JP5329921B2 - Polymer composition and noise suppression sheet containing the polymer composition - Google Patents

Description

  The present invention relates to a polymer composition and a noise suppression sheet. Specifically, the present invention relates to a polymer composition capable of effectively suppressing electromagnetic wave noise in a high frequency region, and a noise suppression sheet including the polymer composition.

  Electronic members used in electronic devices such as personal computers and mobile phones, and electronic members such as CPUs generate electromagnetic waves. Such electromagnetic waves interfere with each other inside the electronic device and cause malfunction of the electronic device. In addition, when an electromagnetic wave generated inside an electronic device is radiated to the outside, it may affect other electronic devices.

In order to solve the above problems, various electromagnetic wave noise suppression materials made of a composite material in which a magnetic material such as metal fine particles or ferrite is blended in a resin have been developed.
For example, Patent Document 1 discloses a thin noise suppression sheet using a soft magnetic metal oxide powder and having a total thickness of 100 μm or less.

Japanese Patent Laid-Open No. 2005-19846

  However, in recent years, with the increase in speed and capacity of information communication, the AC frequency of electronic circuits such as personal computers and mobile phones and the electromagnetic wave frequency used for information communication are becoming higher. For this reason, it has been difficult to effectively suppress electromagnetic waves with the conventionally used ferrite and soft magnetic metals.

  Also in the noise suppression sheet disclosed in Patent Document 1, since the soft magnetic powder used is nickel-zinc ferrite, the composite material using this soft magnetic powder can handle a high frequency region of 2 GHz or more. There is a problem that you can not.

  In addition, electronic devices such as personal computers may ignite internally due to abnormal heat generated by CPUs, capacitors, etc. In order to prevent such internal ignition, members used in electronic devices such as personal computers in recent years Flame retardancy has been demanded.

  In view of the circumstances as described above, the problem to be solved by the present invention is to effectively suppress unnecessary electromagnetic waves in a high frequency region and to have a flame retardant polymer composition and a noise suppression sheet. Is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific amount of hexagonal ferrite and a specific amount of fatty acid ester, fatty acid metal salt, and / or organic are compared with respect to the polymer organic material. The present inventors have found that the above problems can be solved by using a polymer composition containing a silicone compound. The present invention has been completed.

That is, the present invention provides the following polymer composition and noise suppression sheet.
[1]
(I) 100 parts by mass of a polymer organic material;
(B) 110 parts by mass to 4900 parts by mass of hexagonal ferrite;
(C) A polymer composition comprising 1 part by mass to 5 parts by mass of at least one selected from the group consisting of fatty acid esters, fatty acid metal salts, and organic silicone compounds.
[2]
The polymer composition according to [1], wherein (a) includes at least one selected from the group consisting of fluororubber, fluororubber-based thermoplastic elastomer, and fluororesin.
[3]
The polymer composition according to [2], wherein the fluororubber is at least one selected from the group consisting of vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, and tetrafluoroethylene-perfluorovinyl ether rubber. .
[4]
The polymer composition according to [2] or [3], wherein the fluororubber-based thermoplastic elastomer is at least one selected from the group consisting of a block-type fluororubber-based thermoplastic elastomer and a graft-type fluororubber-based thermoplastic elastomer. object.
[5]
The fluororesin is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, polychlorotrimethyl. It is at least one selected from the group consisting of fluoroethylene, ethylene-chlorofluoroethylene copolymer, tetrafluoroethylene-perfluorodioxole copolymer, polyvinyl fluoride, and tetrafluoroethylene-propylene copolymer. The polymer composition according to any one of [2] to [4].
[6]
The (b) is at least one selected from the group consisting of M-type, Z-type, and Y-type hexagonal ferrites represented by the following general formulas (1) to (3): [1] to [5 ] The polymer composition of any one of.
(M type) BaM _X Fe _(12-X) O ₁₉ (1)
(Z-type) Ba ₃ MβFe ₂₄ O ₄₁ (2)
(Y type) Ba ₂ M ₂ Fe ₁₂ O ₂₂ (3)
(In the general formulas (1) to (3), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and the general formula (1) Wherein X is an integer of 0 to 12, and β is a positive number of 0.1 ≦ β ≦ 20 in the general formula (2), part of Ba in the above general formulas (1) to (3) Or all may be substituted with Sr.)
[7]
The polymer composition according to [6], wherein (b) includes M-type hexagonal ferrite represented by the following general formula (4).
Ba (Mα) ₂ Fe ₁₀ O ₁₉ (4)
(In the above general formula (4), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and α is 0.5 ≦ α ≦ 3. 2 is a positive number.)
[8]
The polymer composition according to [6] or [7], wherein (b) includes M-type hexagonal ferrite represented by the following general formula (5).
_{Ba (Ti A Co B Zn C} ) 2 Fe 10 O 19 (5)
(In the above general formula (5), A is a positive number of 0.3 ≦ A ≦ 1.5, B is a positive number of 0.1 ≦ B ≦ 1.0, and C is 0.1 ≦ C. ≦ Positive number of 0.7.)
[9]
Any of [6] to [8], wherein (b) includes a Z-type hexagonal ferrite represented by the general formula (2), and β is a positive number satisfying 0.5 ≦ β ≦ 2.6. 2. The polymer composition according to item 1.
[10]
The polymer composition according to any one of [6] to [9], wherein (b) includes a Z-type hexagonal ferrite represented by the following general formula (6).
Ba ₃ Co _D Zn _E Fe ₂₄ O ₄₁ (6)
(In the general formula (6), D is a positive number satisfying 0.4 ≦ D ≦ 2.0, and E is a positive number satisfying 0.1 ≦ E ≦ 1.0.)
[11]
The polymer composition according to any one of [6] to [10], wherein (b) includes a Y-type hexagonal ferrite represented by the following general formula (7).
Ba ₂ (Zn _F ) ₂ Fe ₁₂ O ₂₂ (7)
(In the general formula (7), F is a positive number of 0.35 ≦ F ≦ 1.35.)
[12]
(D) 7 to 2400 parts by mass of at least one selected from the group consisting of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder, and
The polymer composition according to any one of [1] to [11], wherein the sum of (b) and (d) is 117 to 5100 parts by mass.
[13]
The polymer composition according to [12], wherein the soft magnetic alloy powder is at least one selected from the group consisting of silicon steel, permalloy, and sendust.
[14]
The polymer composition according to [12] or [13], wherein the thermally conductive powder is at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, aluminum oxide, and zinc oxide.
[15]
The polymer composition according to any one of [12] to [14], wherein the conductive powder is at least one selected from the group consisting of conductive carbon black and conductive zinc oxide.
[16]
A noise suppression sheet comprising the polymer composition according to any one of [1] to [15].
[17]
The noise suppression sheet according to [16], further including an adhesive layer laminated on at least one surface of the noise suppression sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the polymer composition which can suppress effectively the unnecessary electromagnetic wave generate | occur | produced in a high frequency area | region can be provided. The noise suppression sheet composed of the polymer composition of the present invention can effectively suppress unnecessary electromagnetic waves in the high frequency region, and has flame retardancy and excellent flexibility.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  The polymer composition of the present embodiment includes (a) 100 parts by mass of a polymer organic material, (b) 110 parts by mass to 4900 parts by mass of hexagonal ferrite, (c) fatty acid ester, fatty acid metal salt, and A polymer composition comprising 1 part by mass to 5 parts by mass of at least one selected from the group consisting of organic silicone compounds.

