阅读说明：本技术 聚丙烯树脂组合物 (Polypropylene resin composition ) 是由 小田义朗 佐藤奎都 于 2018-11-28 设计创作，主要内容包括：本发明涉及一种聚丙烯树脂组合物,其中,含有聚丙烯树脂、具有极性官能团的弹性体和填充材料。本发明的聚丙烯树脂组合物能够良好地适用于音响设备、电器产品、交通工具、建筑物、工业用设备等制品。(The present invention relates to a polypropylene resin composition comprising a polypropylene resin, an elastomer having a polar functional group, and a filler. The polypropylene resin composition of the present invention can be suitably used for products such as audio equipment, electric appliances, vehicles, buildings, and industrial equipment.)

1. A polypropylene resin composition, wherein,

comprising a polypropylene resin, an elastomer having a polar functional group, and a filler.

2. The polypropylene resin composition according to claim 1, wherein,

the polar functional group of the elastomer having a polar functional group is 1 or more selected from an ester group, an amide group, a hydroxyl group, a carboxyl group, an amino group, an acid anhydride group, an epoxy group and a carbodiimide group.

3. The polypropylene resin composition according to claim 1 or 2, wherein,

the elastomer having a polar functional group is 1 or more elastomers selected from the group consisting of a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), a maleic anhydride-modified polystyrene-isobutylene-polystyrene block copolymer (SIBS), a maleic anhydride-modified polystyrene-ethylene-butylene-polyolefin block copolymer (SEBC), and an epoxy-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS).

4. The polypropylene resin composition according to claim 1 to 3, wherein,

the filler is more than 1 selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silicon dioxide.

5. The polypropylene resin composition according to claim 1 to 4, wherein,

in the polypropylene resin composition, the content of the elastomer having a polar functional group is 5 parts by mass or more and 60 parts by mass or less and the content of the filler is 5 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the polypropylene resin.

6. A process for producing a polypropylene resin composition, wherein,

the method comprises the following steps: and a step of melt-kneading an additive and a polypropylene resin, the additive containing a melt-kneaded product of an elastomer having a polar functional group and a filler.

7. The method for producing a polypropylene resin composition according to claim 6, wherein,

the method comprises the following steps: a step (1) for melt-kneading a mixture composed of an elastomer having a polar functional group and a filler; and a step (2) of melt-kneading the kneaded product obtained in the step (1) with a polypropylene resin.

8. A process for producing a polypropylene resin composition, wherein,

the method comprises the following steps: and a step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin.

9. The method for producing a polypropylene resin composition according to claim 8, wherein,

the step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin is carried out by melt-kneading a premix a containing the polypropylene resin and the filler and a premix B containing the polypropylene resin, the elastomer having a polar functional group and the filler.

10. The method for producing a polypropylene resin composition according to claim 9, wherein,

the preblend A further contains a maleic anhydride-modified polyolefin.

11. The method for producing a polypropylene resin composition according to claim 6 to 10, wherein,

the elastomer having a polar functional group is 1 or more elastomers selected from the group consisting of a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), a maleic anhydride-modified polystyrene-isobutylene-polystyrene block copolymer (SIBS), a maleic anhydride-modified polystyrene-ethylene-butylene-polyolefin block copolymer (SEBC), and an epoxy-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS).

12. The method for producing a polypropylene resin composition according to claim 6 to 11,

the filler is more than 1 selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silicon dioxide.

13. An additive, wherein,

a melt-kneaded product containing an elastomer having a polar functional group and a filler.

14. The additive of claim 13, wherein,

the elastomer having a polar functional group is 1 or more elastomers selected from the group consisting of a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), a maleic anhydride-modified polystyrene-isobutylene-polystyrene block copolymer (SIBS), a maleic anhydride-modified polystyrene-ethylene-butylene-polyolefin block copolymer (SEBC), and an epoxy-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS).

15. The additive of claim 13 or 14,

the filler is more than 1 selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silicon dioxide.

16. A vibration damping material, wherein,

a polypropylene resin composition comprising the polypropylene resin composition according to any one of claims 1 to 5 or produced by the method for producing a polypropylene resin composition according to any one of claims 6 to 12.

Technical Field

The present invention relates to a polypropylene resin composition and a method for producing the same. More specifically, the present invention relates to a polypropylene resin composition which can be used as a vibration damping material in acoustic equipment, electric appliances, vehicles, buildings, industrial equipment, and the like, a method for producing the same, an additive for imparting vibration damping properties to the resin composition, and a vibration damping material containing the polypropylene resin composition.

Background

In recent years, various devices have been required to take measures against vibration, and particularly in the fields of automobiles, home electric appliances, precision equipment, and the like, measures against vibration have been required. In general, as a material having high vibration damping properties, there can be mentioned: a material obtained by bonding a metal plate to a vibration absorbing material such as rubber or asphalt; alternatively, a composite material such as a vibration damping steel plate made of a vibration absorbing material is sandwiched between metal plates. These vibration damping materials are configured to hold their shapes by a metal plate having high rigidity and to absorb vibrations by a vibration absorbing material. In addition, as the material composed of only metal, there can be mentioned: an alloy type material which converts kinetic energy into heat energy by utilizing twins or ferromagnetism to absorb vibration. However, the composite material has a problem that the composite material is limited in moldability by bonding different materials, and the composite material has a problem that the product itself is heavy due to the use of the metal steel plate. Further, the alloy type material is heavy because only metal is used, and its vibration damping performance is insufficient.

In view of such conventional techniques, a functional resin composition having a vibration suppressing function has been proposed. For example, patent document 1 discloses a vibration damping resin molded article obtained by molding a polypropylene-based resin composition, wherein the resin composition is obtained by adding and mixing a high-density Polyethylene (PE) and an aromatic hydrocarbon resin to crystalline polypropylene (PP) to obtain a resin component, and mixing a reinforcing inorganic filler to the obtained resin component, and further adding and mixing a hydrogenated product of an aromatic vinyl-conjugated diene block copolymer as the resin component.

