阅读说明：本技术 热塑性树脂组合物 (Thermoplastic resin composition ) 是由 小田义朗 佐藤奎都 于 2020-05-28 设计创作，主要内容包括：本发明涉及一种包含热塑性树脂和在粒子表面结合了高分子接枝链的复合粒子的热塑性树脂组合物。本发明的热塑性树脂组合物可以适宜地用于音响设备、电气产品、建筑物、产业用设备、汽车构件、两轮车构件、容器等产品。(The present invention relates to a thermoplastic resin composition comprising a thermoplastic resin and composite particles each having a polymer graft chain bonded to the surface of the particle. The thermoplastic resin composition of the present invention can be suitably used for products such as audio equipment, electric products, buildings, industrial equipment, automobile parts, two-wheeled vehicle parts, containers, and the like.)

1. A vibration damping material comprising a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

2. The vibration damping material according to claim 1, wherein the graft density of the polymer graft chain is 0.001 chain/nm²Above and 5 chains/nm²The following.

3. The vibration damping material according to claim 1 or 2, wherein the glass transition temperature of the polymer graft chain is from-30 ℃ to 80 ℃.

4. The vibration damping material according to any one of claims 1 to 3, wherein the film thickness of the polymer graft chain in the composite particle is 1nm or more and 1 μm or less.

5. The vibration damping material according to any one of claims 1 to 4, wherein the number average molecular weight of the polymer graft chain in the composite particle is 10,000 or more and 1,000,000 or less.

6. The vibration damping material according to any one of claims 1 to 5, wherein the dispersed particle diameter of the composite particles in the thermoplastic resin composition is 10nm or more and 200 μm or less.

7. The vibration damping material according to any one of claims 1 to 6, wherein a blending amount of the composite particles in the vibration damping material is 1 part by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin.

8. The vibration damping material according to any one of claims 1 to 7, wherein a blending amount of the composite particles in the vibration damping material is 1 mass% or more and 75 mass% or less.

9. The vibration damping material according to any one of claims 1 to 8, wherein the content of the polymer graft chain of the composite particle in the vibration damping material is 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin.

10. The vibration damping material according to any one of claims 1 to 9, wherein a blending amount of the thermoplastic resin in the vibration damping material is 30 mass% or more and 95 mass% or less.

11. The vibration damping material according to any one of claims 1 to 10, wherein the thermoplastic resin is 1 or more resins selected from polyolefin resins, polyamide resins, and ABS resins.

12. The vibration damping material according to any one of claims 1 to 11, wherein the particles are metal oxides, metal oxide salts, metal hydroxides, or metal carbonates.

13. The vibration damping material according to any one of claims 1 to 12, wherein the polymer graft chain is a polymer formed from 1 or 2 or more monomers selected from styrene monomers, nitrile monomers, (meth) acrylic monomers, unsaturated olefins, and conjugated diene monomers.

14. A method for producing a vibration damping material, which comprises the step of melt-kneading a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

15. The method for producing a vibration damping material according to claim 14, comprising a step of bonding the polymer graft chains to the particle surfaces.

16. The method for producing a vibration damping material according to claim 15, wherein the method of bonding the polymer graft chains to the particle surface is a surface graft method in which the polymer graft chains are polymerized from a polymerization initiation point on the particle surface.

17. The method for producing a vibration damping material according to claim 15 or 16, wherein the method for bonding the polymer graft chains to the particle surfaces comprises the following steps 1 and 2,

Step 1: a step of bonding a polymerization initiator group to the particle surface;

and a step 2: and a step of bringing the particles having the polymerization initiation group on the surface into contact with the monomer under living radical polymerization conditions.

18. The method for manufacturing a vibration damping material according to claim 12, wherein the polymerization initiating group is a living radical polymerization initiating group.

19. An additive for improving the vibration damping property of a thermoplastic resin, comprising composite particles having polymer graft chains bonded to the surfaces of the particles.

20. Use of a composite particle having a polymer graft chain bonded to the surface of the particle for improving the vibration damping property of a thermoplastic resin.

21. A method for improving the vibration damping property of a thermoplastic resin, which uses composite particles having polymer graft chains bonded to the particle surfaces.

Technical Field

The present invention relates to a thermoplastic resin composition, a method for producing the same, an additive for improving vibration damping properties of a thermoplastic resin, and a vibration damping material comprising the thermoplastic resin composition.

Background

In recent years, measures against vibration of various devices have been increasingly demanded, and particularly in the fields of automobiles, home electric appliances, precision devices, and the like, measures against vibration have been required. In general, as a material having high vibration damping properties, a material obtained by bonding a metal plate and a vibration absorbing material such as rubber or asphalt, or a composite material such as a vibration damping steel plate obtained by sandwiching a vibration absorbing material between metal plates can be cited. These vibration damping materials are held in shape by a highly rigid metal plate, and absorb vibration by a vibration absorbing material. Further, as the metal alone, an alloy type material that absorbs vibration by converting kinetic energy into thermal energy by twinning or ferromagnetism can be cited. However, the composite material is limited in formability by laminating different raw materials, and has a problem that a product itself becomes heavy because a metal steel plate is used. Further, the alloy type material is heavy because it uses only metal, and is insufficient as vibration damping performance.

In contrast to 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 formed from a polypropylene resin composition in which a reinforcing inorganic filler is blended with a resin component obtained by adding/mixing a high-density Polyethylene (PE) or an aromatic hydrocarbon resin to/with a crystalline polypropylene (PP), wherein the resin composition is further added/mixed with a hydrogenated product of an aromatic vinyl-conjugated diene block copolymer as the resin component.

Documents of the prior art

Patent document

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

Disclosure of Invention

Problems to be solved by the invention

The present invention relates to a novel thermoplastic resin composition having excellent vibration damping properties, a method for producing the same, an additive for improving vibration damping properties of a thermoplastic resin, and a vibration damping material comprising the thermoplastic resin composition.