(I) The polymer organic material used in the present embodiment is not particularly limited. For example, at least one selected from the group consisting of fluororubber, fluororubber-based thermoplastic elastomer, and fluororesin is used. It is preferable to include. (B) By using a polymer organic material having a fluorine atom in the molecular chain as the polymer organic material, a polymer composition excellent in flame retardancy, chemical resistance, low water absorption, and dielectric properties can be obtained. it can.
(A) As a high molecular organic material, it may be used by 1 type and may be used in combination of 2 or more type.

  Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, and tetrafluoroethylene-perfluorovinyl ether rubber.

  Examples of the fluororubber thermoplastic elastomer include two types of fluororubber thermoplastic elastomers, a block type and a graft type, and any of these two types can be used. As the fluororubber thermoplastic elastomer, block type fluororubber thermoplastic elastomer is preferably used.

Block-type fluoroelastomer elastomers use fluoropolymer (soft segment) and fluororesin (hard segment) by utilizing the unique chain transfer reaction behavior (telomerization) exhibited by iodine compounds in radical polymerization of fluoromonomers. ) Is an ABA type thermoplastic elastomer having a triblock bond. These soft segment chains and hard segment chains are firmly bonded in one molecule, and have a structure in which the soft segments are reinforced by chemical bonds at the hard segments. Further, since it has both properties of rubber and resin and has thermoplasticity, it can be molded without undergoing crosslinking, and the molded body has rubber elasticity.
Examples of the monomer constituting the soft segment include vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene. Examples of the soft segment include vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, And perfluoroalkyl vinyl ether-tetrafluoroethylene-vinylidene fluoride terpolymer.
Examples of the monomer constituting the hard segment include vinylidene fluoride, ethylene, and tetrafluoroethylene. Examples of the hard segment include vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-tetrafluoroethylene-hexafluoropropylene terpolymer, and the like. Examples thereof include an original copolymer, 3,3,3-trifluoropropylene-1, 2-trifluoromethyl-3,3,3-trifluoro-1-propylene, and perfluoroalkyl vinyl ether.

  The block-type fluororubber-based thermoplastic elastomer can be represented as-(ABA) n-, A means a resin phase, B means a rubber phase, and n means an integer of 1 or more.

Graft type fluoroelastomer thermoplastic elastomers are obtained by grafting fluoropolymer (hard segment) to fluororubber (soft segment) or graft polymerizing fluororubber (soft segment) to fluororesin (hard segment) Any of these can be used.
Examples of the monomer constituting the soft segment include vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, propylene, and fluorine-containing vinyl ether. Examples of the soft segment include vinylidene fluoride- Hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, tetrafluoroethylene-propylene copolymer, and perfluoroalkyl vinyl ether -Tetrafluoroethylene-vinylidene fluoride terpolymer.
Examples of the monomer constituting the hard segment include vinylidene fluoride, ethylene, tetrafluoroethylene, trifluoroethylene, and fluorine-containing vinyl ether. Examples of the hard segment include polytetrafluoroethylene, polychlorotrifluoroethylene, and polyfluorinated vinyl ether. Vinylidene, vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-vinylidene fluoride-tetrafluoroethylene terpolymer, ethylene-tetrafluoroethylene-hexafluoropropylene terpolymer, ethylene-trichlorofluoroethylene copolymer Polymer, perfluoroalkyl vinyl ether-tetrafluoroethylene copolymer, 3,3,3-trifluoropropylene-1,2-trifluoromethyl-3,3,3-trifluoro 1-propylene, and perfluoroalkyl vinyl ether.

  Examples of the fluororesin include polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, poly Examples include chlorotrifluoroethylene, ethylene-chlorofluoroethylene copolymer, tetrafluoroethylene-perfluorodioxole copolymer, polyvinyl fluoride, and tetrafluoroethylene-propylene copolymer.

