JP2018120921A - Ferrite powder, resin composition, and compact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact which is capable of being stably detected by various metal detectors, and also to provide ferrite powder and a resin composition which are capable of being suitably used for manufacturing the compact.SOLUTION: Ferrite powder of the invention is ferrite powder that can be detected by a metal detector and contains hard ferrite particles and soft ferrite particles. The ferrite powder preferably has a residual magnetization of 20 A m/kg or more and 40 A m/kg or less, a saturation magnetization of 60 A m/kg or more and 90 A m/kg or less, and a coercive force of 40 kA/m or more and 180 kA/m or less, which are obtained by VSM measurement where a magnetic field of 10K 1000/4πA/m is applied.SELECTED DRAWING: None

Description

  The present invention relates to a ferrite powder, a resin composition, and a molded body.

  For example, at the food manufacturing site, there is a problem of foreign matter contamination. When a problem of foreign matter contamination occurs, it becomes a big social problem, which gives great anxiety to consumers, and also gives a big blow to food manufacturers and processors.

  Opportunities for introducing metal detectors to inspect foreign products and inspecting products before shipment are increasing.

  However, since metal detectors cannot detect general plastic materials or the like, even if foreign substances derived from tools such as packaging materials used at the time of manufacture are mixed, they cannot be detected.

  In order to solve such a problem, a work glove including a metal detection material made of a metal such as iron has been proposed (see Patent Document 1).

  However, with such a technique, even if it is mixed as a foreign object, it may not be detected by a metal detector. Further, the metal may not be detected by the metal detector due to a change over time due to a chemical reaction such as an oxidation reaction.

  Even if a specific metal detector is included, it may not be detected stably depending on the type of metal detector.

JP 2009-120974 A

  An object of the present invention is to provide a molded body that can be stably detected by various metal detectors, and to provide a ferrite powder and a resin composition that can be suitably used for manufacturing the molded body. There is.

Such an object is achieved by the present invention described below.
The ferrite powder of the present invention is a ferrite powder that can be detected by a metal detector, and includes hard ferrite particles and soft ferrite particles.

In the ferrite powder of the present invention, the residual magnetization is 20 A · m ² / kg or more and 40 A · m ² / kg or less and the saturation magnetization is 60 A · m ² according to VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied. / Kg or more and 90 A · m ² / kg or less and the coercive force is preferably 40 kA / m or more and 180 kA / m or less.

  In the ferrite powder of the present invention, the hard ferrite particles may include particles containing Sr of 7.8% to 9.0% by mass and Fe of 61.0% to 65.0% by mass. preferable.

  In the ferrite powder of the present invention, the soft ferrite particles may include particles containing Mn in a range of 3.5% to 20.0% by mass and Fe in a range of 50.0% to 70.0% by mass. preferable.

In the ferrite powder of the present invention, when the hard ferrite particle content is X _H [mass%] and the soft ferrite particle content is X _S [mass%], 0.7 ≦ X _H / X _S ≦ It is preferable to satisfy 18 relationships.

  In the ferrite powder of the present invention, the hard ferrite particles preferably have a volume average particle size of 0.1 μm or more and 60 μm or less.

  In the ferrite powder of the present invention, the volume average particle diameter of the soft ferrite particles is preferably 1 μm or more and 100 μm or less.

The resin composition of the present invention includes hard ferrite particles, soft ferrite particles, and a resin material,
It can be detected by a metal detector.

The resin composition of the present invention comprises the ferrite powder of the present invention,
And a resin material.

  In the resin composition of the present invention, the sum of the content of the hard ferrite particles and the content of the soft ferrite particles in the resin composition is preferably 5.0% by mass or more and 90% by mass or less.

  In the resin composition of the present invention, the resin material is polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol (PVA), fluororesin, silicone rubber, butadiene rubber, thermoplastic elastomer, epoxy resin, and silicone resin. It is preferable to include one or more selected from the group consisting of:

The molded body of the present invention includes hard ferrite particles, soft ferrite particles, and a resin material,
The hard ferrite particles and the soft ferrite particles are fixed by a resin material.

  In the molded article of the present invention, the sum of the content of the hard ferrite particles and the content of the soft ferrite particles is preferably 2.0% by mass or more and 20% by mass or less.

The molded article of the present invention is preferably used in food production, processing, and packaging sites.
The molded body of the present invention is preferably used for some or all of cooking utensils, cooking utensils, and food packaging members.

  The molded body of the present invention preferably contains the hard ferrite particles and the soft ferrite particles in a region within 1.0 mm from the surface in the thickness direction.

  ADVANTAGE OF THE INVENTION According to this invention, the molded object which can be detected stably with a various metal detector is provided, and the ferrite powder and resin composition which can be used suitably for manufacture of the said molded object are provided. be able to.

Hereinafter, preferred embodiments of the present invention will be described in detail.
<Ferrite powder>
First, the ferrite powder of the present invention will be described.

  The ferrite powder of the present invention is characterized by containing hard ferrite particles and soft ferrite particles.

  Thereby, the ferrite powder and the compact containing the ferrite powder can be easily detected by the metal detector. In particular, it can be suitably applied to various metal detectors, and can be stably detected by various metal detectors. Therefore, for example, when the ferrite powder of the present invention or at least a part of a molded body containing the ferrite powder is mistakenly mixed in a product such as food, etc., it can be suitably detected by a metal detector, It is possible to effectively prevent the product from being distributed to the outside. In particular, it can be suitably used at various sites where different types of metal detectors are introduced. In general, metal detectors are expensive, and it is not easy to replace them with new metal detectors at sites where metal detectors have already been installed. However, the ferrite powder of the present invention uses existing metal detectors. Even when a machine is used, the existing equipment can be used effectively because it is detected stably.

  The hard ferrite particles and soft ferrite particles constituting the ferrite powder as described above are mainly composed of an oxide, are chemically stable, and are excellent in corrosion resistance and chemical resistance. Therefore, the detection stability by the metal detector is excellent. In particular, when a metal detector composed of a metal material is applied, it may be difficult to detect with a metal detector due to changes over time such as an oxidation reaction. Even when exposed to various environments, the metal detector has excellent detection stability. Moreover, the above ferrite powder is excellent also in the safety | security with respect to a human body.

On the other hand, satisfactory results cannot be obtained with powders that do not satisfy the above-described configuration.
For example, when metal powder is used, it is likely to be altered by a chemical reaction such as oxidation, it is difficult to stably exhibit excellent characteristics, and detection by a metal detector may be difficult. In particular, since the particulate metal (metal particles) has a large surface area, the above-described problems occur more remarkably. In addition, many metal materials are harmful to the human body.

  In addition, when the ferrite powder is composed only of hard ferrite particles (when soft ferrite particles are not included), the saturation magnetization is not higher than that of soft ferrite. When manufacturing the formed molded body, it is necessary to increase the filler filling amount, so that the strength of the molded body is deteriorated and the weight (density) of the molded body is increased.

  In addition, when the ferrite powder is composed only of soft ferrite particles (when hard ferrite particles are not included), magnetization does not occur unless a magnetic field is applied, so the magnetic flux is measured directly with a magnetic sensor. It cannot be detected with a metal detector of the type.

(Hard ferrite particles)
The hard ferrite particles contained in the ferrite powder of the present invention need only be composed of a material containing hard ferrite. For example, the hard ferrite particles may be composed of Ba-based ferrite or the like, but Sr is 7.8% by mass or more. It is preferable to contain 9.0% by mass or less and Fe 61.0% by mass or more and 65.0% by mass or less.

  Thereby, since it will be in the state which magnetic flux always generate | occur | produces from a molded object by performing a magnetization process, it can detect suitably with the metal detector of the type which measures magnetic flux directly with a magnetic sensor.