[ Prior art documents ]

Patent document

Patent document 1: japanese patent laid-open No. 5-331329.

Disclosure of Invention

The present invention relates to the following [1] to [6 ].

[1] A polypropylene resin composition comprising a polypropylene resin, an elastomer having a polar functional group, and a filler.

[2] A method for producing a polypropylene resin composition, comprising: and a step of melt-kneading an additive and a polypropylene resin, the additive containing a melt-kneaded product of an elastomer having a polar functional group and a filler.

[3] A method for producing a polypropylene resin composition, comprising: and a step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin.

[4] The production method according to [3], wherein the step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin is carried out by melt-kneading a premix A containing the polypropylene resin and the filler and a premix B containing the polypropylene resin, the elastomer having a polar functional group and the filler.

[5] An additive comprising a melt-kneaded product of an elastomer having a polar functional group and a filler.

[6] A vibration damping material comprising the polypropylene resin composition according to the above [1] or the polypropylene resin composition produced by the production method according to any one of the above [2] to [4 ].

Detailed Description

However, in the polypropylene resin composition of patent document 1, although the vibration damping property at room temperature is improved, the improvement of the vibration damping property in a high temperature region is small, and the flexural modulus is rather lowered.

The present invention relates to a polypropylene resin composition having excellent vibration damping properties over a wide temperature range while maintaining an elastic modulus, a method for producing the same, an additive for the resin composition, and a vibration damping material containing the polypropylene resin composition.

The present invention can provide a polypropylene resin composition having excellent vibration damping properties while maintaining its elastic modulus, a method for producing the same, an additive for use in the resin composition, and a vibration damping material containing the polypropylene resin composition.

The inventors of the present invention have newly found the following phenomena: by strengthening the interface between the elastomer and the filler added to the polypropylene resin composition by some chemical bonding, not only the elastic modulus of the polypropylene resin composition can be maintained, but also the vibration damping property thereof can be improved. Then, it was confirmed that: the vibration damping property and impact resistance are further improved as compared with the case where the interface between the elastomer and the filler is not reinforced as described in patent document 1. The mechanism is not yet determined, but is presumed as follows: by strengthening the interface between the elastomer and the filler, the strain energy (strain) of the elastomer can be increased.

The polypropylene resin composition of the present invention contains a polypropylene resin, an elastomer having a polar functional group, and a filler.

[ Polypropylene resin ]

The polypropylene resin is a resin containing a repeating unit of propylene preferably 30mol or more in the main chain of the polymer. In the present invention, polypropylene homopolymer, random polypropylene, block polypropylene, chlorinated polypropylene, carboxylic acid-modified polypropylene, derivatives thereof, and mixtures thereof can be used without particular limitation.

The polypropylene resin used in the present invention is not particularly limited, and polypropylene having a weight average molecular weight of 5000 to 500000 is preferably used.

The flowability of the polypropylene resin is preferably 2.0g/10min or more, more preferably 4.0g/10min or more, and on the other hand preferably 50g/10min or less, more preferably 30g/10min or less, when the Melt Flow Rate (MFR) is measured in accordance with JIS K7210, from the viewpoint of easiness of molding processing.

The melting point of the polypropylene resin is preferably 120 ℃ or higher, more preferably 125 ℃ or higher, and on the other hand, preferably 170 ℃ or lower, more preferably 165 ℃ or lower.

The amount of the polypropylene resin in the polypropylene resin composition of the present invention is preferably 35% by mass or more, more preferably 45% by mass or more, and still more preferably 55% by mass or more, from the viewpoint of obtaining a molded article and a vibration damping material which exhibit a desired elastic modulus. On the other hand, from the viewpoint of obtaining a molded article and a vibration damping material which exhibit desired vibration damping properties, the content is preferably 85% by mass or less, more preferably 75% by mass or less, and still more preferably 65% by mass or less.

[ elastomer having polar functional group ]

As the details of the polar functional group of the elastomer having a polar functional group and the elastomer, which will be described later, examples of such elastomers include a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), a maleic anhydride-modified polystyrene-isobutylene-polystyrene block copolymer (SIBS), a maleic anhydride-modified polystyrene-ethylene-butylene-polyolefin block copolymer (SEBC), an epoxy-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), and the like, and maleic anhydride-modified SEBS is preferable from the viewpoint of improving vibration damping properties and impact resistance. For the elastomer having a polar functional group, 1 or 2 or more species may be used.

In the polypropylene resin composition of the present invention, the content of the elastomer having a polar functional group is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, relative to 100 parts by mass of the polypropylene resin, from the viewpoint of improving vibration damping properties; from the viewpoint of suppressing the decrease in flexural modulus, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less. The content of the polar functional group-containing elastomer in the case where 2 or more kinds of elastomers are contained is the total amount thereof.

The polar functional group of the elastomer having a polar functional group is not particularly limited as long as it can be bonded to the filler, and examples thereof include an ester group, an amide group, a hydroxyl group, a carboxyl group, an amino group, an acid anhydride group, an epoxy group, and a carbodiimide group, and from the viewpoint of reactivity, a hydroxyl group, a carboxyl group, an amino group, an acid anhydride group, and an epoxy group are preferable as reactive functional groups, an acid anhydride group and an epoxy group are more preferable, an acid anhydride group is further preferable, and a maleic anhydride group is further preferable. The acid anhydride group may be bonded to another group (for example, a carbodiimide group or the like). The polar functional group introduced into the elastomer may be 1 kind or 2 or more kinds.

