyl unit

[0127] 3) Methacrylate unit and cyanated vinyl unit

[0128] 4) Aromatic vinyl unit and cyanated vinyl unit

[0129] 5) Methacrylate unit, aromatic vinyl unit, and cyanated vinyl unit

[0130] Among them, particularly from the aspect of balancing the impact sound reduction property and physical properties, a combination of 4) having an aromatic vinyl unit and a cyanated vinyl unit and a combination of 5) having a methacrylate unit, an aromatic vinyl unit, and a cyanated vinyl unit are preferred.

[0131] In the case of the combination in the above (2), from the aspect of the impact sound suppression effect, it is preferable that the content ratio of the methacrylate unit is 95 parts by mass to 60 parts by mass and the content ratio of the aromatic vinyl unit is 5 parts by mass to 40 parts by mass in a total of 100 parts by mass of the methacrylate unit and the aromatic vinyl unit.

[0132] In the case of the combination in the above (3), from the aspect of the impact sound suppression effect, it is preferable that the content ratio of the methacrylate unit is 95 parts by mass to 60 parts by mass and the content ratio of the vinyl cyanide unit is 5 parts by mass to 40 parts by mass in a total of 100 parts by mass of the methacrylate unit and the vinyl cyanide unit.

[0133] In the case of the combination in the above (4), from the aspect of impact resistance, it is preferable that the content ratio of the aromatic vinyl unit is 95 parts by mass to 60 parts by mass and the content ratio of the vinyl cyanide unit is 5 parts by mass to 40 parts by mass in a total of 100 parts by mass of the aromatic vinyl unit and the vinyl cyanide unit.

[0134] In the case of the combination in the above (5), from the aspects of the impact sound reduction effect and impact resistance, it is preferable that the content ratio of the methacrylate unit is 60 parts by mass to 80 parts by mass, the content ratio of the aromatic vinyl unit is 35 parts by mass to 15 parts by mass, and the content ratio of the vinyl cyanide unit is 25 parts by mass to 5 parts by mass in a total of 100 parts by mass of the methacrylate unit, the aromatic vinyl unit, and the vinyl cyanide unit.

[0135] The polymer (b2) may also contain structural units derived from other vinyl compounds other than the aromatic vinyl unit, the vinyl cyanide unit, and the alkyl methacrylate unit within the scope not impairing the object of the present invention. However, in order to more effectively obtain the effects brought by the inclusion of the aromatic vinyl unit, the vinyl cyanide unit, and the alkyl methacrylate unit, the content of the structural units derived from other vinyl compounds in 100 parts by mass of the polymer (b2) is preferably 20 parts by mass or less, and particularly preferably 0 to 10 parts by mass.

[0136] Examples of the aromatic vinyl compound constituting the aromatic vinyl unit of the polymer (b2) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinylxylene, p-tert-butylstyrene, ethylstyrene, and the like. Among them, styrene is preferable from the aspect of improving the impact resistance of the obtained molded product.

[0137] These aromatic vinyl compounds may be used alone or in combination of two or more.

[0138] Examples of the vinyl cyanide compound that constitutes the vinyl cyanide unit of the polymer (b2) include acrylonitrile, methacrylonitrile, and the like. Among them, acrylonitrile is preferred from the viewpoint of improving the impact resistance of the obtained molded article.

[0139] These vinyl cyanide compounds can be used alone or in combination of two or more.

[0140] As the methacrylate compound that constitutes the alkyl methacrylate unit of the polymer (b2), a methacrylate compound having 1 to 8 carbon atoms in the alkyl group is preferred. Among them, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate are preferred from the viewpoint of excellent effect of reducing the impact sound of the thermoplastic resin composition blended with the (meth)acrylate polymer (B), and methyl methacrylate is more preferred.

[0141] These methacrylate compounds can be used alone or in combination of two or more.

[0142] Examples of the other vinyl compound that constitutes the other vinyl compound unit include vinyl compounds other than the aromatic vinyl compound, vinyl cyanide compound, and methacrylate compound used in the production of the rubber-reinforced styrenic thermoplastic resin (A1) described later.

[0143] [<Method for producing polymer (b2)>]

[0144] The polymer (b2) is preferably produced by polymerization 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 methacrylate compound and, if necessary, other vinyl compounds in the same polymerization method as that of the vinyl monomer (a1) with respect to the rubbery polymer (g) in the rubber-reinforced styrenic thermoplastic resin (A1) described later.

[0145] [[(Meth)acrylate polymer (B)]]

[0146] [<Content ratio of polymer (b1) and polymer (b2)>]

[0147] As described above, the (meth)acrylate polymer (B) of the present invention is produced by polymerizing one or more of an aromatic vinyl compound, a vinyl cyanide compound, and a methacrylate compound constituting the polymer (b2) in the presence of the polymer (b1), and, if necessary, other vinyl compounds. By this method, a graft copolymer in which at least a part of the polymer (b2) is graft copolymerized to at least a part of the polymer (b1), that is, the (meth)acrylate polymer (B) can be obtained.

[0148] The (meth)acrylate polymer (B) may also contain the polymer (b2) that is not graft polymerized to the polymer (b1), and the polymer (b1) to which the polymer (b2) is not graft polymerized.

[0149] In the content ratio of the polymer (b1) and the polymer (b2) in the (meth)acrylate polymer (B), if the content ratio of the polymer (b1) is too large, although the impact sound reduction property is improved, other mechanical properties may deteriorate or manufacturing difficulties may occur. On the contrary, if the content ratio of the polymer (b1) is too small, when it is mixed with the resin component (A) described later as an impact sound reduction material, sufficient effects may not be exhibited in terms of impact sound suppression and the like.

[0150] From such aspects, the ratio of the polymer (b1) and the polymer (b2) contained in the (meth)acrylate polymer (B) is preferably 70 parts by mass to 20 parts by mass of the polymer (b2) with respect to 30 parts by mass to 80 parts by mass of the polymer (b1) (wherein the total of the polymer (b1) and the polymer (b2) is 100 parts by mass), and more preferably 40 parts by mass to 70 parts by mass of the polymer (b1) and 60 parts by mass to 30 parts by mass of the polymer (b2).

[0151] <Swelling degree of THF-insoluble component>

[0152] The swelling degree (hereinafter sometimes simply referred to as "swelling degree") of the THF-insoluble component of the (meth)acrylate polymer (B) of the present invention measured by the following method is preferably 1000% or more.

[0153] The swelling degree of 1000% or more of the (meth)acrylate polymer (B) of the present invention composed of the polymer (b1) and the polymer (b2) indicates that the molecular weight between crosslinks of the polymer (b1) contained in the (meth)acrylate polymer (B) of the present invention is large and it is easy to swell. If the polymer (b1) is easy to swell, the hindrance of crosslinking to the movement of molecular chains is small, and a significantly excellent impact sound reduction effect is exhibited.

[0154] From the aspect of the effect of reducing the impact sound, the swelling degree of the (meth)acrylate polymer (B) is more preferably 1200% or more, and further preferably 1300% or more. On the other hand, the upper limit of the swelling degree is not particularly limited. In order to obtain better appearance, the swelling degree of the (meth)acrylate polymer (B) is preferably 1200% to 3000%, and more preferably 1300% to 3000%.

[0155] <Method for measuring the swelling degree>

[0156] After immersing the (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble components separated by centrifugation are dried in vacuo, and the weight (weight b) is measured.

[0157] After immersing the obtained THF-insoluble components in THF again for 24 hours, the weight of the sample swollen with THF (weight c) is measured, and the swelling degree of the THF-insoluble components is calculated by the following formula.

[0158] Swelling degree (%) = c / b × 100

[0159] In order to produce the (meth)acrylate polymer (B) with such a swelling degree, no crosslinking agent is used in the production of the polymer (b1), or even if used, it is 0.4 parts by mass or less, particularly 0 to 0.25 parts by mass, per 100 parts by mass of the polymer (b1), and the crosslinked structure in the polymer (b1) is reduced.

[0160] <Gel content>

[0161] The gel content of the (meth)acrylate polymer (B) of the present invention is preferably 90% or less, particularly preferably 88% or less. When the gel content is 90% or less, the effect of reducing the impact sound is excellent. On the other hand, from the aspect of appearance such as gloss, the gel content is preferably 75% or more.

[0162] In order to produce the (meth)acrylate polymer (B) with such a gel content, the amount of the crosslinking agent during the production of the polymer (b1) is adjusted.

[0163] The gel content of the (meth)acrylate polymer (B) is measured by the method described in the items of the following examples.

[0164] <Molecular weight of the acetonitrile-soluble component>

[0165] The weight-average molecular weight of the acetonitrile-soluble component of the (meth)acrylate polymer (B) of the present invention (hereinafter sometimes referred to as "the molecular weight of the acetonitrile-soluble component") is preferably 50,000 to 80,000, particularly preferably 55,000 to 70,000. When the molecular weight of the acetonitrile-soluble component of the (meth)acrylate polymer (B) is within the above range, the impact resistance is excellent.

[0166] In order to produce a (meth)acrylate polymer (B) having such a molecular weight of the acetonitrile-soluble component, it is only necessary to adjust the amount of the chain transfer agent during the production of the polymer (b1).

[0167] The molecular weight of the acetonitrile-soluble component of the (meth)acrylate polymer (B) is measured by the method described in the items of the examples below.

[0168] [Grafting ratio]

[0169] The grafting ratio of the (meth)acrylate polymer (B) of the present invention is preferably 35% to 120%, particularly preferably 40% to 80%. When the grafting ratio is not less than the above lower limit, the impact resistance is excellent. On the other hand, when the grafting ratio is not more than the above upper limit, sufficient fluidity can be ensured in injection molding.

[0170] In order to produce a (meth)acrylate polymer (B) having such a grafting ratio, it is only necessary to adjust the amounts of the polymerization initiator and the chain transfer agent during the production of the polymer (b1).

[0171] The grafting ratio of the (meth)acrylate polymer (B) is measured by the method described in the items of the examples below.

[0172] [Thermoplastic resin composition]

[0173] The thermoplastic resin composition of the present invention contains a resin component (A) containing a rubber-reinforced styrene-based thermoplastic resin (A1) and the impact sound reducing material of the present invention.

[0174] The impact sound reducing material of the present invention is composed of the above-mentioned (meth)acrylate polymer (B) of the present invention.

[0175] The thermoplastic resin composition of the present invention may contain only one kind of the above-mentioned (meth)acrylate polymer (B) of the present invention as the impact sound reducing material, or may contain two or more kinds.

[0176] The thermoplastic resin composition of the present invention preferably contains 95 to 70 parts by mass of a resin component (A) and 5 to 30 parts by mass of a percussion sound reducing material in a total of 100 parts by mass. When the content of the resin component (A) is below the above upper limit and the content of the percussion sound reducing material is above the above lower limit, the percussion sound reducing effect is excellent. On the other hand, when the content of the resin component (A) is above the above lower limit and the content of the percussion sound reducing material is below the above upper limit, the original characteristics of the resin component (A) can be fully exerted. In the thermoplastic resin composition of the present invention, relative to a total of 100 parts by mass of the resin component (A) and the percussion sound reducing material, it is more preferable to contain 95 to 80 parts by mass of the resin component (A) and 5 to 20 parts by mass of the percussion sound reducing material.