On the other hand, if the Sr content in the hard ferrite particles is less than 7.8% by mass, the amount of Fe becomes excessive, and a relatively large amount of Fe ₂ O ₃ is contained in the particles. Depending on the type of metal detector and the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

  On the other hand, when the Sr content in the hard ferrite particles exceeds 9.0% by mass, the amount of Sr becomes excessive, and the particles contain a relatively large amount of SrO, or Sr− other than Sr ferrite. Fe oxide is contained, saturation magnetization is lowered, and depending on the type of the metal detector, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

Further, when the Fe content in the hard ferrite particles is less than 61.0% by mass, the amount of Sr becomes excessive and the particles contain a relatively large amount of SrO, or Sr other than Sr ferrite. -Fe oxide will be contained, saturation magnetization will fall, and depending on the kind of metal detector, etc., it may become difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

Further, if the Fe content in the hard ferrite particles exceeds 65.0 mass%, the amount of Fe becomes excessive, and a relatively large amount of Fe ₂ O ₃ is contained in the particles, so that the saturation magnetization decreases. Depending on the type of metal detector and the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

As described above, the Sr content in the hard ferrite particles is preferably 7.8 mass% or more and 9.0 mass% or less, but is 7.9 mass% or more and 8.9 mass% or less. Is more preferable, and it is further more preferable that it is 8.0 to 8.8 mass%.
Thereby, the effects as described above are more remarkably exhibited.

Further, the content of Fe in the hard ferrite particles is preferably 61.0% by mass or more and 65.0% by mass or less, more preferably 61.1% by mass or more and 64.9% by mass or less. 61.2% by mass or more and 64.8% by mass or less is more preferable.
Thereby, the effects as described above are more remarkably exhibited.

  The content of the metal element constituting the hard ferrite particles can be measured as follows.

  Specifically, 0.2 g of ferrite particles were weighed, a mixture of pure water: 60 ml with 1N hydrochloric acid: 20 ml and 1N nitric acid: 20 ml was heated to prepare an aqueous solution in which ferrite particles were completely dissolved, and ICP analysis was performed. By performing measurement using an apparatus (for example, ICPS-1000IV manufactured by Shimadzu Corporation), the content of the metal element can be obtained.

  For the soft ferrite particles described in detail later, the content of the metal element can be determined in the same manner as described above.

  The hard ferrite constituting the hard ferrite particles as described above may contain components (elements) other than Fe, Sr, and O. Examples of such components include Ti, Si, Cl, Ca, Al, and the like.

  However, the content of components (elements) other than Fe, Sr, and O contained in the hard ferrite constituting the hard ferrite particles as described above is preferably 1.0% by mass or less.

The hard ferrite particles may contain components other than hard ferrite.
However, the content of components other than hard ferrite contained in the hard ferrite particles is preferably 1.0% by mass or less.

The hard ferrite particles may be subjected to a surface treatment.
Examples of the surface treatment agent used for the surface treatment of the particles include a silane coupling agent, a phosphoric acid compound, a carboxylic acid, and a fluorine compound.

  In particular, when hard ferrite particles are surface-treated with a silane coupling agent, the aggregation of hard ferrite particles can be more effectively prevented, and the fluidity of the ferrite powder and the resin composition containing the ferrite powder can be prevented. , The ease of handling can be further improved. Moreover, the dispersibility of the hard ferrite particles in the molded body in the resin composition can be further improved.

  As the silane coupling agent, for example, a silane compound having a silyl group and a hydrocarbon group can be used, and the silane coupling agent particularly has an alkyl group having 8 to 10 carbon atoms as an alkyl group. It is preferable.

  Thereby, aggregation of hard ferrite particles can be further effectively prevented, and the fluidity and ease of handling of the ferrite powder and the resin composition containing the ferrite powder can be further improved. Moreover, the dispersibility of the hard ferrite particles in the molded body in the resin composition can be further improved.

  Examples of the phosphoric acid compound include lauryl phosphate, lauryl-2-phosphate, steareth-2 phosphate, and phosphate ester of 2- (perfluorohexyl) ethylphosphonic acid.

  As the carboxylic acid, for example, a compound (fatty acid) having a hydrocarbon group and a carboxyl group can be used. Specific examples of such compounds include decanoic acid, tetradecanoic acid, octadecanoic acid, cis-9-octadecenoic acid and the like.

  Examples of the fluorine compound include a silane coupling agent as described above, a phosphoric acid compound, and a compound having a structure in which at least a part of hydrogen atoms of the carboxylic acid is substituted with a fluorine atom (fluorine silane compound, fluorine A phosphoric acid compound and a fluorine-substituted fatty acid).

  The volume average particle size of the hard ferrite particles contained in the ferrite powder is not particularly limited, but is preferably 0.1 μm or more and 60 μm or less, more preferably 0.2 μm or more and 50 μm or less, and 0.3 μm or more. More preferably, it is 10 μm or less.

  Thereby, the dispersibility with respect to the resin material of a hard ferrite particle can be improved more, and the resin composition in which the hard ferrite particle was disperse | distributed in the suitable state can be prepared more suitably. Moreover, the intensity | strength of the molded object manufactured using the said resin composition, surface property, and reliability can be improved more. Moreover, the manufacture of the molded object using a resin composition can be performed more stably. Moreover, the color tone of the molded product can be adjusted more suitably.

  On the other hand, if the volume average particle size of the hard ferrite particles is less than the lower limit, depending on the amount of hard ferrite particles used for the production of the resin composition, the hard material may be hard when the resin composition is produced. It takes time to disperse the ferrite particles or it is not preferable because it is dispersed as an aggregate. In addition, since the coloring power of the hard ferrite particles is increased by reducing the particle size, and a color other than black, gray, or brown is easily applied, it is not preferable.

  Further, when the volume average particle size of the hard ferrite particles exceeds the upper limit, depending on the amount of hard ferrite particles used for the production of the resin composition, the shape and size of the molded product produced using the resin composition, etc. However, it is not preferable because the strength and surface property (finish) of the molded body may decrease when the molded body is formed. Further, for example, when an injection molding method is employed as a method for producing a molded body, the resin composition may block the injection path, which is not preferable.

  The volume average particle diameter can be determined, for example, by the following measurement. That is, first, 10 g of powder as a sample and 80 ml of water are placed in a 100 ml beaker, and 2 to 3 drops of a dispersant (sodium hexametaphosphate) are added. Next, dispersion is performed using an ultrasonic homogenizer (for example, UH-150 model manufactured by SMT Co. LTD.). As an ultrasonic homogenizer, SMT. Co. LTD. When using UH-150 manufactured, for example, the output level may be set to 4 and dispersion may be performed for 20 seconds. Thereafter, bubbles formed on the surface of the beaker can be removed and introduced into a microtrack particle size analyzer (for example, Model 9320-X100 manufactured by Nikkiso Co., Ltd.) for measurement.

The residual magnetization of the hard ferrite particles by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 25 A · m ² / kg to 40 A · m ² / kg, and preferably 27 A · m ² / kg. More preferably, it is not less than kg and not more than 38 A · m ² / kg.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the residual magnetization is less than the lower limit, if the ferrite powder content in the molded body manufactured using ferrite powder is not increased, the molded body may be easily detected by a metal detector. It becomes insufficient. Moreover, when the content rate of the ferrite powder in a molded object is raised in order to improve the ease of detection by a metal detector, the toughness and strength of the molded object are likely to decrease.

  Further, if the residual magnetization exceeds the upper limit value, the adjustment of the composition of the hard ferrite particles becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Moreover, even if the remanent magnetization exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

The saturation magnetization of the hard ferrite particles by VSM measurement when a magnetic field of 10K · 1000 / 4πA / m is applied is preferably 45 A · m ² / kg or more and 70 A · m ² / kg or less, and 47 A · m ² / kg. More preferably, it is not less than kg and not more than 65 A · m ² / kg.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the saturation magnetization is less than the lower limit, if the ferrite powder content in the molded body produced using ferrite powder is not increased, the metal detector can easily detect the molded body. It cannot be improved sufficiently. Further, when the content of ferrite powder in the molded body is increased in order to sufficiently improve the ease of detection of the molded body by the metal detector, the toughness and strength of the molded body are likely to be lowered.