The amount of the polar functional group added is not particularly limited, and may be appropriately selected depending on the kind of the polar functional group and the elastomer. For example, in the case where the elastomer having a polar functional group is a maleic anhydride-modified elastomer such as a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), the polar functional group is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and still more preferably 0.3 parts by mass or more, relative to 100 parts by mass of the elastomer before addition, from the viewpoints of suppressing a decrease in elastic modulus and improving vibration damping properties and impact resistance. On the other hand, from the same viewpoint, it is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less. The amount of addition of an acid anhydride such as maleic anhydride in the present embodiment can be measured by acid value titration.

As the elastomer having a polar functional group, a known thermoplastic elastomer can be used as the vibration damping elastomer. The glass transition temperature Tg of the thermoplastic elastomer is preferably-40 ℃ or higher, and preferably 40 ℃ or lower, from the viewpoint of improving vibration damping properties in the high temperature region and the low temperature region. The peak value of tan obtained by the viscoelasticity measurement of the elastomer is preferably 0.5 or more, more preferably 0.8 or more, and still more preferably 1.0 or more. Further, the temperature region in which tan is 0.5 or more is preferably 10 ℃ or more, more preferably 20 ℃ or more, and the temperature region in which tan is 0.5 or more is preferably a temperature region of-40 ℃ to 40 ℃ from the viewpoint of improving vibration damping properties in the high temperature region and the low temperature region. As the thermoplastic elastomer, for example, at least 1 selected from the group consisting of styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, nitrile-based thermoplastic elastomers, fluorine-based thermoplastic elastomers, polybutadiene-based thermoplastic elastomers and silicone-based thermoplastic elastomers is preferable, and from the viewpoint of improving vibration damping properties in a high temperature region and a low temperature region, styrene-based thermoplastic elastomers are preferable. In the present specification, the high temperature region is 35 to 80 ℃ and the low temperature region is-30 to 10 ℃.

The styrene-based thermoplastic elastomer (hereinafter, sometimes referred to as "styrene-based elastomer") is composed of a block a and a block B, wherein the block a is polymerized from a styrene compound constituting a hard segment, and the block B is polymerized from a conjugated diene constituting a soft segment.

Specific examples of such styrene-based elastomers include: polystyrene-isoprene block copolymers (SIS), polystyrene-polybutadiene copolymers (SBS), polystyrene-hydrogenated polybutadiene copolymers (SEBS), polystyrene-hydrogenated polyisoprene-polystyrene block copolymers (SEPS), polystyrene-vinyl-polyisoprene-polystyrene block copolymers (SHIVS), polystyrene-isobutylene-polystyrene block copolymers (SIBS), polystyrene-ethylene-butylene-polyolefin (preferably polypropylene) block copolymers (SEBC), polystyrene-hydrogenated polybutadiene-hydrogenated polyisoprene-polystyrene block copolymers, polystyrene-hydrogenated polybutadiene-polyisoprene-polystyrene block copolymers, and the like. These may be used alone or in combination of two or more. In the present invention, SEBS, SHVIS, SBS, SIS, SIBS, SEBC are preferable, and SEBS is more preferable.

The styrene content in the styrene-based elastomer is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, from the viewpoint of improving vibration damping properties in the high temperature region and the low temperature region. The styrene content in the styrene-based elastomer can be measured by a known method (for example, by NMR).

The elastomer having a polar functional group can be prepared by a known method. For example, a compound having a polar functional group (for example, maleic anhydride or the like) may be directly reacted with an elastomer, a polymer having a polar functional group may be introduced into an elastomer by copolymerization, or the elastomer may be prepared by mixing the elastomer with a component having a polar functional group, and the compound having a polar functional group is preferably directly reacted. If necessary, a known polymerization initiator may be used. The ratio of the elastomer to the compound having a polar functional group is, for example, preferably 0.05 to 3 parts by mass per 100 parts by mass of the elastomer. In addition, it is preferable to remove the residual monomer from the viewpoint of vibration damping properties and impact resistance. As a method for removing the residual monomer, there are cleaning with an organic solvent, suction and exhaust, vaporization, and the like, and cleaning with an organic solvent is preferable.

[ Filler ]

The filler is not particularly limited as long as it is a filler having a polar functional group among known fillers. Among the polar functional groups, a reactive functional group bonded to an elastomer having a polar functional group is preferable. The filler having a reactive functional group includes a plate-like filler, a granular filler, a needle-like filler, a fibrous filler, and the like, and is preferably a plate-like filler. For the filler of the present invention, 1 or 2 or more kinds can be used.

By "bonded to an elastomer" is meant any chemical bond. Examples thereof include hydrogen bond, ionic bond, and covalent bond. As the bond, a strong bond is preferable.

Examples of the reactive functional group include a hydroxyl group, a carboxyl group, and an amino group, and a hydroxyl group is preferable, and a silanol group is more preferable.

Examples of the filler having such a reactive functional group include mica, talc, a glass filler, a cellulose filler, aluminum hydroxide, magnesium hydroxide, silica and the like, and mica, talc and a glass filler are preferable, and mica is more preferable.

In addition, carbonates of alkaline earth metals (for example, magnesium carbonate, calcium carbonate, etc.) can also be preferably used as the filler. That is, as a preferable filler of the present invention, 1 or more kinds of fillers selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica can be exemplified.

From the viewpoint of enhancing the interaction between the elastomer and the filler, the interfacial adhesion surface may be increased by treatment such as reducing the particle size of the filler.

In the polypropylene resin composition of the present invention, the content of the filler is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, per 100 parts by mass of the polypropylene resin, from the viewpoint of improving the flexural elastic modulus; from the viewpoint of suppressing the decrease in vibration damping performance, it is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and still more preferably 60 parts by mass or less. The content when 2 or more fillers are contained is the total amount thereof.