[0177] When the resin component (A) of the thermoplastic resin composition of the present invention contains a rubber-reinforced styrene-based thermoplastic resin (A1) and a styrene-based resin (A2) described later, it is preferably to contain 95 to 70 parts by mass of the resin component (A) and 5 to 30 parts by mass of the percussion sound reducing material in a total of 100 parts by mass, and more preferably to contain 90 to 70 parts by mass of the resin component (A) and 10 to 30 parts by mass of the percussion sound reducing material relative to a total of 100 parts by mass of the resin component (A) and the percussion sound reducing material, and further preferably to contain 90 to 75 parts by mass of the resin component (A) and 10 to 25 parts by mass of the percussion sound reducing material relative to a total of 100 parts by mass of the resin component (A) and the percussion sound reducing material.

[0178] When the resin component (A) of the thermoplastic resin composition of the present invention contains a rubber-reinforced styrene-based thermoplastic resin (A1), a styrene-based resin (A2) and an aromatic polycarbonate resin (A3) described later, it is preferably to contain 95 to 70 parts by mass of the resin component (A) and 5 to 30 parts by mass of the percussion sound reducing material in a total of 100 parts by mass, and more preferably to contain 95 to 80 parts by mass of the resin component (A) and 5 to 20 parts by mass of the percussion sound reducing material relative to a total of 100 parts by mass of the resin component (A) and the percussion sound reducing material, and further preferably to contain 95 to 85 parts by mass of the resin component (A) and 5 to 15 parts by mass of the percussion sound reducing material relative to a total of 100 parts by mass of the resin component (A) and the percussion sound reducing material.

[0179] [Resin component (A)]

[0180] The thermoplastic resin composition of the present invention contains at least a rubber-reinforced styrenic thermoplastic resin (A1) as a resin component (A), and preferably further contains a styrenic resin (A2) or a styrenic resin (A2) and an aromatic polycarbonate resin (A3) together with the rubber-reinforced styrenic thermoplastic resin (A1).

[0181] The resin component (A) of the present invention does not contain the (meth)acrylate polymer (B) of the above-mentioned impact sound reduction material.

[0182] <Rubber-reinforced styrenic thermoplastic resin (A1)>

[0183] The rubber-reinforced styrenic thermoplastic resin (A1) contains a rubbery polymer part and a vinyl copolymer part. Such a rubber-reinforced styrenic thermoplastic resin (A1) can be produced by polymerizing vinyl monomers (a1) such as aromatic vinyl compounds in the presence of a rubbery polymer (g). The details will be described later.

[0184] 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-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-1-butene copolymer, and ethylene-1-butene-non-conjugated diene copolymer as ethylene-α-olefin rubbery polymers; acrylic rubber; silicone rubber; polyurethane rubber; silicone-acrylic IPN rubber; natural rubber; conjugated diene block copolymers; hydrogenated conjugated diene block copolymers; etc. Preferred rubbery polymers (g) will be described later.

[0185] Among them, especially from the aspect of being effective in both impact sound reduction and squeak reduction, as the rubbery polymer (g), an ethylene-α-olefin rubbery polymer is preferred. Among them, from the aspect of being also effective for impact resistance, a rubber-reinforced styrenic thermoplastic resin (A1) obtained by polymerizing vinyl monomers (a1) containing aromatic vinyl compounds and vinyl cyanide compounds in the presence of an ethylene-α-olefin rubbery polymer is preferred. That is, the rubber-reinforced styrenic thermoplastic resin (A1) is preferably a rubber-reinforced styrenic thermoplastic resin (A1) containing a rubbery polymer part and a vinyl copolymer part, the rubbery polymer part being composed of an ethylene-α-olefin rubber, and the vinyl copolymer part containing structural units derived from aromatic vinyl compounds and structural units derived from vinyl cyanide compounds.

[0186] The above ethylene-α-olefin rubbery polymer is not particularly limited, and examples thereof include an ethylene-α-olefin rubbery polymer containing ethylene and an α-olefin having 3 or more carbon atoms. When the total amount of the monomers constituting the above ethylene-α-olefin rubbery polymer is 100% by mass, the content of ethylene is preferably 5% to 95% by mass, more preferably 50% to 90% by mass, and further preferably 60% to 88% by mass.

[0187] Examples of the α-olefin having 3 or more carbon atoms include propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methylbutene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-undecene, and the like. These α-olefins may be contained alone or in combination of two or more. Among the above α-olefins, propylene and 1-butene are preferred.

[0188] When the total amount of the monomers constituting the ethylene-α-olefin rubbery polymer is 100% by mass, the content of the above α-olefin is preferably 95% to 5% by mass, more preferably 50% to 10% by mass, and particularly preferably 40% to 12% by mass.

[0189] The ethylene-α-olefin rubbery polymer may be a binary copolymer composed of ethylene and an α-olefin, or a polymer composed of them and other compounds (ternary copolymer, quaternary copolymer, etc.). Examples of the other compound include non-conjugated diene compounds.

[0190] Examples of the non-conjugated diene compound used in the ethylene-α-olefin rubbery polymer include vinyl norbornenes, cyclic dienes, aliphatic dienes, etc., and dicyclopentadiene and 5-ethylidene-2-norbornene are preferred. These non-conjugated diene compounds may be used alone or in combination of two or more. The content of the non-conjugated diene compound unit in the ethylene-α-olefin rubbery polymer is usually less than 30% by mass, preferably less than 15% by mass.

[0191] The above acrylic rubber is not particularly limited, and preferably a (co)polymer of an alkyl (meth)acrylate compound having 1 to 8 carbon atoms in the alkyl group, or a copolymer of the alkyl (meth)acrylate compound and a vinyl monomer copolymerizable therewith.

[0192] Specific examples of the acrylic alkyl ester compound having 1 to 8 carbon atoms in the alkyl group used herein include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and the like. Specific examples of the methacrylic alkyl ester compound having 1 to 8 carbon atoms in the alkyl group include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and the like. Among these compounds, n-butyl acrylate and 2-ethylhexyl acrylate are preferred. They can be used alone or in combination of two or more.

[0193] Examples of the vinyl monomer copolymerizable with the above (meth)acrylic alkyl ester compound include, for example, polyfunctional vinyl compounds, aromatic vinyl compounds, vinyl cyanide compounds, and the like.

[0194] The polyfunctional vinyl compound refers to a monomer having two or more vinyl groups in one molecule of the monomer. The polyfunctional vinyl compound exhibits a function of crosslinking the (meth)acrylic rubber and serves as a reaction starting point in graft polymerization.

[0195] Specific examples of the polyfunctional vinyl monomer include: polyfunctional aromatic vinyl compounds such as divinylbenzene and divinyltoluene; (meth)acrylates of polyhydric alcohols such as (poly)ethylene glycol dimethacrylate and trimethylolpropane triacrylate; diallyl maleate, diallyl fumarate, triallyl cyanurate, triallyl cyanurate, diallyl phthalate, allyl methacrylate, and the like. These polyfunctional vinyl compounds can be used alone or in combination of two or more.

[0196] As the aromatic vinyl compound and the vinyl cyanide compound, all the compounds described below can be used. In addition, as other copolymerizable monomers, acrylamide, methacrylamide, vinylidene chloride, alkyl vinyl ether having 1 to 6 carbon atoms in the alkyl group, (meth)acrylic alkyl ester having 9 or more carbon atoms in the alkyl group, (meth)acrylic acid, and the like can be cited. They can be used alone or in combination of two or more.

[0197] Regarding the preferred monomer composition of the above-mentioned acrylic rubber, the (meth)acrylic acid alkyl ester compound unit with 1 to 8 carbon atoms in the alkyl group is 80% to 99.99% by mass, more preferably 90% to 99.95% by mass, the polyfunctional vinyl compound unit is 0.01% to 5% by mass, more preferably 0.05% to 2.5% by mass, and the other vinyl monomer unit copolymerizable therewith is 0 to 20% by mass, more preferably 0 to 10% by mass. Among them, the total monomer composition is 100% by mass.

[0198] The volume average particle diameter of the acrylic rubber is preferably 50 nm to 1000 nm, more preferably 50 nm to 700 nm, and particularly preferably 50 nm to 500 nm.

[0199] As the conjugated diene block copolymer, specifically, it is a copolymer containing at least one of the following block A or block C and at least one of the following block B or block A / B; or it is a polymer based on block B or A / B. They can be produced by known anionic polymerization methods, such as the methods disclosed in Japanese Patent Publication No. 47-28915, Japanese Patent Publication No. 47-3252, Japanese Patent Publication No. 48-2423, Japanese Patent Publication No. 48-20038, etc.

[0200] Regarding the specific structure of the conjugated diene block copolymer, if each of the blocks A, B, A / B, and C is defined as follows, substances having the structures shown in the following formulas (1) to (13) can be cited.

[0201] A: Aromatic vinyl compound polymer block

[0202] B: Conjugated diene polymer block

[0203] A / B: Random copolymer pair block of aromatic vinyl compound / conjugated diene

[0204] C: Gradient block composed of a copolymer of conjugated diene and aromatic vinyl compound and with an increasing amount of aromatic vinyl compound

[0205] A - B(1)

[0206] A - B - A(2)

[0207] A - B - C(3)

[0208] A - B1 - B2(4)

[0209] (Here, B1 is a conjugated diene polymer block or a copolymer block of a conjugated diene and an aromatic vinyl compound, and the vinyl bonding amount in the conjugated diene portion is preferably 20% or more. B2 is a conjugated diene polymer block or a copolymer block of a conjugated diene and an aromatic vinyl compound, and the vinyl bond content in the conjugated diene portion is preferably less than 20%. )

[0210] A-A / B(5)

[0211] A-A / B-C(6)

[0212] A-A / B-B(7)

[0213] A-A / B-A(8)

[0214] B2-B1-B2(9)

[0215] (Here, B1 and B2 are the same as above. )

[0216] C-B(10)

[0217] C-B-C(11)

[0218] C-A / B-C(12)

[0219] C-A-B(13)

[0220] As the conjugated diene-based block copolymer, a copolymer having these basic skeletons repeatedly can also be mentioned. The conjugated diene-based block copolymer may also be a conjugated diene-based block copolymer obtained by further coupling it.

[0221] Regarding the substance having the structure of the above formula (4), it is shown in Japanese Patent Laid-Open No. 2-133406. Regarding the substances having the structures of the above formula (5) and the above formula (6), they are shown in Japanese Patent Laid-Open Nos. 2-305814 and 3-72512.