  Further, if the saturation magnetization exceeds the upper limit value, the adjustment of the composition of the hard ferrite particles becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to obtain stable and excellent characteristics. Moreover, even if the saturation magnetization exceeds the upper limit, practically no further improvement in the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector cannot be expected.

  The coercive force of the hard ferrite particles measured by VSM when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 39.7 kA / m or more and 320 kA / m or less, and 55 kA / m or more and 280 kA / m or less. More preferably.

  Thereby, the easiness of detection with the metal detector of the molded object manufactured using a ferrite powder can be improved more. Moreover, the production cost of a molded object can be suppressed.

  On the other hand, if the coercive force is less than the lower limit value, when the molded body manufactured using the ferrite powder of the present invention is magnetized, sufficient magnetization cannot be performed, and the molded body is detected by a metal detector. This is not preferable because the ease of detection may be reduced.

  Further, if the coercive force exceeds the upper limit value, the adjustment of the composition of the hard ferrite particles becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Further, even if the coercive force exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

  The magnetic characteristics can be obtained as follows, for example. That is, first, a target powder (particle) is packed in a cell having an inner diameter of 5 mm and a height of 2 mm, and set in a vibrating sample type magnetic measuring apparatus. Next, an applied magnetic field is applied, sweeping to 10K · 1000 / 4π · A / m, and then the applied magnetic field is reduced to create a hysteresis curve. Saturation magnetization, residual magnetization, and coercive force can be obtained from the data of this curve. For example, VSM-C7-10A (manufactured by Toei Kogyo Co., Ltd.) or the like can be used as the vibration sample type magnetometer.

  The content of the hard ferrite particles in the ferrite powder of the present invention is not particularly limited, but is preferably 42% by mass or more and 93% by mass or less, more preferably 45% by mass or more and 92% by mass or less, and 48 More preferably, it is at least 90% by mass.

  Thereby, while maintaining the density of the resin composition low, the strength of the molded body produced using the resin composition can be further improved, and a metal is detected by applying a magnetic field that varies over time. It is possible to obtain a compact that more suitably corresponds to both the type of metal detector and the type of metal detector that directly measures magnetic flux with a magnetic sensor.

  The hard ferrite particles as described above may be produced by any method, but can be suitably produced, for example, by the method described below.

That is, first, Fe ₂ O ₃ and SrCO ₃ are dry mixed as raw materials.
Dry mixing is performed by, for example, using a Henschel mixer or the like for 1 minute or more, preferably 3 minutes or more and 60 minutes or less for granulation.

Thereafter, the granulated product thus obtained is fired.
The granulated product can be fired using, for example, a stationary electric furnace.

  The firing conditions are not particularly limited. For example, the temperature can be set to 1050 ° C. or higher and 1250 ° C. or lower in the air, and the firing time can be set to 2 hours or longer and 8 hours or shorter (peak).

  Thereafter, the fired product obtained by firing is wet pulverized by a bead mill or the like, washed, dehydrated, dried, and then heat treated.

  The conditions for the heat treatment are not particularly limited. For example, the temperature may be 750 ° C. or more and 1050 ° C. or less, and the heating time may be 0.1 hours or more and 2 hours or less.

(Soft ferrite particles)
The soft ferrite particles contained in the ferrite powder of the present invention may be made of a material containing soft ferrite. For example, the soft ferrite particles may be made of Ni-Zn-Cu based ferrite or the like. It is preferable to contain 5 mass% or more and 20.0 mass% or less, and Fe 50.0 mass% or more and 70.0 mass% or less.

  Thereby, the Curie point of ferrite powder becomes higher, and detection by a metal detector at high temperature can be performed more stably. Further, since the saturation magnetization of the soft ferrite particles themselves is high, even when the content of the soft ferrite particles in the resin composition is smaller, it can be suitably detected by a metal detector.

  On the other hand, if the content of Mn in the soft ferrite particles is less than 3.5% by mass, the amount of Fe becomes excessive, and the resin composition is produced (particularly during mixing and kneading by heating) or molding. When the body is manufactured (particularly during molding by heating), the oxidation reaction easily proceeds, and as a result, the saturation magnetization of the finally obtained molded body may be lowered. As a result, depending on the type of metal detector or the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

  On the other hand, if the content of Mn in the soft ferrite particles exceeds 20.0% by mass, oxidation may progress when a treatment such as pulverization is performed after the main firing, and the saturation magnetization may be lowered. As a result, depending on the type of metal detector or the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

  Further, if the Fe content in the soft ferrite particles is less than 50.0% by mass, it means that the Mn content is increased, and oxidation is performed when processing such as pulverization is performed after the main firing. The saturation magnetization may be lowered. As a result, depending on the type of metal detector or the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

  Further, when the Fe content in the soft ferrite particles exceeds 70.0% by mass, the amount of Fe becomes excessive, and the resin composition is produced (particularly during mixing and kneading by heating) or the molded article is produced. At times (particularly, during molding by heating), the oxidation reaction tends to proceed, and as a result, the saturation magnetization of the finally obtained molded body may be lowered. As a result, depending on the type of metal detector or the like, it may be difficult to detect the ferrite powder or a molded body containing the ferrite powder by the metal detector.

As described above, the content of Mn in the soft ferrite particles is preferably 3.5% by mass or more and 20.0% by mass or less, but is 5.0% by mass or more and 19.0% by mass or less. Is more preferably 6.4% by mass or more and 18.0% by mass or less.
Thereby, the effects as described above are more remarkably exhibited.

Further, the Fe content in the soft ferrite particles is preferably 50.0 mass% or more and 70.0 mass% or less, more preferably 51.0 mass% or more and 66.0 mass% or less. More preferably, it is 52.0 mass% or more and 65.0 mass% or less.
Thereby, the effects as described above are more remarkably exhibited.

  The soft ferrite constituting the soft ferrite particles may contain a component (element) other than Fe, Mn, and O. Examples of such components include Mg, Ti, Si, Cl, Ca, Al, and the like.

  However, the content of components (elements) other than Fe, Mn, and O contained in the soft ferrite constituting the soft ferrite particles is preferably 1.0% by mass or less.

Moreover, the soft ferrite particle may contain components other than soft ferrite.
However, the content of components other than soft ferrite contained in the soft ferrite particles is preferably 1.0% by mass or less.

The soft ferrite particles may be subjected to a surface treatment.
Examples of the surface treatment agent used for the surface treatment of the particles include a silane coupling agent, a phosphoric acid compound, a carboxylic acid, and a fluorine compound.

  In particular, when the soft ferrite particles are surface-treated with a silane coupling agent, the aggregation of the soft ferrite particles can be more effectively prevented, and the fluidity of the ferrite powder and the resin composition containing the ferrite powder can be prevented. , The ease of handling can be further improved. Moreover, the dispersibility of the soft ferrite particles in the molded body in the resin composition can be further improved.

  As the silane coupling agent, for example, a silane compound having a silyl group and a hydrocarbon group can be used, and the silane coupling agent particularly has an alkyl group having 8 to 10 carbon atoms as an alkyl group. It is preferable.

  Thereby, aggregation of soft ferrite particles can be further effectively prevented, and the fluidity and ease of handling of the ferrite powder and the resin composition containing the ferrite powder can be further improved. Moreover, the dispersibility of the soft ferrite particles in the molded body in the resin composition can be further improved.

