Sound-reducing material and thermoplastic resin composition

Abstract

A sound-reducing material comprising a (meth)acrylate polymer (B) having: a polymer (b1) having structural units derived from acrylate compounds and structural units derived from methacrylate compounds, having a glass transition temperature of -15°C to +5°C; and a polymer (b2) comprising one or more structural units selected from the group consisting of structural units derived from methacrylate compounds, structural units derived from aromatic vinyl compounds, and structural units derived from cyanide vinyl compounds, wherein the temperature (peak temperature) at which the main dispersion of polymer (b1) represents tanδ is measured is -5°C to +20°C, and the peak intensity of the peak value is 2.055 or higher.

Description

Technical Field

[0001] This invention relates to impact-reducing materials that, when incorporated into thermoplastic resin compositions, provide molded articles with excellent mechanical properties such as surface gloss, impact resistance, and rigidity, while suppressing impact noise. Furthermore, this invention relates to thermoplastic resin compositions containing such impact-reducing materials. Background Technology

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

[0003] When using resin to mold vehicle parts, it is not only required to meet certain mechanical strength requirements, but also, from the perspective of the livability of the vehicle interior, it is required to reduce the noise generated by the parts and improve the quietness of the vehicle.

[0004] Previous solutions have involved molding automotive interior parts from rubber-reinforced resins using ethylene-α-olefin rubber polymers as the rubber component, thereby maintaining a certain level of mechanical strength while preventing squeaking noises caused by contact between parts (Patent Document 1). However, Patent Document 1 does not yet suppress noises such as the "rattle" sound.

[0005] Some literature suggests that by blending elastomeric block polymers into flame-retardant rubber-reinforced resins, the loss coefficient at the second resonant frequency at 25°C can be increased to 0.02 or higher, thereby suppressing vibrations and obtaining flame-retardant resin compositions with excellent vibration damping properties (Patent Documents 2-4). However, Patent Documents 2-4 do not conduct any research on suppressing noise such as impact sounds.

[0006] As a solution to this problem and capable of providing a thermoplastic resin composition that suppresses the generation of impact noise, preferably maintains the gloss of the molded article well, and further preferably also suppresses the generation of squeaking noise, the applicant has proposed a thermoplastic resin composition comprising at least a rubber-reinforced styrene-based thermoplastic resin (A1), wherein the rubber-reinforced styrene-based thermoplastic resin (A1) contains a specific thermoplastic elastomer as a rubbery component that functions as an impact noise reducing material, and the loss coefficient (η) of the thermoplastic resin composition in the frequency range of 20 Hz to 12,400 Hz is above a specific value (Patent Document 5).

[0007] In addition, in order to improve the appearance of molded articles, such as color development and gloss, and surface impact resistance while maintaining the impact sound reduction effect in Patent Document 5, the applicant proposed a thermoplastic resin composition that is mixed with a hydrogenated copolymer as an impact sound reduction material. The hydrogenated copolymer is formed 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 from aromatic vinyl compounds, and the random portion (II) is mainly composed of structural units from aromatic vinyl compounds and butadiene. When the total copolymer is set to 100% by mass, the content of structural units from aromatic vinyl compounds contained in the block portion (I) and the random portion (II) is 55% to 80% by mass, and it has a main dispersion peak of tanδ above 0°C (Patent Document 6).

[0008] Existing technical documents

[0009] Patent documents

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

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

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

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

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

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

[0016] The problem that the invention aims to solve

[0017] The thermoplastic resin composition in Patent Document 6 is not satisfactory in terms of mechanical properties such as impact resistance, and further improvements are desired in order to expand its applications.

[0018] The purpose of this invention is to provide an impact sound reducing material that, when mixed into a thermoplastic resin composition, can provide molded articles with excellent mechanical properties such as suppression of impact sound generation and impact resistance, as well as a thermoplastic resin composition containing the impact sound reducing material.

[0019] Methods for solving problems

[0020] The inventors have discovered that impact sound reducing materials composed of specific (meth)acrylate polymers can solve the above-mentioned problems.

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

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

[0023] A polymer (b1) having 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) containing 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 reduction material is characterized in that

[0026] For the 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 of this peak is 2.055 or more.

[0027] <Method for Measuring 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 measuring device, both ends of an 8-mm portion of the long side of the measurement sample are fixed with a stretching jig, and tanδ is measured under the following conditions to obtain the peak temperature and peak intensity.

[0030] Measuring device: Dynamic viscoelasticity measuring device ("DMA850" manufactured by TA Instruments) [[ID=三十]]

[0031] Mode: Tension

[0032] Frequency: 1 Hz

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

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

[0035] [2] The impact sound reduction 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] <Method for Measuring Swelling Degree>

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

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

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

[0040] [3] A thermoplastic resin composition comprising: a resin component (A) comprising a rubber-reinforced styrene thermoplastic resin (A1); and the impact sound reducing material described in [1] or [2].

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

[0042] The effects of the invention

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

[0044] The impact noise reduction material of the present invention, composed of a specific (meth)acrylate polymer (B), not only effectively suppresses impact noise but also effectively maintains the mechanical properties of the resulting molded article. By incorporating such an impact noise reduction material of the present invention into resin component (A) comprising a rubber-reinforced styrene thermoplastic resin (A1), not only impact noise but also squeaking noise can be suppressed.

[0045] In the molded articles obtained from the thermoplastic resin composition of the present invention, the (meth)acrylate polymer (B) that functions as a material for reducing impact noise also functions as a component of the thermoplastic resin composition. Therefore, it not only has the acoustic properties of suppressing impact noise and squeaking noise, but also has excellent mechanical strength such as impact resistance and rigidity.

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

[0047] In particular, by forming at least the contact portion of an article having at least two parts that are intermittently in 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 that suppresses or silences impact sounds and squeaking sounds while maintaining sufficient mechanical strength.

[0048] Previous studies on "damping properties" have focused on the continuous vibrations produced on an object when it is subjected to continuous vibrations. In contrast, "impact sound" refers to the instantaneous vibrations produced when other objects collide with each other.

[0049] The time it takes for the two to absorb and disperse energy is completely different.

[0050] To suppress the impact sound, the energy absorption and dispersion speed needs to be set to an extremely instantaneous time.

[0051] "Vibration damping" addresses the vibration noise generated by continuous vibration. In contrast, "impact noise" addresses the sound generated by a sudden impact. In this respect, the two are different. Attached Figure Description

[0052] Figure 1 This is a perspective view of the test piece used for sound pressure measurement in the embodiment. Detailed Implementation

[0053] The embodiments of the present invention will be described in detail below.

[0054] In this invention, "(co)polymerization" refers to homopolymerization and / or copolymerization. "(meth)acrylic acid" refers to acrylic acid and / or methacrylic acid. "(meth)acrylate" refers to acrylate and / or methacrylate.

[0055] A "structural unit" refers to a structural portion of a polymer that originates from a prepolymerized compound (monomer). The proportion of structural units from each compound in the polymer corresponds to the proportion of that compound in the mixture of raw material monomers used in the manufacture of the polymer.

[0056] [Materials to reduce impact noise]

[0057] The impact sound reduction 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”). The (meth)acrylate polymer (B) has: a polymer (b1) having a structural unit derived from an acrylate compound (hereinafter sometimes simply referred to as “acrylate unit”) and a structural unit derived from a methacrylate compound (hereinafter sometimes simply referred to as “methacrylate unit”), and a glass transition temperature of -15°C to +5°C; and 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 (hereinafter sometimes simply referred to as “aromatic vinyl unit”), and a structural unit derived from a vinyl cyanide compound (hereinafter sometimes simply referred to as “vinyl cyanide unit”). For the 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 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 made 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 the long side of the measurement sample, each 8 mm, are fixed with a tensile jig, and tanδ is measured under the following conditions to obtain the peak temperature and peak intensity.

[0061] Measurement device: Dynamic viscoelasticity measurement device (TA Instruments “DMA850”)

[0062] Mode: Tensile

[0063] Frequency: 1 Hz

[0064] Temperature increase 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 acrylate units and methacrylate units, it is possible to suppress noises such as impact sounds. It is considered that this is because the structural units of polar monomers such as methyl methacrylate convert noises such as impact sounds 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 sounds can be suppressed in the room temperature range.

[0069] Furthermore, by setting the temperature (peak temperature) of the main dispersion, which represents tanδ, of the polymer (b1) to be -5℃ to +20℃, and setting the peak intensity of this peak to be 2.055 or higher, an excellent impact sound reduction effect can be obtained.

[0070] Furthermore, polymers (b2) containing the aforementioned specific structural units can exhibit mechanical properties such as impact resistance.

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

[0072] The manner in which polymer (b1) and polymer (b2) in the (meth)acrylate polymer (B) of the present invention exist is not particularly limited, but it is effective to improve impact resistance and is therefore preferred to form a graft copolymer by graft polymerization or the like to at least a portion of polymer (b1) which corresponds to the rubbery portion, to bond polymer (b2) which corresponds to the resin portion.

[0073] In other words, in the (meth)acrylate polymer (B), preferably at least a portion of polymer (b2) is bonded to at least a portion of polymer (b1) by graft polymerization or the like.

[0074] Therefore, the (meth)acrylate polymer (B) preferably consists of a graft copolymer in which at least a portion of polymer (b2) is grafted onto at least a portion of polymer (b1) and a (co)polymer constituting the ungrafted polymer (b2) polymer (b1). The (meth)acrylate polymer (B) may further comprise polymer (b1) of the ungrafted polymer (b2). The (meth)acrylate polymer (B) may further comprise other components such as additives.

[0075] [Polymer(b1)]

[0076] <Structural Unit>

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

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

[0079] From this perspective, it is preferable that the polymer (b1) contains 57 to 72 parts by mass of acrylate units and 43 to 28 parts by mass of methacrylate units in a total of 100 parts by mass. More preferably, the acrylate units are 61 to 70 parts by mass and the methacrylate units are 39 to 30 parts by mass.

[0080] The polymer (b1) may contain structural units other than acrylate units and methacrylate units without prejudice to the purpose of the invention. Examples of such structural units include those derived from the crosslinking agents described later.