  (A) The polymer organic material may include at least one polymer organic material selected from the group consisting of the above-described fluororubber, fluororubber-based thermoplastic elastomer, and fluororesin. Examples of such high molecular organic materials include natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, ethylene-propylene-diene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, butyl rubber, halogenated butyl rubber, silicone rubber, and acrylic rubber. Examples thereof include natural rubber and synthetic rubber such as rubber and chlorinated polyethylene, and resins such as ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer. These rubbers and resins may be used alone or in combination of two or more.

In the present embodiment, the hexagonal ferrite means a ferrite in which a crystal lattice exhibiting a high resonance frequency by having magnetic anisotropy in the c-plane and in the c-axis direction takes a hexagonal columnar form.
In general, hexagonal ferrite is classified into M-type, Z-type, Y-type, W-type, X-type, or U-type depending on the difference in composition and structure.

The (b) hexagonal ferrite used in the present embodiment is not particularly limited. For example, from the viewpoint of the effect of suppressing unnecessary electromagnetic waves (noise), that is, from the viewpoint of electromagnetic wave absorption characteristics, the following general formula It is preferably at least one selected from the group consisting of M-type, Z-type, and Y-type hexagonal ferrite represented by (1) to (3).
(M type) BaM _X Fe _(12-X) O ₁₉ (1)
(Z-type) Ba ₃ MβFe ₂₄ O ₄₁ (2)
(Y type) Ba ₂ M ₂ Fe ₁₂ O ₂₂ (3)
In the general formulas (1) to (3), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and in the general formula (1) , X is an integer of 0 to 12, and β is a positive number of 0.1 ≦ β ≦ 20 in the general formula (2).
Part or all of Ba in the general formulas (1) to (3) may be substituted with Sr.

(B) When the hexagonal ferrite includes the M-type hexagonal ferrite represented by the general formula (1) and X is 2 in the general formula (1), the molar ratio of the Fe component to the M component is set to the Fe component. : M component = 10: When represented by α ′, α ′ is preferably a positive number in the range of 1.0 ≦ α ′ ≦ 6.4, and is M-type hexagonal represented by the following general formula (4) Crystalline ferrite is preferable.
(M type) Ba (Mα) ₂ Fe ₁₀ O ₁₉ (4)
In the general formula (4), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and α is 0.5 ≦ α ≦ 3.2. It is preferable that it is a positive number within the range.
In general formula (4), when α is 0.5 or more, a polymer composition having a large noise suppressing effect can be obtained, and when α is 3.2 or less, the noise suppressing effect is maximized. The resonance frequency can be increased.

  M in the general formula (1) or general formula (4) preferably contains at least Co, more preferably a combination of Ti and Co, and more preferably Ti, from the viewpoint of noise suppression effect. A combination of Co and Zn.

When M in the general formula (1) or the general formula (4) is a combination of Ti, Co, and Zn, it is preferably an M-type hexagonal ferrite represented by the following general formula (5).
_{Ba (Ti A Co B Zn C} ) 2 Fe 10 O 19 (5)
In the general formula (5), A is a positive number in the range of 0.3 ≦ A ≦ 1.5, B is a positive number in the range of 0.1 ≦ B ≦ 1.0, and C Is preferably a positive number in the range of 0.1 ≦ C ≦ 0.7. When each range of A, B, and C is equal to or higher than the lower limit value, a polymer composition having a large noise suppressing effect can be obtained, and when each range is equal to or lower than the upper limit value, the noise suppressing effect is maximized. The resonance frequency can be increased.

  (B) When the hexagonal ferrite includes the Z-type hexagonal ferrite represented by the above general formula (2), when the molar ratio of the Fe component and the M component is represented by Fe component: M component = 24: β, β is A positive number in the range of 0.5 ≦ β ≦ 2.6 is preferable. When β is 0.5 or more, a polymer composition having a large noise suppression effect can be obtained, and when β is 2.6 or less, the resonance frequency at which the noise suppression effect is maximized can be increased. it can.

  M in the general formula (2) preferably contains at least Co, more preferably a combination of Co and Zn, from the viewpoint of the noise suppression effect. When M in the general formula (2) includes Co, and further when M includes Co and Zn, the resonance frequency at which the noise suppression effect is maximized can be increased and the noise suppression effect is also increased. It becomes possible.

When M in the general formula (2) is a combination of Co and Zn, it is preferably a Z-type hexagonal ferrite represented by the following general formula (6).
Ba ₃ Co _D Zn _E Fe ₂₄ O ₄₁ (6)
In the general formula (6), D is a positive number in the range of 0.4 ≦ D ≦ 2.0, and E is a positive number in the range of 0.1 ≦ E ≦ 1.0. preferable. When each range of D and E is equal to or higher than the lower limit value, a polymer composition having a large noise suppression effect can be obtained, and when each range is equal to or lower than the upper limit value, resonance that maximizes the noise suppression effect The frequency can be increased.

  (B) When the hexagonal ferrite contains the Y-type hexagonal ferrite represented by the general formula (3), M in the general formula (3) contains Zn from the viewpoint of the noise suppression effect. Is preferred. When M in the general formula (3) contains Zn, the resonance frequency at which the noise suppression effect is maximized can be increased, and the noise suppression effect can be increased.

When M in the general formula (3) is Zn, it is preferably a Y-type hexagonal ferrite represented by the following general formula (7).
Ba ₂ (Zn _F ) ₂ Fe ₁₂ O ₂₂ (7)
F in the general formula (7) is preferably a positive number in the range of 0.35 ≦ F ≦ 1.35. When F is 0.35 or more, a polymer composition having a large noise suppression effect can be obtained, and when F is 1.35 or less, the resonance frequency at which the noise suppression effect is maximized can be increased. it can.