  Examples of the phosphoric acid compound include lauryl phosphate, lauryl-2-phosphate, steareth-2 phosphate, and phosphate ester of 2- (perfluorohexyl) ethylphosphonic acid.

  As the carboxylic acid, for example, a compound (fatty acid) having a hydrocarbon group and a carboxyl group can be used. Specific examples of such compounds include decanoic acid, tetradecanoic acid, octadecanoic acid, cis-9-octadecenoic acid and the like.

  Examples of the fluorine compound include a silane coupling agent as described above, a phosphoric acid compound, and a compound having a structure in which at least a part of hydrogen atoms of the carboxylic acid is substituted with a fluorine atom (fluorine silane compound, fluorine A phosphoric acid compound and a fluorine-substituted fatty acid).

  The volume average particle diameter of the soft ferrite particles contained in the ferrite powder is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 1 μm or more and 80 μm or less, and 1 μm or more and 70 μm or less. Further preferred.

  Thereby, the dispersibility with respect to the resin material of a soft ferrite particle can be improved more, and the resin composition which disperse | distributed the soft ferrite particle in the suitable state can be prepared more suitably. Moreover, the intensity | strength of the molded object manufactured using the said resin composition, surface property, and reliability can be improved more. Moreover, the manufacture of the molded object using a resin composition can be performed more stably. Moreover, the color tone of the molded product can be adjusted more suitably.

  On the other hand, if the volume average particle size of the soft ferrite particles is less than the lower limit, depending on the amount of soft ferrite particles used for the production of the resin composition, the soft ferrite particles may be softened during the production of the resin composition described later. It takes time to disperse the ferrite particles or it is not preferable because it is dispersed as an aggregate. In addition, since the coloring power of the soft ferrite particles is increased by reducing the particle size, and a color other than black, gray, or brown is easily applied, it is not preferable.

  In addition, when the volume average particle diameter of the soft ferrite particles exceeds the upper limit, depending on the amount of soft ferrite particles used for the production of the resin composition, the shape and size of the molded body produced using the resin composition, etc. However, it is not preferable because the strength and surface property (finish) of the molded body may decrease when the molded body is formed. Further, for example, when an injection molding method is employed as a method for producing a molded body, the resin composition may block the injection path, which is not preferable.

When the volume average particle size of the hard ferrite particles contained in the ferrite powder is D _H [μm] and the volume average particle size of the soft ferrite particles contained in the ferrite powder is D _S [μm], 0.5 ≦ D _It is preferable that the relationship of _S / D _H ≦ 50 is satisfied, more preferably the relationship of 0.5 ≦ D _S / D _H ≦ 40 is satisfied, and the relationship of 0.5 ≦ D _S / D _H ≦ 30 is satisfied. It is more preferable to satisfy.

  This can further improve the dispersibility of the soft ferrite particles in the molded body in the resin composition, and more effectively prevent the occurrence of unintended compositional variations in the molded body in the resin composition. be able to.

The saturation magnetization of the soft ferrite particles by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 85 A · m ² / kg or more and 98 A · m ² / kg or less, and 87 A · m ² / kg. More preferably, it is not less than kg and not more than 97 A · m ² / kg.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the saturation magnetization is less than the lower limit, if the ferrite powder content in the molded body produced using ferrite powder is not increased, the molded body may be easily detected by a metal detector. It becomes insufficient. Moreover, when the content rate of the ferrite powder in a molded object is raised in order to improve the ease of detection by a metal detector, the toughness and strength of the molded object are likely to decrease.

  Further, when the saturation magnetization exceeds the upper limit, the adjustment of the composition of the soft ferrite particles is complicated in order to realize the magnetic characteristics, and it becomes difficult to obtain stable and excellent characteristics. Moreover, even if the saturation magnetization exceeds the upper limit, practically no further improvement in the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector cannot be expected.

The residual magnetization of the soft ferrite particles measured by VSM when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 4.5 A · m ² / kg or more and 40 A · m ² / kg or less. It is more preferable that it is not less than 0.0 A · m ² / kg and not more than 37 A · m ² / kg.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the residual magnetization is less than the lower limit, if the ferrite powder content in the molded body manufactured using ferrite powder is not increased, the molded body may be easily detected by a metal detector. It becomes insufficient. Moreover, when the content rate of the ferrite powder in a molded object is raised in order to improve the ease of detection by a metal detector, the toughness and strength of the molded object are likely to decrease.

  If the remanent magnetization exceeds the upper limit value, the adjustment of the composition of the soft ferrite particles becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Moreover, even if the remanent magnetization exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

  The coercive force of the soft ferrite particles by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 550 A / m or more and 6500 A / m or less, and 600 A / m or more and 5300 A / m or less. Is more preferable.

  Thereby, the easiness of detection with the metal detector of the molded object manufactured using a ferrite powder can be improved more. Moreover, the production cost of a molded object can be suppressed.

  On the other hand, if the coercive force is less than the lower limit value, when the molded body manufactured using the ferrite powder of the present invention is magnetized, sufficient magnetization cannot be performed, and the molded body is detected by a metal detector. This is not preferable because the ease of detection may be reduced.

  Further, if the coercive force exceeds the upper limit value, the adjustment of the composition of the ferrite powder becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Further, even if the coercive force exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

  In addition, the Curie temperature (Curie point) of the soft ferrite particles is preferably 400 ° C. or higher, and more preferably 450 ° C. or higher.

  As a result, the heat resistance of the ferrite powder, the resin composition containing the same, and the molded product produced using these can be further improved, and the detection by the metal detector is effective even when exposed to a higher temperature. Can be done. In addition, Curie temperature can be calculated | required by the measurement based on JISC2560-1.

  The content of the soft ferrite particles in the ferrite powder of the present invention is not particularly limited, but is preferably 7% by mass or more and 58% by mass or less, more preferably 8% by mass or more and 55% by mass or less. More preferably, it is at least 50% by mass.

  Thereby, the detection with the metal detector of the type which detects a metal by applying the magnetic field which fluctuates with time can be performed suitably.

When the content of hard ferrite particles in the ferrite powder of the present invention is X _H [mass%] and the content of soft ferrite particles is X _S [mass%], 0.7 ≦ X _H / X _S ≦ 18 The relationship is preferably satisfied, the relationship 0.8 ≦ X _H / X _S ≦ 12 is more preferable, and the relationship 1 ≦ X _H / X _S ≦ 10 is more preferable.

  Thereby, while maintaining the density of the resin composition low, the strength of the molded body produced using the resin composition can be further improved, and a metal is detected by applying a magnetic field that varies over time. It is possible to obtain a compact that more suitably corresponds to both the type of metal detector and the type of metal detector that directly measures magnetic flux with a magnetic sensor.

  The soft ferrite particles as described above may be produced by any method, but can be suitably produced, for example, by the method described below.

That is, first, at least one of MnCO ₃ and Mn ₃ O ₄ is mixed as a raw material with Fe ₂ O ₃ . The raw materials may be mixed by either wet mixing or dry mixing. The raw materials can be mixed using, for example, a Henschel mixer or a ball mill.
The obtained mixture is pre-baked to obtain a pre-sintered product.

  The firing conditions for the pre-baking are not particularly limited, and can be suitably performed, for example, in the air at a temperature of 800 ° C. or higher and 1200 ° C. or lower.

  Thereafter, the temporarily sintered product is pulverized. The temporary sintered product can be pulverized using, for example, a rod mill, a ball mill, or the like.

  In addition to the pulverized product of the temporary sintered body, a composition containing water, a binder such as polyvinyl alcohol (PVA), and a dispersant is prepared, and the composition is sprayed and dried to obtain granulated powder.

The composition is prepared, for example, by adding a binder such as water, polyvinyl alcohol (PVA), and a dispersing agent to the coarsely pulverized product of the pre-sintered product and subjecting it to a fine pulverization (wet pulverization) treatment. May be.
Then, ferrite powder is obtained by carrying out main baking of the granulated powder.