[ maleic anhydride-modified polyolefin ]

The polypropylene resin composition of the present invention may further contain a maleic anhydride-modified polyolefin. The molded article of the polypropylene resin composition containing such components is more preferable because the strength and/or vibration damping property are improved. The maleic anhydride-modified polyolefin is preferably maleic anhydride-modified polypropylene, and in the present invention, a commercially available product, for example, "Youmex" manufactured by Sanyo chemical industries, Ltd.

In the polypropylene resin composition of the present invention, the content of the maleic anhydride-modified polyolefin is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and further preferably 0.5 part by mass or more, relative to 100 parts by mass of the polypropylene resin, from the viewpoint of strength and/or vibration damping properties; from the viewpoint of cost performance, it is preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and still more preferably 0.7 parts by mass or less.

[ optional Components ]

The polypropylene resin composition of the present invention may contain, as other components than the above, a chain extender, a plasticizer, an organic crystal nucleating agent, an inorganic crystal nucleating agent, a hydrolysis inhibitor, a flame retardant, an antioxidant, a lubricant such as hydrocarbon wax or an anionic surfactant, an ultraviolet absorber, an antistatic agent, an antifogging agent, a light stabilizer, a pigment, an antifungal agent, an antibacterial agent, a foaming agent, and the like, within a range not to impair the effects of the present invention. In addition, other polymer materials or other resin compositions may be contained within a range not to impair the effects of the present invention.

[ examples of the Process for producing Polypropylene resin composition ]

Specific examples of the method for producing the polypropylene resin composition of the present invention include a production method comprising a step of melt-kneading an additive containing a melt-kneaded product of an elastomer having a polar functional group and a filler with a polypropylene resin. As a more preferable embodiment of the production method, there is a production method including: a step (1) for melt-kneading a mixture containing an elastomer having a polar functional group and a filler; and (2) melt-kneading the kneaded product obtained in the step (1) with a polypropylene resin. A more preferred embodiment includes a production method including: a step (1) for melt-kneading a mixture composed of an elastomer having a polar functional group and a filler; and (2) melt-kneading the kneaded product obtained in the step (1) with a polypropylene resin. For the melt kneading, a known kneading machine such as a closed kneader, a single-screw or twin-screw extruder, or an open roll type kneading machine can be used. After the melt-kneading, the melt-kneaded product can be dried or cooled by a known method. Alternatively, the raw materials may be uniformly mixed in advance using a henschel mixer, a high-speed mixer, or the like, and then subjected to melt kneading.

The preferred ratio of the elastomer having a polar functional group to the filler, the additive containing a melt-kneaded product, or the preferred ratio of the kneaded product obtained in the step (1) to the polypropylene resin can be calculated based on the numerical value ranges described in the polypropylene resin of the present invention and the like.

As another specific example of the method for producing the polypropylene resin composition of the present invention, there may be mentioned a production method comprising: a step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin (hereinafter referred to as "kneading step"). The melt kneading may be performed using a known kneader as described above, and the preferred ratio of each component may be calculated based on the numerical value range described in the polypropylene resin of the present invention and the like.

As one of preferable embodiments for carrying out the above-described simultaneous steps, there can be mentioned: a method in which the above components constituting the polypropylene resin composition are divided into two groups and the two groups are melt-kneaded. More specifically, there may be mentioned: a method of melt-kneading a premix a containing a polypropylene resin and a filler, and a premix B containing a polypropylene resin, an elastomer having a polar functional group, and a filler. By carrying out the integrated process in this manner, the following effects can be exhibited: the bending strength and heat resistance of the molded article of the obtained resin composition are further improved, or the vibration damping property is improved while the bending strength and heat resistance are maintained. The mechanism of such an effect is not clear, but it is presumed that: the interaction between the components is promoted in each premix, and as a result, the properties of the molded article are improved.

< Polypropylene resin >

In this embodiment, the polypropylene resin is used as distributed in the preblend a and the preblend B. The kind of the polypropylene resin in the preblend A may be the same as or different from that in the preblend B. The total amount of the polypropylene resin content in the preblend a and the preblend B (same as the polypropylene resin content in the polypropylene resin composition of the present invention described above) is preferably 35% by mass or more, more preferably 45% by mass or more, further preferably 55% by mass or more, and on the other hand, preferably 85% by mass or less, more preferably 75% by mass or less, further preferably 65% by mass or less in the obtained polypropylene resin composition. The ratio of the polypropylene resin in the preblend A to the polypropylene resin in the preblend B (preblend A: preblend B) is not particularly limited, but is preferably 20:80 to 80:20, more preferably 30:70 to 70:30, and further preferably 40:60 to 60:40 in terms of mass ratio from the viewpoint of mixability.

< Filler >

In this embodiment, the filler is used by being distributed in the premixes a and B. The kind of the filler in the preblend A may be the same as or different from that in the preblend B. The total amount of the content of the filler in the preblend a and the preblend B (the same as the content of the filler in the polypropylene resin composition of the present invention described above) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, further preferably 15 parts by mass or more, and on the other hand, preferably 70 parts by mass or less, more preferably 65 parts by mass or less, further preferably 60 parts by mass or less, based on 100 parts by mass of the polypropylene resin. The ratio of the filler in the preblend a to the filler in the preblend B (preblend a: preblend B) is not particularly limited, but is preferably 10:90 to 50:50, more preferably 20:80 to 45:55, and further preferably 7:25 to 11:20 in terms of mass ratio from the viewpoint of dispersibility and interaction promotion.

< elastomer having polar functional group >

In this embodiment, an elastomer having a polar functional group is mixed in the premix B. The total amount of the elastomer content in the preblend a and the preblend B is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more, and on the other hand, is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and still more preferably 60 parts by mass or less, with respect to 100 parts by mass of the polypropylene resin.