Means for solving the problems

The present invention relates to the following [1] to [4 ].

[1] A thermoplastic resin composition comprising a thermoplastic resin and composite particles having polymer graft chains bonded to the surfaces of the particles.

[2] A method for producing a thermoplastic resin composition, which comprises a step of melt-kneading a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

[3] An additive for improving the vibration damping property of a thermoplastic resin, comprising composite particles having polymer graft chains bonded to the surfaces of the particles.

[4] A vibration damping material comprising the thermoplastic resin composition as described in [1] containing a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

[5] A vibration damping material comprising a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

[6] A method for producing a vibration damping material, which comprises the step of melt-kneading a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

[7] Use of a composite particle having a polymer graft chain bonded to the particle surface for improving the vibration damping property of a thermoplastic resin.

[8] A method for improving the vibration damping property of a thermoplastic resin, which uses composite particles having polymer graft chains bonded to the particle surfaces.

Effects of the invention

According to the present invention, a novel thermoplastic resin composition having excellent vibration damping properties, a method for producing the same, an additive for improving vibration damping properties of a thermoplastic resin, and a vibration damping material comprising the thermoplastic resin composition can be provided.

Detailed Description

The inventor and the like newly found that: the elastomer and the filler added to the thermoplastic resin composition are bonded to each other to reinforce the interface therebetween, thereby improving the vibration damping property. This mechanism is not clear, and it is presumed that the strain energy in the elastomer can be increased by strengthening the interface between the elastomer and the filler. In addition, the present inventors have newly found that: as the composite particles in which the elastomer and the filler are bonded to each other, composite particles obtained by a surface Grafting (Grafting from) method in which a polymer graft chain corresponding to the elastomer is polymerized from a polymerization start point on the surface of the particles serving as the filler are used, whereby excellent vibration damping properties can be obtained. This is presumed to be due to: by the surface grafting method, the polymer graft chains are bonded to the particle surface at a high density, and the interface between them can be significantly strengthened.

[ thermoplastic resin composition ]

The thermoplastic resin composition of the present invention comprises a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

[ thermoplastic resin ]

Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, ABS resins, polystyrene resins, polycarbonate resins, vinyl chloride resins, and acrylic resins. Among them, from the viewpoint of moldability and the like, and the ease of handling of the obtained resin composition, 1 or 2 or more species selected from the group consisting of polyolefin resins, polyamide resins, and ABS resins are preferable, 1 or 2 or more species selected from the group consisting of polyolefin resins are more preferable, and polypropylene resins are even more preferable.

The weight average molecular weight of the thermoplastic resin is not particularly limited, and a molecular weight of 5000 to 500000 or the like can be used.

The amount of the thermoplastic resin to be blended in the thermoplastic resin composition of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 50% by mass or more, from the viewpoint of obtaining a molded article or a vibration damping material which exhibits a desired elastic modulus. On the other hand, from the viewpoint of obtaining a molded body or a vibration damping material that exhibits desired vibration damping properties, it is preferably 95% by mass or less, more preferably 80% by mass or less, and still more preferably 75% by mass or less. The amount of 2 or more thermoplastic resins added is the total amount of the thermoplastic resins.

[ composite particles ]

The composite particles are particles in which polymer graft chains are bonded to the particle surfaces. The particles may be formed using a known filler, and include metal oxides, metal oxide salts, metal hydroxides, metal carbonates, cellulose, and the like, preferably 1 or 2 or more selected from the group consisting of metal oxides, metal oxide salts, metal hydroxides, and metal carbonates, more preferably 1 or 2 or more selected from the group consisting of silica such as silica and silicates such as mica and talc, and still more preferably silica. The shape of the particles is not particularly limited, and examples thereof include plate-like, granular, needle-like, and fibrous shapes. In the present specification, the case where only "particles" are described refers to particles used for producing composite particles. The polymer graft chain may be a homopolymer or copolymer of a styrene monomer, a nitrile monomer, (meth) acrylic monomer, an unsaturated olefin, a conjugated diene monomer, or the like, and from the viewpoint of obtaining a molded article or a vibration damping material exhibiting desired vibration damping properties, a homopolymer or copolymer of 1 or 2 or more species selected from acrylic acid, methacrylic acid, and derivatives thereof is preferable, a homopolymer or copolymer of 1 or 2 or more species selected from methacrylic acid and derivatives thereof is more preferable, and polybutylmethacrylate is even more preferable. From the viewpoint of obtaining a molded body or a vibration damping material that exhibits desired vibration damping properties, the bonding is preferably a chemical bond, and more preferably a covalent bond.

From the viewpoint of exhibiting vibration damping properties, the glass transition temperature (Tg) of the polymer graft chain in the composite particle is preferably-30 ℃ or higher, more preferably-10 ℃ or higher, even more preferably 25 ℃ or higher, and from the same viewpoint, preferably 80 ℃ or lower, more preferably 50 ℃ or lower, even more preferably 40 ℃ or lower. The glass transition temperature (Tg) of the polymer graft chains in the composite particles may be 2 or more, or may have a Tg other than a Tg of-30 ℃ or more and 80 ℃ or less. The glass transition temperature (Tg) of the polymer graft chains in the composite particles can be controlled by the monomer, molecular weight, and molecular weight distribution used in the production of the composite particles. For example, in the case of composite particles, it is known that when the graft density increases and the polymer chains become extended chains, the Tg increases. In addition, in this case, Tg can be controlled by adjusting the graft density. In the temperature range around Tg, tan δ, which is a viscoelastic property of the resin, becomes extremely large, and is effective in expressing vibration damping properties, and by controlling Tg, vibration damping properties in a desired temperature range can be improved. The glass transition temperature (Tg) was measured by the method described in the examples below.