[0081] By incorporating structural units from the crosslinking agent into the polymer (b1), the appearance, such as gloss, becomes better. However, if the proportion of structural units from the crosslinking agent is high, the swelling degree of the resulting (meth)acrylate polymer (B) decreases, thus impairing its effectiveness as a sound-reducing material.

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

[0083] Polymer (b1) may also contain structural units derived from vinyl compounds other than acrylate and methacrylate units. Examples of such vinyl compounds include aromatic vinyl compounds and cyanide vinyl compounds, which are illustrated in the description of rubber-reinforced styrene thermoplastic resin (A1) described later. However, from the viewpoint of more effectively obtaining the aforementioned effects of polymer (b1) containing acrylate and methacrylate units, when polymer (b1) contains structural units derived from other vinyl compounds, the proportion of such units is preferably 20 parts by mass or less, and particularly preferably 0 to 10 parts by mass, out of 100 parts by mass of 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 preferred. Among them, ethyl acrylate, n-butyl acrylate, and n-ethylhexyl acrylate are preferred from the perspective of excellent impact resistance of the thermoplastic resin composition obtained by blending (meth)acrylate polymer (B), and n-butyl acrylate is more preferred.

[0085] These alkyl acrylate compounds can 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 viewpoint of excellent impact sound reduction effect of the thermoplastic resin composition obtained by blending (meth)acrylate polymer (B), methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and 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 crosslinking agents include allyl methacrylate, dibutyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, polyester dimethacrylate, polyurethane dimethacrylate, polybutadiene dimethacrylate, divinylbenzene, trivinylbenzene, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, diallyl dimethyl ammonium chloride, and polyglycerol poly(meth)acrylate.

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

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

[0091] The polymer (b1) can be manufactured by conventional methods using a mixture of monomers comprising acrylate compounds and methacrylate compounds, as well as crosslinking agents and other vinyl compounds as needed, in proportions of the preferred structural units described above.

[0092] There are no particular limitations on the manufacturing method of polymer (b1). Examples of manufacturing methods for polymer (b1) include emulsion polymerization of a monomer mixture comprising acrylate compounds and methacrylate compounds, as well as a crosslinking agent and other vinyl compounds used as needed.

[0093] As a manufacturing method for polymer (b1) using emulsion polymerization, one example is copolymerization in the presence of an emulsifier by adding acrylate compounds, methacrylate compounds, and crosslinking agents and other vinyl compounds (hereinafter sometimes referred to as "raw material monomer mixtures") and free radical initiators to an aqueous solvent.

[0094] The addition of the free radical initiator and the mixture of raw material monomers and the crosslinking agent can be done in one step, in batches, or continuously.

[0095] As emulsifiers, carboxylic acid emulsifiers such as alkali metal salts of oleic acid, palmitic acid, stearic acid, rosin acid, and alkenyl succinic acid; anionic emulsifiers selected from alkyl sulfates, sodium alkylbenzene sulfonate, sodium alkyl sulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfate, etc.; and other known emulsifiers can be used alone or in combination of two or more.

[0096] The amount of emulsifier added is preferably 0.01 to 3.0 parts by mass, more preferably 0.05 to 2.0 parts by mass, relative to the total 100 parts by mass of the raw material monomer mixture, which is preferred from the perspective of controlling the particle size of polymer (b1).

[0097] The initiator used in the manufacture of polymer (b1) is a free radical polymerization initiator for free radical polymerization, and its type is not particularly limited. Examples of free radical polymerization initiators include azo polymerization initiators, photopolymerization initiators, inorganic peroxides, organic peroxides, and redox initiators composed of organic peroxides, transition metals, and reducing agents. Among these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that can initiate polymerization by heating are preferred. Only one type may be used, or two or more types may be used in combination.

[0098] Examples of azo polymerization initiators include 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carboxynitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, 4,4'-azobis(4-cyanopentanoic acid), and dimethyl 2,2'-azobis(cyclohexane-1-carboxynitrile). Nitrogen di(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.

[0099] Examples of inorganic peroxides include potassium persulfate, sodium persulfate, ammonium persulfate, and hydrogen peroxide.

[0100] Examples of organic peroxides include, for instance, peroxide ester compounds. Specific examples include α,α'-bis(neodecanylperoxide)diisopropylbenzene, cumyl peroxide neodecanoate, 1,1,3,3-tetramethylbutyl peroxide neodecanoate, 1-cyclohexyl-1-methylethyl peroxide neodecanoate, tert-hexyl peroxide neodecanoate, tert-butyl peroxide neodecanoate, tert-hexyl perpentanoate, tert-butyl perpentanoate, 1,1,3,3-tetramethylbutyl peroxide-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxide)hexane, 1-cyclohexyl-1-methylethyl peroxide-2-ethylhexanoate, and peroxide-2- tert-hexyl hexanoate, tert-butyl hexanoate 2-hexyl hexanoate 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-toluyl 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 peroxyacetate, tert-butyl m-toluyl benzoate peroxide, tert-butyl peroxybenzoate 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, 4,4-bis(tert-butyl peroxide)valerate n-butyl ester, 2,2-bis(4,4-di-tert-butyl peroxidecyclohexyl)propane, α,α'-bis(tert-butyl peroxide)diisopropylbenzene, dicumyl peroxide Compounds, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, dilauroyl peroxide, diisononoyl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, dimethylbis(tert-butylperoxide)-3-hexyne, bis(tert-butylperoxide)isopropylbenzene, bis(tert-butylperoxide)trimethylcyclohexane, butyl bis(tert-butylperoxy)valerate, tert-butyl 2-ethylperoxyhexanoate, benzoyl peroxide, p-menthane hydroperoxide, and tert-butyl peroxide, etc.

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

[0102] Based on 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, for example, it is 0.001 part by mass to 3 parts by mass.

[0103] 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 within 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 effect of reducing the impact sound 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 manufacture the polymer (b1) with a glass transition temperature within the above range, it is only necessary to adjust the ratio of acrylate to methacrylate.

[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 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.

[0112] Using the following dynamic viscoelasticity measurement device, both ends of each 8 mm portion 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.

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

[0114] Mode: Tensile

[0115] Frequency: 1 Hz

[0116] ​

[0117] Measurement temperature: -60℃~+60℃

[0118] If the peak temperature of polymer (b1) is -5℃ to +20℃, the impact sound reduction effect is excellent. From this point of view, the peak temperature of polymer (b1) is preferably 0 to +20℃, and particularly preferably 0 to +15℃.

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

[0120] To manufacture a polymer (b1) that satisfies such a peak temperature and peak intensity of tanδ, the optimal monomers constituting polymer (b1) are selected, and the amount of crosslinking agent is adjusted.

[0121] [Polymer(b2)]

[0122] <Structural Unit>

[0123] Polymer (b2) is one or more polymers (b2) selected from the group consisting of structural units selected from methacrylate compounds (methacrylate units), structural units selected from aromatic vinyl compounds (aromatic vinyl units), and structural units selected from cyanide vinyl compounds (cyanide vinyl units).

[0124] Examples of combinations of structural units contained in polymer (b2) include the following 1) to 5), but are not limited to the following examples at all.

[0125] 1) Methacrylate unit alone

[0126] 2) Methacrylate units and aromatic vinyl units

[0127] 3) Methacrylate unit and vinyl cyanide unit

[0128] 4) Aromatic vinyl units and cyanide vinyl units

[0129] 5) Methacrylate units, aromatic vinyl units, and cyanide vinyl units

[0130] In particular, considering both impact sound reduction and physical properties, 4) having a combination of aromatic vinyl units and cyanide vinyl units, and 5) having a combination of methacrylate units, aromatic vinyl units and cyanide vinyl units are preferred.

[0131] In the case of the combination described in 2), from the perspective of suppressing impact sound, it is preferable that the proportion of methacrylate units in a total of 100 parts by mass is 95 to 60 parts by mass and the proportion of aromatic vinyl units is 5 to 40 parts by mass.

[0132] In the case of the combination described in 3) above, from the perspective of suppressing impact sound, it is preferable that the proportion of methacrylate unit in a total of 100 parts by mass of methacrylate unit and vinyl cyanide unit is 95 parts by mass to 60 parts by mass and the proportion of vinyl cyanide unit is 5 parts by mass to 40 parts by mass.

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

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

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

[0136] Examples of aromatic vinyl compounds that constitute the aromatic vinyl units of polymer (b2) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene or p-methylstyrene, vinylxylene, p-tert-butylstyrene, ethylstyrene, etc. Among these, styrene is preferred from the perspective of improving the impact resistance of the resulting molded article.

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

[0138] Examples of cyanide vinyl compounds that constitute the cyanide vinyl unit of polymer (b2) include acrylonitrile and methacrylonitrile. Among these, acrylonitrile is preferred from the perspective of improving the impact resistance of the resulting molded article.

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

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

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

[0142] Other vinyl compounds that constitute other vinyl compound units include those other than aromatic vinyl compounds, cyanide vinyl compounds, and methacrylate compounds used in the manufacture of the rubber-reinforced styrene thermoplastic resin (A1) described later.

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

[0144] Polymer (b2) is preferably manufactured in the presence of polymer (b1) by using a mixture of one or more of aromatic vinyl compounds, cyanide vinyl compounds and methacrylate compounds and other vinyl compounds as needed, in the same polymerization method as that used for the polymerization of vinyl monomers (a1) to rubber polymer (g) in rubber-reinforced styrene thermoplastic resin (A1) described later.

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

[0146] <Ratio of polymer (b1) to 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), together with other vinyl compounds used as required. 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 a polymer (b2) that is not graft polymerized to the polymer (b1), and a polymer (b1) to which the polymer (b2) is not graft polymerized.

[0149] In the content ratio of the polymer (b1) to the polymer (b2) in the (meth)acrylate polymer (B), if the content ratio of the polymer (b1) is too high, 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 low, when mixed with the resin component (A) described later as an impact sound reduction material, sufficient effects may not be achieved in terms of impact sound suppression.