< premix A >

The preblend A contains a polypropylene resin and a filler.

The content of the polypropylene resin in the premix a is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more, and on the other hand, is preferably 93% by mass or less, more preferably 90% by mass or less, and still more preferably 88% by mass or less, from the viewpoint of dispersibility and miscibility.

The filler that can be mixed in the preblend a is preferably 1 or more fillers selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica as described above, and more preferably contains a glass filler from the viewpoint of improving flexural strength and heat resistance. The content of the filler in the premix a is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, and on the other hand, is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of exerting the desired effects.

The preblend a preferably further contains a maleic anhydride-modified polyolefin from the viewpoint of improving the strength and/or vibration damping property of a molded article of the polypropylene resin composition. From the viewpoint of exerting the desired effect, the content of the maleic anhydride-modified polyolefin in the preliminary mixture a is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and even more preferably 0.9% by mass or more, and on the other hand, is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.1% by mass or less.

The preblended product a may contain any other components than the above components as long as the physical properties of the molded article are not degraded.

The preblend a can be prepared by melt-kneading the respective components using the aforementioned kneader.

< premix B >

The preblend B contains a polypropylene resin, an elastomer having a polar functional group, and a filler.

The content of the polypropylene resin in the premix B is preferably 30% by mass or more, more preferably 35% by mass or more, and still more preferably 38% by mass or more, and on the other hand, is preferably 55% by mass or less, more preferably 50% by mass or less, and still more preferably 46% by mass or less, from the viewpoint of dispersibility and miscibility.

As described above, the elastomer having a polar functional group which can be mixed in the preliminary kneaded material B is preferably 1 or more selected from the group consisting of a maleic anhydride-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), a maleic anhydride-modified polystyrene-isobutylene-polystyrene block copolymer (SIBS), a maleic anhydride-modified polystyrene-ethylene-butylene-polyolefin block copolymer (SEBC), and an epoxy-modified polystyrene-hydrogenated polybutadiene copolymer (SEBS), from the viewpoint of improving vibration damping properties. From the viewpoint of exerting the desired effect, the content of the elastomer having a polar functional group in the premix B is preferably 25% by mass or more, more preferably 30% by mass or more, and still more preferably 35% by mass or more, and on the other hand, is preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 41% by mass or less.

The filler that can be mixed in the preblend B is preferably 1 or more fillers selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica as described above, and more preferably contains calcium carbonate from the viewpoint of improving vibration damping properties. The content of the filler in the premix B is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 18% by mass or more, and on the other hand, is preferably 35% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less, from the viewpoint of exerting the desired effects.

The preblended product B may contain any other components than the above components as long as the physical properties of the molded article are not degraded.

The preblend B can be prepared by melt-kneading the respective components using the aforementioned kneader.

< method for producing Polypropylene resin composition of the present embodiment >

The polypropylene resin composition can be produced by melt-kneading the above-mentioned preblend a and preblend B together using the above-mentioned kneader or a known injection molding machine.

[ additives ]

The additive of the present invention includes a melt-kneaded product of an elastomer having a polar functional group and a filler, and may optionally contain, in addition to the melt-kneaded product, a chain extender, a plasticizer, an organic crystal nucleating agent, an inorganic crystal nucleating agent, a hydrolysis inhibitor, a flame retardant, an antioxidant, a lubricant such as a hydrocarbon-based wax or an anionic surfactant, an ultraviolet absorber, an antistatic agent, an antifogging agent, a light stabilizer, a pigment, an antifungal agent, an antibacterial agent, a foaming agent, and the like, within a range in which the effects of the present invention are not impaired. The additive of the present invention may further contain a part of the resin melt-kneaded together (for example, 0.1 to 50.0 mass% in the additive). The additive of the present invention can be used as an additive for various resins.

Examples of the resin to which the additive of the present invention is added include polyethylene resin, polystyrene resin, vinyl chloride resin, ABS resin, acrylic resin, polyamide resin, and polyester resin, in addition to the polypropylene resin described above. As described above, by melt-kneading such an additive with a resin, the vibration damping property and impact resistance of the obtained resin composition can be improved.

The content of the elastomer having a polar functional group in the additive is preferably 10.0% by mass or more, more preferably 15.0% by mass or more, and further preferably 20.0% by mass or more, from the viewpoint of vibration damping properties and impact resistance; from the same viewpoint, it is preferably 55.0% by mass or less, more preferably 50.0% by mass or less, and still more preferably 45.0% by mass or less. The content of the filler in the additive is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, and further preferably 40.0% by mass or more, from the viewpoint of vibration damping properties and impact resistance; from the same viewpoint, it is preferably 90.0% by mass or less, more preferably 85.0% by mass or less, and still more preferably 80.0% by mass or less. One of the preferred embodiments of the additive of the present invention is an additive composed of an elastomer having a polar functional group and a filler.

In the elastomer having a polar functional group, an unreacted product to which the polar functional group is added may remain. From the viewpoint of improving the effect of the present invention, it is preferable to remove the unreacted product, and the removal method is preferably solvent washing or distillation removal, among which solvent washing is preferable, and acetone washing is more preferable.

When the above-mentioned additive, polypropylene resin composition, premix A or premix B is prepared, the melt-kneading temperature and melt-kneading time cannot be set generally because of the kind of raw materials used, but melt-kneading is preferably carried out at 170 to 240 ℃ for 15 to 900 seconds.

The polypropylene resin composition of the present invention can be suitably used as a vibration damping material for products such as audio equipment, electric appliances, buildings, industrial equipment, and the like, or parts or housings thereof by applying various molding methods such as injection molding, extrusion molding, and thermoforming.

For example, when a part or a housing containing the polypropylene resin composition of the present invention is produced by injection molding, pellets of the polypropylene resin composition are filled in an injection molding machine and injected into a mold to be molded.

