JP2012119579A - Resin-magnetic substance composite material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin-magnetic substance composite material with which a molding including magnetic substances uniformly dispersed therein can be obtained, and also to provide a method for easily producing the resin-magnetic substance composite material.SOLUTION: There are provided: a resin-magnetic substance composite material including a thermoplastic resin, a metal magnetic substance and a flocculant; and a method for producing a resin-magnetic substance composite material including a thermoplastic resin, a metal magnetic substance and a flocculant. The method for producing a resin-magnetic substance composite material comprises a step of mixing a thermoplastic resin and a metal magnetic substance with a solution containing a flocculant to produce an aggregate containing the thermoplastic resin, the metal magnetic substance and the flocculant.

Description

  The present invention relates to a resin magnetic composite material and a method for producing the same.

  With the recent increase in the speed and frequency of electronic devices, there is an increasing demand for miniaturization and thinning of components and devices used in these devices. For example, the mounting density of elements has increased, and mutual interference between elements has increased. There is a concern that noise radiation will adversely affect the operation of the equipment. These problems are harmonics of the signal used, and it is necessary to suppress the generation of noise by suppressing the harmonics. In particular, with the recent increase in operation speed, the operation clock frequency of microcomputers has reached several hundred MHz, and the harmonics of this operation clock signal are in the GHz frequency band, and noise countermeasures in the GHz frequency band are required. It has been.

  Therefore, in an insulator used for a circuit board of an electronic device, a magnetic substance-containing insulator has come to be used. As such a magnetic substance-containing insulator, for example, a plurality of magnetic particles and The thing containing the insulator to hold | maintain is illustrated (for example, refer patent document 1).

  However, in such a magnetic substance-containing insulator, when a coating film is formed using an insulating varnish and a film is formed, the magnetic substance settles due to a large difference in specific gravity of components in the varnish. Dispersion state worsens, resulting in a concentration difference in the thickness direction of the film, resulting in a non-uniform film, and when making a dry film, in the part where the concentration of the magnetic material is high, the film is difficult to peel off from the substrate, The workability was poor, and as a result, the characteristics were affected.

JP 2006-269134 A

  The present invention can provide a resin magnetic composite material capable of obtaining a molded product in which a magnetic material is uniformly dispersed. Moreover, such a resin magnetic composite material can be easily manufactured.

  The present inventors use a flocculant in a resin magnetic composite material including a thermoplastic resin and a metal magnetic body to agglomerate the thermoplastic resin and the metal magnetic body, and in the aggregate with the thermoplastic resin. By finding a resin magnetic composite material that does not have non-uniform aggregation due to sedimentation of the metal magnetic body, and by obtaining a molded product in which the magnetic body is uniformly dispersed by the material, The present invention has been completed.

That is, the present invention provides the resin magnetic composite materials described in the following items (1) to (3) and the resin magnetic composite materials described in the following items (4) to (5). Configured by the method.
(1) A resin magnetic composite material comprising a thermoplastic resin, a metal magnetic material and a flocculant.
(2) The resin magnetic composite material according to item (1), wherein the resin magnetic composite material is a powder containing a thermoplastic resin, a metal magnetic material, and a flocculant.
(3) The resin magnetic composite material according to item (1) or (2), wherein the flocculant is polyethylene oxide.
(4) A method for producing a resin magnetic composite material including a thermoplastic resin, a metal magnetic body and a flocculant, wherein the thermoplastic resin and the metal magnetic body are mixed in a solution containing the flocculant, and the thermoplastic resin And a method for producing a resin magnetic composite material, comprising the step of generating an aggregate comprising a metal magnetic body and a flocculant.
(5) The method for producing a resin magnetic composite material according to item (4), including a step of pulverizing the aggregate.

  According to the resin magnetic material composite material of the present invention, a molded product in which the magnetic material is uniformly dispersed can be obtained. Moreover, according to the manufacturing method of the resin magnetic composite material of the present invention, the resin magnetic composite material can be easily provided.