[0150] From such aspects, the ratio of the polymer (b1) to the polymer (b2) contained in the (meth)acrylate polymer (B) is preferably 70 to 20 parts by mass of the polymer (b2) with respect to 30 to 80 parts by mass of the polymer (b1) (where the total of the polymer (b1) and the polymer (b2) is 100 parts by mass), and more preferably 40 to 70 parts by mass of the polymer (b1) and 60 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] A 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 crosslinking points 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 perspective of reducing impact noise, the swelling degree of the (meth)acrylate polymer (B) is more preferably 1200% or more, and even more preferably 1300% or more. On the other hand, there is no particular upper limit to the swelling degree, but in order to improve the appearance, the swelling degree of the (meth)acrylate polymer (B) is preferably 1200% to 3000%, and more preferably 1300% to 3000%.

[0155] <Methods for determining the degree of swelling>

[0156] After impregnating (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble components separated by centrifugation were vacuum dried and their weight (weight b) was determined.

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

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

[0159] In order to manufacture (meth)acrylate polymers (B) that meet such swelling requirements, no crosslinking agent is used in the manufacture of polymer (b1), or even if it is used, the amount is less than 0.4 parts by mass, especially 0 to 0.25 parts by mass, in 100 parts by mass of polymer (b1), thereby reducing the crosslinking structure in polymer (b1).

[0160] <Gel content>

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

[0162] To manufacture a (meth)acrylate polymer (B) with such a gel content, the amount of crosslinking agent during the manufacturing of polymer (b1) can be adjusted.

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

[0164] <Molecular weight of acetonitrile-soluble components>

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

[0166] To manufacture a (meth)acrylate polymer (B) with a molecular weight of acetonitrile-soluble components, the amount of chain transfer agent used in the manufacture of polymer (b1) can be adjusted.

[0167] The molecular weight of the acetonitrile-soluble component of the (meth)acrylate polymer (B) was determined by the method described in the following examples.

[0168] <Grafting rate>

[0169] The grafting rate of the (meth)acrylate polymer (B) of the present invention is preferably 35% to 120%, and particularly preferably 40% to 80%. If the grafting rate is above the lower limit mentioned above, excellent impact resistance is achieved. On the other hand, if the grafting rate is below the upper limit mentioned above, sufficient flowability can be ensured during injection molding.

[0170] To produce a (meth)acrylate polymer (B) with such a grafting rate, the amounts of polymerization initiator and chain transfer agent during the manufacturing of polymer (b1) can be adjusted.

[0171] The grafting rate of the (meth)acrylate polymer (B) was determined by the method described in the following examples.

[0172] [Thermoplastic resin composition]

[0173] The thermoplastic resin composition of the present invention contains a resin component (A) comprising 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 (meth)acrylate polymer (B) of the present invention described above.

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

[0176] The thermoplastic resin composition of the present invention preferably contains 95 to 70 parts by weight of resin component (A) and 5 to 30 parts by weight of impact sound reducing material in a total of 100 parts by weight. If the content of resin component (A) is below the aforementioned upper limit and the content of impact sound reducing material is above the aforementioned lower limit, the impact sound reduction effect is excellent. On the other hand, if the content of resin component (A) is above the aforementioned lower limit and the content of impact sound reducing material is below the aforementioned upper limit, the inherent properties of resin component (A) can be fully utilized. In the thermoplastic resin composition of the present invention, relative to a total of 100 parts by weight of resin component (A) and impact sound reducing material, it is more preferable to contain 95 to 80 parts by weight of resin component (A) and 5 to 20 parts by weight of impact sound reducing material.

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

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

[0179] [Resin Component (A)]

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

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

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

[0183] Rubber-reinforced styrene-based thermoplastic resin (A1) comprises a rubbery polymer portion and a vinyl copolymer portion. Such rubber-reinforced styrene-based thermoplastic resin (A1) can be manufactured by polymerizing vinyl monomers (a1) such as aromatic vinyl compounds in the presence of a rubbery polymer (g). Details are described below.

[0184] Examples of rubber-based polymers (g) include conjugated diene rubbers such as polybutadiene, polyisoprene, butadiene-styrene copolymer, and butadiene-acrylonitrile copolymer; olefin-based rubber polymers such as ethylene-α-olefin copolymers, ethylene-propylene copolymers, ethylene-propylene-non-conjugated diene copolymers, ethylene-1-butene copolymers, and ethylene-1-butene-non-conjugated diene copolymers; acrylic rubbers; silicone rubbers; polyurethane rubbers; silicone-acrylic IPN rubbers; natural rubber; conjugated diene block copolymers; hydrogenated conjugated diene block copolymers; and so on. Preferred rubber-based polymers (g) are described below.

[0185] In particular, considering its effectiveness in reducing both impact noise and squeaking noise, an ethylene-α-olefin-based rubber polymer (g) is preferred as the rubber polymer. Furthermore, considering its effectiveness in impact resistance, a rubber-reinforced styrene-based thermoplastic resin (A1) obtained by polymerizing a vinyl monomer (a1) containing an aromatic vinyl compound and a cyanide vinyl compound in the presence of an ethylene-α-olefin-based rubber polymer is preferred. That is, the rubber-reinforced styrene-based thermoplastic resin (A1) is preferably a rubber-reinforced styrene-based thermoplastic resin (A1) comprising a rubber polymer portion and a vinyl copolymer portion, wherein the rubber polymer portion is composed of an ethylene-α-olefin-based rubber, and the vinyl copolymer portion comprises structural units derived from an aromatic vinyl compound and structural units derived from a cyanide vinyl compound.

[0186] The aforementioned ethylene-α-olefin rubber polymers are not particularly limited, and examples include ethylene-α-olefin rubber polymers containing ethylene and α-olefins having 3 or more carbon atoms. When the total amount of monomers constituting the aforementioned ethylene-α-olefin rubber polymer is set to 100% by mass, the ethylene content is preferably 5% to 95% by mass, more preferably 50% to 90% by mass, and even more preferably 60% to 88% by mass.

[0187] Examples of α-olefins 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, and 1-undecene. These α-olefins may be a single species or a combination of two or more. Among the aforementioned α-olefins, propylene and 1-butene are preferred.

[0188] When the total amount of monomers constituting the ethylene-α-olefin rubber polymer is set to 100% by mass, the content of the 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] Ethylene-α-olefin rubber polymers can be binary copolymers composed of ethylene and α-olefins, or polymers composed of them and other compounds (terpolymers, tetrpolymers, etc.). Non-conjugated diene compounds can be cited as examples of other compounds.

[0190] Examples of non-conjugated diene compounds used in ethylene-α-olefin rubber polymers include alkenyl norbornene, cyclic dienes, and aliphatic dienes, with dicyclopentadiene and 5-ethylidene-2-norbornene being preferred. These non-conjugated diene compounds can be used alone or in combination of two or more. The content of non-conjugated diene compound units in ethylene-α-olefin rubber polymers is typically less than 30% by mass, preferably less than 15% by mass.

[0191] The above-mentioned acrylic rubber is not particularly limited, but preferably a (co)polymer of an alkyl (meth)acrylate compound having 1 to 8 carbon atoms, or a copolymer of the alkyl (meth)acrylate compound with a vinyl monomer that can copolymerize therewith.

[0192] Specific examples of alkyl acrylate compounds having 1 to 8 carbon atoms in the alkyl group used herein include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and cyclohexyl acrylate. Specific examples of alkyl methacrylate compounds having 1 to 8 carbon atoms in the alkyl group include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate. 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 vinyl monomers that can copolymerize with the aforementioned (meth)acrylate alkyl ester compounds include, for example, multifunctional vinyl compounds, aromatic vinyl compounds, and cyanide vinyl compounds.

[0194] Multifunctional vinyl compounds are monomers that contain two or more vinyl groups in a single molecule. These compounds function to crosslink (meth)acrylic rubbers and act as the initiation point for graft polymerization.

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

[0196] All of the compounds described below can be used as aromatic vinyl compounds and cyanide vinyl compounds. In addition, other copolymerizable monomers include acrylamide, methacrylamide, vinylidene chloride, alkyl vinyl ethers with 1 to 6 carbon atoms in the alkyl group, alkyl esters of (meth)acrylate with 9 or more carbon atoms in the alkyl group, and (meth)acrylic acid. They can be used alone or in combination of two or more.

[0197] Regarding the preferred monomer composition of the aforementioned acrylic rubber, alkyl (meth)acrylate compound units with 1 to 8 carbon atoms comprise 80% to 99.99% by mass, more preferably 90% to 99.95% by mass; polyfunctional vinyl compound units comprise 0.01% to 5% by mass, more preferably 0.05% to 2.5% by mass; and other vinyl monomer units capable of copolymerizing with it comprise 0% to 20% by mass, more preferably 0% to 10% by mass. The total monomer composition is 100% by mass.

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

[0199] As a conjugated diene block copolymer, specifically, it is a copolymer comprising at least one of the following blocks A or C, and at least one of the following blocks B or A / B; or it is a polymer based on block B or A / B. They can be manufactured by known anionic polymerization methods, such as those disclosed in Japanese Patent Publication Nos. 47-28915, 47-3252, 48-2423, and 48-20038.

[0200] Regarding the specific structure of conjugated diene block copolymers, each block A, B, A / B and C is defined as follows, and substances with structures shown in formulas (1) to (13) can be given examples.

[0201] A: Aromatic vinyl compound polymer block

[0202] B: Conjugated diene polymer block

[0203] A / B: Random copolymerization of aromatic vinyl compounds / conjugated dienes in block copolymers

[0204] C: A graded block consisting of a copolymer of conjugated dienes and aromatic vinyl compounds, with a gradual increase in aromatic vinyl compounds.

[0205] AB(1)

[0206] ABA(2)

[0207] ABC(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, wherein the vinyl bond content of 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, wherein the vinyl bond content of the conjugated diene portion is preferably less than 20%.)

[0210] AA / B(5)

[0211] AA / BC(6)

[0212] AA / BB(7)

[0213] AA / BA(8)

[0214] B2-B1-B2(9)

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

[0216] CB(10)

[0217] CBC(11)

[0218] CA / BC(12)

[0219] CAB(13)

[0220] As conjugated diene block copolymers, copolymers that repeatedly have these basic skeletons can also be cited. Conjugated diene block copolymers can also be conjugated diene block copolymers obtained by further coupling them.