The graft density of the polymer graft chains in the composite particles is preferably 0.001 chains/nm from the viewpoint of increasing the strain energy in the elastomer²Above, more preferably 0.01 chain/nm²Above, more preferably 0.1 chain/nm²The above. On the other hand, from the viewpoint of ease of grafting of the polymer chain, it is preferably 5 chains/nm²Hereinafter, 3 chains/nm is more preferable²Hereinafter, 1 chain/nm is more preferable²Hereinafter, more preferably 0.3 chain/nm²The following. The graft density was measured by the method described in the examples below.

From the viewpoint of efficiently increasing the strain energy in the elastomer, the thickness of the polymer graft chain in the composite particle is preferably 1nm or more, more preferably 3nm or more, and still more preferably 5nm or more. From the same viewpoint, the particle diameter is preferably 1 μm or less, more preferably 100nm or less, still more preferably 40nm or less, and still more preferably 15nm or less. The film thickness of the polymer graft chain was calculated by the method described in the examples below.

From the viewpoint of controlling the film thickness of the polymer graft chains, the number average molecular weight of the polymer graft chains in the composite particles is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 30,000 or more. From the same viewpoint, it is preferably 1,000,000 or less, more preferably 500,000 or less, and still more preferably 200,000 or less. The number average molecular weight of the polymer graft chain is measured by the method described in the examples below.

The amount of the composite particles to be blended in the thermoplastic resin composition of the present invention is preferably 1 mass% or more, more preferably 10 mass% or more, even more preferably 20 mass% or more, and even more preferably 25 mass% or more, from the viewpoint of exhibiting vibration damping properties. On the other hand, from the viewpoint of obtaining a molded article or a vibration damping material that exhibits a desired elastic modulus, the content is preferably 75% by mass or less, more preferably 60% by mass or less, still more preferably 55% by mass or less, and still more preferably 50% by mass or less. The amount of the composite particles added when 2 or more kinds of the composite particles are contained is the total amount of the composite particles.

From the viewpoint of exhibiting vibration damping properties, the amount of the composite particles to be blended in the thermoplastic resin composition of the present invention is preferably 1 part by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, and further preferably 40 parts by mass or more, per 100 parts by mass of the thermoplastic resin. On the other hand, from the viewpoint of obtaining a molded article or a vibration damping material that exhibits a desired elastic modulus, it is preferably 300 parts by mass or less, more preferably 200 parts by mass or less, still more preferably 100 parts by mass or less, and still more preferably 90 parts by mass or less. From the viewpoint of exhibiting vibration damping properties, the content of the polymer graft chain in the composite particle in the thermoplastic resin composition of the present invention is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, per 100 parts by mass of the thermoplastic resin. On the other hand, from the viewpoint of obtaining a molded article or a vibration damping material that exhibits a desired elastic modulus, the amount is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and still more preferably 40 parts by mass or less.

From the viewpoint of exhibiting vibration damping properties, the dispersed particle diameter of the composite particles in the thermoplastic resin composition of the present invention is preferably 10nm or more, more preferably 100nm or more, and still more preferably 1 μm or more, and from the same viewpoint, is preferably 200 μm or less, more preferably 100 μm or less, and still more preferably 10 μm or less. The composite particles may be present alone or in aggregates. The dispersed particle diameter of the composite particles was measured by the method described in the examples below.

[ method for producing composite particles ]

The composite particles are obtained by bonding polymer graft chains to the particle surface. The method of bonding the polymer graft chain to the particle surface is not particularly limited as long as the method is a method capable of grafting the polymer chain, but a surface grafting method in which the polymer graft chain is polymerized from the polymerization starting point on the particle surface is preferable. The polymerization method is not particularly limited, and examples thereof include radical polymerization, anionic polymerization, and cationic polymerization. Among them, from the viewpoint of ease of controlling the molecular weight and molecular weight distribution of the polymer chain and the ease of grafting of various copolymers, living radical polymerization, living anion polymerization, and living cation polymerization are preferable, and from the viewpoint of applicability to a wide range of monomers, living radical polymerization is more preferable. As the living radical polymerization method, an atom transfer radical polymerization method (ATRP method), reversible addition fragmentation chain transfer polymerization method (RAFT method), nitroxide stable radical polymerization method (NMP method), and the like can be used, and from the same viewpoint, the atom transfer radical polymerization method (ATRP method) is preferable.

More specifically, the method for producing the composite particles includes the following step 2, and the following step 1 may be performed as needed. The following steps 1 and 2 can be carried out under known conditions for living radical polymerization.

Step 1: bonding a polymerization initiator group to the surface of the particle

And a step 2: a step of bringing particles having a polymerization initiation group on the surface thereof into contact with a monomer under living radical polymerization conditions

The particles having a polymerization initiator group on the surface in step 2 are not particularly limited as long as they have a binding group for binding the polymer chain to the particle surface. From the viewpoint of bonding the polymer graft chains to the particle surfaces, the polymerization initiator group is a living radical polymerization initiator group, preferably an atom transfer radical polymerization initiator group, more preferably a haloacyl group, still more preferably an α -bromoacyl group, and still more preferably a 2-bromoisobutyryl group. The compounds which become the starting materials for the binding group moiety are the following compounds: a compound having a group bonded to the particle surface and a polymerization initiating group, and the like. The step 1 has a step of introducing an amino group or a hydroxyl group to the particle surface and a step of introducing a polymerization initiator, and preferably has a step of introducing an amino group or a hydroxyl group to the particle surface and then introducing a polymerization initiator to the particle surface from the viewpoint of bonding a polymer graft chain to the particle surface. The compound used in the step of introducing an amino group or a hydroxyl group into the particle surface is a compound having a group bonded to the particle surface and an amino group or a hydroxyl group, and is preferably a silane compound, more preferably an aminoalkylsilane compound, and even more preferably 3-aminopropyltrimethoxysilane, from the viewpoint of availability. The compound used in the step of introducing a polymerization initiator group to the particle surface is a compound having a polymerization initiator group and a functional group reactive with an amino group or a hydroxyl group, and is preferably a halogenated alkanoic acid derivative, more preferably a brominated alkanoic acid derivative, even more preferably a 2-bromo-2-methylpropanoic acid derivative, and even more preferably 2-bromoisobutyryl bromide, from the viewpoint of bonding a polymer graft chain to the particle surface. The particles have a polymerization initiating group, for example, when they originally have a polymerization initiating site, when they have a polymerization initiating site formed as a result of surface treatment by plasma treatment or the like, and therefore, the step 1 is not necessary, and when silica, mica, talc, glass filler or the like having no polymerization initiating group is used, the step 1 can be performed. In step 1, a silane coupling agent not containing a polymerization initiator group may be added to the silane coupling agent containing a polymerization initiator group and used from the viewpoint of adjusting the graft density. In the step of bonding the polymerization initiator groups to the particle surfaces in step 1, a method of dispersing the particles in a dispersion medium is preferred from the viewpoint of not aggregating the particles.