  The present invention is a resin magnetic composite material including a thermoplastic resin, a metal magnetic body and a flocculant. By using the flocculant, the thermoplastic resin and the metal magnetic body are aggregated and coagulated with the thermoplastic resin. It is possible to obtain a resin magnetic composite material that does not have uneven aggregation due to sedimentation of the metal magnetic body in the aggregate, and a molded product in which the magnetic body is uniformly dispersed can be obtained.

  In addition, the present invention is characterized by comprising a step of mixing a thermoplastic resin and a metal magnetic material with a solution containing a flocculant to produce an aggregate containing the thermoplastic resin, the metal magnetic material and the flocculant. This is a method for producing a resin magnetic composite material, and the resin magnetic composite material can be easily obtained by forming such an aggregate.

  The thermoplastic resin used in the present invention is a resin that has the ability to generate fluidity by heating and can be molded by using it, specifically, polyethylene, polypropylene, polybutene, polymethylpentene, polystyrene. , Polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, styrene / acrylonitrile copolymer, styrene / butadiene / acrylonitrile copolymer, ethylene / vinyl acetate copolymer, polyacetal, polymethyl methacrylate, methacryl / styrene copolymer, acetic acid Cellulose, polycarbonate, polyurethane, polyamide resin, cyclic olefin resin, fluorine resin, nylon, polyphenylene ether, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, etc. Otherwise, these modified resins may also be used. Among these, those having a low melting point, for example, those having a temperature exceeding room temperature and not higher than 200 ° C. have good workability as a composite material, and the properties of the resin are appropriately selected for use.

  The metal magnetic material used in the present invention is a metal that can be magnetized. Specifically, metals such as Fe, Ni, and Co, and further, Fe—Co alloys, Fe—Cr alloys, Fe— Examples of the alloy include Ni alloys, Ni—Co alloys, Fe—Cr—Si alloys, Fe—Ni—Mo alloys, Fe—Si alloys, and Fe—Si—Al alloys. Furthermore, what added 1 or more types of subcomponent among Al, Co, Cr, Cu, Mn, Mo, Nb, Ti, and Zn to the said metal and alloy, etc. are mentioned.

  Subcomponents such as Al, Co, Cr, Cu, Mn, Mo, Nb, Ti, and Zn contained in the metal magnetic material have an effect such as a decrease in magnetic flux density if the content is excessively increased. The total amount of the components is preferably 10% by mass or less, particularly preferably 5% by mass or less. Further, as another subcomponent, trace components other than the above-mentioned elements (for example, O, C, P, Mn, etc.) may be derived from the raw material of the alloy or mixed in the manufacturing process of the alloy. It is acceptable as long as the purpose is not impaired. These trace components are preferably 1% by mass or less in total.

The metal magnetic material is used in a powder form, and examples of the shape of the powder include a spherical shape, a flat shape, a granular shape, a plate shape, and a needle shape, and any of them is suitable in the present invention.
As the particle diameter (longest part) of the powder, those having a size of about 0.1 to 100 μm can be used, but in order to obtain the uniformity of the components in the resulting aggregate, 20 μm or less is particularly preferable.

  The flocculant used in the present invention is capable of uniformly aggregating the thermoplastic resin and the metal magnetic material. As such a flocculant, those generally used as water purification agents such as water and sewage, human waste treatment, and factory wastewater can be used. For example, polymer flocculants (polyacrylamide, polyethylene oxide (nonionic polymer) Flocculant), polyacrylic acid, acrylamide / acrylic acid copolymer, acrylamide / sodium acrylate copolymer (anionic polymer flocculant), polyacrylamide polymer flocculant, dimethylaminoethyl acrylate polymer flocculant , Copolymer of acrylamide / dimethylaminoethyl acrylate methyl chloride quaternary salt (cationic polymer flocculant)), iron flocculant (polyferric sulfate), sulfuric acid band (aluminum sulfate), PAC (polyaluminum chloride) ) And the like. Furthermore, the aggregating agent functions as a binder for metal magnetic materials or a thermoplastic resin of the metal magnetic material, and is preferably one that can further improve the agglomerate generation work. Among these aggregating agents, a polymer aggregating agent and the like are preferable. The type of the polymer flocculant is not particularly limited, but nonionic and anionic ones are preferable, and nonionic ones are more preferable. In addition, the flocculant used by this invention can also be used individually by 1 type, However, You may use it in combination of 2 or more type.