[0221] The substance with the structure of formula (4) above is shown in Japanese Patent Application Publication No. 2-133406. The substance with the structure of formula (5) and formula (6) above is shown in Japanese Patent Application Publication No. 2-305814 and Japanese Patent Application Publication No. 3-72512.

[0222] Examples of conjugated dienes used herein include 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, and chloroprene. To enable industrial use and obtain conjugated diene block copolymers with excellent physical properties, 1,3-butadiene, isoprene, and 1,3-pentadiene are preferred as conjugated dienes, with 1,3-butadiene being more preferred.

[0223] Examples of aromatic vinyl compounds used herein include 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., with styrene and α-methylstyrene being preferred, and styrene being particularly preferred.

[0224] The ratio of aromatic vinyl compounds to conjugated diene in the conjugated diene block copolymer is 0–70 / 100–30 by mass, preferably 0–60 / 100–40, and more preferably 0–50 / 100–50. Where aromatic vinyl compounds are necessary, the ratio is preferably 10–70 / 90–30. If the content of aromatic vinyl compounds exceeds 70% by mass, the copolymer is resinous and performs poorly as a rubber component, which is not preferred.

[0225] The amount of vinyl bonding in the conjugated diene portion of a conjugated diene block typically ranges from 5% to 80%.

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

[0227] In the above structural formula, the number-average molecular weight of part A 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 gel permeation chromatography (GPC).

[0229] The amount of vinyl bonds in conjugated diene compounds can be adjusted using amines such as N,N,N',N'-tetramethylethylenediamine, trimethylamine, triethylamine, and diazocyclo(2,2,2)octaamine; ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; thioethers; phosphines; phosphoramides; alkylbenzene sulfonates; and potassium or sodium alkoxides.

[0230] Examples of coupling agents used in this invention include diethyl adipate, divinylbenzene, methyldichlorosilane, silicon tetrachloride, butyltrichlorosilane, tin tetrachloride, butyltrichlorosilane, dimethylsilane, germanium tetrachloride, 1,2-dibromoethane, 1,4-chloromethylbenzene, bis(trichlorosilyl)ethane, epoxidized linseed oil, toluene diisocyanate, and 1,2,4-benzene triisocyanate.

[0231] The hydrogenated conjugated diene block copolymer is a partially hydrogenated or fully hydrogenated product formed by hydrogenating at least 30%, preferably 50%, of the carbon-carbon double bonds in the conjugated diene portion of the above-mentioned conjugated diene block copolymer, and more preferably a hydrogenated product formed by hydrogenating at least 90%.

[0232] The hydrogenation reaction of conjugated diene block copolymers can be carried out by known methods. Furthermore, by adjusting the hydrogenation rate using known methods, the target hydrogenated conjugated diene block copolymer can be obtained. Specific methods are disclosed in Japanese Patent Application Publication Nos. 42-8704, 43-6636, 63-4841, 63-5401, 2-133406, and 1-297413.

[0233] In the rubber polymer (g) used in this invention, from the perspective of mechanical properties such as impact resistance and rigidity, and appearance such as gloss, the gel content is preferably 70% by mass or less. More preferably, the gel content of the rubber polymer (g) is 80% by mass or more, and even more preferably 90% by mass or more.

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

[0235] 1 g of rubber polymer (g) was added to 100 ml of toluene and allowed to stand at room temperature for 48 hours. Then, it was filtered through a 100-mesh wire mesh (mass W1 g). The toluene-insoluble components and the wire mesh were vacuum dried at 80°C for 6 hours and weighed (mass W2 g). Substituting W1 and W2 into formula (i) below, the gel content was obtained.

[0236] In ethylene-propylene rubber polymers, there exist substances that contain ethylene crystals. When using such rubber polymers, the gel content is determined by dissolving them at a temperature of 80°C.

[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 crosslinking monomer, the type and amount of molecular weight regulator, polymerization time, polymerization temperature, polymerization conversion rate, etc. when manufacturing rubber polymer (g).

[0239] Preferred materials for the rubber polymer (g) used in this invention include ethylene-α-olefin rubber polymers such as polybutadiene, butadiene-styrene copolymer, ethylene-propylene copolymer, and ethylene-propylene-nonconjugated diene copolymer, acrylic rubber, silicone rubber, conjugated diene block copolymer, and hydrogenated conjugated diene block copolymer. More preferably, ethylene-α-olefin rubber polymers such as ethylene-propylene copolymer and ethylene-propylene-nonconjugated diene copolymer, acrylic rubber, conjugated diene block copolymer, and hydrogenated conjugated diene block copolymer are used. Particularly preferred are acrylic rubber, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, conjugated diene block copolymer, and hydrogenated conjugated diene block copolymer. Most preferably, ethylene-propylene copolymer is used.

[0240] Rubber polymers (g) can be obtained by methods known as emulsion polymerization, solution polymerization, bulk polymerization, and suspension polymerization. Among these, acrylic rubbers are preferably manufactured by emulsion polymerization. Ethylene-propylene copolymers, ethylene-propylene-nonconjugated diene copolymers, conjugated diene block copolymers, and hydrogenated conjugated diene block copolymers are preferably manufactured by solution polymerization. Polybutadiene and butadiene-styrene copolymers are preferably manufactured by solution polymerization.

[0241] The rubber-reinforced styrene thermoplastic resin (A1) is obtained by polymerizing an aromatic vinyl compound or an aromatic vinyl compound and other vinyl monomers (a1) capable of copolymerizing with the aromatic vinyl compound in the presence of the aforementioned 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 capable of copolymerizing with the aromatic vinyl compound.

[0242] The rubber-reinforced styrene-based thermoplastic resin (A1) is preferably obtained by polymerizing 20 to 97 parts by mass of an aromatic vinyl compound, or an aromatic vinyl compound and other vinyl monomers (a1) capable of copolymerizing with the aromatic vinyl compound, in the presence of 3 to 80 parts by mass of the above-mentioned rubbery polymer (g) (wherein, the total amount of the rubbery polymer (g) and the vinyl monomers (a1) is 100 parts by mass). More preferably, the rubbery polymer (g) is 7 to 65 parts by mass, and the vinyl monomers (a1) are 35 to 93 parts by mass.

[0243] As the aromatic vinyl compounds used herein, all substances described in block A of the aromatic vinyl compound polymer of the aforementioned conjugated diene block copolymer can be used. Styrene and α-methylstyrene are particularly preferred. They can be used alone or in combination of two or more.

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

[0245] Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile. They can be used alone or in combination of two or more. Using vinyl cyanide compounds imparts chemical resistance. The amount of vinyl cyanide compound used is typically 0 to 60% by mass, preferably 5% to 50% by mass, as a percentage of the total amount of vinyl monomer (a1).

[0246] Examples of (meth)acrylate compounds include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. They can be used alone or in combination of two or more. Surface hardness is improved by using (meth)acrylate compounds. The amount of (meth)acrylate compound used is typically 0–80% by mass, based on its proportion in the total amount of the vinyl monomer (a1).

[0247] Examples of maleimide compounds include maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, and N-benzylmaleimide. They can be used alone or in combination of two or more. To introduce the maleimide unit, imidization can be performed after copolymerization of maleic anhydride. Heat resistance can be imparted by using maleimide compounds. The amount of maleimide compound used is typically 1% to 60% by mass, based on its proportion in the total amount of the vinyl monomer (a1).

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

[0249] Examples of unsaturated compounds containing epoxy groups include glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. They can be used alone or in combination of two or more.

[0250] Examples of unsaturated compounds containing hydroxyl groups 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, and N-(4-hydroxyphenyl)maleimide. They can be used alone or in combination of two or more.

[0251] Examples of unsaturated compounds containing an oxazoline group include vinyloxazoline. They can be used alone or in combination of two or more.

[0252] Examples of unsaturated compounds containing anhydride groups include maleic anhydride, itaconic anhydride, and citraconic anhydride. They can be used alone or in combination of two or more.

[0253] Examples of substituted or unsubstituted amino-containing unsaturated compounds include aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, phenylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylethyleneamine, acrylamine, N-methylpropyleneamine, acrylamide, N-methylacrylamide, and p-aminostyrene. They can be used alone or in combination of two or more.

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

[0255] Regarding the amount of monomers other than aromatic vinyl compounds in the vinyl monomer (a1), when the total amount of vinyl monomer (a1) 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.

[0256] More preferred combinations of monomers constituting the vinyl monomer (a1) are 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-phenylmaleimide, styrene / methyl methacrylate / cyclohexylmaleimide, etc., and even more preferred are any combination of styrene alone, styrene / acrylonitrile = 65 / 45 to 90 / 10 (mass ratio), styrene / methyl methacrylate = 80 / 20 to 20 / 80 (mass ratio), styrene / acrylonitrile in the range of 20 to 80% by mass of styrene and the total of acrylonitrile and methyl methacrylate in the range of 20 to 80% by mass of acrylonitrile and methyl methacrylate.

[0257] Rubber-reinforced styrene-based thermoplastic resin (A1) can be manufactured by known polymerization methods, such as emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, and combinations thereof. In the aforementioned polymerization methods, when the rubber polymer (g) is a substance obtained by emulsion polymerization, the rubber-reinforced styrene-based thermoplastic resin (A1) can also be manufactured by emulsion polymerization. Furthermore, when the rubber polymer (g) is a substance obtained by solution polymerization, the rubber-reinforced styrene-based thermoplastic resin (A1) is generally preferably manufactured by bulk polymerization, solution polymerization, and suspension polymerization. However, even if the rubber polymer (g) is produced by solution polymerization, if the rubber polymer (g) is emulsified using a known method, the rubber-reinforced styrene-based thermoplastic resin (A1) can be manufactured by emulsion polymerization. Even if the rubber polymer (g) is produced by emulsion polymerization, after solidification and separation, the rubber-reinforced styrene-based thermoplastic resin (A1) can be manufactured by bulk polymerization, solution polymerization, and suspension polymerization.