[0222] As the conjugated diene used here, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, etc. can be mentioned. In order to be industrially utilized and obtain a conjugated diene-based block copolymer having excellent physical properties, as the conjugated diene, 1,3-butadiene, isoprene, 1,3-pentadiene are preferred, and 1,3-butadiene is more preferred.

[0223] As the aromatic vinyl compound used herein, styrene, tert-butylstyrene, α-methylstyrene, p-methylstyrene, hydroxystyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, fluorostyrene, p-tert-butylstyrene, ethylstyrene, vinylnaphthalene, divinylbenzene, 1,1-diphenylstyrene, N,N-diethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, vinylpyridine, etc. can be mentioned. Styrene and α-methylstyrene are preferred, and styrene is particularly preferred.

[0224] The ratio of the aromatic vinyl compound / conjugated diene in the conjugated diene block copolymer is 0 to 70 / 100 to 30 by mass ratio, preferably 0 to 60 / 100 to 40, and more preferably 0 to 50 / 100 to 50. In the case where an aromatic vinyl compound is essential, the ratio of the aromatic vinyl compound / conjugated diene is preferably 10 to 70 / 90 to 30. If the content of the aromatic vinyl compound exceeds 70% by mass, it becomes resinous and the effect as a rubber component is poor, which is not preferred.

[0225] The vinyl bonding amount of the conjugated diene portion in the conjugated diene block is usually in the range of 5% to 80%.

[0226] The number average molecular weight of the conjugated diene block copolymer is usually 10,000 to 1,000,000, preferably 20,000 to 500,000, and more preferably 20,000 to 200,000.

[0227] Among them, the number average molecular weight of part A of the above structural formula is preferably in the range of 3,000 to 150,000. The number average molecular weight of part B is preferably in the range of 5,000 to 200,000.

[0228] Here, the number average molecular weight is a value obtained by measurement using gel permeation chromatography (GPC).

[0229] The adjustment of the vinyl bonding amount of the conjugated diene compound can be carried out using amines such as N,N,N',N'-tetramethylethylenediamine, trimethylamine, triethylamine, diazacyclo(2,2,2)octamine, etc.; ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, etc.; thioethers; phosphines; phosphoramides; alkylbenzenesulfonates; alcoholates of potassium or sodium.

[0230] As the coupling agent used in the present invention, diethyl adipate, divinylbenzene, methyldichlorosilane, silicon tetrachloride, butyltrichlorosilane, tin tetrachloride, butyltrichlorotin, dimethylchlorosilane, germanium tetrachloride, 1,2-dibromoethane, 1,4-chloromethylbenzene, bis(trichlorosilyl)ethane, epoxidized linseed oil, toluene diisocyanate, 1,2,4-benzenetriisocyanate, etc. can be mentioned.

[0231] The hydrogenated conjugated diene-based block copolymer is a partial hydride or a complete hydride in which at least 30% or more, preferably 50% or more of the carbon-carbon double bonds in the conjugated diene portion of the above-mentioned conjugated diene-based block copolymer are hydrogenated, and more preferably a hydride in which 90% or more are hydrogenated.

[0232] The hydrogenation reaction of the conjugated diene-based block copolymer can be carried out by a known method. In addition, by adjusting the hydrogenation rate using a known method, the target hydrogenated conjugated diene-based block copolymer can be obtained. As specific methods, there are the methods disclosed in Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 63-5401, Japanese Unexamined Patent Publication No. 2-133406, Japanese Unexamined Patent Publication No. 1-297413, etc.

[0233] In the rubbery polymer (g) used in the present invention, from the aspects of mechanical properties such as impact resistance and rigidity, and appearance such as gloss, the gel content is preferably 70% by mass or less. The gel content of the rubbery polymer (g) is more preferably 80% by mass or more, and further preferably 90% by mass or more.

[0234] Here, the gel content can be determined by the method shown below.

[0235] Put 1 g of the rubbery polymer (g) into 100 ml of toluene and let it stand at room temperature for 48 hours. Then filter it using a 100-mesh wire mesh (mass is W1 g), and vacuum-dry the toluene-insoluble component and the wire mesh obtained after filtration at 80 °C for 6 hours and weigh it (mass is W2 g). Substitute W1 and W2 into the following formula (i) to obtain the gel content.

[0236] In the ethylene-propylene rubbery polymer, there is a substance having ethylene crystals. In the case of using such a rubbery polymer, it is dissolved at a temperature of 80 °C to determine the gel content.

[0237] Gel content = [[W2 (g) - W1 (g)] / 1 (g)] × 100 (i)

[0238] The gel content can be adjusted by appropriately setting the type and amount of the crosslinkable monomer, the type and amount of the molecular weight regulator, the polymerization time, the polymerization temperature, the polymerization conversion rate, etc. during the production of the rubbery polymer (g).

[0239] Preferred substances of the rubbery polymer (g) used in the present invention among the above substances are polybutadiene, butadiene-styrene copolymer, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer and other ethylene-α-olefin rubbery polymers, acrylic rubber, silicone rubber, conjugated diene block copolymer, hydrogenated conjugated diene block copolymer. More preferably, they are ethylene-α-olefin rubbery polymers such as ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, acrylic rubber, conjugated diene block copolymer, hydrogenated conjugated diene block copolymer. Particularly preferably, they are acrylic rubber, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, conjugated diene block copolymer and hydrogenated conjugated diene block copolymer. Most preferably, it is ethylene-propylene copolymer.

[0240] The rubbery polymer (g) can be obtained by methods such as emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization, etc. which are well-known methods. Among these, acrylic rubber is preferably manufactured by emulsion polymerization. Ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, conjugated diene block copolymer and hydrogenated conjugated diene block copolymer are preferably manufactured by solution polymerization. Polybutadiene and butadiene-styrene copolymer are preferably manufactured by solution polymerization.

[0241] The rubber-reinforced styrenic thermoplastic resin (A1) is obtained by polymerizing an aromatic vinyl compound or an aromatic vinyl compound and other vinyl monomers (a1) copolymerizable with the aromatic vinyl compound in the presence of the above rubbery polymer (g). That is, the vinyl monomer (a1) can be a single aromatic vinyl compound or a mixture of an aromatic vinyl compound and other vinyl monomers copolymerizable with the aromatic vinyl compound.

[0242] The rubber-reinforced styrenic thermoplastic resin (A1) is preferably obtained by polymerizing 20 parts by mass to 97 parts by mass of an aromatic vinyl compound or an aromatic vinyl compound and other vinyl monomers (a1) copolymerizable with the aromatic vinyl compound in the presence of 3 parts by mass to 80 parts by mass of the above rubbery polymer (g) (wherein the total of the rubbery polymer (g) and the vinyl monomer (a1) is 100 parts by mass). Regarding this ratio, more preferably, the rubbery polymer (g) is 7 parts by mass to 65 parts by mass and the vinyl monomer (a1) is 35 parts by mass to 93 parts by mass.

[0243] As the aromatic vinyl compound used herein, all the substances described in the aromatic vinyl compound polymer block A of the above conjugated diene block copolymer can be used. Particularly preferably, they are styrene and α-methylstyrene. They can be used alone or in combination of two or more.

[0244] As other vinyl monomers capable of copolymerizing with aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylate compounds, maleimide compounds, and other unsaturated compounds containing various functional groups can be mentioned. As other unsaturated compounds containing various functional groups, unsaturated acid compounds, unsaturated compounds containing an epoxy group, unsaturated compounds containing a hydroxyl group, unsaturated compounds containing an acid anhydride group, unsaturated compounds containing an oxazoline group, substituted or unsubstituted unsaturated compounds containing an amino group, etc. can be mentioned. These other vinyl monomers can be used alone or in combination of two or more.

[0245] As vinyl cyanide compounds, acrylonitrile, methacrylonitrile, etc. can be mentioned. They can be used alone or in combination of two or more. By using vinyl cyanide compounds, chemical resistance can be imparted. The amount of vinyl cyanide compounds is usually 0 to 60% by mass, preferably 5% to 50% by mass, based on the total amount of vinyl monomer (a1).

[0246] As (meth)acrylate compounds, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc. can be mentioned. They can be used alone or in combination of two or more. By using (meth)acrylate compounds, the surface hardness is increased. The amount of (meth)acrylate compounds is usually 0 to 80% by mass, based on the total amount of vinyl monomer (a1).

[0247] As maleimide compounds, maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, N-benzylmaleimide, etc. can be mentioned. They can be used alone or in combination of two or more. In order to introduce maleimide units, imidization can be carried out after copolymerizing maleic anhydride. By using maleimide compounds, heat resistance can be imparted. The amount of maleimide compounds is usually 1% to 60% by mass, based on the total amount of vinyl monomer (a1).

[0248] As unsaturated acid compounds, acrylic acid, methacrylic acid, ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, cinnamic acid, etc. can be mentioned. They can be used alone or in combination of two or more.

[0249] As unsaturated compounds containing an epoxy group, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, etc. can be mentioned. They can be used alone or in combination of two or more.

[0250] Examples of the unsaturated compound containing a hydroxyl group include 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-3-methyl-1-propene, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, N-(4-hydroxyphenyl) maleimide, and the like. They may be used alone or in combination of two or more.

[0251] Examples of the unsaturated compound containing an oxazoline group include vinyl oxazoline and the like. They may be used alone or in combination of two or more.

[0252] Examples of the unsaturated compound containing an acid anhydride group include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. They may be used alone or in combination of two or more.

[0253] Examples of the substituted or unsubstituted unsaturated compound containing an amino group include 2-(dimethylamino)ethyl methacrylate, 2-(phenylamino)ethyl methacrylate, N-vinyl diethylamine, N-acetylvinylamine, allylamine, N-methylallylamine, acrylamide, N-methylacrylamide, 4-aminostyrene, and the like. They may be used alone or in combination of two or more.

[0254] When blending the rubber-reinforced styrene-based thermoplastic resin (A1) with the styrene-based resin (A2) and the aromatic polycarbonate resin (A3) in the case of using the above various other unsaturated compounds containing functional groups, the compatibility between the two may be improved. The amount of the above various other unsaturated compounds containing functional groups is usually 0.1% by mass to 20% by mass, preferably 0.1% by mass to 10% by mass, based on the total amount of the rubber-reinforced styrene-based thermoplastic resin (A1) and the styrene-based resin (A2).

[0255] Regarding the amount of the monomers other than the aromatic vinyl compound in the vinyl monomer (a1), when the total amount of the vinyl monomer (a1) is set to 100% by mass, it is usually 80% by mass or less, preferably 60% by mass or less, more preferably 50% by mass or less.