  The structure of (b) hexagonal ferrite used in the present embodiment can be specified by fluorescent X-ray analysis (XRF). Specifically, it can be measured by quantitative analysis by the Fundamental Parameter method using a wavelength dispersive X-ray fluorescence analyzer.

  (B) The particle shape of hexagonal ferrite is not particularly limited, and examples thereof include powder, sphere, plate, and flat shape.

  (B) When the hexagonal ferrite is in a powder form, the average particle size of the (b) hexagonal ferrite powder particles is preferably 1 μm to 50 μm, more preferably 1 μm to 10 μm. When the average particle size is 1 μm or more, workability during processing can be improved, and when the average particle size is 50 μm or less, workability when forming a polymer composition into a sheet can be increased, and tensile strength can be increased. And a noise suppression sheet excellent in flexibility and the like.

(B) One type of hexagonal ferrite may be used, or two or more types may be used in combination.
When using two or more types in combination, combine at least two or more types of hexagonal ferrites with different particle sizes, such as combining hexagonal ferrite with a large average particle size and hexagonal ferrite with a small average particle size. It can also be used. When hexagonal ferrites having different average particle diameters are combined and mixed with (a) a polymer organic material, voids between (b) hexagonal ferrite particles in the mixture can be reduced. In addition, (b) the packing ratio of (b) hexagonal ferrite to the polymer organic material can be increased.
In the present embodiment, the noise suppression effect of the polymer composition can be improved by using (b) hexagonal ferrite in combination.

  (B) When the hexagonal ferrite particles are spherical, workability is facilitated.

  When the particle shape of the hexagonal ferrite is plate-like or flat, (b) the hexagonal ferrite can be easily oriented when forming the polymer composition into a sheet. If the plate-like or flat (b) hexagonal ferrite can be oriented in a direction parallel to the sheet surface, the noise suppression effect of the obtained noise suppression sheet can be easily improved, and the sheet thickness can be reduced. It can be made thinner.

  (B) When the hexagonal ferrite is plate-shaped or flat, (b) the thickness of the hexagonal ferrite particles is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 1 μm. (B) When the thickness of the hexagonal ferrite particles is 0.05 μm or more, (b) due to mechanical stress applied during processing such as mixing with a polymer organic material, A flat shape can be maintained. (B) When the thickness of the hexagonal ferrite particles is 5 μm or less, the thickness of the sheet can be reduced.

(Ii) a specific surface area of the hexagonal ferrite is ^{preferably, 0.3m 2 / g~2m 2 / g} . When the specific surface area is 0.3 m ² / g or more, a noise suppressing sheet having excellent flexibility can be obtained, and when the specific surface area is 2 m ² / g or less, (a) a polymer organic material ( B) Workability when mixing hexagonal ferrite can be improved. In addition, (b) the packing ratio of (b) hexagonal ferrite to the polymer organic material can be increased, so that a polymer composition having a large noise suppressing effect can be obtained.

(B) The hexagonal ferrite surface may be treated with a coupling agent. By treating the surface of the hexagonal ferrite with a coupling agent, the compatibility between (b) the polymer organic material and (b) the hexagonal ferrite can be improved, and (b) the workability of the hexagonal ferrite, Dispersibility can be easily improved.
(B) The method of treating hexagonal ferrite with a coupling agent is not particularly limited, but the coupling agent is previously treated on the surface of (b) hexagonal ferrite by a mechanical or chemical method. And (b) a method of treating the coupling agent on the hexagonal ferrite surface by simultaneously mixing the coupling agent when mixing (b) the polymer organic material and (b) hexagonal ferrite. Is mentioned.

  Examples of the coupling agent used in the present embodiment include isopropyl triisostearoyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite). ) Titanate, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl bis (ditridecyl phosphite) titanate, isopropyl trioctanoyl titanate, isopropyl tridodecylbenzene sulfonyl titanate, isopropyl tri (dioctyl phosphate) titanate, bis (dioctyl pyrophosphate) ethylene Titanate, isopropyl dimethacrylisostearoyl titanate, tetra (2, Titanium coupling agents such as -diallyloxymethyl-1-butyl) bis (ditridecyl phosphite) titanate, isopropyl tricumyl phenyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, and isopropyl isostearoyl diacryl titanate: γ -Aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxy-propyltrimethoxysilane, β- (3,4-epoxy-cyclohexyl) ethyltrimethoxysilane, vinyl Triethoxysilane, vinyl-tris (2-methoxyethoxy) silane, γ-mercaptopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-meta Lilooxypropyltrimethoxysilane, N- (3-triethoxysilylpropyl) urea, methyltrimethoxysilane, octadecyltriethoxylalane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, γ-ani Silanes such as linopropyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, methyltrichlorosilane, polyalkylene oxide silanes, and perfluoroalkyltrimethoxysilanes Coupling agent: Aluminum coupling agent such as acetoalkoxyaluminum diisopropylate, zirconium coupling agent, chromium coupling agent, iron coupling agent Examples thereof include a pulling agent and a tin-based coupling agent. A coupling agent may be used independently and may be used in combination of 2 or more type.

(B) The amount of hexagonal ferrite is (b) 110 parts by mass to 4900 parts by mass with respect to 100 parts by mass of the polymer organic material.
(B) The amount of hexagonal ferrite is preferably 330 to 1900 parts by mass, and more preferably 450 to 1000 parts by mass. (B) When the compounding amount of hexagonal ferrite is 110 parts by mass or more, a polymer composition having a large noise suppressing effect can be obtained. (B) When the blending amount of hexagonal ferrite is 4900 parts by mass or less, a polymer composition having excellent workability can be obtained, and when formed into a sheet, a sheet having excellent flexibility can be obtained. .