[0258] In the case of manufacturing via emulsion polymerization, polymerization initiators, chain transfer agents, emulsifiers, etc., are used. All of these can be well-known substances.

[0259] Examples of polymerization initiators include cumene hydroperoxide, terpene hydroperoxide, diisopropylbenzene hydroperoxide, tetramethylbutyl hydroperoxide, tert-butyl hydroperoxide, potassium persulfate, and azobisisobutyronitrile. As polymerization initiation aids, various reducing agents, sugar-containing ferric pyrophosphate formulations, and hyposulfate formulations are preferred redox systems.

[0260] Examples of chain transfer agents include octyl thiols, n-dodecyl thiols, tert-dodecyl thiols, n-hexyl thiols, and terpenoids.

[0261] As emulsifiers, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, aliphatic sulfonates such as sodium lauryl sulfate, higher fatty acid salts such as potassium laurate, potassium stearate, potassium oleate, and potassium palmitate, and rosin salts such as potassium rosinate can be used.

[0262] In emulsion polymerization, the vinyl monomer (a1) can be added all at once in the presence of the complete rubber polymer (g) for polymerization, or it can be added in stages or continuously. Alternatively, a portion of the rubber polymer (g) can be added during polymerization.

[0263] After emulsion polymerization, the resulting emulsion is usually coagulated using a coagulant. It is then washed with water and dried to obtain a powder of rubber-reinforced styrene-based thermoplastic resin (A1). At this point, coagulation can be performed after appropriately blending emulsions of two or more rubber-reinforced styrene-based thermoplastic resins (A1) obtained through emulsion polymerization.

[0264] Alternatively, the emulsion of styrene-based resin (A2) can be appropriately blended and then solidified.

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

[0266] Powder of rubber-reinforced styrene thermoplastic resin (A1) can also be obtained by spray drying the emulsion.

[0267] When manufacturing rubber-reinforced styrene-based thermoplastic resins (A1) via solution polymerization, solvents that can be used are typically non-reactive polymerization solvents used in free radical polymerization. Examples of solvents include aromatic hydrocarbons such as ethylbenzene and toluene; ketones such as methyl ethyl ketone and acetone; and acetonitrile, dimethylformamide, and N-methylpyrrolidone.

[0268] The polymerization temperature is typically between 80°C and 140°C, preferably between 85°C and 120°C. A polymerization initiator can be used during polymerization, or polymerization can be carried out via thermal polymerization without an initiator.

[0269] As polymerization initiators, organic peroxides such as ketone peroxide, dialkyl peroxide, diacyl peroxide, peroxide ester, hydrogen peroxide, azobisisobutyronitrile, and benzoyl peroxide can be used appropriately.

[0270] When using chain transfer agents, thiols, terpenoids, α-methylstyrene dimers, etc., can be used.

[0271] When manufacturing rubber-reinforced styrene-based thermoplastic resins (A1) via bulk polymerization or suspension polymerization, polymerization initiators, chain transfer agents, etc., as described in solution polymerization can be used.

[0272] The residual monomer content in the rubber-reinforced styrene thermoplastic resin (A1) obtained by the above polymerization methods is generally less than 10,000 ppm, preferably less than 5,000 ppm.

[0273] The rubber-reinforced styrene thermoplastic resin (A1) obtained by polymerizing vinyl monomer (a1) in the presence of rubber polymer (g) includes a copolymer formed by grafting copolyvinyl monomer (a1) onto rubber polymer (g) and an ungrafted component (copolymer of vinyl monomer (a1)) not grafted onto rubber polymer (g).

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

[0275] The grafting rate can be calculated using the following formula (ii).

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

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

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

[0279] In the case where only aromatic vinyl compounds are used as vinyl monomers (a1), methyl ethyl ketone is used instead of acetone for determination.

[0280] The intrinsic viscosity [η] of the acetone-soluble component of rubber-reinforced styrene thermoplastic resin (A1) (measured at 30°C using methyl ethyl ketone as a solvent) is typically 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 size of the grafted rubber polymer particles dispersed in the rubber-reinforced styrene-based thermoplastic resin (A1) is typically 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 size is less than 50 nm, the impact resistance tends to deteriorate. If the rubber particle size exceeds 3,000 nm, the surface appearance of the molded article tends to deteriorate.

[0282] By making the refractive index of the copolymer of the rubbery polymer (g) and the vinyl monomer (a1) substantially uniform, and / or by making the particle size of the dispersed rubbery polymer (g) substantially below the wavelength of visible light (typically below 1,500 nm), a transparent rubber-reinforced styrene thermoplastic resin (A1) can be obtained. These transparent resins can also be used as the rubber-reinforced styrene thermoplastic resin (A1) of the present invention.

[0283] Rubber-reinforced styrene thermoplastic resin (A1) can be used alone or by mixing two or more copolymers with different components in terms of composition and properties.

[0284] [Styrene-based resin (A2)]

[0285] As a styrene-based resin (A2), it is a (co)polymer formed 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 used herein, and as the other vinyl monomers capable of copolymerizing with the aromatic vinyl compound, all substances described as vinyl monomers (a1) in rubber-reinforced styrene-based thermoplastic resin (A1) can be used.

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

[0287] Regarding the content of monomers other than aromatic vinyl compounds in the vinyl monomer (a2), when the total amount of 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] Preferred styrene-based resins (A2) include homopolymers of styrene, styrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-methyl methacrylate copolymers, styrene-maleimide compound copolymers, and copolymers thereof with the aforementioned unsaturated compounds containing functional groups.

[0289] Styrene-based resin (A2) can be manufactured by emulsion polymerization, bulk polymerization, solution polymerization, suspension polymerization, and combinations thereof, which are known polymerization methods as described in the above-described method for manufacturing rubber-reinforced styrene-based thermoplastic resin (A1).

[0290] Styrene-based resins (A2) can be used alone or by mixing two or more copolymers with different compositions and properties.

[0291] [Aromatic polycarbonate resin (A3)]

[0292] Regarding aromatic polycarbonate resins (A3), all substances obtained by known polymerization methods, such as those obtained through interfacial condensation polymerization of dihydroxyaryl compounds with phosgene or transesterification reaction (melt condensation) of dihydroxyaryl compounds with carbonate compounds such as diphenyl carbonate, can be used.

[0293] Examples of the aforementioned 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 sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, hydroquinone, resorcinol, etc. Furthermore, polyorganosiloxanes terminalized with hydroxyaryloxy groups can also be used (e.g., see U.S. Patent No. 3,419,634). They can be used alone or in combination of two or more. Among these, 2,2-bis(4-hydroxyphenylpropane) (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. A higher molecular weight results in increased mechanical strength of the molded article, but tends to reduce its appearance due to decreased flowability. Two or more aromatic polycarbonate resins with different molecular weights can also be used as the aromatic polycarbonate resin (A3).

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

[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 styrene-based thermoplastic resin (A1) and styrene-based resin (A2)]

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

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

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

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

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

[0304] If it falls within the above range, the heat resistance and flowability will be better.

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

[0306] [Other Resins]

[0307] The resin component (A) of the present invention may contain other resins besides rubber-reinforced styrene thermoplastic resin (A1), styrene resin (A2), and aromatic polycarbonate resin (A3) without compromising the purpose of the present invention.

[0308] Other examples of resins include polyolefin resins, vinyl chloride resins, acrylic resins, polyester resins, polyamide resins, polyacetal resins, polyphenylene ether resins, and polyaryl sulfide resins. These thermoplastic resins can 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 resin component (A) comprising rubber-reinforced styrene thermoplastic resin (A1), styrene resin (A2), aromatic polycarbonate resin (A3) and other resins.

[0310] [Other ingredients]

[0311] The thermoplastic resin composition of the present invention may contain other components besides the resin component (A) and the impact sound reducing material, within the scope that does not impair the purpose of the present invention.

[0312] <Slippery agent>

[0313] The thermoplastic resin composition of the present invention may contain a slip-improving agent. The slip-improving agent imparts slip properties to the thermoplastic resin composition, thereby facilitating the assembly of articles made from the molded articles obtained from the thermoplastic resin composition of the present invention, and suppressing noise such as squeaking from the articles made from the molded articles during use.

[0314] Representative examples of lubrication agents include low molecular weight oxidized polyethylene, ultra-high molecular weight polyethylene, polytetrafluoroethylene, low molecular weight (e.g., number average molecular weight 10,000 or less) polyolefin waxes, silicone oils, etc., as described in Japanese Patent Application Publication No. 2011-137066.

[0315] Polyolefin waxes are preferably polyethylene waxes with a melting point of 0 to 120°C.

[0316] When polyolefin waxes having such melting points or other additives with melting points between 0 and 120°C are added to the thermoplastic resin compositions of the present invention, even if the rubbery portion of the rubber-reinforced styrene-based thermoplastic resin (A1) does not have a melting point (Tm), the generation of noise such as squeaking can be suppressed. These slip-improving agents can be used alone or in combination of two or more.

[0317] When a sliding agent is incorporated into the thermoplastic resin composition of the present invention, the amount incorporated is preferably 0.1 to 10 parts by weight relative to 100 parts by weight of rubber-reinforced styrene thermoplastic resin (A1).

[0318] <Anti-heat aging agent>

[0319] To obtain molded articles with suppressed squeaking and high surface gloss, an anti-heat aging agent can be added to the thermoplastic resin composition of the present invention. There are no particular limitations on the anti-heat aging agent, as long as it is an anti-heat aging agent blended in rubber or the like. Phenolic antioxidants and phosphorus antioxidants are preferred as anti-heat aging agents.

[0320] Examples of phenolic antioxidants include those represented by the following general formula (I), which have a phenolic group having a tert-butyl group at the ortho position.

[0321] [Chemistry 1]

[0322]

[0323] (where R is in the formula) 1 and R 2 Each can independently represent an alkyl group having 1 to 8 hydrogen atoms or carbon atoms; t-Bu represents tert-butyl.