As the vibration damping elastomer, a known monomer constituting a thermoplastic elastomer can be used in step 2. Examples of the monomer constituting the thermoplastic elastomer include styrene monomers, nitrile monomers, (meth) acrylic monomers, unsaturated olefins, and conjugated diene monomers, and monomers having a specific group in a side chain thereof can be used. In the step of bringing the particles having a polymerization initiator group on the surface thereof into contact with the monomer in step 2 under living radical polymerization conditions, a method of dispersing and polymerizing the particles, the monomer, and the composite particles in a dispersion medium is preferable from the viewpoint of not aggregating the particles, the monomer, and the composite particles.

After polymerization, the composite particles may be optionally purified. In the purification step of the composite particles, a method of dispersing the polymer in a dispersion medium and removing the solvent is preferred from the viewpoint of not aggregating the composite particles. Further, a method of removing the metal catalyst used in the polymerization step is preferable.

The thermoplastic resin composition of the present invention may contain, as other components than those described 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 which is 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, other polymer materials, and the like.

[ Process for producing thermoplastic resin composition ]

The method for producing the thermoplastic resin composition of the present invention includes a production method including a step of melt-kneading a thermoplastic resin and composite particles each having a polymer graft chain bonded to the particle surface. For the melt kneading, a known kneader such as a closed kneader, a single-screw or twin-screw extruder, or an open roll type kneader can be used. After the melt-kneading, the melt-kneaded product can be dried or cooled according to a known method. The raw materials may be previously mixed homogeneously using a henschel mixer, a super mixer, or the like, and then subjected to melt kneading. The melt kneading temperature and the melt kneading time are not generally determined depending on the kind of the raw material to be used, and are preferably 170 to 240 ℃ and 15 to 900 seconds.

In the step of melt-kneading the thermoplastic resin and the composite particles having polymer graft chains bonded to the particle surfaces, the amount of the composite particles having polymer graft chains bonded to the particle surfaces is preferably 1 part by mass or more, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more, based on 100 parts by mass of the thermoplastic resin, and from the same viewpoint of vibration damping performance, is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 90 parts by mass or less.

[ additives ]

The additive of the present invention comprises composite particles in which polymer graft chains are bonded to the particle surfaces. The additive of the present invention may optionally contain chain extenders, plasticizers, organic crystal nucleating agents, inorganic crystal nucleating agents, hydrolysis inhibitors, flame retardants, antioxidants, lubricants as hydrocarbon-based waxes or anionic surfactants, ultraviolet absorbers, antistatic agents, antifogging agents, light stabilizers, pigments, mildewcides, antibacterial agents, foaming agents, and the like. 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 improving vibration damping properties of a thermoplastic resin. Therefore, the present invention also discloses a method for improving the vibration damping property of a thermoplastic resin, using composite particles in which polymer graft chains are bonded to the particle surfaces.

[ vibration damping Material ]

The thermoplastic resin composition of the present invention can be suitably used as a vibration damping material for products such as audio equipment, electric products, buildings, industrial equipment, automobile parts, two-wheeled vehicle parts, containers, and the like, or parts or housings thereof, by using various molding methods such as injection molding, extrusion molding, thermoforming, and the like.

For example, in the case of producing a part or a housing containing the thermoplastic resin composition of the present invention by injection molding, the thermoplastic resin composition of the present invention is obtained by filling pellets in an injection molding machine, injecting the pellets into a mold, and molding the pellets.

As the injection molding, a known injection molding machine can be used. There may be mentioned, for example, an injection molding machine having a cylinder and a screw inserted through the interior thereof as main constituent elements [ J75E-D, J110AD-180H (manufactured by Nippon Steel works Co., Ltd.) ], and the like. The raw materials for the thermoplastic resin composition of the present invention may be supplied to a cylinder and directly melt-kneaded, but it is preferable to fill the raw materials melt-kneaded in advance into an injection molding machine.

In addition, when a molding method other than injection molding is used, molding may be performed by a known method, and is not particularly limited.

The molded article of the thermoplastic resin composition of the present invention can be suitably used as a vibration damping material for products such as audio equipment, electric products, buildings, industrial equipment, automobile parts, two-wheel vehicle parts, and containers, or parts and housings thereof. The application of these components can be appropriately set according to the manufacturing method, application position, and intended purpose of the components, the housing, the device, and the equipment, and can be used according to a conventional method in the art.

The present invention also discloses the following vibration damping material and a method for manufacturing the same.

＜1＞

A vibration damping material comprising a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

＜2＞

The vibration damping material according to < 1 >, wherein the graft density of the polymer graft chains is preferably 0.001 chains/nm²Above, more preferably 0.01 chain/nm²Above, more preferably 0.1 chain/nm²The above.

＜3＞

The vibration damping material according to < 1 > or < 2 >, wherein the graft density of the polymer graft chains is preferably 5 chains/nm²Hereinafter, 3 chains/nm is more preferable²Hereinafter, 1 chain/nm is more preferable²Hereinafter, more preferably 0.3 chain/nm²The following.