  The firing conditions for the main firing are not particularly limited, and can be suitably performed, for example, in nitrogen (in a non-oxidizing atmosphere) at a temperature of 1000 ° C. or higher and 1300 ° C. or lower.

  The ferrite powder of the present invention may contain other particles in addition to the hard ferrite particles and soft ferrite particles as described above.

  The volume average particle size of the constituent particles of the ferrite powder is not particularly limited, but is preferably 0.1 μm or more and 95 μm or less, and more preferably 0.2 μm or more and 75 μm or less.

  Thereby, the dispersibility with respect to the resin material of a ferrite powder can be improved more, and manufacture of the resin composition containing a ferrite powder and a resin material can be performed more suitably. Moreover, the intensity | strength of the molded object manufactured using the said resin composition, surface property, and reliability can be improved more. Moreover, the manufacture of the molded object using a resin composition can be performed more stably. Moreover, the color tone of the molded product can be adjusted more suitably.

The residual magnetization of the ferrite powder by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 20 A · m ² / kg or more and 40 A · m ² / kg or less, and 27 A · m ² / kg. More preferably, it is 38 A · m ² / kg or less.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the residual magnetization is less than the lower limit, if the ferrite powder content in the molded body manufactured using ferrite powder is not increased, the molded body may be easily detected by a metal detector. It becomes insufficient. Moreover, when the content rate of the ferrite powder in a molded object is raised in order to improve the ease of detection by a metal detector, the toughness and strength of the molded object are likely to decrease.

  Further, if the remanent magnetization exceeds the upper limit, the adjustment of the composition of the ferrite powder becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to obtain stable and excellent characteristics. Moreover, even if the remanent magnetization exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

The saturation magnetization of the ferrite powder by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 60 A · m ² / kg or more and 90 A · m ² / kg or less, and 63 A · m ² / kg. More preferably, it is 85 A · m ² / kg or less.

  Thereby, the toughness of a molded object, intensity | strength, etc. can be improved more, improving the ease of the detection with the metal detector of the molded object manufactured using ferrite powder more. Moreover, it is advantageous also in suppressing the production cost of the molded body.

  On the other hand, if the saturation magnetization is less than the lower limit, if the ferrite powder content in the molded body produced using ferrite powder is not increased, the molded body may be easily detected by a metal detector. It becomes insufficient. Moreover, when the content rate of the ferrite powder in a molded object is raised in order to improve the ease of detection by a metal detector, the toughness and strength of the molded object are likely to decrease.

  Further, if the saturation magnetization exceeds the upper limit value, the adjustment of the composition of the ferrite powder becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Moreover, even if the saturation magnetization exceeds the upper limit, practically no further improvement in the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector cannot be expected.

  The coercive force of the ferrite powder by VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied is preferably 40 kA / m or more and 180 kA / m or less, and preferably 44 kA / m or more and 170 kA / m or less. More preferred.

  Thereby, the easiness of detection with the metal detector of the molded object manufactured using a ferrite powder can be improved more. Moreover, the production cost of a molded object can be suppressed.

  On the other hand, if the coercive force is less than the lower limit value, when the molded body manufactured using the ferrite powder of the present invention is magnetized, sufficient magnetization cannot be performed, and the molded body is detected by a metal detector. This is not preferable because the ease of detection may be reduced.

  Further, if the coercive force exceeds the upper limit value, the adjustment of the composition of the ferrite powder becomes complicated in order to realize the magnetic characteristics, and it becomes difficult to stably obtain excellent characteristics. Further, even if the coercive force exceeds the upper limit, practically, it is not possible to further improve the ease of detection of the ferrite powder or a molded body containing the ferrite powder by a metal detector.

  In particular, when the ferrite powder satisfies the above-mentioned conditions for residual magnetization, saturation magnetization, and coercive force, the density of the resin composition is kept low, and the molded body produced using the resin composition In addition to improving the strength, both metal detectors that detect metals by applying a magnetic field that changes over time, and metal detectors that measure magnetic flux directly with a magnetic sensor Thus, it is possible to obtain a molded article corresponding more suitably.

  The ferrite powder of the present invention may be produced by any method. For example, the ferrite powder can be suitably produced by mixing hard ferrite particles and soft ferrite particles separately produced by the method described above. it can.

<Resin composition>
Next, the resin composition of the present invention will be described.

  The resin composition of the present invention contains hard ferrite particles, soft ferrite particles, and a resin material, and can be detected by a metal detector.

  Such a resin composition can be suitably obtained by mixing the above-described ferrite powder and a resin material. In other words, the resin composition of the present invention may contain the above-described ferrite powder and a resin material.

  Such a resin composition of the present invention can be suitably used for the production of a molded article excellent in the ease of detection by a metal detector and the stability of detection.

The resin composition of the present invention may be obtained by mixing a composition containing only one of hard ferrite particles and soft ferrite particles and a composition containing only the other of hard ferrite particles and soft ferrite particles. Can be obtained. More specifically, for example, the resin composition of the present invention can be obtained by mixing a composition containing hard ferrite particles and a resin material and a composition containing soft ferrite particles and a resin material, It can be obtained by mixing a composition containing hard ferrite particles and a resin material and soft ferrite particles (powder), and can be obtained by mixing hard ferrite particles and a composition containing soft ferrite particles and a resin material. Can do.
Even in such a case, the same effect as described above can be obtained.

  Even in such a case, it is preferable that the hard ferrite particles and soft ferrite particles contained in the resin composition satisfy the same conditions as described in the description of the ferrite powder of the present invention.

  In the following description, in the production of the resin composition, even when the ferrite powder of the present invention as a mixed powder containing the hard ferrite particles and the soft ferrite particles as described above is not used, the resin composition finally obtained When hard ferrite particles and soft ferrite particles are included, the hard ferrite particles and soft ferrite particles are collectively referred to as ferrite powder.

  In the resin composition of the present invention, the ferrite powder (hard ferrite particles and soft ferrite particles) may be contained in any form, but is preferably present dispersed in the resin material.

  Thereby, the ease of handling of the resin composition is further improved, and the molded body to be described in detail later can be more suitably molded. In addition, it is possible to effectively prevent unintentional variation in the content of ferrite powder (hard ferrite particles and soft ferrite particles) in each part of the molded body, and ferrite powder (hard ferrite particles and soft ferrite particles). The certainty of detection by a metal detector of a molded body containing can be further improved.

  The content of ferrite powder in the resin composition (sum of the content of hard ferrite particles and the content of soft ferrite particles) is not particularly limited, but is preferably 5.0% by mass or more and 90% by mass or less. 7.0 mass% or more and 88 mass% or less is more preferable.

  Thereby, the moldability of the molded body can be further improved, the toughness, strength, reliability, etc. of the molded body can be further improved, and the ease of detection by the metal detector of the molded body can be improved. Stability can be further improved. Moreover, it can prevent effectively that specific gravity of a molded object becomes large too much.

  On the other hand, when the content of ferrite powder in the resin composition (sum of the content of hard ferrite particles and the content of soft ferrite particles) is less than the lower limit, depending on the composition of the hard ferrite particles, There is a possibility that the molded body is easily detected by a metal detector and the stability of detection is insufficient.

  Further, when the content of ferrite powder in the resin composition (the sum of the content of hard ferrite particles and the content of soft ferrite particles) exceeds the upper limit, the moldability of the molded product is lowered and the molded product There is a possibility that the toughness, strength, reliability, etc. of the steel will be lowered.

  As a resin material contained in the resin composition, for example, various thermoplastic resins, various curable resins, and the like can be used.