[0324] In the above general formula (I), the substituent R 1 and R 2 Each is preferably a hydrogen atom, a tert-butyl group, or a methyl group, more preferably a hydrogen atom or a methyl group, and especially preferably R. 1 In the case of hydrogen atoms. Specifically, the phenolic antioxidants used in this invention are preferably compounds having one or more groups represented by the above general formula (I), and more preferably compounds represented by any one of the following formulas (C1), (C2) and (C3).

[0325] [Chemistry 2]

[0326]

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

[0328] [Chemistry 3]

[0329]

[0330] (where R is in the formula) 3 and R 4 Each can independently represent an alkyl group having 1 to 8 hydrogen atoms or carbon atoms. R is particularly preferred. 3 and R 4 (It is a t-C4H9 base.)

[0331] When the heat-resistant aging agent is incorporated into the thermoplastic resin composition of the present invention, and the thermoplastic resin composition of the present invention is set to 100 parts by weight, the amount of the agent incorporated is preferably 0.01 parts by weight to 5 parts by weight, more preferably 0.02 parts by weight to 3 parts by weight, further preferably 0.03 parts by weight to 2 parts by weight, and particularly preferably 0.03 parts by weight to 1 part by weight. Examples of the most preferred ranges for the amount of the heat-resistant aging agent include 0.02 parts by weight to 0.6 parts by weight, 0.02 parts by weight to 0.2 parts by weight, 0.03 parts by weight to 0.6 parts by weight, or 0.03 parts by weight to 0.2 parts by weight. When the amount of the heat-resistant aging agent is within the above ranges, the molded article has excellent gloss and a good appearance.

[0332] <Other Additives>

[0333] Other additives that can be blended into the thermoplastic resin composition of the present invention include antioxidants, ultraviolet absorbers, weathering agents, fillers, antistatic agents, flame retardants, antifogging agents, lubricants, antibacterial agents, antifungal agents, tackifiers, plasticizers, colorants, graphite, carbon black, carbon nanotubes, and pigments (including, for example, pigments that impart functional properties such as infrared absorption and reflection). They can be used individually or in combination of two or more.

[0334] The amount of these other additives mixed in is typically 0.1 to 30 parts by weight relative to 100 parts by weight of resin component (A).

[0335] [Method for manufacturing thermoplastic resin composition]

[0336] The thermoplastic resin composition of the present invention can be manufactured as follows: the components are mixed in a specified mixing ratio using a drum mixer, Henschel mixer, or the like, and then melt-blended under appropriate conditions using a mixer such as a single-screw extruder, twin-screw extruder, Banbury mixer, kneader, roller, or feeder. A twin-screw extruder is preferred. Furthermore, when blending the components, they can be blended in one step or in multiple steps, in stages.

[0337] Alternatively, after mixing using a Banbury mixer, kneader, etc., the mixture can be extruded into granules.

[0338] The melting and mixing temperature is usually 180℃~240℃, preferably 190℃~230℃.

[0339] [Optimal physical properties, etc.]

[0340] The preferred properties of the thermoplastic resin composition of the present invention will be described below. Specifically, the properties of the thermoplastic resin composition of the present invention described below were measured using the methods described in the examples described later.

[0341] Maximum sound pressure level

[0342] From the perspective of suppressing impact sound, when measured by the method described in the following examples, the maximum sound pressure level in the frequency range of 20 Hz to 20,000 Hz is preferably less than 68.9 dB in a thermoplastic resin composition that does not contain aromatic polycarbonate resin (A3) and preferably less than 70.5 dB in a thermoplastic resin composition that contains aromatic polycarbonate resin (A3).

[0343] <Noise Risk Value>

[0344] The noise risk value of the thermoplastic resin composition of the present invention, as measured by the method described in the following examples, is preferably 3 or less.

[0345] <Mechanical Properties & 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 as measured by the methods described in the following examples.

[0347] (Preferred properties of thermoplastic resin compositions excluding aromatic polycarbonate resin (A3))

[0348] Charpy impact strength (23℃): 8kJ / m 2 above

[0349] Tensile yield stress: above 38 MPa

[0350] Bending strength: ≥58MPa

[0351] Flexural modulus of elasticity: above 1850 MPa

[0352] Flexural temperature under load (1.8 MPa): Above 87℃

[0353] Rockwell hardness: 95 or higher

[0354] (Preferred properties of thermoplastic resin compositions containing aromatic polycarbonate resin (A3))

[0355] Charpy impact strength (23℃): 50kJ / m 2 above

[0356] Charpy impact strength (-30℃): 25kJ / m 2 above

[0357] Tensile yield stress: above 42 MPa

[0358] Bending strength: ≥62MPa

[0359] Flexural modulus: above 1750 MPa

[0360] Load flexural temperature (1.8 MPa): above 100℃

[0361] Rockwell hardness: 100 or higher

[0362] Liquidity

[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 following examples is preferably 6 cm. 3 / 10min. 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 following examples is preferably 10cm. 3 / 10min. or more.

[0364] <Gloss>

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

[0366] [Molded product]

[0367] The molded articles of the present invention can be manufactured 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, and powder sintering lamination molding.

[0368] The thermoplastic resin composition of the present invention possesses the aforementioned excellent properties; therefore, molded articles of the present invention, formed from the thermoplastic resin composition of the present invention, can be used in vehicle interior and exterior products. For example, they can be used as seatbelt buckles, upper storage boxes, cup holders, door panels, door handles, door storage boxes, door liners, pillar decorations, consoles, control boxes, rearview mirrors, sun visors, center panels, ventilators, air conditioners, air conditioning panels, heater controller panels, plate-shaped paddles, valve discs, louvers, etc., pipes, instrument panels, instrument housings, instrument sun visors, upper instrument panel decorations, lower instrument panel decorations, A / T indicators, "double-position switches" (sliding parts, sliding plates), switch rockers, grids, etc. Front de-icing devices, grille side de-icing devices, cover clusters, cover mounts and other cover-type components (cover switches, cover radios, etc.), pocket-type components (pocket decorations, card pockets, etc.), steering wheel horn gaskets, cup holders, switch components, switch boxes, auxiliary handles and other handles, steering wheels, armrests, exterior parts for vehicle navigation, camera covers, camera monitoring systems, head-up displays, rear-seat entertainment systems, glove boxes, glove box ratchets, storage boxes, ratchet teeth on covers located in storage boxes, rearview mirrors, rearview lights, armrests, etc. Vehicle interior parts such as speaker brackets, navigation panels, overhead consoles, clock indicators, and SOS switches; vehicle exterior parts such as front grilles, wheel covers, bumpers, mudguards, spoilers, trim strips, door mirrors, radiator grilles, rear combination lights, headlights, turn signals, and outward-opening handles; exterior and interior components such as housings and shells of office equipment and household appliances; components around switches; moving parts; table lock components; table drawers; paper trays for copiers; lighting fixtures such as straight-tube LED lights, bulb-type LED lights, bulb-type fluorescent lights, ceiling light panels, covers, and connectors; household appliances such as mobile phones, tablet terminals, rice cookers, refrigerators, microwave ovens, gas stoves, vacuum cleaners, dishwashing machines, air purifiers, air conditioners, heaters, televisions, and tape recorders; OA equipment such as printers, fax machines, copiers, personal computers, and projectors; audio equipment such as organs and electronic pianos; lids for cosmetic containers; and battery cell housings are particularly suitable for use as vehicle interior parts.

[0369] The molded article of the present invention can 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 having at least two components that have the potential to come into contact with each other, and the two components having the potential to produce a striking sound when they 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 have the potential to come into contact with each other, and at least a portion of the other component that has the potential to come 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 have the potential to come into contact with each other, and at least a portion of the first component that has the potential to come into contact with the second component is formed of the thermoplastic resin composition of the present invention. In this case, the first component is preferably formed wholly or partially or entirely of the portion that comes into contact with the second component, using the thermoplastic resin composition of the present invention.

[0371] The second component that the first component contacts can be a component molded from the thermoplastic resin composition of the present invention, or it can be a component molded from a resin other than the thermoplastic resin composition of the present invention, or a component formed from other materials such as metal.

[0372] Examples of resins other than the thermoplastic resin composition of the present invention include polypropylene resins, rubber-reinforced aromatic vinyl 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, etc.

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

[0374] Regarding the method of fitting the two parts, there are no particular limitations as long as the two parts fit together loosely. For example, it can be a snap-fit, screw-fit, or latch-fit. Examples of such items include those with push-open opening and closing parts (such as covers or doors) that use a ram lock or magnetic lock. More specifically, in vehicle interior components, examples include opening and closing parts such as sunglasses trays.

[0375] Example

[0376] The present invention will be described in more detail below through examples. The present invention is not limited to the following examples. In the following text, unless otherwise stated, "parts" and "%" are terms of mass.

[0377] [raw materials]

[0378] In the following examples and comparative examples, the raw materials used in the manufacture of the thermoplastic resin composition are resin components manufactured by the methods described below and commercially available products described below.