  As a method of using the above flocculant, the flocculant is added directly to a mixture of a thermoplastic resin and a metal magnetic material which are sufficiently mixed and dispersed in advance, or mixed with a solvent such as water and added as a flocculant solution. The method of doing is mentioned.

  In the resin magnetic composite material of the present invention, the ratio between the resin and the metal magnetic material is not particularly limited in obtaining an aggregate, but considering the strength of the molded product, the moldability of the composite material, and the properties of the composite material molded product In the total amount of the resin and the metal magnetic body, the resin is preferably about 20% by volume to 80% by volume. The ratio of the aggregating agent is not limited as long as the resin and the metal magnetic material can be aggregated and does not affect the properties of the composite material. About 01-0.5 mass% is preferable.

  As the method for producing the resin magnetic composite material of the present invention, the thermoplastic resin and the metal magnetic powder are mixed, and the mixture is mixed with a coagulant solution prepared in advance. Thus, an agglomerate containing a thermoplastic resin, a metal magnetic material, and an aggregating agent is generated. Here, when the aggregate is mixed using a stirrer or the like, the dispersion state of the metal magnetic material becomes more preferable. Next, the aggregate can be dried with an evaporator or a dryer, and the dried aggregate can be pulverized with a mortar or the like to obtain a resin magnetic composite material. The resin magnetic composite material of the present invention is preferably used as a powder obtained by pulverization in order to obtain a molded product in a uniformly dispersed state without sedimentation of the magnetic material. The particle size of such powder is preferably 60 μm or less.

  The flocculant solution can be used by dissolving the flocculant in a solvent such as water. As a ratio of the flocculant and the solvent in the flocculant solution, for example, the flocculant can be used in an amount of 100 to 5000 times the mass.

  Further, the thermoplastic resin can be used in the form of powder. In that case, in order to improve the dispersibility in the composite material, a finer particle diameter is preferable, and the average particle diameter is, for example, about 100 μm. The following are preferable, those of 30 μm or less are more preferable, and those of about 1 μm are more preferable.

  The resin composite material obtained as described above may be used, for example, after being formed into a film shape, or a molded product may be obtained using a mold, or it may be dissolved in a solvent and used as a varnish.

  When used as a powder, the resin composite material obtained as described above can be molded by applying a known molding means, that is, a compression molding method, an extrusion molding method, an injection molding method, a cast molding method, or the like. However, the form of molding of the resin composite material may be any form. For example, a powdery resin composite material may be compressed on a hot plate to be formed into a sheet, and a plurality of these may be stacked and compressed to have a predetermined thickness.

  In addition, the resin composite molding material of the present invention can use a molded product such as a sheet or a molded product obtained by molding for a substrate or an element such as an electric component or an electronic component.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these examples.