[0256] A more preferred combination of monomers constituting the vinyl monomer (a1) is styrene alone, styrene / acrylonitrile, styrene / methyl methacrylate, styrene / acrylonitrile / methyl methacrylate, styrene / acrylonitrile / glycidyl methacrylate, styrene / acrylonitrile / 2-hydroxyethyl methacrylate, styrene / acrylonitrile / (meth)acrylic acid, styrene / N-phenyl maleimide, styrene / methyl methacrylate / cyclohexyl maleimide, etc. Further preferred is styrene alone, styrene / acrylonitrile = 65 / 45 to 90 / 10 (mass ratio), styrene / methyl methacrylate = 80 / 20 to 20 / 80 (mass ratio), and any combination of styrene / acrylonitrile / methyl methacrylate in the range where the styrene content is 20 to 80% by mass and the total of acrylonitrile and methyl methacrylate is 20 to 80% by mass.

[0257] The rubber-reinforced styrenic thermoplastic resin (A1) can be produced by known polymerization methods, such as emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, and polymerization methods combining them. In the above polymerization methods, when the rubbery polymer (g) is a substance obtained by emulsion polymerization, the rubber-reinforced styrenic thermoplastic resin (A1) can be similarly produced by emulsion polymerization in the production. Further, when the rubbery polymer (g) is a substance obtained by solution polymerization, the rubber-reinforced styrenic thermoplastic resin (A1) is usually preferably produced by bulk polymerization, solution polymerization, and suspension polymerization. However, even if the rubbery polymer (g) is produced by solution polymerization, if the rubbery polymer (g) is emulsified by a known method, the rubber-reinforced styrenic thermoplastic resin (A1) can be produced by emulsion polymerization. Even if the rubbery polymer (g) is produced by emulsion polymerization, the rubber-reinforced styrenic thermoplastic resin (A1) can be produced by bulk polymerization, solution polymerization, and suspension polymerization after solidifying and separating it.

[0258] In the case of production by emulsion polymerization, a polymerization initiator, a chain transfer agent, an emulsifier, etc. are used. All of them can use known substances.

[0259] Examples of the polymerization initiator include cumene hydroperoxide, terpinyl hydroperoxide, diisopropylbenzene hydroperoxide, tetramethylbutyl hydroperoxide, tert-butyl hydroperoxide, potassium persulfate, azobisisobutyronitrile, etc. As the polymerization initiator aid, redox systems such as various reducing agents, a sugar-containing ferric pyrophosphate formulation, and a hyposulfite formulation are preferably used.

[0260] Examples of the chain transfer agent include octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, n-hexyl mercaptan, terpinolene, etc.

[0261] As an emulsifier, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, aliphatic sulfonates such as sodium lauryl sulfate; higher fatty acid salts such as potassium laurate, potassium stearate, potassium oleate, potassium palmitate; rosin acid salts such as potassium rosinate, etc. can be used.

[0262] In the emulsion polymerization, regarding the use method of the rubbery polymer (g) and the vinyl monomer (a1), the vinyl monomer (a1) can be added all at once in the presence of the whole amount of the rubbery polymer (g) for polymerization, or can be added in portions or continuously for polymerization. In addition, a part of the rubbery polymer (g) can also be added during the polymerization.

[0263] After the emulsion polymerization, the obtained emulsion is usually coagulated using a coagulant. Thereafter, the rubber-reinforced styrenic thermoplastic resin (A1) powder is obtained by washing with water and drying. At this time, coagulation can be carried out after appropriately blending two or more emulsions of the rubber-reinforced styrenic thermoplastic resin (A1) obtained by emulsion polymerization.

[0264] Coagulation can also be carried out after appropriately blending the emulsion of the styrenic resin (A2).

[0265] As the coagulant, inorganic salts such as calcium chloride, magnesium sulfate, magnesium chloride; acids such as sulfuric acid, acetic acid, citric acid, malic acid can be used.

[0266] The rubber-reinforced styrenic thermoplastic resin (A1) powder can also be obtained by spray-drying the emulsion.

[0267] The solvents that can be used in the case of manufacturing the rubber-reinforced styrenic thermoplastic resin (A1) by solution polymerization are non-reactive polymerization solvents usually used in radical polymerization. As the solvent, for example, aromatic hydrocarbons such as ethylbenzene, toluene; ketones such as methyl ethyl ketone, acetone; acetonitrile, dimethylformamide, N-methylpyrrolidone, etc. can be cited.

[0268] The polymerization temperature is usually in the range of 80 °C to 140 °C, preferably 85 °C to 120 °C. A polymerization initiator can be used during the polymerization, or polymerization can be carried out by thermal polymerization without using a polymerization initiator.

[0269] As the polymerization initiator, organic peroxides such as peroxoketones, dialkyl peroxides, diacyl peroxides, peresters, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, etc. can be appropriately used.

[0270] In the case of using a chain transfer agent, for example, thiols, terpinolene, α-methylstyrene dimer, etc. can be used.

[0271] In the case of producing the rubber-reinforced styrenic thermoplastic resin (A1) by bulk polymerization or suspension polymerization, polymerization initiators, chain transfer agents, etc. described in solution polymerization can be used.

[0272] The amount of monomers remaining in the rubber-reinforced styrenic thermoplastic resin (A1) obtained by each of the above polymerization methods is usually 10,000 ppm or less, preferably 5,000 ppm or less.

[0273] The rubber-reinforced styrenic thermoplastic resin (A1) obtained by polymerizing the vinyl monomer (a1) in the presence of the rubbery polymer (g) contains a copolymer obtained by graft copolymerizing the vinyl monomer (a1) onto the rubbery polymer (g) and a non-grafted component (a (co)polymer of the vinyl monomer (a1)) that is not grafted to the rubbery polymer (g).

[0274] The grafting rate of the rubber-reinforced styrenic thermoplastic resin (A1) is preferably adjusted to generally 5% by mass to 100% by mass, preferably 10% by mass to 90% by mass, more preferably 15% by mass to 85% by mass, and particularly preferably 20% by mass to 80% by mass. The grafting rate can be changed by various factors such as the type and amount of the polymerization initiator, the type and amount of the chain transfer agent, the polymerization method, the contact time between the vinyl monomer (a1) and the rubbery polymer (g) during polymerization, the type of the rubbery polymer (g), and the polymerization temperature.

[0275] The grafting rate can be determined by the following formula (ii).

[0276] Grafting rate (% by mass) = {(T - S) / S} × 100 (ii)

[0277] In the above formula (ii), T is the mass (g) of the insoluble component obtained as follows: 1 g of the rubber-reinforced styrenic thermoplastic resin (A1) is put into 20 ml of acetone, shaken with a shaker for 2 hours, and then centrifuged for 60 minutes using a centrifuge (rotation speed: 32,000 rpm) to separate the insoluble component and the soluble component to obtain the mass of the insoluble component.

[0278] S is the mass (g) of the rubbery polymer (g) contained in 1 g of the rubber-reinforced styrenic thermoplastic resin (A1).

[0279] When only an aromatic vinyl compound is used as the vinyl monomer (a1), methyl ethyl ketone is used instead of acetone for the measurement.

[0280] The intrinsic viscosity [η] of the acetone-soluble component of the rubber-reinforced styrenic thermoplastic resin (A1) (measured at 30 °C using methyl ethyl ketone as the solvent) is generally 0.15 dl / g to 1.2 dl / g, preferably 0.2 dl / g to 1.0 dl / g, and more preferably 0.2 dl / g to 0.8 dl / g.

[0281] The average particle diameter of the grafted rubber polymer particles dispersed in the rubber-reinforced styrenic thermoplastic resin (A1) is generally 50 nm to 3,000 nm, preferably 50 nm to 2,500 nm, and particularly preferably 50 nm to 2,000 nm. When the rubber particle diameter is less than 50 nm, the impact resistance tends to deteriorate. If the rubber particle diameter exceeds 3,000 nm, the surface appearance of the molded product tends to deteriorate.

[0282] By making the refractive index of the copolymer of the rubber polymer (g) and the vinyl monomer (a1) used substantially the same, and / or making the particle diameter of the dispersed rubber polymer (g) substantially below the wavelength of visible light (generally 1,500 nm or less), a rubber-reinforced styrenic thermoplastic resin (A1) having transparency can be obtained. These transparent resins can also be used as the rubber-reinforced styrenic thermoplastic resin (A1) of the present invention.

[0283] The rubber-reinforced styrenic thermoplastic resin (A1) can be used alone as one kind, or two or more components having different copolymerization compositions, physical properties, etc. can be mixed and used.

[0284] [Styrenic resin (A2)]

[0285] As the styrenic resin (A2), it is a (co)polymer obtained by polymerizing an aromatic vinyl compound, or an aromatic vinyl compound and other vinyl monomers (a2) capable of copolymerizing with the aromatic vinyl compound. That is, the vinyl monomer (a2) can be a single aromatic vinyl compound, or a mixture of an aromatic vinyl compound and other vinyl monomers capable of copolymerizing with the aromatic vinyl compound. As the aromatic vinyl compound and other vinyl monomers capable of copolymerizing with the aromatic vinyl compound used herein, all the substances described as the vinyl monomer (a1) in the rubber-reinforced styrenic thermoplastic resin (A1) can be used.

[0286] The vinyl monomer (a2) can be the same as or different from the above vinyl monomer (a1).

[0287] Regarding the content of monomers other than aromatic vinyl compounds in the vinyl monomer (a2), when the total amount of the vinyl monomer (a2) is set to 100% by mass, it is usually 80% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less.

[0288] As the preferred styrene resin (A2), there can be mentioned homopolymers of styrene, styrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-methyl methacrylate copolymers, styrene-maleimide compound copolymers, and copolymers of these with the above-mentioned unsaturated compounds containing functional groups.

[0289] The styrene resin (A2) can be produced by emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, which are well-known polymerization methods described in the method for producing the above-mentioned rubber-reinforced styrene-based thermoplastic resin (A1), and methods obtained by combining them.

[0290] The styrene resin (A2) can be used alone as one kind, or two or more components with different copolymerization compositions, physical properties, etc. can be mixed and used.

[0291] [Aromatic polycarbonate resin (A3)]

[0292] Regarding the aromatic polycarbonate resin (A3), all substances obtained by known polymerization methods such as those obtained by the interfacial polycondensation method of dihydroxyaryl compounds and phosgene, and the transesterification reaction (melt polycondensation) of dihydroxyaryl compounds and carbonate compounds such as diphenyl carbonate can be used.

[0293] Examples of the above-mentioned 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-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-tert-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. In addition, it can also be a polyorganosiloxane having a hydroxyaryloxy end (for example, refer to the specification of U.S. Patent No. 3,419,634), etc. They can be used alone as one kind or in combination of two or more kinds. Among these, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is preferred.

[0294] The viscosity-average molecular weight of the aromatic polycarbonate resin (A3) is preferably 12,000 to 40,000, more preferably 15,000 to 35,000, and particularly preferably 18,000 to 30,000. If the molecular weight is high, the mechanical strength of the resulting molded article increases, but the appearance of the molded article tends to deteriorate due to a decrease in fluidity. As the aromatic polycarbonate resin (A3), two or more aromatic polycarbonate resins having different molecular weights can also be used.