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

[0380] Manufacturing of (A1-1)

[0381] In a polymerization vessel equipped with a stirrer, 280 parts of water, 60 parts of polybutadiene emulsion (weight average particle size 0.26 μm, gel content 90%), 0.3 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, and 0.01 parts of disodium EDTA (ethylenediaminetetraacetate) were added. After deoxygenation, the mixture was heated to 60°C under a nitrogen atmosphere with stirring. Then, a monomer mixture consisting of 10 parts acrylonitrile, 30 parts styrene, 0.2 parts tert-dodecyl mercaptan, and 0.3 parts cumene hydroperoxide was continuously added dropwise over 5 hours at 60°C. After the addition was complete, the polymerization temperature was maintained at 65°C, and the mixture was stirred continuously for 1 hour before polymerization was stopped, yielding a graft copolymer emulsion. The polymerization conversion rate was 98%. Subsequently, 0.2 parts of 2,2'-methylene-bis(4-ethylene-6-tert-butylphenol) were added to the obtained emulsion, and calcium chloride was added for coagulation. After washing, filtering and drying, powdered ABS resin (A1-1) was obtained. The grafting rate 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] Manufacturing of (A1-2)

[0383] In a 20L stainless steel autoclave equipped with a ribbon-type agitator, a continuous additive addition device, a thermometer, etc., an ethylene-propylene copolymer (ethylene / propylene = 78 / 22 (%), Mooney viscosity (ML) was added as an ethylene-α-olefin rubber polymer. 1+420 parts of a high-pressure reactor containing 20 parts of styrene (melting point (Tm) of 40℃ and glass transition temperature (Tg) of -50℃), 55 parts of styrene, 23 parts of acrylonitrile, 0.5 parts of tert-dodecyl mercaptan, and 110 parts of toluene were added. The internal temperature was raised to 75℃, and the contents of the reactor were stirred for 1 hour to form a homogeneous solution. Then, 0.45 parts of tert-butyl isopropyl peroxide monocarbonate were added, and the internal temperature was further raised to 100℃. While maintaining this temperature, the stirring speed was kept at 100 rpm to carry out the polymerization reaction. From the 4th hour after the start of the polymerization reaction, the internal temperature was raised to 120℃, and the reaction was carried out for another 2 hours while maintaining this temperature, thus ending the polymerization reaction. The internal temperature was then cooled to 100°C. 0.2 parts of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenol)-propionate and 0.02 parts of dimethyl silicone oil KF-96-100cSt (trade name: Shin-Etsu Silicone Co., Ltd.) were added. The reaction mixture was then discharged from the autoclave, and unreacted substances and solvents were removed by steam distillation. Further processing was carried out using... An extruder with an exhaust port (barrel temperature 220℃, vacuum 760mmHg) substantially degassed the volatile components, producing granules. The resulting AES resin (A1-2) had a grafting rate of 70% and an intrinsic viscosity [η] of 0.47 dl / g for the acetone-soluble component.

[0384] [Styrene-based resin (A2)]

[0385] Manufacturing of (A2-1)

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

[0387] Manufacturing of (A2-2)

[0388] 250 parts of water and 1.0 part of sodium palmitate were added to a polymerization vessel equipped with a stirrer. After deoxygenation, the mixture was heated to 70°C under a nitrogen stream while stirring. Then, 0.4 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, and 0.01 parts of disodium ethylenediaminetetraacetate were added. At a polymerization temperature of 70°C, a monomer mixture consisting of 70 parts of α-methylstyrene, 25 parts of acrylonitrile, 5 parts of styrene, 0.5 parts of tert-dodecyl mercaptan, and 0.2 parts of cumene hydroperoxide was continuously added dropwise over 7 hours. After the dropwise addition was completed, the polymerization temperature was maintained at 75°C, and the mixture was stirred continuously for 1 hour before polymerization was stopped, yielding a copolymer emulsion. The polymerization conversion rate was 99%. Calcium chloride was then added to the resulting emulsion for coagulation. After washing, filtering, and drying, a powdered 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 Co., Ltd. is used.

[0392] [Sound Reduction Material (B)]

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

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

[0395] <Sound Reduction Material (BX-8)>

[0396] Asahi Kasei Corporation produces styrene-butadiene copolymer hydrogenated compound "S1605" (styrene content: 66%, hydrogenation rate: 95%).

[0397] [Methods for determining polymers]

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

[0399] [Glass transition temperature (Tg)]

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

[0401] [Weight-average particle size]

[0402] The model was determined using the "Microtrac Model: 9230UPA" manufactured by Nikkiso Corporation, and obtained through the photon correlation method.

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

[0404] The emulsion of polymer (b1) is coagulated and dried to obtain a sample of polymer (b1). Then, the sample is formed 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 then cut into a length of 36 mm × width of 10 mm to prepare the test sample.

[0405] Using the following dynamic viscoelasticity measuring apparatus, fix 8 mm portions at both ends of the long side of the sample with tensile clamps, and measure Tanδ under the following conditions to determine the peak temperature and peak intensity.

[0406] Measuring apparatus: Dynamic viscoelasticity measuring apparatus (TA Instruments "DMA850")

[0407] Mode: Stretch

[0408] Frequency: 1Hz

[0409] Heating rate: 5℃ / minute

[0410] Measurement temperature: -60℃~+60℃

[0411] [Swelling degree of THF insoluble components]

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

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

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

[0415] The swelling degree here refers to the swelling degree of the grafted structure contained in the (meth)acrylate polymer (B). However, if the grafted structure does not have a cross-linking structure, it cannot be obtained as a THF-insoluble component. Since the swelling degree cannot be accurately determined due to its solubility in THF, when the gel content is less than 1%, the swelling degree is judged to be above 3000%.

[0416] [Gel content]

[0417] 1 g of (meth)acrylate polymer (B) was added to 100 ml of THF and allowed to stand at room temperature for 48 hours. The mixture was then filtered through a 100-mesh wire mesh (mass W1 g). The filtered THF insoluble components and the wire mesh were vacuum dried at 80°C for 6 hours and weighed (mass W2 g). Substituting W1 and W2 into formula (i) below, the gel content was obtained.

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

[0419] Grafting rate

[0420] 1 g of (meth)acrylate polymer (B) was added to 20 mL of acetonitrile. After shaking for 2 hours, the resulting acetonitrile suspension was centrifuged at 32,000 rpm for 60 minutes to separate the precipitate (acetonitrile-insoluble component) and the acetonitrile solution (acetonitrile-soluble component). The precipitate (acetonitrile-insoluble component) was then dried, and its mass (T(g)) was measured. The grafting rate was calculated using the following formula.

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

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

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

[0424] Under the conditions shown below, the weight-average molecular weight of the acetonitrile-soluble component obtained in the above evaluation of grafting rate was determined by gel permeation chromatography. A calibration curve was prepared using standard polystyrene, and the molecular weight was calculated from the relationship between the holding time and the molecular weight.

[0425] Device: Waters GPC-244

[0426] Pillar: Made by Tosoh Corporation, "TSK-gel-GMH"

[0427] Solvent: THF

[0428] Flow rate 0.8 mL / min

[0429] Measurement temperature: 23℃

[0430] [Manufacturing (R-1)]

[0431] Monomer mixture (I) was prepared by mixing 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 (hereinafter referred to as AMA) as a crosslinking agent.

[0432] 220 parts by mass of water and 0.1 parts of sodium dodecylbenzenesulfonate as an emulsifier were added to a 10L glass reactor equipped with a stirring device, a raw material and additive addition device, a thermometer, and a heating device. The internal temperature was raised to 70°C under a nitrogen flow while stirring. At 70°C, 84% by mass of an aqueous solution containing 0.01 parts by mass of ethylenediaminetetraacetic acid tetrasodium dihydrate, 0.002 parts by mass of ferrous sulfate heptahydrate, and 0.3 parts by mass of formaldehyde bisulfite (hereinafter referred to as RED aqueous solution) was added to the reactor. Immediately thereafter, 100 parts by mass of monomer mixture (I) and 0.2 parts by mass of cumene hydroperoxide were added continuously over 3 hours. One hour after the start of the dropwise addition, an aqueous solution containing 1.6 parts by mass of dodecylbenzenesulfonic acid was added to the reactor in 20 parts by mass of water. Immediately after the continuous addition of monomer mixture (I), the remaining 16% by mass of RED aqueous solution and 0.005 parts of cumene hydroperoxide were added to the reactor. The internal temperature of the reactor was then maintained at 70°C for 30 minutes to end the polymerization reaction and obtain an acrylic rubber polymer (R-1) emulsion.

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

[0434] The weight-average particle size of the obtained acrylic rubber polymer (R-1) particles, as determined by the above method, is 150 nm.

[0435] The glass transition temperature (Tg) of the film obtained by drying the acrylic rubber polymer (R-1) emulsion was determined by the above method.

[0436] In addition, the peak intensity and peak temperature of Tanδ were determined using the methods described above.

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

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

[0439] Except for the proportions shown in Tables 1A and 1B, acrylic rubber polymers (R-2) to (R-12) and (RX-1) to (RX-9) are manufactured in the same manner as (R-1).

[0440] Among them, the amount of sodium dodecylbenzenesulfonate at the start of (R-1) polymerization was adjusted in the range of 0.10 parts to 0.33 parts, thereby obtaining the acrylic rubber polymers with weight average particle sizes shown in Tables 1A and 1B.

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

[0442] Table 1B also records the peak intensity and peak temperature of Tg and tanδ of the commercially available Asahi Kasei Corporation styrene-butadiene copolymer hydride "S1605".

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

[0444] Monomer mixture (II) was prepared by mixing 30.4 parts of styrene (hereinafter referred to as ST), 9.6 parts of acrylonitrile (hereinafter referred to as AN), and 0.05 parts of tert-butyl mercaptan. 60 parts of the above-mentioned acrylic rubber polymer (R-1) emulsion (converted to solids content), 12 parts of water, and 0.36 parts of sodium dodecylbenzenesulfonate were added to a glass reactor used in the manufacture of acrylic rubber polymer (R-1) emulsion, and the mixture was heated to 70°C under a nitrogen atmosphere while stirring. At 70°C, 52% by mass of an aqueous solution (RED aqueous solution) containing 0.003 parts of ethylenediaminetetraacetic acid tetrasodium dihydrate, 0.001 parts of ferrous sulfate heptahydrate, and 0.05 parts of formaldehyde bisulfite dissolved in 2 parts of water was added to the reactor. Immediately afterwards, the total amount of monomer mixture (II) and 0.06 parts of tert-butyl hydrogen peroxide were continuously added over 2 hours and 30 minutes to carry out polymerization. After initiating polymerization for 150 minutes, the remaining 48% by mass of the RED aqueous solution and 0.03 parts of tert-butyl hydrogen peroxide were added to the reactor. After maintaining the temperature at this time for 60 minutes, the polymerization was terminated to obtain the graft copolymer (B-1) emulsion.