＜4＞

The vibration damping material according to any one of < 1 > - < 3 >, wherein the glass transition temperature of the polymer graft chain is preferably-30 ℃ or higher, more preferably-10 ℃ or higher, further preferably 10 ℃ or higher, and further preferably 25 ℃ or higher.

＜5＞

The vibration damping material according to any one of < 1 > - < 4 >, wherein the glass transition temperature of the polymer graft chain is preferably 80 ℃ or lower, more preferably 50 ℃ or lower, and still more preferably 40 ℃ or lower.

＜6＞

The vibration damping material according to any one of < 1 > - < 5 >, wherein the film thickness of the polymer graft chains in the composite particles is preferably 1nm or more, more preferably 3nm or more, and still more preferably 5nm or more.

＜7＞

The vibration damping material according to any one of < 1 > - < 6 >, wherein the film thickness of the polymer graft chains in the composite particles is preferably 1 μm or less, more preferably 100nm or less, further preferably 40nm or less, and further preferably 15nm or less.

＜8＞

The vibration damping material according to any one of < 1 > - < 7 >, wherein the number average molecular weight of the polymer graft chains in the composite particles is preferably 10,000 or more, more preferably 20,000 or more, and still more preferably 30,000 or more.

＜9＞

The vibration damping material according to any one of < 1 > - < 8 >, wherein the number average molecular weight of the polymer graft chains in the composite particles is preferably 1,000,000 or less, more preferably 500,000 or less, and still more preferably 200,000 or less.

＜10＞

The vibration damping material according to any one of < 1 > - < 9 >, wherein the dispersed particle diameter of the composite particles in the thermoplastic resin composition of the present invention is preferably 10nm or more, more preferably 100nm or more, and still more preferably 1 μm or more.

＜11＞

The vibration damping material according to any one of < 1 > - < 10 >, wherein the dispersed particle diameter of the composite particles in the thermoplastic resin composition of the present invention is preferably 200 μm or less, more preferably 100 μm or less, and still more preferably 10 μm or less.

＜12＞

The vibration damping material according to any one of < 1 > - < 11 >, wherein the amount of the composite particles in the vibration damping material is preferably 1 part by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, and further preferably 40 parts by mass or more, based on 100 parts by mass of the thermoplastic resin.

＜13＞

The vibration damping material according to any one of < 1 > - < 12 >, wherein the amount of the composite particles to be mixed in the vibration damping material is preferably 300 parts by mass or less, more preferably 200 parts by mass or less, further preferably 100 parts by mass or less, and further preferably 90 parts by mass or less, based on 100 parts by mass of the thermoplastic resin.

＜14＞

The vibration damping material according to any one of < 1 > - < 13 >, wherein the amount of composite particles incorporated in the vibration damping material is preferably 1% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, and further preferably 25% by mass or more.

＜15＞

The vibration damping material according to any one of < 1 > - < 14 >, wherein the amount of composite particles incorporated in the vibration damping material is preferably 75% by mass or less, more preferably 60% by mass or less, still more preferably 55% by mass or less, and still more preferably 50% by mass or less.

＜16＞

The vibration damping material according to any one of < 1 > - < 15 >, wherein the content of the polymer graft chains in the composite particles in the vibration damping material is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, based on 100 parts by mass of the thermoplastic resin.

＜17＞

The vibration damping material according to any one of < 1 > - < 16 >, wherein the content of the polymer graft chains in the composite particles in the vibration damping material is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and still more preferably 40 parts by mass or less, based on 100 parts by mass of the thermoplastic resin.

＜18＞

The vibration damping material according to any one of < 1 > - < 17 >, wherein the amount of the thermoplastic resin blended in the vibration damping material is preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 50% by mass or more.

＜19＞

The vibration damping material according to any one of < 1 > - < 18 >, wherein the amount of the thermoplastic resin blended in the vibration damping material is preferably 95% by mass or less, more preferably 80% by mass or less, and still more preferably 75% by mass or less.

＜20＞

The vibration damping material according to any one of < 1 > < 19 >, wherein the thermoplastic resin is preferably 1 or 2 or more selected from polyolefin resins, polyamide resins and ABS resins, more preferably 1 or 2 or more selected from polyolefin resins, and still more preferably a polypropylene resin.

＜21＞

The vibration damping material according to any one of < 1 > - < 20 >, wherein the particles are 1 or 2 or more selected from metal oxides, metal oxide salts, metal hydroxides and metal carbonates, more preferably 1 or 2 or more selected from silica such as silica and silicates such as mica and talc, and still more preferably silica.

＜22＞

The vibration damping material according to any one of < 1 > - < 21 >, wherein the polymer graft chain is preferably a polymer formed from 1 or 2 or more monomers selected from styrene monomers, nitrile monomers, (meth) acrylic monomers, unsaturated olefins and conjugated diene monomers, more preferably a homopolymer or copolymer of 1 or 2 or more monomers selected from acrylic acid, methacrylic acid and derivatives thereof, still more preferably a homopolymer or copolymer of 1 or 2 or more monomers selected from methacrylic acid and derivatives thereof, and still more preferably polybutylmethacrylate.

＜23＞

A method for producing a vibration damping material, which comprises the step of melt-kneading a thermoplastic resin and composite particles having polymer graft chains bonded to the particle surfaces.

＜24＞

The method of producing a vibration damping material according to < 23 >, which comprises a step of bonding a polymer graft chain to the particle surface.

＜25＞

The method of producing a vibration damping material according to < 24 >, wherein the method of bonding the polymer graft chains to the particle surface is a surface grafting method of polymerizing the polymer graft chains from a polymerization initiation point on the particle surface.