  (C) At least one selected from the group consisting of fatty acid esters, fatty acid metal salts, and organosilicone compounds used in the present embodiment is not particularly limited. As long as it has compatibility and (b) an effect of imparting lubricity to the polymer organic material, an effect as a lubricant, or (b) an effect of improving the dispersibility of hexagonal ferrite, It can be suitably selected according to (a) the polymer organic material to be used.

Examples of the fatty acid constituting the fatty acid ester and the fatty acid metal salt include linear or branched saturated fatty acids or unsaturated fatty acids having 3 to 30 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid. , Linoleic acid, linolenic acid, ricinoleic acid, arachidic acid, arachidonic acid and the like. The said fatty acid may be 1 type in a compound, and may be contained as 2 or more types of mixtures.
Examples of the alcohol constituting the fatty acid ester include linear, branched or cyclic lower alcohols having 10 or less carbon atoms.
The metal constituting the fatty acid metal salt is, for example, at least one selected from Zn, Na, Mg, Ca, Co, Ni, Ba, Fe, Al, Cu, and Mn.

  Examples of the organic silicone compound include silicone oils such as dimethyl silicone oil, methylphenyl silicone oil, and methyl hydrogen silicone oil, epoxy, alkyl, alkyl aroxy, amino, carboxyl, alcohol, fluorine, alkyl aroxy polyether, And modified silicone compounds modified with polyether or the like, fluorosilicone rubber, methylphenyl silicone rubber, dimethyl silicone rubber, methyl vinyl silicone rubber and the like.

  (C) The fatty acid ester, the fatty acid metal salt, and the organic silicone compound may be used alone or as a mixture of two or more.

(C) The fatty acid ester, the fatty acid metal salt, and the organic silicone compound may contain an inorganic compound powder as a carrier, and (C) the fatty acid ester, the fatty acid metal salt, and the organic silicone are added to the inorganic compound powder. It is preferable that a system compound is supported.
(C) The fatty acid ester, the fatty acid metal salt, and the organosilicone compound are supported on the inorganic compound powder, so that (c) the dispersibility of the fatty acid ester, the fatty acid metal salt, and the organosilicone compound is polymerized. Can be improved in the product.

The inorganic compound powder is not particularly limited as long as it does not affect the physical properties and noise suppression effect of the polymer composition.
Examples of the inorganic compound powder include silica, talc, clay, magnesium silicate, aluminum oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and diatomaceous earth.
(C) When the fatty acid ester, the fatty acid metal salt, and the organic silicone compound include an inorganic compound powder, the content of the inorganic compound powder includes the fatty acid ester, the fatty acid metal salt, the organic silicone compound, and the inorganic compound powder. It is preferable that it is 5 mass%-50 mass% with respect to the total mass with a body, and it is more preferable that it is 5 mass%-25 mass%.
When the content of the inorganic compound powder is 5% by mass or more, the effect as a carrier can be exhibited, the workability can be improved, and when the content is 50% by mass or less, (i) a polymer The (c) fatty acid ester, the fatty acid metal salt, and the organic silicone compound with respect to the organic material can exhibit the lubricity effect and the effect as a processing aid for the inorganic compound powder.

(C) The amount of the fatty acid ester, fatty acid metal salt, and organic silicone compound is 1 part by mass to 5 parts by mass with respect to 100 parts by mass of the polymer organic material (a).
(C) The amount of fatty acid ester, fatty acid metal salt, and organic silicone compound is preferably 1 part by mass to 5 parts by mass, and more preferably 1 part by mass to 3 parts by mass. (C) When the blending amount of the fatty acid ester, the fatty acid metal salt, and the organic silicone compound is 1 part by mass or more, processability and extrusion moldability can be improved. (C) When the blending amount of the fatty acid ester, the fatty acid metal salt, and the organic silicone compound is 5 parts by mass or less, the noise suppression effect can be easily maintained from the viewpoint of cost and performance.

The polymer composition of the present embodiment may further include (d) at least one selected from the group consisting of soft magnetic ferrite, soft magnetic alloy powder, heat conductive powder, and conductive powder.
(D) The soft magnetic ferrite, soft magnetic alloy powder, heat conductive powder, and conductive powder may be used alone or as a mixture of two or more.

Examples of the soft magnetic ferrite include MnFe ₂ O ₄ , CoFe ₂ O ₄ , NiFe ₂ O ₄ , CuFe ₂ O ₄ , ZnFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₃ O ₄ , Cu—Zn ferrite, Ni— Zn ferrite, Mn-Zn-ferrite, etc. are mentioned.
Examples of the soft magnetic alloy powder include Fe—Ni, Fe—Co, Fe—Cr, Fe—Si, Fe—Al, Fe—Cr—Si, Fe—Cr—Al, Fe—Al—Si, and Fe—. Pt etc. are mentioned. As the soft magnetic alloy powder, silicon steel, permalloy, and sendust are preferable from the viewpoint of noise suppression effect.
When the polymer composition further contains soft magnetic ferrite or soft magnetic alloy powder, the frequency range of electromagnetic waves that can be suppressed by the polymer composition can be expanded.

Examples of the thermally conductive powder include silica, titanium oxide, zirconia, bengara, zinc oxide, aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, graphite, silicon nitride, boron nitride, aluminum nitride, beryllia, silicon carbide. Inorganic compound powders such as boron carbide, titanium carbide, graphite, and carbon black, and metal powders such as silver, copper, aluminum, zinc, nickel, iron, tin, stainless steel, and copper alloy .
When the polymer composition further contains the heat conductive powder, it is possible to obtain a polymer composition having both the noise suppressing effect and the heat conductive performance.
As the heat conductive powder, aluminum hydroxide, magnesium hydroxide, aluminum oxide, and zinc oxide are preferable from the viewpoint of heat conductivity.