For injection molding, a known injection molding machine can be used. For example, a molding machine having a cylinder and a screw inserted therein as main components [ J75E-D, J110 AD-180H (manufactured by Nippon Steel Co., Ltd.) ] and the like ] can be mentioned. Further, the raw materials of the polypropylene resin composition may be supplied to a cylinder and directly melt-kneaded, but it is preferable to fill the raw materials after preliminary melt-kneading into an injection molding machine.

When a molding method other than injection molding is applied, the molding may be performed by a known method, and is not particularly limited.

[ molded article or vibration damping Material ]

The molded article of the polypropylene resin composition of the present invention or the polypropylene resin composition produced by the production method of the present invention can be suitably used as a vibration damping material for products such as acoustic equipment, electric appliances, buildings, industrial equipment, or parts or housings thereof. Further, since the molded article of the polypropylene resin composition of the present invention is made of a single material and has a high flexural modulus, it can be suitably used for products requiring weight reduction such as automobiles, railways, and aircrafts, parts thereof, and housings thereof while maintaining a sufficient shape and having excellent vibration damping performance by using a single material without using a high-rigidity material such as a metal steel plate.

Examples of the applications of the polypropylene resin composition of the present invention or the polypropylene resin composition produced by the production method of the present invention to vibration damping materials include materials for housings of audio devices, such as speakers, televisions, radio cassette recorders, headphones, audio sets, audio players, compact discs, F L OPPY (registered trademark), video devices, electric appliances with cooling functions, such as electric drills and electric screwdrivers, computers, projectors, servers, POS systems, washing machines, clothes dryers, air conditioners, sewing machines, dish washers, complex machines, printers, scanners, hard disk drives, cameras, air cleaners, cellular phones, hair dryers, components for housings of electric products with vibration sources, such as housings, door cases, rocker covers.

The application of the polypropylene resin composition of the present invention to products such as audio equipment, electric appliances, vehicles, buildings, industrial equipment, or parts or housings thereof can be appropriately set depending on the production method, application location, and intended purpose of the parts, housings, devices, and equipment, and can be used according to a method generally used in the art.

The polypropylene resin composition of the present invention or the polypropylene resin composition produced by the production method of the present invention can be suitably used for fans and structural parts of fans. For example, it can be applied to: electric appliances with compressors such as microwave ovens, refrigerators, and the like; cooling fan devices installed in casing boxes of electronic devices such as electronic cameras, image recording and playing devices, computers, and projectors; cooling fan devices for radiating heat such as radiators and condensers of vehicle air conditioning devices, or cooling fans or fan devices for blowing air such as ventilation fans, electric fans, and air conditioners (fan heaters); a motor cover for an electric appliance; audio equipment such as speakers, televisions, radio recorders, headphones, combination audio, and the like; products having various fans such as building materials such as sound-proof walls, pipes, and piping ducts.

Examples of the fan include centrifugal fans such as sirocco fans and turbo fans, crossflow fans such as crossflow fans, diagonal flow fans, propeller fans, and fans that are rotationally driven by a motor driven by a direct current or an alternating current.

The size of the fan varies depending on the kind and the purpose, and for example, a fan having a profile Φ of 10mm to 10000mm is cited. The size of the blade is 10mm to 10000mm in length and 10mm to 10000mm in width.

As for the frequencies exhibiting significant vibration damping effect, noise reduction effect, there can be enumerated: the frequency of a rotational noise peak from F NZk/60, the frequency of the rotation or vibration of the motor, the resonance frequency of the fan, the resonance frequency of the structural member, and the like. Since noise of a low frequency is generated when the above-mentioned frequency exists on the low frequency side, it can be predicted that: as an effect when the vibration damping material is used, low frequency noise can be reduced. Assuming that the above-mentioned frequencies exist on the high frequency side, since high-frequency noise is generated, it can be predicted that: as an effect when the vibration damping material is used, high-frequency noise can be reduced.

In addition, when the frequency of the peak of the rotational noise from F ═ NZk/60, the frequency generated by the rotation or vibration of the motor, the resonance frequency of the fan, and the resonance frequency of the structural members overlap each other, the noise is significantly increased, but when the fan formed of the polypropylene resin composition of the present invention is used, the noise can be reduced.

In order to reduce fan noise, it is sufficient that at least one of the following vibrations can be suppressed: suppressing the vibration of the blades of the fan; suppressing vibration of structural components (e.g., a fan case, a fan housing, a motor cover, a duct, a wind deflector, a bell mouth, an engine cover, etc.) in the vicinity of the fan; suppressing vibration from a motor that rotates a fan; and to suppress vibration and the like from the housing of the motor.

The application of the fan made of the polypropylene resin composition of the present invention to products such as audio equipment, electric appliances, vehicles, buildings, industrial equipment, parts thereof, or housings thereof can be appropriately set depending on the production methods, application places, and intended purposes of the parts, housings, devices, and equipment, and can be used according to a method generally used in the art.

The present invention further discloses the following polypropylene resin composition, a method for producing the polypropylene resin composition, an additive, and a vibration damping material.

< 1 > a polypropylene resin composition comprising a polypropylene resin, an elastomer having a polar functional group and a filler.

< 2 > the polypropylene resin composition according to the above < 1 >, wherein the maleic anhydride-modified polyolefin is preferably contained, and the maleic anhydride-modified polypropylene is more preferably contained.

< 3 > the polypropylene resin composition according to the above < 1 > or < 2 >, wherein the polar functional group of the elastomer having a polar functional group is preferably at least 1 kind selected from the group consisting of an ester group, an amide group, a hydroxyl group, a carboxyl group, an amino group, an acid anhydride group, an epoxy group and a carbodiimide group.