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

[0446] [Manufacturing of (B-2)~(B-13) and (BX-1)~(BX-9)]

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

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

[0449] The acrylic rubber polymers (R-1) to (R-12) are equivalent to the polymer (b1) of the present invention, and the graft copolymers (B-1) to (B-13) are equivalent to the (meth)acrylate polymers (B) of the present invention formed by grafting polymer (b2) onto 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] [Preparation of Thermoplastic Resin Compositions]

[0459] The raw materials shown in Tables 3A, 3B, 4A, and 4B were mixed in the proportions indicated in the tables. The mixture was then melt-blended at 250°C using a twin-screw extruder (model name "TEX44, Nippon Steel Works") to produce granules. The resulting resin compositions were then subjected to the following measurements and evaluations. The results are shown in Tables 3A, 3B, 4A, and 4B.

[0460] [Evaluation Method]

[0461] <Sound pressure measurement of impact sound>

[0462] Using various thermoplastic resin compositions, injection molding was performed at a barrel temperature of 240°C, a mold temperature of 60°C, and an injection rate of 10 g / s 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 drilled at positions 5 mm from the top and 5 mm from the left, and 5 mm from the top and 5 mm from the right, respectively, to create the molded body. Figure 1 The test piece is shown. Next, a kite string is passed through the two holes in the test piece, and the test piece is suspended using an H-shaped bracket, clamps, and sleeves. It should be noted that the clamps are set at a height of 28cm from the experimental platform. Additionally, the center of the test piece surface is set at a height of 18cm from the experimental platform. The distance from the clamps suspending the test piece to the top of the test piece is 6cm. Furthermore, using the H-shaped bracket, clamps, and sleeves, a sound pressure level microphone (trade name: 378B02) manufactured by PCB Piezotronics is positioned 10cm away from the center of the suspended test piece surface in the vertical direction, facing the test piece surface. The sound pressure level microphone is also set at a height of 18cm from the experimental platform.

[0463] An impact hammer (trade name: 086E80) manufactured by Piezotronics, a company capable of measuring impact force, was used to strike the center of the test piece surface opposite to where the aforementioned microphone was located with a force of 35 to 40 N. The sound pressure microphone recorded the sound at this time, and the sound pressure was converted into a spectrum using a Fourier transform analyzer (trade 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 measurements were conducted in a room at 23°C.

[0465] <Attenuation of the impact sound>

[0466] Perform the same procedure as for measuring the sound pressure level of the impact sound, using an Oros Fourier transform analyzer (trade name: Multi JOB FFT Analyzer OR34J-4) to measure the time change of the sound pressure level. The time required from the generation of the sound until the sound pressure stabilizes at one-quarter of its maximum value is taken as the decay 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-based resin formulations of Examples I-1 to 18 and Comparative Examples I-1 to 11. In the PC alloy-based 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] According to ISO 1133, the melt volume flow rate of each thermoplastic resin composition was determined at a temperature of 240°C and a load of 98 N.

[0470] Charpy Impact Strength

[0471] The granules of the thermoplastic resin composition obtained by melt mixing are molded into molded articles 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") at a barrel temperature of 240°C and a mold temperature of 60°C, to produce molded articles for Charpy impact testing.

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

[0473] <Tensive Yield Stress>

[0474] The determination was made in accordance with ISO 527.

[0475] <Tension Elongation at Break>

[0476] The determination was made in accordance with ISO 527.

[0477] <Tension Modulus>

[0478] The determination was made in accordance with ISO 527.

[0479] <Bending Strength>

[0480] The determination was made in accordance with ISO 178.

[0481] <Flexural modulus of elasticity (rigidity)>

[0482] The determination was made in accordance with ISO 178.

[0483] <Load flexural temperature>

[0484] The determination was performed according to ISO 75 under a load of 1.8 MPa.

[0485] Rockwell hardness

[0486] The determination was made in accordance with ISO 2039.

[0487] <Gloss>

[0488] 100 parts of each thermoplastic resin composition granules and 0.8 parts of carbon black were mixed using a Henschel mixer. The mixture was then fed into an extruder heated to 250°C for kneading to obtain black granules. The black granules were injection molded at a barrel temperature of 240°C, a die temperature of 60°C, and an injection rate of 20 g / s 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] The reflectance (%) of the surface of the molded body was measured using a "Gloss Meter VG7000" manufactured by Nippon Denshoku Kogyo Co., Ltd., according to ISO 2813 at an incident angle of 60° and a reflection angle of 60°. The higher the reflectance, the better the surface appearance.

[0490] <Squeaking sound assessment (noise risk value)>

[0491] Various thermoplastic resin compositions were injection molded using a Toshiba Machine Manufacturing IS-170FA injection molding machine at a barrel temperature of 250°C, an injection pressure of 50 MPa, and a mold temperature of 60°C to obtain injection molded plates 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 the plate using a circular saw. After chamfering the ends with #100 sandpaper, fine burrs were removed with a cutting knife. These two pieces were used as test pieces.

[0492] Two test pieces were aged for 300 hours in an oven set at 80℃±5℃. After cooling at 25℃ for 24 hours, the large and small test pieces were fixed in a Ziegler SSP-02 stick-slip testing machine. The noise risk value was measured after three rubs with an amplitude of 20mm under four conditions: a load of 5N, 40N, and speeds of 1mm / s and 10mm / s, at an atmosphere of 23℃ and 50% RH. The value of the condition with the highest measured noise risk value was taken as the final value. The higher the noise risk value, the higher the risk of squeaking. A noise risk value below 3 is considered good.

[0493] [Table 3A]

[0494]

[0495] [Table 3B]

[0496]

[0497] [Table 4A]

[0498]

[0499] [Table 4B]

[0500]

[0501] Based on the above results, the thermoplastic composition of the embodiment of the impact sound reducing material composed of the (meth)acrylate polymer (B) of the present invention exhibits excellent impact sound attenuation, good gloss, excellent appearance, and excellent mechanical strength such as impact resistance.

[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, which used (meth)acrylate polymers that did not meet the requirements of this invention as impact sound reduction materials, was poor.

[0503] Comparative Example I-11, which uses conventional thermoplastic elastomers as impact sound reduction materials, has poor impact resistance, while Comparative Example II-11 has poor low-temperature impact resistance.

[0504] Although the invention has been described in detail using specific methods, it will be apparent to those skilled in the art that various modifications can be made within the scope of achieving the inventive effect.

[0505] This application is based on Japanese Patent Application 2022-192966, filed on December 1, 2022, the entire contents of which are incorporated herein by reference.< / mvr>

Claims

1. A thermoplastic resin composition comprising a resin component (A) and an impact sound reducing material, The resin component (A) comprises a rubber-reinforced styrene thermoplastic resin (A1), a styrene resin other than the rubber-reinforced styrene thermoplastic resin (A1) (A2), and other resins as appropriate; or it comprises a rubber-reinforced styrene thermoplastic resin (A1), a styrene resin other than the rubber-reinforced styrene thermoplastic resin (A1) (A2), an aromatic polycarbonate resin (A3), and other resins as appropriate. When the resin component (A) is composed of a rubber-reinforced styrene-based thermoplastic resin (A1), a styrene-based resin (A2) other than the rubber-reinforced styrene-based thermoplastic resin (A1), and other resins as appropriate, the thermoplastic resin composition contains 95 to 70 parts by weight of the resin component (A) and 5 to 30 parts by weight of the impact sound-reducing material in a total of 100 parts by weight, wherein... When resin component (A) contains other resins, the content of the other resins in resin component (A) is 50% by mass or less. When the resin component (A) is composed of a rubber-reinforced styrene-based thermoplastic resin (A1), a styrene-based resin other than the rubber-reinforced styrene-based thermoplastic resin (A1) (A2), an aromatic polycarbonate resin (A3), and other resins as appropriate, the thermoplastic resin composition contains 95 to 85 parts by weight of the resin component (A) and 5 to 15 parts by weight of the impact sound-reducing material in an amount totaling 100 parts by weight, wherein, when the resin component (A) contains other resins, the content of the other resins in the resin component (A) is 50% by weight or less. The impact sound reducing material is composed of a (meth)acrylate polymer (B), which has the following characteristics: Polymer (b1), having structural units derived from acrylate compounds and structural units derived from methacrylate compounds, has a glass transition temperature of -15°C to +5°C; and Polymer (b2), comprising one or more structural units selected from the group consisting of structural units derived from methacrylate compounds, structural units derived from aromatic vinyl compounds, and structural units derived from cyanide vinyl compounds. In the (meth)acrylate polymer (B), at least a portion of polymer (b2) is grafted to at least a portion of polymer (b1) via graft polymerization. Regarding the ratio of polymer (b1) to polymer (b2) in the (meth)acrylate polymer (B), polymer (b2) comprises 70 to 20 parts by mass relative to 30 to 80 parts by mass of polymer (b1), wherein the total of polymer (b1) and polymer (b2) is 100 parts by mass. For the polymer (b1), the peak temperature representing the main dispersion of tanδ, as determined by the following method, is -5℃ to +20℃, and the peak intensity of this peak is 2.055 or higher. The method for determining Tanδ is as follows: Using polymer (b1), a sheet with a thickness of 1.0 mm to 1.1 mm is formed by hot pressing at a set temperature of 150 °C. A sample with a length of 36 mm and a width of 10 mm is cut from the sheet to prepare the test sample. Using the following dynamic viscoelasticity measuring apparatus, fix 8 mm portions at both ends of the long side of the sample with tensile clamps, measure tanδ under the following conditions, and determine the peak temperature and peak intensity. Measuring apparatus: TA Instruments "DMA850" dynamic viscoelasticity measuring apparatus. Mode: Stretch Frequency: 1Hz Heating rate: 5℃ / minute Measurement temperature: -60℃~+60℃.

2. The thermoplastic resin composition according to claim 1, wherein, The swelling degree of the THF-insoluble component of (meth)acrylate polymer (B), as determined by the following method, is over 1000%. The method for determining the degree of swelling is as follows: After impregnating (meth)acrylate polymer (B) in tetrahydrofuran (THF) for 24 hours, the insoluble components separated by centrifugation were vacuum dried and their weight was determined, i.e., weight b. After the obtained THF-insoluble component was immersed in THF again for 24 hours, the weight of the sample swollen by THF, i.e., weight c, was measured, and the degree of swelling of the THF-insoluble component was calculated using the following formula. Swelling degree (%) = c / b × 100.

Images