Examples of the conductive powder include metal powders such as copper, silver, nickel, aluminum, zinc, stainless steel, and stainless steel, conductive carbon black, carbon nanotube, conductive zinc oxide, conductive titanium oxide, and indium oxide. Inorganic compound powders, and metal fiber fillers such as stainless steel fibers.
When the polymer composition further contains the conductive powder, it is possible to obtain a polymer composition having both the noise suppression effect and the conductivity.
As the conductive powder, conductive carbon black and conductive zinc oxide are preferable from the viewpoint of conductivity and workability.

(D) The blending amount of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder is 7 parts by mass to 2400 parts by mass with respect to 100 parts by mass of the polymer organic material, In addition, the sum of (b) the amount of hexagonal ferrite and (d) the amount of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder is: It is preferable that they are 117 mass parts-5100 mass parts with respect to 100 mass parts.
(D) When the blending amount of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder is 7 parts by mass or more, the desired performance of (d) can be sufficiently obtained. By being 2400 mass parts or less, the noise suppression effect in a high frequency area | region can be made high.
(B) The total amount of hexagonal ferrite and (d) soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder is 117 parts by mass or more. The suppression effect can be increased, and the desired performance of (b) hexagonal ferrite and (d) can be sufficiently obtained, and workability and workability can be improved by being 5100 parts by mass or less. It can be made high and it can be set as the noise suppression sheet | seat which is excellent in a softness | flexibility.

  (D) Soft magnetic ferrite, soft magnetic alloy powder, heat conductive powder, and conductive powder are blended in (b) hexagonal ferrite and (d) soft magnetic ferrite, soft magnetic alloy powder, heat conduction. It is preferable that it is 3 mass%-55 mass% with respect to the total weight with the compounding quantity of conductive powder and electroconductive powder, and it is more preferable that it is 5 mass%-50 mass%. (D) When the blending amount of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder is 3% by mass or more, the desired performance possessed by (d) can be sufficiently obtained. In addition, when it is 55% by mass or less, a sufficient noise suppression effect can be obtained.

In this Embodiment, you may mix | blend flame retardants, such as an organic halide, a metal hydroxide, and a phosphorus compound, in order to provide a polymer composition with a flame retardance.
Examples of the flame retardant include hexabromobenzene, decabromobenzyl phenyl ether, decabromobenzyl phenyl oxide, tetrabromobisphenol, tetrabromophthalic anhydride, tetrabromobisphenol A, tricresyl phosphate, triphenyl phosphate, triallyl phosphate, Trichloroethyl phosphate, halogen-containing condensed phosphate, phosphazene, chlorinated paraffin, perchloropentacyclodecane, aluminum hydroxide, magnesium hydroxide, antimony trioxide, antimony pentoxide, zinc borate, ammonium bromide, titanium phosphate, etc. Is mentioned.

  In the present embodiment, the polymer composition includes a softener, an antioxidant, an ozone degradation inhibitor, an anti-aging agent, sulfur or other vulcanizing agent, a vulcanization accelerator, a vulcanization acceleration aid, a peroxide. Additives such as zinc oxide and stearic acid can be blended as needed.

  The polymer composition of the present embodiment is a pressure kneader, a Banbury mixer, a biaxial extrusion, and other components (b) to (c) and other components than the above (b) to (c) as necessary. It can manufacture by kneading | mixing using kneading machines, such as a machine, a uniaxial extruder, and a roll mixer.

The noise suppression sheet of the present embodiment is a noise suppression sheet including a polymer composition.
The noise suppression sheet can be produced by forming the polymer composition into a sheet by a method such as injection molding, transfer molding, press molding, T-die extrusion molding, calendar molding, and roll rolling. These molding processes may be performed in the presence of a magnetic field or an electric field as necessary, or may be performed while irradiating ultrasonic waves, electromagnetic waves, or ultraviolet rays.

  After the polymer composition of the present embodiment is mixed with a solvent and uniformly dispersed, the noise suppression sheet may be formed by applying to a support and drying. After impregnating a varnish obtained by mixing and uniformly dispersing the polymer composition with a solvent into a fibrous sheet such as cloth, paper, glass cloth, etc., the solvent is volatilized to thereby remove the fibrous sheet and the polymer composition. A noise suppression sheet may be manufactured as a composite.

The noise suppression sheet may have an adhesive layer laminated on at least one surface of the noise suppression sheet. When the noise suppression sheet further has an adhesive layer on at least one surface, it can be easily attached to a desired location.
The method of laminating the adhesive layer on at least one surface of the noise suppression sheet is not particularly limited, and a method of sticking a double-sided tape to the noise suppression sheet surface or applying an adhesive to the noise suppression sheet surface Examples thereof include a method, a method in which a sheet or film pre-applied with an adhesive and a noise suppression sheet are bonded together.

  The thickness of the noise suppression sheet is preferably 0.05 mm to 3 mm. When the thickness of the noise suppression sheet is 0.05 mm or more, the noise suppression effect can be increased, and when the thickness is 3 mm or less, it is suitable for application to an object that requires downsizing of electronic equipment and the like. It is.

The polymer composition of the present embodiment and the noise suppression sheet including the polymer composition can effectively suppress electromagnetic waves in a high frequency region.
In the present embodiment, the high frequency region means a region of 1 GHz or more, and particularly means a region of 2.5 GHz or more, and the polymer composition and the noise suppression sheet of the present embodiment are prominent in the high frequency region. Shows the effect of suppressing electromagnetic waves.

  Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to these examples.

  Tables 1 to 4 show the materials used in Examples and Comparative Examples.