Example 1
16.4 g of metal magnetic material (Ni-Fe alloy, manufactured by Pacific Sawa, average particle size 10 μm) and 2 g of polystyrene (manufactured by PS Japan) powder (average particle size 14 μm) (metal magnetic material and thermoplastic resin) The volume ratio of the mixture was 1: 1) in advance by mixing with a small mixer to make it uniform, and this was put into a 100 ML beaker, and further an aqueous solution of polyethylene oxide (“PEO-29” manufactured by Sumitomo Seika Co., Ltd.) (Weight% concentration) 22 g was added and stirred with a magnetic stirrer to obtain an aggregate. The obtained agglomerates were mixed using a rotation / revolution mixer, and this mixture was dried with a dryer at 110 ° C. for 8 hours to obtain dried agglomerates. Furthermore, the dried aggregate was pulverized in a mortar to obtain a resin magnetic composite powder.
A resin magnetic material composite powder 15 g thus obtained was placed on a heating plate and pressed at 230 ° C. and a pressure of 25 Mpa for 10 minutes to produce a film having a thickness of about 100 μm. About 10 to 15 films obtained by repeating the above operation were overlapped and heated and pressed in the same manner as described above to obtain a sheet having a thickness of 1 mm. The thus obtained sheet was evaluated for the relative dielectric constant at a frequency of 100 MHz by the impedance analyzer using the capacitance method, and the average value was 56.5 and the standard deviation was 2.89. Further, when the cross section of the sheet was observed with a scanning electron microscope (magnification: 2500 times), the magnetic material was uniformly dispersed, and the dispersibility in the thickness direction of the sheet was good.

(Example 2)
In Example 1, a sheet having a thickness of 1 mm was obtained in the same manner as in Example 1 except that polystyrene powder (manufactured by PS Japan, average particle diameter 200 μm) was used instead of polystyrene powder (average particle diameter 14 μm). The average value of the relative dielectric constant of the sheet at a frequency of 100 MHz was 54.0, the standard deviation was 3.01, and the cross section of the sheet was observed with a scanning electron microscope. The dispersibility of was good.

(Example 3)
In Example 1, 20 g of a modified polyacrylamide (“A-110” manufactured by MT Aquapolymer Co.) aqueous solution (0.05 wt% concentration) was used instead of 22 g of the polyethylene oxide aqueous solution (0.05 wt% concentration). Obtained a sheet having a thickness of 1 mm in the same manner as in Example 1. The average dielectric constant of the sheet at a frequency of 100 MHz is 53.0, the standard deviation is 3.31, and the cross section of the sheet is observed with a scanning electron microscope. The dispersibility of was good.

(Comparative Example 1)
2 g of polystyrene (manufactured by PS Japan) pellets are dissolved in 18 g of toluene, and 16.4 g of magnetic metal (Ni—Fe alloy, Pacific Sowa, average particle size 10 μm) powder is added to the solution. And mixed. Using the obtained mixture, a film having a thickness of about 100 μm was produced by a casting method.
About 10 to 15 films thus obtained were superposed, placed on a heating plate, and pressed at 230 ° C. and a pressure of 25 Mpa for 10 minutes to obtain a sheet having a thickness of 1 mm. The thus obtained sheet was evaluated for the relative permittivity at a frequency of 100 MHz by the impedance analyzer using the capacitance method, and the average value was 45.3 and the standard deviation was 10.7. When the cross section of the sheet was observed with a scanning electron microscope, the density of the magnetic material was confirmed in the cross section of the sheet, and the dispersibility was poor.

(Comparative Example 2)
In Example 1, although it stirred with the magnetic stirrer without adding polyethylene oxide aqueous solution, the aggregate was not obtained.

Claims (5)

A resin magnetic composite material comprising a thermoplastic resin, a metal magnetic material and a flocculant. The resin magnetic body composite material according to claim 1, wherein the resin magnetic body composite material is a powder containing a thermoplastic resin, a metal magnetic body, and a flocculant. The resin magnetic composite material according to claim 1, wherein the flocculant is polyethylene oxide. A method for producing a resin magnetic composite material including a thermoplastic resin, a metal magnetic material and a flocculant, wherein the thermoplastic resin and the metal magnetic material are mixed with a solution containing the flocculant, and the thermoplastic resin and the metal magnetic material are mixed. A method for producing a resin magnetic composite material comprising a step of producing an aggregate containing a body and a flocculant. The manufacturing method of the resin magnetic body composite material of Claim 4 which has the process of grind | pulverizing the said aggregate.