＜26＞

The method of producing a vibration damping material according to < 25 >, wherein the polymerization method is preferably radical polymerization, anion polymerization or cation polymerization, more preferably living radical polymerization, living anion polymerization or living cation polymerization, further preferably living radical polymerization, further preferably atom transfer radical polymerization (ATRP method), reversible addition fragmentation chain transfer polymerization (RAFT method), or nitroxide stable radical polymerization (NMP method), further preferably atom transfer radical polymerization (ATRP method).

＜27＞

The method of producing a vibration damping material according to any one of < 24 > to < 26 >, wherein the method of bonding the polymer graft chains to the particle surfaces comprises the following steps 1 and 2.

Step 1: bonding a polymerization initiator group to the surface of the particle

And a step 2: a step of bringing particles having a polymerization initiation group on the surface thereof into contact with a monomer under living radical polymerization conditions

＜28＞

The method of producing a vibration damping material according to < 27 >, wherein the polymerization initiator is a living radical polymerization initiator, preferably an atom transfer radical polymerization initiator, more preferably a haloacyl group, still more preferably an α -haloacyl group, yet more preferably an α -bromoacyl group, and yet more preferably a 2-bromoisobutyryl group.

＜29＞

The method of producing a vibration damping material according to < 27 > or < 28 >, wherein the step 1 includes a step of introducing an amino group or a hydroxyl group to the particle surface and a step of introducing a polymerization initiator, and preferably includes a step of introducing a polymerization initiator to the particle surface after the step of introducing an amino group or a hydroxyl group to the particle surface.

＜30＞

The method of producing a vibration damping material according to any one of < 27 > - < 29 >, wherein the compound used in the step of introducing an amino group or a hydroxyl group into the particle surface is a compound having a group bonded to the particle surface and an amino group or a hydroxyl group, preferably a silane compound, more preferably an aminoalkylsilane compound, and still more preferably 3-aminopropyltrimethoxysilane.

＜31＞

The method of producing a vibration damping material according to any one of < 27 > - < 30 >, wherein the compound used in the step of introducing the polymerization initiating group to the particle surface is a compound having a functional group that reacts with the polymerization initiating group and an amino group or a hydroxyl group, preferably a halogenated alkanoic acid derivative, more preferably a brominated alkanoic acid derivative, still more preferably a 2-bromo-2-methylpropanoic acid derivative, and still more preferably 2-bromoisobutyryl bromide.

Examples

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

< glass transition temperature of Polymer graft chains in composite particles >

Measured by the method of JIS K7121. The heat capacity was measured by heating the composite particles from 40 ℃ to 200 ℃ at 10 ℃ per minute using a differential scanning calorimeter (DSC 7020, manufactured by Hitachi high tech). The midpoint glass transition temperature Tmg (° c) is determined as the temperature of the intersection of the straight lines equidistant in the vertical axis direction from the extended straight lines of the respective base lines in the DSC thermogram and the curve of the stepwise change portion of glass transition.

< number average molecular weight of Polymer graft chains in composite particles >

The number average molecular weight of the polymer graft chain in the composite particle was determined by measuring the number average molecular weight of the polymer chain not bonded to the composite particle, which was produced simultaneously in the step of producing the composite particle, as the number average molecular weight of the polymer graft chain. In Gel Permeation Chromatography (GPC), the number average molecular weight was measured using GMHHR-H + GMHHR-H (cation) as a column, chloroform as a solvent, and polystyrene as a standard for the equivalent molecular weight under conditions of a flow rate of 1.0 mL/min and a column temperature of 40 ℃.

< graft Density of Polymer graft chains in composite particles >

The graft amount (W) and the number average molecular weight (Mn) of the graft chain were measured, and the graft density (chain/nm) was determined by the following formula²). The graft amount was determined by thermogravimetric loss measurement (TG). More specifically, the weight loss rate at this time was measured by raising the temperature from 40 ℃ to 500 ℃ at 10 ℃/min in the air. The number average molecular weight of the graft chain was determined by the Gel Permeation Chromatography (GPC) method shown below.

Graft Density (chains/nm)²) Graft amount (g/nm)²) Number average molecular weight of graft chain X (Avoganlo constant)

< film thickness of Polymer graft chains in composite particles >

The film thickness was calculated by the following equation. The polymer density is defined as the polymer density of the polymer graft chain, which is the density of the polymer chain not bonded to the composite particle, generated simultaneously in the step of producing the composite particle. Measured by the pycnometer method based on JIS K7112.

[ mathematical formula 1]

< dispersed particle diameter of composite particle >

The composite particles in the thermoplastic resin composition were observed with a Scanning Electron Microscope (SEM) on the cross-sectional surface of a test piece of the thermoplastic resin. From the image observed by the scanning electron microscope, the cross sections of 30 composite particles were selected, and the respective major diameters were visually read, and the average value was taken as the dispersed particle diameter.

Condition

The device comprises the following steps: field emission scanning electron microscope (S-4000, manufactured by Hitachi institute of technology)

Acceleration rate: 10kV

Beam spot diameter: 8mm

Multiplying power: 400 to 5000 times of

[ preparation of composite particle 1]

a) Bonding a polymerization initiator group to the surface of the particle

a-1) introduction of amino groups into the surface of silica microparticles

40g of silica fine particles (SILFIL NSS-3N, Tokuyama, average particle size 120nm) and 2g of 3-aminopropyltrimethoxysilane (KBM-903, shin-Etsu chemical Co., Ltd.) were added to 200mL of ethanol. The mixture was stirred at room temperature for 12 hours. Thereafter, the reaction mixture was washed with ethanol, and the silica fine particles were collected by a centrifuge and then heated at 110 ℃ for 1 hour to obtain amino group-introduced silica fine particles.

a-2) introduction of polymerization initiating group to surface of amino group-introduced silica fine particle