(Examples 1-5 and 7-31 and Comparative Examples 1-5)
According to the compounding prescription shown in Tables 5-9, it knead | mixed for 20 minutes on 100 degreeC conditions using the 60cc lab plast mill (made by Toyo Seiki Co., Ltd.), and obtained the polymer composition.
And the obtained polymer composition was press-molded on 180 degreeC and 10 Mpa conditions using the press molding machine, and the sheet | seat of the polymer composition of thickness 2mm was obtained.

(Example 6)
According to the formulation shown in Table 5, a polymer composition and a sheet were obtained in the same manner as in Example 1 except that kneading was performed for 30 minutes at 150 ° C.

  Evaluation was carried out by the methods shown in the following (1) to (5) using the respective sheets obtained in Examples and Comparative Examples. The evaluation results are shown in Tables 5-9.

(1) Evaluation of first noise suppression effect The first noise suppression effect was evaluated according to the transmission attenuation power ratio method. Specifically, on a micro split line (MSL) having a line width of 2.2 mm and a characteristic impedance of 50Ω, the entire substrate is covered with a sheet having a width of 100 mm and a length of 50 mm, which is the size of the MSL substrate. The S parameter value of S21 was obtained, and the electromagnetic wave absorption amount (R) of each sheet at 5 GHz and 10 GHz was obtained by the following formula (1).
(R) = 10 × log [10 ^{S21 / 10} / (1-10 ^{S11 / 10} )] [dB] (1)

(2) Evaluation of Second Noise Suppression Effect Evaluation of the second noise suppression effect was performed using an S-parameter system reflection method coaxial tube type. Specifically, S11 parameter values were measured using a network analyzer in an empty state in which no sample was inserted, and designated S11 (standard). Next, a ring-shaped test piece having an outer diameter of 7 mm and an inner diameter of 3 mm was inserted so that no gap was formed in the coaxial rod, and the S11 parameter of each sheet was measured in a state where the ends of the coaxial rod were short-circuited. A piece). The reflection attenuation amount of each sheet was calculated from the following formula (2). The frequency at which the return loss is maximized and the return loss at this frequency were determined as the return loss at the peak frequency and peak frequency.
[Reflection loss] = [S11 (test piece)]-[S11 (standard)] [dB] (2)

(3) Flexibility test As shown in FIG. 1, the 10 cm square composition sheet was folded so that the bending radius was 2 cm, and after folding, the hand was released and the state of the sheet was observed. If there was no crack, etc., and it was restored to its original state before bending, it was marked as ◯, and if it was cracked and it was not restored, it was marked as x.

(4) Flammability test After indirect flame for 10 seconds on a strip-shaped test piece of length 125mm, width 13mm and thickness 0.5mm, the gas burner flame is separated from the test piece and the burning time is measured. did. Immediately after extinguishing the flame, the test piece was again subjected to a gas burner flame for 10 seconds, and then the gas burner flame was separated from the test piece and the burning time was measured. If the total of the first and second flammable and nonflammable combustion times was within 10 seconds, it was rated as ◯.

(5) Thermal conductivity Thermal conductivity was measured using a rapid thermal conductivity meter KEMTHRM QTM-D3 type (manufactured by Kyoto Electronics Industry). Specifically, a sheet sample to be measured was placed on a standard sample with a known thermal conductivity, and the overall thermal conductivity (Q1) of the standard sample and the sheet was measured. When the thermal conductivity of the reference sample is (Q2), the deviation (ε) is obtained from the following formula (3), the deviation (ε) is plotted against log (Q2), and the deviation (ε) becomes zero. The thermal conductivity of was determined by interpolation. Reference samples include silicone rubber (Q2) = 0.241 (W / m · K), rubber plate (Q2) = 0.536 (W / m · K), quartz glass (Q2) = 1.416 ( W / m · K) and zirconia (Q2) = 3.277 (W / m · K) were used.
(Ε) = [(Q1) − (Q2)] / (Q2) (3)

As shown in Table 5, in Examples 1 to 4, the noise suppression effect tended to improve as the amount of hexagonal ferrite added increased. Moreover, in Example 5, even when different types of processing aids were used as (c), good results were obtained in noise suppression effect, flexibility, and flame retardancy. Furthermore, in Examples 6 and 7, (i) even when the composition of the polymer organic material was changed, the noise suppression effect, flexibility, and flame retardancy were good.
On the other hand, in Comparative Example 1, since the blending amount of (b) hexagonal ferrite was less than 110 parts by mass, a sufficient noise suppression effect could not be obtained. Moreover, in the comparative example 2, since the compounding quantity of (b) hexagonal ferrite exceeded 4900 mass parts, the softness | flexibility of the sheet | seat was impaired. In Comparative Example 3 where (C) was not blended, the flexibility of the sheet was poor.

  As shown in Table 6, in Examples 9 to 16, (b) even when M-type hexagonal ferrites having different compositions are blended as hexagonal ferrite, the noise suppression effect, flexibility, and flame retardancy are good results. was gotten. It has been confirmed that the frequency (peak frequency) at which the return loss is maximized is changed by changing the composition of (b) M-type hexagonal ferrite.

  As shown in Tables 7 and 8, in Examples 17 to 25, when (b) hexagonal ferrite, Y-type hexagonal ferrite and Z-type hexagonal ferrite are blended, noise suppression effect, flexibility, and Good results were obtained for flame retardancy. It was also confirmed that the frequency (peak frequency) at which the return loss was maximized was changed by changing the compositions of the Y-type hexagonal ferrite and the Z-type hexagonal ferrite.