[0295] Here, regarding the viscosity-average molecular weight of the aromatic polycarbonate resin (A3), the specific viscosity (ηsp) measured at a concentration of [0.7 g / 100 ml (dichloromethane)] at 20 °C using dichloromethane as a solvent can usually be inserted into the following formula (iii) for calculation.

[0296] Viscosity-average molecular weight = ([η] × 8130) 1.205 (iii)

[0297] Here, [η] = [(ηsp × 1.12 + 1) 1 / 2 - 1] / 0.56C. C represents the concentration.

[0298] [Content of rubber-reinforced styrenic thermoplastic resin (A1) and styrenic resin (A2)]

[0299] When the resin component (A) of the present invention contains a rubber-reinforced styrenic thermoplastic resin (A1) and a styrenic resin (A2), the contents of the rubber-reinforced styrenic thermoplastic resin (A1) and the styrenic resin (A2) in 100% by mass of the resin component (A) are preferably 0.1% by mass to 99% by mass and 1% by mass to 99.9% by mass, respectively.

[0300] If it is within the above range, the heat resistance and fluidity are good.

[0301] Regarding the content ratio of the rubber-reinforced styrenic thermoplastic resin (A1) and the styrenic resin (A2), it is more preferably that the rubber-reinforced styrenic thermoplastic resin (A1) is 1% by mass to 80% by mass and the styrenic resin (A2) is 20% by mass to 99% by mass, and further preferably that the rubber-reinforced styrenic thermoplastic resin (A1) is 5% by mass to 60% by mass and the styrenic resin (A2) is 40% by mass to 95% by mass.

[0302] [Content of rubber-reinforced styrenic thermoplastic resin (A1), styrenic resin (A2) and aromatic polycarbonate resin (A3)]

[0303] When the resin component (A) of the present invention contains a rubber-reinforced styrenic thermoplastic resin (A1), a styrenic resin (A2), and an aromatic polycarbonate resin (A3), the contents of the rubber-reinforced styrenic thermoplastic resin (A1), the styrenic resin (A2), and the aromatic polycarbonate resin (A3) in 100% by mass of the resin component (A) are preferably 0.1% by mass to 89% by mass, 1% by mass to 89.9% by mass, and 10% by mass to 98.9% by mass, respectively.

[0304] If it is within the above range, the heat resistance and fluidity are better.

[0305] Regarding the content ratios of the rubber-reinforced styrenic thermoplastic resin (A1), the styrenic resin (A2), and the aromatic polycarbonate resin (A3), it is more preferably that the rubber-reinforced styrenic thermoplastic resin (A1) is 1% by mass to 60% by mass, the styrenic resin (A2) is 5% by mass to 64% by mass, and the aromatic polycarbonate resin (A3) is 35% by mass to 94% by mass, and further preferably that the rubber-reinforced styrenic thermoplastic resin (A1) is 5% by mass to 50% by mass, the styrenic resin (A2) is 8% by mass to 55% by mass, and the aromatic polycarbonate resin (A3) is 40% by mass to 87% by mass.

[0306] [Other resins]

[0307] The resin component (A) of the present invention may contain other resins other than the rubber-reinforced styrenic thermoplastic resin (A1), the styrenic resin (A2), and the aromatic polycarbonate resin (A3) within the range that does not impair the object of the present invention.

[0308] Examples of other resins include polyolefin resins, vinyl chloride resins, acrylic resins, polyester resins, polyamide resins, polyacetal resins, polyphenylene ether resins, polyarylene sulfide resins, etc. These thermoplastic resins may be used alone or in combination of two or more.

[0309] When the thermoplastic resin composition of the present invention contains these other resins, their content is preferably 50% by mass or less, particularly preferably 30% by mass or less in 100% by mass of the resin component (A) containing the rubber-reinforced styrenic thermoplastic resin (A1), the styrenic resin (A2), the aromatic polycarbonate resin (A3), and other resins.

[0310] [Other components]

[0311] The thermoplastic resin composition of the present invention may contain other components other than the above resin component (A) and the impact sound reducing material within the range that does not impair the object of the present invention.

[0312] <Slip property imparting agent>

[0313] The thermoplastic resin composition of the present invention may contain a lubricity-imparting agent. The lubricity-imparting agent can impart the following effects: imparting lubricity to the thermoplastic resin composition, thereby not only facilitating the assembly of an article composed of a molded article obtained from the thermoplastic resin composition of the present invention, but also suppressing the generation of noises such as squeaking in the article composed of the molded article during use.

[0314] As a representative example of the lubricity-imparting agent, low-molecular-weight oxidized polyethylene, ultra-high-molecular-weight polyethylene, polytetrafluoroethylene, low-molecular-weight (for example, number-average molecular weight of 10,000 or less) polyolefin wax, silicone oil, etc. described in JP-A-2011-137066 can be cited.

[0315] As the polyolefin wax, polyethylene wax having a melting point of 0 to 120°C is preferred.

[0316] When a polyolefin wax having such a melting point or other additives having a melting point of 0 to 120°C is added to the thermoplastic resin composition of the present invention, even if the rubbery portion of the rubber-reinforced styrenic thermoplastic resin (A1) does not have a melting point (Tm), the effect of suppressing the generation of noises such as squeaking can be obtained. These lubricity-imparting agents can be used alone or in combination of two or more.

[0317] When a lubricity-imparting agent is blended in the thermoplastic resin composition of the present invention, the blending amount is preferably 0.1 part by mass to 10 parts by mass relative to 100 parts by mass of the rubber-reinforced styrenic thermoplastic resin (A1).

[0318] <Heat aging-resistant agent>

[0319] In order to obtain a molded article with suppressed generation of squeaking and high surface gloss, a heat aging-resistant agent can be added to the thermoplastic resin composition of the present invention. As the heat aging-resistant agent, there is no particular limitation as long as it is a heat aging-resistant agent blended in rubber or the like. As the heat aging-resistant agent, phenolic antioxidants and phosphorus-based antioxidants are preferred.

[0320] As the phenolic antioxidant, for example, a phenolic antioxidant having a phenol group with a tert-butyl group at the ortho position represented by the following general formula (I) can be cited.

[0321] [Chemical formula 1]

[0322]

[0323] (In the formula, R 1 and R 2 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and t-Bu represents a tert-butyl group.)

[0324] In the above general formula (I), the substituent R 1 and R 2 are each independently preferably a hydrogen atom, a tert-butyl group or a methyl group, more preferably a hydrogen atom or a methyl group, and particularly preferably the case where R 1 is a hydrogen atom. Specifically, the phenolic antioxidant used in the present invention is preferably a compound having one or two or more groups represented by the above general formula (I), and more preferably a compound represented by any one of the following formulas (C1), (C2) and (C3).

[0325] [Chemical formula 2]

[0326]

[0327] Examples of the phosphorus-based antioxidant include compounds represented by the following general formula (II).

[0328] [Chemical formula 3]

[0329]

[0330] (In the formula, R 3 and R 4 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Particularly preferably, R 3 and R 4 are t-C4H9 groups.)

[0331] When a heat aging resistant agent is blended in the thermoplastic resin composition of the present invention, when the thermoplastic resin composition of the present invention is set to 100 parts by mass, the blending amount is preferably 0.01 part by mass to 5 parts by mass, more preferably 0.02 part by mass to 3 parts by mass, still more preferably 0.03 part by mass to 2 parts by mass, and particularly preferably 0.03 part by mass to 1 part by mass. As the most preferable blending amount range of the heat aging resistant agent, 0.02 part by mass to 0.6 part by mass, 0.02 part by mass to 0.2 part by mass, 0.03 part by mass to 0.6 part by mass, or 0.03 part by mass to 0.2 part by mass can be cited. When the blending amount of the heat aging resistant agent is within the above range, the molded product has excellent gloss and a good appearance can be obtained.

[0332] [Other Additives]

[0333] Examples of other additives that can be blended in the thermoplastic resin composition of the present invention include antioxidants, ultraviolet absorbers, weathering agents, fillers, antistatic agents, flame retardancy imparting agents, antifogging agents, lubricants, antibacterial agents, mildewproof agents, tackifiers, plasticizers, colorants, graphite, carbon black, carbon nanotubes, pigments (including, for example, pigments imparting functions such as infrared absorption and reflection ability). They can be used alone or in combination of two or more.

[0334] The blending amount of these other additives is generally 0.1 part by mass to 30 parts by mass relative to 100 parts by mass of the resin component (A).

[0335] [Method for manufacturing a thermoplastic resin composition]

[0336] The thermoplastic resin composition of the present invention can be manufactured as follows: After mixing each component according to a specified mixing ratio using a drum mixer, Henschel mixer, etc., it is melt-kneaded under appropriate conditions using a single-screw extruder, twin-screw extruder, Banbury mixer, kneader, roll, feeder, etc. The preferred kneading machine is a twin-screw extruder. In addition, when kneading each component, these components can be kneaded all at once, or can be kneaded in multiple steps and in portions.

[0337] It is also possible to granulate using an extruder after kneading using a Banbury mixer, kneader, etc.

[0338] The melt-kneading temperature is generally 180°C to 240°C, preferably 190°C to 230°C.

[0339] [Preferred physical properties, etc.]

[0340] The preferred physical properties, etc. of the thermoplastic resin composition of the present invention will be described below. Regarding the physical properties, etc. of the thermoplastic resin composition of the present invention described below, specifically, they are measured by the methods described in the items of the examples described later.

[0341] <Maximum sound pressure>

[0342] For the thermoplastic resin composition of the present invention, from the aspect of suppressing impact sounds, when measured by the methods described in the items of the examples described later, the maximum sound pressure in the frequency range of 20 Hz to 20,000 Hz is preferably less than 68.9 dB in the thermoplastic resin composition not containing the aromatic polycarbonate resin (A3), and preferably less than 70.5 dB in the thermoplastic resin composition containing the aromatic polycarbonate resin (A3).

[0343] <Noise risk value>

[0344] The noise risk value of the thermoplastic resin composition of the present invention measured by the methods described in the items of the examples described later is preferably 3 or less.

[0345] <Mechanical properties and heat resistance>

[0346] The thermoplastic resin composition of the present invention preferably maintains high mechanical strength and heat resistance, and the thermoplastic resin composition of the present invention preferably has the following physical properties when measured by the values described in the items of the examples described later.