In a 500mL eggplant-shaped flask, 40g of the amino group-introduced silica fine particles, 200mL of anhydrous THF, 1mL of anhydrous triethylamine (manufactured by Tokyo chemical industry Co., Ltd.), and 1mL of 2-bromoisobutyryl bromide (BIBB manufactured by Tokyo chemical industry Co., Ltd.) were placed, and the mixture was stirred at room temperature for 2 hours. Thereafter, the silica fine particles introduced with the polymerization initiator group, in which 2-bromoisobutyryl bromide was introduced as the polymerization initiator group, were washed with THF and methanol, recovered by a centrifuge, and then stored as a methanol solution of the silica fine particles introduced with the polymerization initiator group.

b) A step of bringing particles having a polymerization initiation group on the surface thereof into contact with a monomer under living radical polymerization conditions

Into a 500-mL round bottom flask, 40g of the prepared methanol solution containing the silica fine particles having a polymerization initiator, 160mL of methanol, 40mL of water, and 35g of butyl methacrylate (manufactured by Tokyo chemical industry Co., Ltd.) were charged, and nitrogen bubbling was performed for 1 hour. Then, a methanol solution prepared by stirring 11mg of Cu (II) Br (manufactured by Tokyo chemical industry Co., Ltd.) and 90mg of pentamethyldiethylenetriamine (manufactured by Tokyo chemical industry Co., Ltd.) in 2mL of methanol was injected. After sufficiently stirring, 90mg of an aqueous solution of ascorbic acid (manufactured by Tokyo chemical industry Co., Ltd.) was poured to initiate polymerization. Thereafter, the temperature was raised to 40 ℃ and the mixture was stirred for 4 hours. Thereafter, the silica fine particles grafted with polybutylmethacrylate were washed with methanol and recovered by a centrifuge. The content of the polymer graft chain was 35.5% by mass.

[ preparation of composite particles 2]

b) A step of bringing particles having a polymerization initiation group on the surface thereof into contact with a monomer under living radical polymerization conditions

In a 500-mL eggplant-shaped flask, 40g of an anisole solution containing silica fine particles having a polymerization initiator group prepared in the same step as step a) of preparing the composite particles 1, 20mL of anisole, and 60g of butyl methacrylate (Tokyo chemical Co., Ltd.) were charged, the temperature was raised to 60 ℃, and after sufficiently stirring, nitrogen bubbling was performed for 1 hour. Thereafter, an anisole solution prepared by stirring 144mg of Cu (I) Br (manufactured by Tokyo chemical industry Co., Ltd.) and 346mg of pentamethyldiethylenetriamine (manufactured by Tokyo chemical industry Co., Ltd.) in 2mL of anisole was injected to initiate polymerization. After which it was stirred for 10 hours. Thereafter, the resulting dispersion was dispersed in chloroform, washed with methanol and aqueous ammonia, and the solvent was dried to obtain silica fine particles to which polybutylmethacrylate was grafted. The content of the polymer graft chain was 32.0 mass%.

[ preparation of composite particles 3]

The composite particles were produced in the same manner as in the case of composite particles 2 except that the amount of silica fine particles charged was changed to 6g, the amount of anisole charged was changed to 60mL, the amount of butyl methacrylate charged was changed to 180g, the polymerization temperature was changed to 80 ℃, the amount of Cu (I) Br stirred in anisole 2mL was changed to 431mg, the amount of pentamethyldiethylenetriamine was changed to 1040mg, and the polymerization time was changed to 5 minutes.

[ preparation of composite particles 4]

Prepared in the same manner as the composite particles 3 except that the polymerization time was changed to 15 minutes.

[ preparation of composite particles 5]

Prepared in the same manner as the composite particles 3 except that the polymerization time was changed to 30 minutes.

[ preparation of composite particles 6]

The composite particles 2 were produced in the same manner as in the above example except that the amount of the silica fine particles charged was changed to 20g, the amount of anisole charged was changed to 3mL, the amount of butyl methacrylate charged was changed to 100g, and the polymerization temperature was changed to 80 ℃.

[ preparation of composite particles 7]

The composite particles were prepared in the same manner as in the case of the composite particles 3, except that the silica fine particles were changed to Nipsil AQ and the polymerization time was changed to 20 minutes.

[ preparation of composite particles 8]

The production was carried out in the same manner as for the composite particles 3 except that the silica fine particles were changed to the mica fine particles A-21S and the polymerization time was changed to 20 minutes.

[ preparation of composite particles 9 ]

The composite particles were produced in the same manner as in the case of composite particles 3, except that the amount of silica fine particles charged was changed to 12g, the amount of cu (i) Br charged was changed to 861mg, the amount of pentamethyldiethylenetriamine charged was changed to 2080mg, the polymerization time was changed to 10 minutes, and butyl methacrylate was changed to hexyl methacrylate (manufactured by tokyo chemical industries).

[ preparation of thermoplastic resin composition ]

Examples 1 to 3 and comparative example 1

c) Process for melt-kneading composite particles and thermoplastic resin

Each of the components shown in Table 1 was compounded in the amount shown in Table 1 by using Labo Plastomill (manufactured by Toyo Seiki Seisaku-Sho Ltd.), and melt-kneaded at 200 ℃ to obtain a thermoplastic resin composition.

Examples 4 to 13 and comparative examples 15 to 17

Thermoplastic resin compositions were obtained in the same manner as in examples 1 to 3, except that the compounding ratios were changed to those shown in tables 2 and 3.

Example 14

Thermoplastic resin compositions were obtained in the same manner as in examples 1 to 3, except that the compounding was changed as shown in Table 3, the melt kneading temperature was changed to 240 ℃, the melt temperature for press molding was changed to 240 ℃, and the cooling temperature was changed to 80 ℃.