As shown in Table 9, in Examples 26 to 31, (d) by blending an appropriate amount of the thermal conductive powder, the thermal conductivity is reduced without reducing the noise suppression effect, flexibility, and flame retardancy. I was able to improve.
On the other hand, in Comparative Example 4, since the blending amount of (b) hexagonal ferrite is less than 110 parts by mass, a sufficient noise suppression effect cannot be obtained, and (b) hexagonal ferrite and (d) thermal conductivity. Since the total amount of powder was less than 117 parts by mass, no improvement in thermal conductivity was observed. In Comparative Example 5, (b) the amount of hexagonal ferrite exceeds 4900 parts by mass, and (b) the total amount of hexagonal ferrite and (d) thermally conductive powder exceeds 5100 parts by mass. As a result, the flexibility of the sheet decreased.

The present invention provides a polymer composition and a noise suppression sheet that can effectively suppress unnecessary electromagnetic waves in a high frequency region and have flame retardancy.
The polymer composition and noise suppression sheet of the present invention can be industrially used as an electronic member used in electronic devices such as personal computers and mobile phones, and electronic members such as CPUs.

An evaluation method of the flexibility test in the present embodiment will be described.

Explanation of symbols

1 sheet

Claims (16)

(Ii) 100 parts by mass of a polymer organic material containing at least one selected from the group consisting of fluororubber, fluororubber thermoplastic elastomer, and fluororesin;
(B) 110 parts by mass to 4900 parts by mass of hexagonal ferrite;
(C) A polymer composition comprising 1 part by mass to 5 parts by mass of at least one selected from the group consisting of fatty acid esters, fatty acid metal salts, and organic silicone compounds.   2. The polymer composition according to claim 1, wherein the fluororubber is at least one selected from the group consisting of a vinylidene fluoride rubber, a tetrafluoroethylene-propylene rubber, and a tetrafluoroethylene-perfluorovinyl ether rubber. .   The polymer composition according to claim 1 or 2, wherein the fluororubber-based thermoplastic elastomer is at least one selected from the group consisting of a block-type fluororubber-based thermoplastic elastomer and a graft-type fluororubber-based thermoplastic elastomer.   The fluororesin is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, polychlorotrimethyl. It is at least one selected from the group consisting of fluoroethylene, ethylene-chlorofluoroethylene copolymer, tetrafluoroethylene-perfluorodioxole copolymer, polyvinyl fluoride, and tetrafluoroethylene-propylene copolymer. The polymer composition according to any one of claims 1 to 3. The (b) is at least one selected from the group consisting of M-type, Z-type, and Y-type hexagonal ferrites represented by the following general formulas (1) to (3). The polymer composition according to any one of the above.
(M type) BaM _X Fe _(12-X) O ₁₉ (1)
(Z-type) Ba ₃ MβFe ₂₄ O ₄₁ (2)
(Y type) Ba ₂ M ₂ Fe ₁₂ O ₂₂ (3)
(In the general formulas (1) to (3), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and the general formula (1) In the formula, X is an integer of 0 to 11 , and β is a positive number of 0.1 ≦ β ≦ 20 in the general formula (2), part of Ba in the above general formulas (1) to (3) Or all may be substituted with Sr.) The polymer composition according to claim 5, wherein (b) comprises M-type hexagonal ferrite represented by the following general formula (4).
Ba (Mα) ₂ Fe ₁₀ O ₁₉ (4)
(In the above general formula (4), M is one or a combination of two or more selected from the group consisting of Ti, Co, Ni, Zn, Mn, and Cu, and α is 0.5 ≦ α ≦ 3. 2 is a positive number.) The polymer composition according to claim 5 or 6, wherein (b) comprises M-type hexagonal ferrite represented by the following general formula (5).
_{Ba (Ti A Co B Zn C} ) 2 Fe 10 O 19 (5)
(In the above general formula (5), A is a positive number of 0.3 ≦ A ≦ 1.5, B is a positive number of 0.1 ≦ B ≦ 1.0, and C is 0.1 ≦ C. ≦ Positive number of 0.7.)   The said (b) contains the Z-type hexagonal ferrite represented by the said General formula (2), and (beta) is a positive number of 0.5 <= (beta) <= 2.6. A polymer composition according to 1. The polymer composition according to any one of claims 5 to 8, wherein (b) comprises a Z-type hexagonal ferrite represented by the following general formula (6).
Ba ₃ Co _D Zn _E Fe ₂₄ O ₄₁ (6)
(In the general formula (6), D is a positive number satisfying 0.4 ≦ D ≦ 2.0, and E is a positive number satisfying 0.1 ≦ E ≦ 1.0.) The polymer composition according to any one of claims 5 to 9, wherein (b) comprises a Y-type hexagonal ferrite represented by the following general formula (7).
Ba ₂ (Zn _F ) ₂ Fe ₁₂ O ₂₂ (7)
(In the general formula (7), F is a positive number of 0.35 ≦ F ≦ 1.35.) (D) 7 to 2400 parts by mass of at least one selected from the group consisting of soft magnetic ferrite, soft magnetic alloy powder, thermally conductive powder, and conductive powder, and
The polymer composition according to any one of claims 1 to 10, wherein the sum of (b) and (d) is 117 to 5100 parts by mass.   The polymer composition according to claim 11, wherein the soft magnetic alloy powder is at least one selected from the group consisting of silicon steel, permalloy, and sendust.   The polymer composition according to claim 11 or 12, wherein the thermally conductive powder is at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, aluminum oxide, and zinc oxide.   The polymer composition according to any one of claims 11 to 13, wherein the conductive powder is at least one selected from the group consisting of conductive carbon black and conductive zinc oxide.   The noise suppression sheet | seat containing the polymer composition of any one of Claims 1-14.   The noise suppression sheet according to claim 15, further comprising an adhesive layer laminated on at least one surface of the noise suppression sheet.

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