[0347] (Preferred Physical Properties of Thermoplastic Resin Composition Excluding Aromatic Polycarbonate Resin (A3))

[0348] Charpy impact strength (23°C): 8 kJ / m 2 or more

[0349] Tensile yield stress: 38 MPa or more

[0350] Flexural strength: 58 MPa or more

[0351] Flexural modulus of elasticity: 1850 MPa or more

[0352] Heat distortion temperature (1.8 MPa): 87°C or more

[0353] Rockwell hardness: 95 or more

[0354] (Preferred Physical Properties of Thermoplastic Resin Composition Containing Aromatic Polycarbonate Resin (A3))

[0355] Charpy impact strength (23°C): 50 kJ / m 2 or more

[0356] Charpy impact strength (-30°C): 25 kJ / m 2 or more

[0357] Tensile yield stress: 42 MPa or more

[0358] Flexural strength: 62 MPa or more

[0359] Flexural modulus of elasticity: 1750 MPa or more

[0360] Heat distortion temperature (1.8 MPa): 100°C or more

[0361] Rockwell hardness: 100 or more

[0362] <Flowability>

[0363] When the thermoplastic resin composition of the present invention does not contain aromatic polycarbonate resin (A3) as resin component (A), the MVR measured by the method described in the items of the following examples is preferably 6 cm 3 / 10 min. or more. When the thermoplastic resin composition of the present invention contains aromatic polycarbonate resin (A3), the MVR measured by the method described in the items of the following examples is preferably 10 cm 3 / 10 min. or more.

[0364] <Gloss>

[0365] The gloss of the thermoplastic resin composition of the present invention, as measured by the method described in the items of the following examples, is preferably 88% or more, particularly preferably 95% or more.

[0366] [Molded article]

[0367] The molded article of the present invention can be produced by molding the thermoplastic resin composition using known molding methods such as injection molding, gas injection molding, compression molding, sheet extrusion molding, vacuum molding, profile extrusion molding, foam molding, material extrusion deposition method, powder sintering lamination molding, etc.

[0368] Since the thermoplastic resin composition of the present invention has the excellent properties as described above, the molded article of the present invention formed by molding the thermoplastic resin composition of the present invention can be used for vehicle interior parts and exterior parts. For example, it can be used as a buckle of a seat belt, an upper storage box, a cup holder, a door trim, a door handle, a door storage box, a door inner lining, a pillar ornament, a console, a control box, an in-vehicle rearview mirror, a sun visor, a center panel, a ventilator, an air conditioner, an air conditioner panel, a heater controller panel, a plate-shaped blade, a valve flap, a shutter, etc., a pipe, an instrument panel, an instrument housing, an instrument sun visor, an upper decoration of the instrument panel, a lower decoration of the instrument panel, an A / T indicator, "two-position switches (sliding part, sliding plate), switch rocker, grille front de-icing device, grille side de-icing device, cover cluster, mask mounting devices such as mask switches, mask radios, etc., pocket-like items (pocket decoration, card pocket, etc.), a steering wheel horn washer, a cup holder, switch parts, switch boxes, auxiliary handles such as handles, a steering wheel, an armrest, exterior parts for in-vehicle navigation, a camera cover, a camera monitoring system, a head-up display, a rear seat entertainment system, a glove box, a glove box ratchet, a storage box, a ratchet of a cover located in the storage box, etc., an in-vehicle rearview mirror, a rearview lamp, an armrest, a speaker bracket, a navigation panel, an overhead console, a clock indicator, an SOS switch, etc. for vehicle interior parts, a front grille, a wheel cover, a bumper, a fender, a spoiler, a decorative strip, a door mirror, a radiator grille, a rear combination lamp, a headlamp, a turn signal lamp, a handle of an outside door handle, etc. for vehicle exterior parts, exterior parts, interior parts, parts around switches, parts of movable parts, desk lock parts, desk drawers, paper trays of copiers, straight tube type LED lamps, bulb type LED lamps, bulb type fluorescent lamps, panels, covers, connectors, etc. of ceiling lamps, mobile phones, tablet terminals, rice cookers, refrigerators, microwave ovens, gas stoves, vacuum cleaners, dishwashers, air cleaners, air conditioners, heaters, televisions, tape recorders, etc. for household appliances, printers, fax machines, copiers, personal computers, projectors, etc. for OA equipment, audio appliances, organs, digital pianos, etc. for audio equipment, covers of cosmetic containers, battery unit housings, etc., and can be particularly preferably used as vehicle interior parts.

[0369] The molded article of the present invention may be composed of one component or two or more components. The molded article of the present invention can be suitably used as a component of an article that has at least two components that may come into contact with each other, and there is a risk of generating a striking sound when the two components come into contact with each other.

[0370] According to the present invention, for example, an article can be provided that has at least two components that may come into contact with each other, and at least a part of a part of another component that has a possibility of coming into contact with at least one of the two components is formed of the thermoplastic resin composition of the present invention. In other words, according to the present invention, an article can be provided that has at least a first component and a second component that may come into contact with each other, and at least a part of a part of the first component that has a possibility of coming into contact with the second component is formed of the thermoplastic resin composition of the present invention. In this case, it is preferable that the whole of the first component or a part or all of the part in contact with the second component is formed of the thermoplastic resin composition of the present invention.

[0371] The second component contacted by the first component may be a component molded from the thermoplastic resin composition of the present invention, or may be a component molded from a resin other than the thermoplastic resin composition of the present invention, or a component formed of another material such as metal.

[0372] Examples of resins other than the thermoplastic resin composition of the present invention include polypropylene-based resins, rubber-reinforced aromatic vinyl-based resins such as ABS resins, acrylic resins such as polymethyl methacrylate, polycarbonate resins, polycarbonate / ABS alloys, nylon resins, nylon / ABS alloys, PET resins, PET / ABS alloys, PBT / ABS alloys, thermoplastic elastomers, thermosetting elastomers, and the like.

[0373] As the article having at least a first component and a second component that may come into contact with each other, there is no particular limitation as long as the first component and the second component have the possibility of coming into contact with each other as described above. For example, an article in which the first component and the second component are adjacent to each other with a gap therebetween, but intermittently come into contact due to the action of external forces such as vibration and opening / closing operations can be cited. More specifically, an article in which the two components are loosely fitted can be cited.

[0374] Regarding the fitting method of the two components, there is no particular limitation as long as the two components are loosely fitted. For example, it can be a snap fit, a screw fit, or a snap engagement. As such an article, for example, an article having an opening / closing part (such as a lid or a door) formed by using a latch or a magnetic lock to form a push-open type can be cited. More specifically, among vehicle interior components, opening / closing components such as a sunglasses tray can be cited.

[0375] Examples

[0376] The present invention will be described more specifically by way of examples. The present invention is not limited to the following examples. In the following text, unless otherwise specified, "parts" and "%" are based on mass.

[0377] [Raw materials]

[0378] In the following examples and comparative examples, in the production of the thermoplastic resin composition, the raw materials used are the resin components produced by the following method and the following commercially available products.

[0379] [Rubber-reinforced styrene-based thermoplastic resin (A1)]

[0380] <Manufacture of (A1-1)>

[0381] Into a polymerization vessel equipped with a stirrer, 280 parts of water, 60 parts (in terms of solid content) of a polybutadiene emulsion having a weight-average particle diameter of 0.26 μm and a gel content of 90% as a diene-based rubber polymer, 0.3 part of sodium formaldehyde sulfoxylate, 0.0025 part of ferrous sulfate, and 0.01 part of disodium ethylenediaminetetraacetate were charged. After deoxidation, while stirring in a nitrogen stream, the mixture was heated to 60°C, and then a monomer mixture composed of 10 parts of acrylonitrile, 30 parts of styrene, 0.2 part of tert-dodecyl mercaptan, and 0.3 part of cumene hydroperoxide was continuously added dropwise at 60°C over 5 hours. After the addition was completed, the polymerization temperature was set to 65°C, and stirring was continued for 1 hour, and then the polymerization was terminated to obtain a graft copolymer emulsion. The polymerization conversion rate was 98%. Thereafter, 0.2 part of 2,2'-methylene-bis(4-vinyl-6-tert-butylphenol) was added to the obtained emulsion, and calcium chloride was added for coagulation. After passing through the washing, filtration, and drying processes, a powdery ABS resin (A1-1) was obtained. The graft ratio of the obtained ABS resin (A1-1) was 40%, and the intrinsic viscosity [η] of the acetone-soluble component was 0.38 dl / g.

[0382] <Manufacture of (A1-2)>

[0383] Into a 20 L stainless steel autoclave equipped with a ribbon-type stirring paddle, an auxiliary agent continuous addition device, a thermometer, etc., an ethylene-propylene copolymer (ethylene / propylene = 78 / 22 (%), Mooney viscosity (ML 1+4, 100 °C) 20, melting point (Tm) is 40 °C, glass transition temperature (Tg) is -50 °C) 22 parts, styrene 55 parts, acrylonitrile 23 parts, tert-dodecyl mercaptan 0.5 part, toluene 110 parts. The internal temperature is raised to 75 °C, and the contents of the autoclave are stirred for 1 hour to form a homogeneous solution. Thereafter, 0.45 part of tert-butyl peroxyisopropyl monocarbonate is added, and the internal temperature is further raised. After reaching 100 °C, while maintaining this temperature, the stirring speed is set to 100 rpm for polymerization reaction. Starting from the 4th hour after the start of the polymerization reaction, the internal temperature is raised to 120 °C, and the reaction is further carried out for 2 hours while maintaining this temperature to end the polymerization reaction. Thereafter, the internal temperature is cooled to 100 °C, 0.2 part of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 0.02 part of dimethyl silicone oil KF-96-100 cSt (trade name: manufactured by Shin-Etsu Silicone Co., Ltd.) are added, and then the reaction mixture is discharged from the autoclave. The unreacted substances and solvents are removed by steam distillation, and further, a extruder with a vent port (barrel temperature 220 °C, vacuum degree 760 mmHg) is used to substantially degas the volatile components to form pellets. The grafting rate of the obtained AES resin (A1-2) is 70%, and the intrinsic viscosity [η] of the acetone-soluble component is 0.47 dl / g.

[0384] [Styrene resin (A2)]

[0385] <Manufacture of (A2-1)>

[0386] As the AS resin (A2-1), an acrylonitrile-styrene copolymer with the proportions of acrylonitrile units and styrene units being 27% and 73% respectively, intrinsic viscosity [η] (in methyl ethyl ketone, 30 °C) being 0.47 dl / g, and glass transition temperature (Tg) being 103 °C is used.

[0387] <Manufacture of (A2-2)>

[0388] In a polymerization vessel equipped with a stirrer, 250 parts of water and 1.0 part of sodium palmitate were charged. After deoxidation, the mixture was heated to 70 °C with stirring in a nitrogen stream. Further, 0.4 part of sodium formaldehyde sulfoxylate, 0.0025 part of ferrous sulfate, and 0.01 part of disodium ethylenediaminetetraacetate were added. Then, a monomer mixture composed of 70 parts of α-methylstyrene, 25 parts of acrylonitrile, 5 parts of styrene, 0.5 part of tert-dodecyl mercaptan, and 0.2 part of cumene hydroperoxide was continuously added dropwise at a polymerization temperature of 70 °C over 7 hours. After the addition was completed, the polymerization temperature was raised to 75 °C, and stirring was continued for 1 hour to end the polymerization, obtaining an emulsion of the copolymer. The polymerization conversion rate was 99%. Subsequently, calcium chloride was added to the obtained emulsion for coagulation, and after undergoing washing, filtration, and drying processes, a powdery heat-resistant AS resin (A2-2) was obtained. The intrinsic viscosity [η] of the acetone-soluble component of the obtained heat-resistant AS resin (A2-2) was 0.40 dl / g.