  More specifically, for example, polyolefins such as polyethylene, polypropylene, poly- (4-methylpentene-1), ethylene-propylene copolymer, cyclic polyolefin; modified polyolefin; polystyrene; butadiene-styrene copolymer; acrylonitrile- Butadiene-styrene copolymer (ABS resin); acrylonitrile-styrene copolymer (AS resin); polyvinyl chloride; polyvinylidene chloride; ethylene-vinyl acetate copolymer (EVA); polyamide (example: nylon 6, nylon 46) , Nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66); polyimide; polyamideimide; acrylic resin such as polymethyl methacrylate; polycarbonate (PC); Polyvinyl alcohol (PVA); ethylene-vinyl alcohol copolymer (EVOH); polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyarylate, aromatic polyester (liquid crystal polymer), etc. Polyether; Polyacetal (POM); Polyphenylene oxide; Modified polyphenylene oxide; Polyetherketone (PEK); Polyetheretherketone (PEEK); Polyetherimide; Polysulfone; Polyethersulfone; Polyphenylenesulfide; Polytetrafluoro Fluorine resins such as ethylene and polyvinylidene fluoride; silicone rubber, isoprene rubber, butadiene rubber, nitrile rubber, natural rubber, etc. Materials: Various thermoplastic elastomers such as styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluororubber, chlorinated polyethylene; epoxy resin; phenol Resins; Urea resins; Melamine resins; Unsaturated polyesters; Silicone resins; Polyurethanes, etc., and copolymers, blends, polymer alloys, etc. mainly composed of these, and combinations of one or more of these Can be used.

  Among them, the resin materials contained in the resin composition are polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol (PVA), fluororesin, silicone rubber, butadiene rubber, thermoplastic elastomer, epoxy resin, and silicone resin. It is preferable to include one or more selected from the group consisting of:

  Thereby, the dispersion stability of the ferrite powder (hard ferrite particles and soft ferrite particles) in the resin composition is further improved, and the moldability of the molded body can be further improved. Moreover, the toughness, strength, reliability and the like of the molded body can be further improved.

  In particular, when the particles constituting the ferrite powder (at least one of hard ferrite particles and soft ferrite particles) are subjected to surface treatment with a silane coupling agent, the adhesion with various resins is improved. The dispersion stability of the ferrite powder (hard ferrite particles and soft ferrite particles) in the resin composition can be further improved, and the moldability of the molded body can be further improved.

  Further, the resin material contained in the resin composition may have a composition different from that of the resin material contained in the molded body produced using the resin composition. For example, the resin material contained in the resin composition may be a precursor (for example, a monomer, dimer, trimer, oligomer, prepolymer, etc.) of the resin material contained in the final molded body.

  Although the content rate of the resin material in a resin composition is not specifically limited, It is preferable that it is 8.0 to 95 mass%, and it is more preferable that it is 10 to 90 mass%.

  Thereby, the moldability of the molded body can be further improved, the toughness, strength, reliability, etc. of the molded body can be further improved, and the ease of detection by the metal detector of the molded body can be improved. Stability can be further improved.

  On the other hand, when the content of the resin material in the resin composition is less than the lower limit, the moldability of the molded body is lowered, and the toughness, strength, reliability, etc. of the molded body may be lowered. .

  Further, when the content of the resin material in the resin composition exceeds the upper limit, the content of ferrite powder (hard ferrite particles and soft ferrite particles) is relatively lowered, depending on the composition of the hard ferrite particles, There is a possibility that the ease of detection of the molded body by the metal detector and the stability of detection may be insufficient.

  The resin composition of the present invention may contain ferrite powder (hard ferrite particles and soft ferrite particles) and a resin material, and may further contain other components (other components).

  Examples of such components (other components) include various colorants such as pigments and dyes, various fluorescent materials, various phosphorescent materials, various phosphorescent materials, solvents, infrared absorbing materials, ultraviolet absorbers, dispersants, and surfactants. Polymerization initiator; Polymerization accelerator; Cross-linking agent; Polymerization inhibitor; Sensitizer; Plasticizer; Slip agent (leveling agent); Penetration accelerator; Wetting agent (humectant); Antistatic agent; Fixing agent; Agent; antifungal agent; antioxidant agent; chelating agent; pH adjuster; thickener; alumina, silica, titanium oxide, magnesium oxide, antimony oxide, calcium oxide, zinc oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate , Potassium titanate, glass fiber, carbon fiber, gypsum fiber, metal fiber, metal particle, graphite, talc, clay, mica, wollastonite, zonotlite, hydrotalcite Anticoagulants; fillers such as zeolite defoamer; blowing agents.

  The resin composition of the present invention may be in any form, and examples of the form of the resin composition include powder, pellets, dispersions, slurries, gels, etc., but pellets are preferred.

  Thereby, the ease of handling of a resin composition improves more, and manufacture of the molded object using a resin composition can be performed more suitably. Moreover, the storage stability of the resin composition can be further improved, and deterioration of the constituent components of the resin composition during storage can be more effectively prevented.

  When the resin composition is a pellet, the volume average particle diameter is preferably 1 mm or more and 10 mm or less, and more preferably 2 mm or more and 7 mm or less.

  Thereby, the ease of handling of the resin composition is further improved, and a molded article using the resin composition can be more suitably produced.

  The resin composition of the present invention can be produced, for example, by mixing the above-described ferrite powder (hard ferrite particles and soft ferrite particles) and a resin material. Mixing of ferrite powder (hard ferrite particles and soft ferrite particles) and resin materials is, for example, a planetary mixer, a twin screw mixer, a kneader, a Banbury mixer, a stirring kneader such as an oven roll, a single screw extruder, a twin screw extrusion It can carry out suitably by using a mixing device (kneading device) such as a machine.

  Moreover, you may further use other components as mentioned above, for example in the case of mixing as needed.

<Molded body>
Next, the molded product of the present invention will be described.

  The molded body of the present invention includes hard ferrite particles, soft ferrite particles, and a resin material, and the hard ferrite particles and the soft ferrite particles are fixed by a resin material.

  Thereby, the molded object which can be stably detected with a various metal detector can be provided.

  In addition, by including hard ferrite particles and soft ferrite particles, the strength, durability, etc. of the molded body can be further improved. For example, when an external force such as tension or bending is applied, particularly a large external force is applied. In some cases, even when an external force is repeatedly applied, a part of the molded body is more effectively prevented from being detached by cutting or the like. Therefore, it is possible to more effectively prevent a part of the molded body from being mixed into the product or the like as a foreign substance.

  Such a molded article of the present invention can be suitably produced using the above-described resin composition of the present invention.

  The molded body of the present invention includes, for example, a composition containing hard ferrite particles and no soft ferrite particles (first composition), and a composition containing soft ferrite particles and no hard ferrite particles (first composition). 2 composition) can also be produced.

  In this case, for example, the content ratio of the hard ferrite particles and the content ratio of the soft ferrite particles can be varied easily and reliably in each part of the molded body. More specifically, for example, a compact having a first region having a high content of hard ferrite particles and a second region having a high content of soft ferrite particles as compared with the first region is suitably used. Can be manufactured.

  The molded body of the present invention only needs to contain hard ferrite particles and soft ferrite particles in at least a part thereof, and may have, for example, a region containing neither hard ferrite particles nor soft ferrite particles.

  More specifically, for example, it has a base portion made of a material other than the resin composition of the present invention, and a surface layer provided on the surface of the base portion and formed using the resin composition of the present invention. It may be.

  Even in the above case, it is preferable that the hard ferrite particles and soft ferrite particles contained in the compact satisfy the same conditions as described in the description of the ferrite powder of the present invention.

  In the following description, in the production of a molded body, when the ferrite powder of the present invention as a mixed powder containing hard ferrite particles and soft ferrite particles as described above is not used, or in the molded body, hard ferrite particles and soft ferrite are used. Even when the particles are included separately in different regions, when the hard ferrite particles and soft ferrite particles are included in the molded body, the hard ferrite particles and soft ferrite particles are collectively referred to as ferrite powder.