< loss factor >

An automatic press molding machine (manufactured by Toyo Seiki Seisaku-Sho Ltd.) was used to melt the melt at 200 ℃ and then cool the melt at 30 ℃ to mold a loss factor test piece (127 mm. times.12.7 mm. times.1.6 mm). The loss coefficient of this test piece was calculated by the half-width method from the peak of the secondary resonance of the frequency response function measured by the center resonance method based on JIS K7391. The loss factor measurement software MS 18143 was used in a system (both manufactured by B & K) including a Type 3160 oscillator, a Type 2718 amplifier, a Type 4810 vibration exciter, and a Type 8001 acceleration sensor. The measurement environment was controlled by a thermostatic bath (PU-3J, manufactured by Espec corporation), and the measurement was performed at a temperature ranging from 0 ℃ to 80 ℃. The results at 20 ℃ and 80 ℃ are shown in tables 1 to 3.

[ Table 1]

[ Table 2]

[ Table 3]

The details of each component shown in tables 1 to 3 are as follows.

Polypropylene: MA03 (manufactured by Japan Polypropylene corporation)

PBMA: polybutylmethacrylate (manufactured by Sigma-Aldrich Co., Ltd.)

SiO₂：SILFIL NSS-3N (manufactured by Tokuyama corporation)

GF: t-480 (manufactured by Nippon electronic Nitri)

SiO of the composite particles 7₂: nipsil AQ (manufactured by Tosoh Silica Co., Ltd.)

Mica of the composite particle 8: A-21S (manufactured by Yamaguchi Mica Co., Ltd.)

Polyamide: amilan CM1017 (manufactured by Dongli Co., Ltd.)

ABS: toyolac 7000-314 (manufactured by Toyoli corporation)

The thermoplastic resin compositions of example 3 and comparative example 1 were injection-molded, and the following flat plate vibration test, fan vibration test and fan rotational noise test were performed. The results are shown in tables 4 and 5.

< Flat plate vibration test >

The thermoplastic resin compositions of example 3 and comparative example 1 were injection-molded using an injection molding machine (J11 AD-180H, manufactured by Japan Steel works) to form a flat test piece (100 mm. times.100 mm. times.2 mm). The barrel temperature was set to 200 ℃ from the nozzle tip side to the 5 th unit, 170 ℃ for the remaining 1 unit, and 45 ℃ below the hopper. The mold temperature was set at 50 ℃. In the vibration test, a system (manufactured by B & K) comprising an oscillator of Type 3160, an amplifier of Type 2718, an exciter of Type 4810, an acceleration sensor of Type 8001, and a noise meter of 4189-A-029 was used. The center part of the flat plate molding is fixed to an acceleration sensor by attaching it to a contact tip, and then vibration is randomly applied, and the vibration level is calculated from the ratio of the vibration acceleration detected by the acceleration sensor to the excitation force in the range of 20Hz to 12000 Hz. Further, the noise level was calculated from the ratio of the sound pressure detected by a noise meter at a plate center height of 100mm to the exciting force. The measurement environment was controlled to 20 ℃ or 80 ℃ in a thermostatic bath (PU-3J, manufactured by Espec Co., Ltd.). If the numerical value is small, it can be judged that the vibration and noise are further reduced.

< Fan vibration test >

The thermoplastic resin compositions of example 3 and comparative example 1 were injection-molded using an injection molding machine (SE 180D, manufactured by Sumitomo heavy machinery industries, Ltd.) to form a molded article of a flat fan having the same shape as that of a flat fan (PLF125-18, diameter 150mm, 8 blades) manufactured by Funtec. The barrel temperature was set to 200 ℃ from the nozzle tip side to the 5 th unit, 170 ℃ for the remaining 1 unit, and 45 ℃ below the hopper. The mold temperature was set at 50 ℃. In the vibration test, a system (manufactured by B & K) comprising an oscillator of Type 3160, an amplifier of Type 2718, an exciter of Type 4810, an acceleration sensor of Type 8001, and a noise meter of 4189-A-029 was used. A central portion of a flat fan is attached to a contact tip and fixed to an acceleration sensor, and then vibration is randomly applied, and a vibration level is calculated from a ratio of vibration acceleration detected by the acceleration sensor to an excitation force in a range of 20Hz to 12000 Hz. The measurement environment was controlled to 80 ℃ in a thermostatic bath (PU-3J, manufactured by Espec Co., Ltd.). If the numerical value is small, it can be judged that the vibration is further reduced.

< Fan rotation noise test >

The same flat fan molded body as described above was used. The fan molded body was attached to a rotating shaft of a motor (AC motor manufactured by suzuki motor) and rotated at each rotational speed. The noise generated at this time was collected by a noise meter (4189-A-029, manufactured by B & K) at a position 100mm from the side of the fan and 200mm below the side, and subjected to FFT analysis. The measurement time was 60 seconds, the average frequency at 1 frequency was 358 times, and the frequency weighting characteristic was analyzed by the a characteristic. The measurement environment was controlled to 80 ℃ in a thermostatic bath (PU-3J, manufactured by Espec Co., Ltd.). In the FFT analysis of fan noise at each rotation speed, the frequency and noise level of the rotational noise peak corresponding to F2 NZ/60 were measured. If the numerical value is small, it can be judged that the rotational noise is further reduced.

[ Table 4]

[ Table 5]

As is clear from Table 1, the thermoplastic resin composition of example 3 comprising composite particles in which polymer graft chains are bonded to the particle surfaces has a higher loss factor at any temperature of 20 ℃ and 80 ℃ and is excellent in vibration damping properties than the thermoplastic resin composition of comparative example 1 in which an equal amount of filler and elastomer are added in a state in which they are not bonded. This confirms that in tables 4 and 5, vibration and noise can be further reduced in the injection molded samples. Further, as shown in tables 1 to 3, examples 1, 2, 4 to 13, 16 and 17, which include composite particles in which polymer graft chains are bonded to the particle surfaces, example 14 using a polyamide resin, and example 15 using an ABS resin, also had high loss coefficients and excellent vibration damping properties.

Industrial applicability

The thermoplastic resin composition of the present invention can be suitably used for products such as audio equipment, electric products, buildings, industrial equipment, automobile parts, two-wheeled vehicle parts, containers, and the like.