< 4 > the polypropylene resin composition according to any one of the above < 1 > to < 3 >, wherein the elastomer having a polar functional group is preferably at least 1 thermoplastic elastomer selected from the group consisting of styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, nitrile-based thermoplastic elastomers, fluorine-based thermoplastic elastomers, polybutadiene-based thermoplastic elastomers and silicone-based thermoplastic elastomers, more preferably a styrene-based thermoplastic elastomer, and still more preferably a styrene-based thermoplastic elastomer, and yet more preferably a polystyrene-isoprene block copolymer (SIS), a polystyrene-polybutadiene copolymer (SBS), a polystyrene-hydrogenated polybutadiene copolymer (SEBS), a polystyrene-hydrogenated polyisoprene-polystyrene block copolymer (SEPS), At least 1 of polystyrene-vinyl-polyisoprene-polystyrene block copolymer (SHIVS), polystyrene-isobutylene-polystyrene block copolymer (SIBS), polystyrene-ethylene-butylene-polyolefin (preferably polypropylene) block copolymer (SEBC), polystyrene-hydrogenated polybutadiene-hydrogenated polyisoprene-polystyrene block copolymer, polystyrene-hydrogenated polybutadiene-polyisoprene-polystyrene block copolymer.

< 5 > the polypropylene resin composition as defined in any one of the above < 1 > -4 >, wherein the elastomer having a polar functional group is preferably at least 1 kind selected from the group consisting of maleic anhydride-modified SEBS, maleic anhydride-modified SIBS, maleic anhydride-modified SEBC, and epoxy-modified SEBS.

< 6 > the polypropylene resin composition as defined in any one of the above < 1 > to < 5 >, wherein the filler is preferably at least 1 filler selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica.

< 7 > the polypropylene resin composition as defined in any one of the above < 1 > to < 6 >, wherein the amount of the polypropylene resin in the polypropylene resin composition is preferably 35% by mass or more, more preferably 45% by mass or more, further preferably 55% by mass or more, on the other hand, preferably 85% by mass or less, more preferably 75% by mass or less, further preferably 65% by mass or less; the content of the elastomer having a polar functional group in the polypropylene resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more, and on the other hand, is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less, relative to 100 parts by mass of the polypropylene resin; the content of the filler in the polypropylene resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, and on the other hand, is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 60 parts by mass or less, with respect to 100 parts by mass of the polypropylene resin.

< 8 > the polypropylene resin composition as defined in any one of the above < 1 > to < 7 >, wherein the amount of the polypropylene resin in the polypropylene resin composition is preferably 35% by mass or more, more preferably 45% by mass or more, further preferably 55% by mass or more, on the other hand, preferably 85% by mass or less, more preferably 75% by mass or less, further preferably 65% by mass or less; the content of the elastomer having a polar functional group in the polypropylene resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more, and on the other hand, is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less, relative to 100 parts by mass of the polypropylene resin; the content of the filler in the polypropylene resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, and on the other hand, is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 60 parts by mass or less, with respect to 100 parts by mass of the polypropylene resin; the content of the maleic anhydride-modified polyolefin in the polypropylene resin composition is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and still more preferably 0.5 part by mass or more, and on the other hand, is preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and still more preferably 0.7 part by mass or less, with respect to 100 parts by mass of the polypropylene resin.

< 9 > a method for producing a polypropylene resin composition, which comprises: and a step of melt-kneading an additive and a polypropylene resin, the additive containing a melt-kneaded product of an elastomer having a polar functional group and a filler.

< 10 > the method for producing a polypropylene resin composition as described above < 9 >, comprising: a step (1) for melt-kneading a mixture composed of an elastomer having a polar functional group and a filler; and (2) melt-kneading the kneaded product obtained in the step (1) with a polypropylene resin.

< 11 > a method for producing a polypropylene resin composition, which comprises: and a step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin.

< 12 > the process for producing a polypropylene resin composition as described in < 11 > above, wherein the step of melt-kneading the elastomer having a polar functional group, the filler and the polypropylene resin is carried out by melt-kneading a premix A containing the polypropylene resin and the filler with a premix B containing the polypropylene resin, the elastomer having a polar functional group and the filler.

< 13 > the process for producing a polypropylene resin composition as described in the above < 12 >, wherein the premix A further preferably contains a maleic anhydride-modified polyolefin, more preferably a maleic anhydride-modified polypropylene.

< 14 > the method for producing a polypropylene resin composition according to any one of the above < 9 > to < 13 >, wherein the elastomer having a polar functional group is preferably at least 1 elastomer selected from the group consisting of maleic anhydride-modified SEBS, maleic anhydride-modified SIBS, maleic anhydride-modified SEBC, and epoxy-modified SEBS.

< 15 > the method for producing a polypropylene resin composition according to any one of the above < 9 > to < 14 >, wherein the filler is preferably at least 1 filler selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica.

< 16 > the method for producing a polypropylene resin composition according to any one of the above < 12 > to < 15 >, wherein the ratio of the polypropylene resin in the preblend A to the polypropylene resin in the preblend B (preblend A: preblend B) is preferably 20:80 to 80:20, more preferably 30:70 to 70:30, further preferably 40:60 to 60:40 in terms of mass ratio; the ratio of the filler in the preblend A to the filler in the preblend B (preblend A: preblend B) is preferably 10:90 to 50:50, more preferably 20:80 to 30:70, and still more preferably 7:25 to 11:20 in terms of mass ratio.