  The molded body preferably includes at least hard ferrite particles and soft ferrite particles in the vicinity of the surface thereof.

  More specifically, the molded body preferably contains hard ferrite particles and soft ferrite particles in a region within 1.0 mm in the thickness direction from the surface, and within 0.5 mm in the thickness direction from the surface. It is more preferable that hard ferrite particles and soft ferrite particles are included in the region.

  The vicinity of the surface of the molded body is a part that is particularly easily detached from the molded body. Therefore, by including hard ferrite particles and soft ferrite particles in such a region, the effect of the present invention is more remarkably exhibited.

  Note that such a molded body can be preferably manufactured by applying a magnetic field from the direction to be the surface of the molded body, for example, when the molded body is molded (the resin material is softened or melted). . In particular, in the case of a molded body having a relatively large thickness, the above-described ferrite can be unevenly distributed in the vicinity of the surface of the molded body, and the effects as described above can be exhibited more remarkably.

  Further, for example, the molded body has a first layer having a higher content of hard ferrite particles than the soft ferrite particles and a second content having a higher content of soft ferrite particles than the hard ferrite particles in a region near the surface. And may have a layer.

  Thus, when the resin composition is magnetized, the amount of magnetic field lines generated in the vertical direction (normal direction) of the layer generated from the resin composition differs between the second layer and the first layer. Can do. The first layer may or may not contain soft ferrite particles, and the second layer may or may not contain hard ferrite particles. Further, the first layer and the second layer may be in contact with each other, or at least one intermediate layer may be interposed between these layers. Further, there is no clear boundary between the first layer and the second layer, and the composition may continuously change.

  In particular, the presence of the first layer on the outer surface side of the molded body with respect to the second layer improves the ease of detection by a metal detector, and makes contact with the second layer (the ferrite described above). The effect of suppressing the influence of the lines of magnetic force generated from the resin composition on the base material not containing particles is expected.

  The content of the ferrite powder (the sum of the content of hard ferrite particles and the content of soft ferrite particles) in the molded product of the present invention varies depending on the use of the molded product, but is 2.0 mass% or more and 20 mass%. % Or less, more preferably 2.5% by mass or more and 18% by mass or less.

  Thereby, while being able to improve the toughness of a molded object, intensity | strength, reliability, etc., the ease of being detected with the metal detector of a molded object, and the stability of a detection can be improved more. Moreover, it can prevent effectively that specific gravity of a molded object becomes large too much.

  In addition, in addition to the portion containing the hard ferrite particles or the soft ferrite particles, the molded body has a portion not containing the hard ferrite particles and the soft ferrite particles, the hard ferrite particles or the soft ferrite particles In the containing part, it is preferable to satisfy the conditions regarding the content rate as described above.

The molded body of the present invention may be used for the purpose of detection by a metal detector, in other words, all or part of the molded body (for example, a section of the molded body) may be applied to inspection by a metal detector. However, the molded article of the present invention can be used for, for example, food production, processing, and packaging (including packaging, the same applies hereinafter), cosmetics, and quasi-drugs. Manufacturing, processing, packaging site, pharmaceutical manufacturing, processing, packaging site, products other than the above, processing, packaging site, medical site, cell culture, tissue culture, organ culture, genetic recombination And the like for use in the field of performing biological treatment such as, and for use in the field of performing chemical treatment such as synthesis of compounds.
Especially, it is preferable that the molded object of this invention is used in manufacture of a foodstuff, a process, and a packaging field.

  Foods are required to have high safety, but are generally manufactured, processed, and packaged in an environment in which foreign substances are easily mixed. Therefore, by applying the present invention to articles used in the field of food production, processing, and packaging, the effects of the present invention are more remarkably exhibited.

  In addition, articles used in food manufacturing and processing sites include many articles that are applied to microwave ovens (for example, various cooking utensils, various containers, trays, wrap films, etc.). Since ferrite, which is a metal material, is used, it can be suitably adapted to the use of a microwave oven.

  Further, the soft ferrite as described above can generate heat (especially suitable heat generation up to a predetermined temperature in which excessive temperature rise is prevented) when applied to a microwave oven by adjusting the composition. For this reason, by including soft ferrite particles, for example, the cooking time can be shortened, the baking color of the food can be adjusted, and the like.

  In addition, since metal detectors have been introduced in food manufacturing, processing, and packaging sites for a relatively long time, various types of metal detectors exist in these sites. Since the molded body of the present invention is suitably and stably detected by various metal detectors, the existing equipment can be used effectively, and the molded body of the present invention can be used for various types of metal detectors. The effects of the present invention are more prominent when used in the production, processing, and packaging sites of foods in which there is.

  In addition, in this specification, in addition to solid form and semi-solid form (gel form, such as a jelly and a pudding), the form of food includes liquid form, and the concept of food includes drinks and the like. Food additives and supplements (health supplements) are also included in the concept of food. In addition to natural products such as animal-derived meat, seafood, plant-derived vegetables, fruits, seeds, grains, beans, seaweed, and processed products thereof, artificial sweeteners, artificial seasonings such as artificial seasonings, etc. New synthetic products are also included in the concept of food.

  Examples of molded products used in the production and processing of food include cooking appliances, cooking utensils, cooking utensils, tableware, clothing (articles worn on the human body), and packaging members used for food packaging And articles used in association therewith, as well as articles used for maintenance and repair of these.

  More specifically, for example, hot plate, stove, gas burner, oven, toaster, microwave oven, dishwasher, dish dryer, scale (scale), kitchen timer, thermometer, water purifier, water purification filter (cartridge) Cooking equipment such as pans, pans, kettles, lids, knives, scissors, ladle, spatula, peeler, slicer, mixer, chopper, masher, rolling pin, mudler, whisk, pestle, bowl, drainer Bowl, cutting board, mat, rice paddle, mold, die cutting, lye removal, grater (food grader), frying (turner), pick, drainer, sieve, mill, drop lid, ice tray, grill, tongs, egg slicer Cooking utensils such as bowls, measuring cups, measuring spoons; towels, kitchen paper, towels, towels, paper towels, Cutting utensils, wrap film, oven paper, squeezed bags, virtues, pans and other cooking utensils; dishes, cups, bowls, chopsticks (including chopsticks), spoons, forks, knives, shellfish thigh legs Tableware such as take-out appliances (crab spoon, crab fork); Apron, lab coat, mask, gloves, shoes, socks, underwear, hat, glasses, etc. (articles worn on the human body); food laminate film, etc. Food packaging films, packaging tubes, food storage bottles, plastic sealed containers, and other food packaging materials; dried fish nets, hoses, chopping boards, tableware, sponges, scourers, detergent containers, grindstones, sharpeners These constituent members and the like can be mentioned, but are not limited thereto.

  In particular, the molded article of the present invention is preferably used for some or all of cooking utensils, cooking utensils, and food packaging members.

  Thereby, such a molded body has a high possibility that at least a part of the molded body will be mixed into the food, particularly in the production, processing, and packaging sites of the food. Therefore, when the present invention is applied to the molded body as described above, the effects of the present invention are more remarkably exhibited.

  In addition, when applied at a medical site, for example, when a medical device or medical device is left in the body during surgery, it can be easily detected, leading to a serious medical malpractice case. It can prevent more effectively.

  Various molding methods can be used as a method for producing a molded body, such as an injection molding method (insert molding method, multicolor molding method, sandwich molding method, injection molding method, etc.), extrusion molding method, inflation molding method, Examples include a T-die film molding method, a laminate molding method, a blow molding method, a hollow molding method, a compression molding method, a calendar molding method and the like, an optical molding method, a three-dimensional layered molding method, and the like.