[0389] [Aromatic polycarbonate resin (A3)]

[0390] <(A3-1)>

[0391] As the PC resin (A3-1), an aromatic polycarbonate resin manufactured by Mitsubishi Engineering-Plastics Corporation was used.

[0392] [Impact sound reduction material (B)]

[0393] As the impact sound reduction material (B), the impact sound reduction materials (B-1) to (B-16) manufactured in Examples I-1 to I-16 described below or the impact sound reduction materials (BX-1) to (BX-7) manufactured in Comparative Examples I-1 to I-7 were used respectively.

[0394] The impact sound reduction material (BX-8) of Comparative Example I-8 was the following commercially available product.

[0395] <Impact sound reduction material (BX-8)>

[0396] Hydride of styrene-butadiene copolymer “S1605” manufactured by Asahi Kasei Corporation (styrene content: 66%, hydrogenation rate: 95%)

[0397] [Measurement methods of polymers]

[0398] The evaluation methods for various physical properties and characteristics of the polymers in Examples and Comparative Examples are as described below.

[0399] [Glass transition temperature (Tg)]

[0400] According to JIS K7121, using a differential scanning calorimeter (TA Instruments "Q200"), a DSC curve was measured under the conditions of one heating from -90 °C to 50 °C (the first run), then cooling to -90 °C, and then heating from -90 °C to 50 °C at 10 °C / min (the second run). The glass transition temperature at the midpoint of the second run obtained from this DSC curve was taken as the glass transition temperature in the present invention.

[0401] [Weight average particle size]

[0402] It was determined by the photon correlation method using "Microtrac Model: 9230UPA" manufactured by Nikkiso Co., Ltd.

[0403] [Peak intensity and peak temperature of Tanδ]

[0404] The emulsion of polymer (b1) was coagulated and dried to obtain a sample of polymer (b1). Then, the sample was molded into a sheet with a thickness of 1.0 mm to 1.1 mm by hot pressing at a set temperature of 150 °C, and cut into a length of 36 mm × width of 10 mm to prepare a measurement sample.

[0405] Using the following dynamic viscoelasticity measurement device, both ends of the long side of the sample with a length of 8 mm each were fixed with a tensile fixture, and Tanδ was measured under the following conditions to obtain the peak temperature and peak intensity.

[0406] Measurement device: Dynamic viscoelasticity measurement device (TA Instruments "DMA850")

[0407] Mode: Tensile

[0408] Frequency: 1 Hz

[0409] Heating rate: 5 °C / min

[0410] Measurement temperature: -60 °C to +60 °C

[0411] [Swelling degree of THF-insoluble component]

[0412] After impregnating the (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble component separated by centrifugation was vacuum dried and weighed (weight b).

[0413] After impregnating the obtained THF-insoluble component in THF again for 24 hours, the weight of the sample swollen with THF was measured (weight c), and the swelling degree of the THF-insoluble component was calculated by the following formula.

[0414] Swelling degree (%) = c / b × 100

[0415] The degree of swelling here refers to the degree of swelling of the graft structure contained in the (meth)acrylate polymer (B). However, when the graft structure does not have a crosslinked structure, it cannot be obtained in the form of a THF-insoluble component. Since it dissolves in THF and the accurate degree of swelling cannot be determined, when the gel content is 1% or less, the degree of swelling is determined to be 3000% or more.

[0416] [Gel content]

[0417] Put 1 g of the (meth)acrylate polymer (B) into 100 ml of THF, let it stand at room temperature for 48 hours, then filter it through a 100-mesh wire mesh (with a mass of W1 g), and vacuum-dry the filtered THF-insoluble component and the wire mesh at 80 °C for 6 hours, and weigh (with a mass of W2 g). Substitute W1 and W2 into the following formula (i) to obtain the gel content.

[0418] Gel content = [[W2 (g) - W1 (g)] / 1 (g)] × 100 (i)

[0419] [Grafting rate]

[0420] Add 1 g of the (meth)acrylate polymer (B) to 20 mL of acetonitrile, shake it with a shaker for 2 hours, then centrifuge the resulting suspended acetonitrile solution with a centrifuge (rotation speed: 32,000 rpm) for 60 minutes, and separate the precipitate component (acetonitrile-insoluble component) and the acetonitrile solution (acetonitrile-soluble component). Then, dry the precipitate component (acetonitrile-insoluble component) and measure its mass (T (g)), and calculate the grafting rate through the following formula.

[0421] In the following formula, T is the mass (g) of the acetonitrile-insoluble component of the (meth)acrylate polymer (B). S is the mass (g) of the rubbery polymer (b1) contained in 1 g of the (meth)acrylate polymer (B).

[0422] Grafting rate (mass %) = {(T - S) / S} × 100

[0423] [Molecular weight of acetonitrile-soluble component]

[0424] Under the conditions shown below, measure the polystyrene-equivalent weight-average molecular weight of the acetonitrile-soluble component obtained in the evaluation of the above grafting rate by gel permeation chromatography, make a calibration curve with standard polystyrene, and calculate it from the relationship between this molecular weight and the retention time.

[0425] Apparatus: "GPC-244" manufactured by Waters

[0426] Column: "TSK-gel-GMH" manufactured by Tosoh

[0427] Solvent: THF

[0428] Flow rate: 0.8 mL / min

[0429] Measurement temperature: 23 °C

[0430] [Manufacture of (R-1)]

[0431] Mix 71.22 parts of n-butyl acrylate (hereinafter referred to as BA), 28.55 parts of methyl methacrylate (hereinafter referred to as MMA), and 0.23 parts of allyl methacrylate as a crosslinking agent (hereinafter referred to as AMA) to prepare a monomer mixture (I).

[0432] Charge 220 parts of water and 0.1 part of sodium dodecylbenzenesulfonate as an emulsifier into a 10 L glass reactor equipped with a stirring device, a raw material and additive adding device, a thermometer, a heating device, etc. While stirring, raise the internal temperature to 70 °C under a nitrogen stream. At the moment when 70 °C is reached, charge 84% by mass of an aqueous solution (hereinafter referred to as RED aqueous solution) in which 0.01 part of disodium ethylenediaminetetraacetate dihydrate, 0.002 part of ferrous sulfate heptahydrate, and 0.3 part of sodium formaldehyde sulfoxylate are dissolved in 8.5 parts of water into the reactor. Immediately thereafter, continuously add 100 parts of the monomer mixture (I) and 0.2 part of cumene hydroperoxide over 3 hours. At the moment 1 hour after the start of dropping, charge an aqueous solution in which 1.6 parts of dodecylbenzenesulfonic acid are dissolved in 20 parts of water into the reactor. Immediately after the continuous addition of the monomer mixture (I) is completed, charge the remaining 16% by mass of the RED aqueous solution and 0.005 part of cumene hydroperoxide into the reactor, and further keep the internal temperature of the reactor at 70 °C for 30 minutes, then terminate the polymerization reaction to obtain an acrylic rubber polymer (R-1) emulsion.

[0433] The polymerization conversion rate at this time is 97%.

[0434] For the obtained acrylic rubber polymer (R-1) particles, the weight-average particle diameter measured by the above method is 150 nm.

[0435] For the film obtained by drying the acrylic rubber polymer (R-1) emulsion, measure the glass transition temperature (Tg) by the above method.

[0436] In addition, measure the peak intensity and peak temperature of Tanδ by the above method.

[0437] The results are shown in Table 1A.

[0438] [Manufacture of (R-2) to (R-12) and (RX-1) to (RX-9)]

[0439] In addition to setting the ratios shown in Tables 1A and 1B, acrylic rubber polymers (R-2) to (R-12) and (RX-1) to (RX-9) were respectively produced in the same manner as (R-1).

[0440] Among them, for sodium dodecylbenzenesulfonate at the start of polymerization of (R-1), the amount used was adjusted within the range of 0.10 part to 0.33 part, whereby acrylic rubber polymers having the weight-average particle diameters shown in Tables 1A and 1B were obtained.

[0441] The measurement results of the weight-average particle diameters, Tg, peak intensity of tanδ, and peak temperature of these acrylic rubber polymers are shown in Tables 1A and 1B.

[0442] In Table 1B, the Tg, peak intensity of tanδ, and peak temperature measured for the hydride "S1605" of a commercially available styrene-butadiene copolymer manufactured by Asahi Kasei Corporation are also shown.

[0443] [Production of (B-1)]

[0444] 30.4 parts of styrene (hereinafter simply referred to as ST), 9.6 parts of acrylonitrile (hereinafter simply referred to as AN), and 0.05 part of tert-butyl mercaptan were mixed to prepare a monomer mixture (II). 60 parts (in terms of solid content) of the above-mentioned acrylic rubber polymer (R-1) emulsion, 12 parts of water, and 0.36 part of sodium dodecylbenzenesulfonate were charged into a glass reactor used for the production of the acrylic rubber polymer (R-1) emulsion, and the temperature was raised to 70°C under a nitrogen stream while stirring. At the moment when the temperature reached 70°C, 52% by mass of an aqueous solution (RED aqueous solution) in which 0.003 part of disodium ethylenediaminetetraacetate dihydrate, 0.001 part of ferrous sulfate heptahydrate, and 0.05 part of sodium formaldehyde sulfoxylate were dissolved in 2 parts of water was charged into the reactor, and then the total amount of the monomer mixture (II) and 0.06 part of tert-butyl hydroperoxide were continuously added over 2 hours and 30 minutes, and polymerization was carried out. 150 minutes after the initiation of polymerization, the remaining 48% by mass of the RED aqueous solution and 0.03 part of tert-butyl hydroperoxide were charged into the reactor, and after maintaining at this temperature for 60 minutes, the polymerization was terminated to obtain a graft copolymer (B-1) emulsion.

[0445] The graft copolymer (B-1) emulsion was coagulated, washed with water, and dried to obtain a powdery graft copolymer (B-1). The gel content, swelling degree, grafting rate, and molecular weight of the acetonitrile-soluble component of the obtained graft copolymer (B-1) were measured, and the results are shown in Table 2A.

[0446] [Production of (B-2) to (B-13) and (BX-1) to (BX-9)]

[0447] Using the acrylic rubber polymers (R-2) to (R-12), (RX-1) to (RX-9) obtained above, with the blending ratios shown in Tables 2A and 2B, graft copolymers (B-2) to (B-13) and (BX-1) to (BX-9) were respectively produced in the same manner as (B-1) except for this.

[0448] The measurement results of the gel content, swelling degree, graft ratio, and molecular weight of the acetonitrile-soluble component of these graft copolymers are shown in Tables 2A and 2B.