< 17 > the method for producing a polypropylene resin composition as defined in any one of the above < 12 > to < 16 >, wherein the total amount of the polypropylene resin contents in the premixture A and the premixture B is preferably 35% by mass or more, more preferably 45% by mass or more, further preferably 55% by mass or more, and on the other hand, is preferably 85% by mass or less, more preferably 75% by mass or less, further preferably 65% by mass or less; the total amount of the content of the elastomer having a polar functional group in the preblend a and the preblend B is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, and on the other hand, is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 60 parts by mass or less, with respect to 100 parts by mass of the polypropylene resin; the total amount of the filler contained in the preblend a and the preblend B is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, and on the other hand, is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 60 parts by mass or less, with respect to 100 parts by mass of the polypropylene resin; the total amount of the maleic anhydride-modified polyolefin in the preblend a and the preblend B is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and further preferably 0.5 part by mass or more, and on the other hand, is preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and further preferably 0.7 parts by mass or less, based on 100 parts by mass of the polypropylene resin.

< 18 > the method for producing a polypropylene resin composition as defined in any one of the above < 12 > to < 17 >, wherein the filler which can be mixed in the preliminary mixture A is preferably at least 1 kind selected from the group consisting of mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica, and more preferably contains a glass filler.

< 19 > the method for producing a polypropylene resin composition as defined in any one of the above < 12 > to < 18 >, wherein the content of the polypropylene resin in the premix A is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, on the other hand, preferably 93% by mass or less, more preferably 90% by mass or less, further preferably 88% by mass or less; the content of the filler in the preblend a is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 12% by mass or more, and on the other hand, is preferably 35% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less; the content of the maleic anhydride-modified polyolefin in the preblend a is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and further preferably 0.9% by mass or more, and on the other hand, is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and further preferably 1.1% by mass or less.

< 20 > the method for producing a polypropylene resin composition according to any one of the above < 12 > -19 >, wherein the elastomer having a polar functional group which can be mixed in the preliminary mixture B is preferably at least 1 kind selected from the group consisting of maleic anhydride-modified SEBS, maleic anhydride-modified SIBS, maleic anhydride-modified SEBC, and epoxy-modified SEBS; the filler which can be mixed in the preblend B is preferably at least 1 filler selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica, and more preferably contains calcium carbonate.

< 21 > the method for producing a polypropylene resin composition as defined in any one of the above < 12 > to < 20 >, wherein the content of the polypropylene resin in the premix B is preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 38% by mass or more, on the other hand, preferably 55% by mass or less, more preferably 50% by mass or less, further preferably 46% by mass or less; the content of the elastomer having a polar functional group in the preblend B is preferably 25% by mass or more, more preferably 30% by mass or more, and further preferably 35% by mass or more, and on the other hand, is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 41% by mass or less; the filler in the preblend B is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 18% by mass or more, and on the other hand, is preferably 35% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less.

< 22 > the method for producing a polypropylene resin composition as described in any one of the above < 12 > to < 21 >, wherein the polypropylene resin composition is produced by melt-kneading the preblend A and the preblend B together using a kneader.

< 23 > the method for producing a polypropylene resin composition according to any one of the above < 9 > to < 22 >, wherein the melt kneading temperature at the time of producing the polypropylene resin composition, the premix A and/or the premix B is preferably 170 to 240 ℃ and the melt kneading time is preferably 15 to 900 seconds.

< 24 > the polypropylene resin composition according to any one of the above < 1 > to < 8 > or the polypropylene resin composition produced by the method for producing a polypropylene resin composition according to any one of the above < 9 > to < 23 >, wherein the composition is preferably applied to a fan or a structural member of a fan, more preferably applied to: electric appliances with compressors such as microwave ovens, refrigerators, and the like; cooling fan devices installed in casing boxes of electronic devices such as electronic cameras, image recording and playing devices, computers, and projectors; cooling fan devices for radiating heat such as radiators and condensers of air conditioning devices for vehicles, or cooling fans or fan devices for blowing air such as ventilation fans, electric fans, and air conditioners (fan heaters); a motor cover for an electric appliance; audio equipment such as speakers, televisions, radio recorders, headphones, combination audio, and the like; products having various fans such as building materials such as sound-proof walls, pipes, and piping ducts.

< 25 > an additive comprising a melt-kneaded mixture of an elastomer having a polar functional group and a filler.

< 26 > the additive as stated above < 25 >, wherein the elastomer having a polar functional group is preferably at least 1 elastomer selected from the group consisting of maleic anhydride-modified SEBS, maleic anhydride-modified SIBS, maleic anhydride-modified SEBC, and epoxy-modified SEBS.

< 27 > the additive as described above < 25 > or < 26 >, wherein the filler is preferably 1 or more fillers selected from mica, talc, glass filler, calcium carbonate, cellulose filler, aluminum hydroxide, magnesium hydroxide and silica.

< 28 > the additive according to any one of the above < 25 > to < 27 >, wherein the resin to which the additive is added is preferably the above-mentioned polypropylene resin, polyethylene resin, polystyrene resin, vinyl chloride resin, ABS resin, acrylic resin, polyamide resin and/or polyester resin.

< 29 > the additive as described in any one of the above < 25 > - < 28 >, wherein the content of the elastomer having a polar functional group in the additive is preferably 10.0% by mass or more, more preferably 15.0% by mass or more, further preferably 20.0% by mass or more, on the other hand, preferably 55.0% by mass or less, more preferably 50.0% by mass or less, further preferably 45.0% by mass or less; the content of the filler in the additive is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, and still more preferably 40.0% by mass or more, and on the other hand, is preferably 90.0% by mass or less, more preferably 85.0% by mass or less, and still more preferably 80.0% by mass or less.

< 30 > a vibration damping material comprising the polypropylene resin composition described in any one of the above < 1 > to < 8 > or the polypropylene resin composition produced by the method for producing the polypropylene resin composition described in any one of the above < 9 > to < 23 >.

< 31 > the vibration damping material according to the above < 30 >, wherein the vibration damping material is preferably a vibration damping material used for products such as audio equipment, electric appliances, buildings, industrial equipment, or parts or housings thereof.