[0449] The acrylic rubber polymers (R-1) to (R-12) correspond to the polymer (b1) of the present invention, and the graft copolymers (B-1) to (B-13) correspond to the (meth)acrylate polymer (B) of the present invention in which the polymer (b2) is graft-polymerized onto the polymer (b1).

[0450] [Table 1A]

[0451]

[0452] [Table 1B]

[0453]

[0454] [Table 2A]

[0455]

[0456] [Table 2B]

[0457]

[0458] [Examples I-1 to 18, II-1 to 18, Comparative Examples I-1 to 11, II-1 to 11][Manufacture of Thermoplastic Resin Composition]

[0459] The raw materials shown in Tables 3A, 3B, 4A, and 4B were mixed at the blending ratios shown in these tables. Thereafter, melt-kneading was performed at 250 °C using a twin-screw extruder (model name "TEX44, Japan Steel Works, Ltd.") to produce pellets. The obtained resin composition was used for the following measurements and evaluations. The results are shown in Tables 3A, 3B, 4A, and 4B.

[0460] [Evaluation Method]

[0461] <Measurement of Sound Pressure of Impact Sound>

[0462] Using each thermoplastic resin composition, injection molding was carried out under the conditions of a barrel temperature of 240 °C, a mold temperature of 60 °C, and an injection rate of 10 g / sec to obtain a plate-shaped molded body with a length of 80 mm, a width of 54 mm, and a thickness of 2.4 mm. Holes with a diameter of 1 mm were respectively drilled at a position 5 mm from the upper edge and 5 mm from the left edge of the molded product, and at a position 5 mm from the upper edge and 5 mm from the right edge of the molded product using a drill press to produce Figure 1 the test piece shown. Then, a single kite string was passed through the two holes of the above test piece, and the above test piece was suspended using an H-shaped bracket, a clip, and a sleeve. It should be noted that at this time, the clip was set at a height of 28 cm from the experimental table. In addition, the center of the surface of the test piece was set at a height of 18 cm from the experimental table. At this time, the distance from the clip suspending the test piece to the upper edge of the test piece was 6 cm. In addition, using an H-shaped bracket, a clip, and a sleeve, a sound pressure microphone (product name: 378B02) manufactured by PCB Piezotronics was set facing the surface of the test piece at a position 10 cm away from the center of the surface of the suspended test piece in the vertical direction with respect to the surface of the test piece. In addition, the above sound pressure microphone was set at a height of 18 cm from the experimental table.

[0463] The center of the surface of the test piece on the opposite side where the above microphone was set was struck with 35 to 40 N using an impact hammer (product name: 086E80) manufactured by PCB Piezotronics that can measure the impact force, the sound at this time was collected using the above sound pressure microphone, and it was converted into the spectrum of the sound pressure using a Fourier transform analyzer (product name: Multi JOB FFTAnalyzer OR34J-4) manufactured by Oros. The maximum value of the sound pressure (dB) and its frequency (Hz) in the obtained spectrum were used as the measured values.

[0464] The measurement was carried out in a room at room temperature of 23 °C.

[0465] <Attenuation of the impact sound>

[0466] The same operation as the sound pressure measurement of the above impact sound was carried out, and the time change of the sound pressure was measured using a Fourier transform analyzer (product name: Multi JOB FFT Analyzer OR34J-4) manufactured by Oros. The time required from the generation of the sound until the sound pressure stabilized to 1 / 4 of the maximum sound pressure was used as the attenuation time of the impact sound.

[0467] The attenuation of the impact sound is preferably shorter than 0.008 seconds, and more preferably shorter than 0.006 seconds in the styrene resin formulations of Examples I-1 to 18 and Comparative Examples I-1 to 11. In the PC alloy formulations of Examples II-1 to 18 and Comparative Examples II-1 to 11, it is preferably shorter than 0.008 seconds, and more preferably shorter than 0.007 seconds.

[0468] <mvr>

[0469] The melt volume flow rate of each thermoplastic resin composition was measured according to ISO 1133 under the conditions of a temperature of 240°C and a load of 98 N.

[0470] <Charpy impact strength>

[0471] Pellets of the thermoplastic resin composition obtained by melt kneading were molded into a molded product with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., "IS55FP-1.5A") under the conditions of a barrel temperature of 240°C and a mold temperature of 60°C to produce a molded product for Charpy impact test.

[0472] For the obtained molded product (Type B1, notched: single notch of Shape A), the Charpy impact strength (impact direction: edgewise) was measured according to ISO 179-1:2013 Edition at a test temperature of 23°C or -30°C. The higher the Charpy impact strength, the more excellent the impact resistance.

[0473] <Tensile yield stress>

[0474] Measurement was carried out according to ISO 527.

[0475] <Tensile fracture elongation>

[0476] Measurement was carried out according to ISO 527.

[0477] <Tensile elastic modulus>

[0478] Measurement was carried out according to ISO 527.

[0479] <Flexural strength>

[0480] Measurement was carried out according to ISO 178.

[0481] <Flexural elastic modulus (rigidity)>

[0482] Measurement was carried out according to ISO 178.

[0483] <Heat distortion temperature>

[0484] Measurement was carried out according to ISO 75 under a load condition of 1.8 MPa.

[0485] <Rockwell hardness>

[0486] Measurement was carried out according to ISO 2039.

[0487] <Gloss>

[0488] 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 for kneading to obtain black pellets. The black pellets were injection-molded under the conditions of a barrel temperature of 240 °C, a mold temperature of 60 °C, and an injection rate of 20 g / sec to obtain a plate-shaped molded body with a length of 100 mm, a width of 100 mm, and a thickness of 3 mm.

[0489] Using a "Gloss Meter VG7000" manufactured by Nippon Denshoku Industries Co., Ltd., the reflectance (%) of the surface of the molded body at an incident angle of 60° and a reflection angle of 60° was measured in accordance with ISO2813. The higher the reflectance, the more excellent the surface appearance.

[0490] <Squeak evaluation (noise risk value)>

[0491] Each thermoplastic resin composition was injection-molded using an IS-170FA injection molding machine manufactured by Toshiba Machine under the conditions of a barrel temperature of 250 °C, an injection pressure of 50 MPa, and a mold temperature of 60 °C to obtain an injection-molded plate with a length of 150 mm, a width of 100 mm, and a thickness of 4 mm. Test pieces with a length of 60 mm, a width of 100 mm, and a thickness of 4 mm and a length of 50 mm, a width of 25 mm, and a thickness of 4 mm were cut from this plate using a circular saw. After chamfering the ends with sandpaper numbered #100, fine burrs were removed with a cutting knife, and two plates of the size were used as test pieces.

[0492] The two test pieces were aged in an oven adjusted to 80 °C ± 5 °C for 300 hours, cooled at 25 °C for 24 hours, and then the large and small test pieces were fixed to a stick-slip testing machine SSP-02 manufactured by ZIEGLER. Under the atmosphere of a temperature of 23 °C and a humidity of 50% RH, the noise risk value after friction three times with an amplitude of 20 mm was measured under four conditions of a load of 5 N, 40 N, a speed of 1 mm / sec, and 10 mm / sec. The value of the condition with the largest measured noise risk value was extracted as the measured value. The larger the noise risk value, the higher the risk of squeak generation. If the noise risk value is 3 or less, it is good.

[0493] [Table 3A]

[0494]

[0495] [Table 3B]

[0496]

[0497] [Table 4A]

[0498]

[0499] [Table 4B]

[0500]

[0501] Based on the above results, the impact sound attenuation effect of the thermoplastic composition of the example in which the impact sound reduction material composed of the (meth)acrylate polymer (B) of the present invention is admixed is excellent, the gloss is also good, the appearance is also excellent, and the mechanical strength such as impact resistance is also excellent.

[0502] On the other hand, the impact sound reduction effect of the thermoplastic resin compositions of Comparative Examples I-1 to 10 and Comparative Examples II-1 to 10 using a (meth)acrylate polymer that does not satisfy the requirements of the present invention as the impact sound reduction material is poor.

[0503] The impact resistance of Comparative Example I-11 using a conventional thermoplastic elastomer as the impact sound reduction material is poor, and the low-temperature impact resistance of Comparative Example II-11 is poor.

[0504] Although the present invention has been described in detail in a specific manner, it is obvious to those skilled in the art that various changes can be made within the scope of achieving the invention effect.

[0505] This application is based on Japanese Patent Application No. 2022-192966 filed on December 1, 2022, and the entire contents thereof are incorporated herein by reference.< / mvr>

Claims

1. A material for reducing impact sound, which is composed of a (meth)acrylate polymer (B), and the (meth)acrylate polymer (B) has: Polymer (b1), which has a structural unit derived from an acrylate compound and a structural unit derived from a methacrylate compound, and a glass transition temperature of -15°C to +5°C; and Polymer (b2), which contains one or more selected from the group consisting of a structural unit derived from a methacrylate compound, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from a cyanated vinyl compound, The material for reducing impact sound is characterized in that For the polymer (b1), the peak temperature, which is the temperature representing the peak of the main dispersion of tanδ measured by the following method, is -5°C to +20°C, and the peak intensity as this peak is 2.055 or more. <Method for Measuring Tanδ> Using the polymer (b1), a sheet with a thickness of 1.0 mm to 1.1 mm is hot-pressed at a set temperature of 150°C, and a measurement sample is made by cutting out a length of 36 mm × width of 10 mm from this sheet; Using the following dynamic viscoelasticity measurement device, both ends of each 8 mm part of the long side of this measurement sample are fixed with a tensile jig, and tanδ is measured under the following conditions to obtain the peak temperature and peak intensity. Measurement device: Dynamic viscoelasticity measurement device ("DMA850" manufactured by TA Instruments) Mode: Tensile Frequency: 1 Hz Heating rate: 5°C / minute Measurement temperature: -60°C to +60°C.

2. The material for reducing impact sound according to claim 1, wherein The swelling degree of the THF-insoluble component of the (meth)acrylate polymer (B) determined by the following method is 1000% or more. <Method for Measuring Swelling Degree> After immersing the (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble component separated by centrifugation is vacuum-dried, and the weight is measured as weight b. After immersing the obtained THF-insoluble component in THF again for 24 hours, the weight of the sample swollen with THF is measured as weight c, and the swelling degree of the THF-insoluble component is calculated by the following formula. Swelling degree (%) = c / b × 100.

3. A thermoplastic resin composition, which contains: a resin component (A) containing a rubber-reinforced styrene-based thermoplastic resin (A1); and the material for reducing impact sound according to claim 1.

4. A thermoplastic resin composition, which contains: a resin component (A) containing a rubber-reinforced styrene-based thermoplastic resin (A1); and the material for reducing impact sound according to claim 2.

5. The thermoplastic resin composition according to claim 3 or 4, which comprises 95 parts by mass to 70 parts by mass of the resin component (A) and 5 parts by mass to 30 parts by mass of the impact sound reducing material, wherein, The total of the resin component (A) and the impact sound reduction material is 100 parts by mass.

Images