Moreover, when a resin composition contains curable resin, the hardening reaction of the said curable resin is performed. The curing reaction varies depending on the type of the curable resin and the like, but can be performed by heating or irradiation with energy rays such as ultraviolet rays.
Moreover, you may use in combination of multiple types of resin composition at the time of manufacture of a molded object.

  Further, when the molded body has a base portion formed using a composition not containing ferrite powder and a surface layer provided on the base portion and formed using a composition containing ferrite powder, Using various methods such as dipping, brushing, and other printing methods on the base manufactured by such methods as casting, forging, and powder injection molding (PIM (Powder Injection Molding)) The surface layer may be formed.

  Moreover, you may magnetize at the time of shaping | molding of a molded object. Thereby, it is possible to further improve the ease of detection of the formed body by the metal detector and the stability of the detection.

  Moreover, you may manufacture a molded object by performing post-processing, such as grinding and grinding | polishing, with respect to the molded object obtained by the above shaping | molding methods.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to these.

  For example, in the embodiment described above, in the resin composition, the case where ferrite powder (hard ferrite particles and soft ferrite particles) is present dispersed in the resin material has been mainly described. For example, ferrite powder (hard ferrite particles and soft ferrite particles) is precipitated in a liquid, and may be used after being dispersed by stirring or the like, if necessary. For example, the resin composition of the present invention may be a dispersion in which ferrite powder (hard ferrite particles and soft ferrite particles) and resin particles are dispersed in a volatile liquid. Further, the resin composition of the present invention may have a configuration in which, for example, ferrite powder (hard ferrite particles and soft ferrite particles) and resin powder are simply mixed.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

<< 1 >> Manufacture of Ferrite Powder Prior to the manufacture of the ferrite powders of Examples and Comparative Examples, an aggregate of hard ferrite particles and an aggregate of soft ferrite particles were manufactured as follows.

<Manufacture of aggregates of hard ferrite particles>
(Experimental example H1)
First, Fe ₂ O ₃ and SrCO ₃ were prepared, and these were put into a Henschel mixer at a molar ratio of 5.6: 1.0, and dry-mixed and granulated for 10 minutes.

  Using the fixed electric furnace, the obtained granulated material was fired in the atmosphere at 1075 ° C. for 4 hours (peak).

  Further, the fired product obtained by the above firing is wet pulverized using a bead mill at a solid content of 60% by mass for 30 minutes, washed, dehydrated, dried, and then in the atmosphere at 850 ° C. for 1 hour (peak). Heat treatment was performed to obtain an aggregate of hard ferrite particles.

  The Sr content in the hard ferrite particles thus obtained was 8.78% by mass, and the Fe content was 62.3% by mass.

The content of the metal element in the particles was determined as follows. Specifically, 0.2 g of target particles were weighed, a mixture of pure water: 60 ml and 1N hydrochloric acid: 20 ml and 1N nitric acid: 20 ml was heated to prepare an aqueous solution in which the particles were completely dissolved. The content of each metal element was determined by performing measurement using an analyzer (ICPS-1000IV, manufactured by Shimadzu Corporation). In addition, it calculated | required similarly about each experimental example described later.
The volume average particle size of the hard ferrite particles was 1.8 μm.

  The volume average particle diameter was determined by the following measurement. That is, first, 10 g of particles as a sample and 80 ml of water were placed in a 100 ml beaker, and 2 drops of a dispersant (sodium hexametaphosphate) were added. Subsequently, dispersion was performed using an ultrasonic homogenizer (UH-150 type manufactured by SMT Co. LTD.). At this time, the output level of the ultrasonic homogenizer was set to 4, and dispersion was performed for 20 seconds. Thereafter, bubbles formed on the surface of the beaker were removed and introduced into a Microtrac particle size analyzer (for example, Model 9320-X100 manufactured by Nikkiso Co., Ltd.) for measurement. In addition, it calculated | required similarly about each experimental example described later.

Further, when the hard ferrite particles were measured using a vibration sample type magnetometer, saturation magnetization: 55.8 A · m ² / kg, residual magnetization: 33.4 A · m ² / kg, coercive force: 285 kA / M.

  The above magnetic properties were obtained as follows. That is, first, an aggregate of particles to be measured was packed in a cell having an inner diameter of 5 mm and a height of 2 mm, and set in a vibrating sample type magnetometer (VSM-C7-10A manufactured by Toei Kogyo Co., Ltd.). Next, an applied magnetic field was applied, sweeping was performed to 10K · 1000 / 4π · A / m, and then the applied magnetic field was decreased to prepare a hysteresis curve. Thereafter, saturation magnetization, residual magnetization, and coercive force were obtained from the data of this curve. In addition, it calculated | required similarly about each experimental example, each Example, and each comparative example which are mentioned later.

(Experimental examples H2, H3)
Aggregates of hard ferrite particles were produced in the same manner as in Experimental Example H1 except that the ratio of materials used for the production of the granulated material was as shown in Table 1.

(Experimental example H4)
First, Fe ₂ O ₃ and SrCO ₃ were prepared, and these were mixed at a molar ratio of 5.75: 1.0. Next, this mixture was pulverized for 4.5 hours with a dry media mill (vibration mill, 1/8 inch diameter stainless steel beads), and the obtained pulverized product was formed into pellets of about 1 mm square using a roller compactor. After removing the coarse powder with a vibrating sieve having a mesh opening of 3 mm and then removing the fine powder with a vibrating sieve having a mesh opening of 0.5 mm, the pellets are heated at 1080 ° C. for 3 hours in a rotary electric furnace and temporarily fired. The preliminary sintered body was obtained.

Next, using a dry media mill (vibration mill, 1/8 inch diameter stainless steel beads), pulverize until the volume average particle size becomes about 4 μm, then add water, and further wet media mill (vertical type) It grind | pulverized for 10 hours using the bead mill and a 1/16 inch diameter stainless steel bead, and the aqueous solution (20 mass% solution) of polyvinyl alcohol (PVA) as a binder was added there, and the slurry was obtained. The solid content in the slurry was 55.0% by mass, and the binder content was 1.0% by mass.
Next, the obtained slurry was spray-dried with a spray dryer to obtain a granulated product.

  Then, the particle size adjustment of the obtained granulated material was performed, and further, it heated at 650 degreeC for 2 hours with the rotary electric furnace, and the binder was removed.

  Thereafter, using a fixed electric furnace, the obtained granulated product was fired in the atmosphere at 1185 ° C. for 4 hours (peak), and further crushed and classified to obtain an aggregate of hard ferrite particles.

The Sr content in the hard ferrite particles thus obtained was 8.52% by mass, and the Fe content was 62.7% by mass.
The volume average particle size of the hard ferrite particles was 15.0 μm.

Further, when the hard ferrite particles were measured using a vibration sample type magnetometer (VSM-C7-10A manufactured by Toei Kogyo Co., Ltd.), saturation magnetization: 55.3 A · m ² / kg, residual magnetization: 32 .4A ^· m 2 / kg, a coercive force: was 161kA / m.

(Experimental example H5)
Aggregates of hard ferrite particles were produced in the same manner as in Experimental Example H4 except that the conditions for the pulverization treatment for the temporary sintered body, the conditions for spray drying using a spray dryer, and the conditions for adjusting the particle size for the granulated product were changed.

  The volume average particle size of the hard ferrite particles thus obtained was 39.0 μm.

  For Experimental Examples H1 to H5 described above, the manufacturing conditions for the aggregates of hard ferrite particles are summarized in Table 1, and the characteristics of the aggregates of hard ferrite particles are summarized in Table 2.

<Manufacture of aggregates of soft ferrite particles>
(Experimental example S1)
First, Fe ₂ O ₃ and Mn ₃ O ₄ were prepared, and these were put into a Henschel mixer at a molar ratio of 8.0: 0.67, followed by dry mixing for 10 minutes. Was pelletized with a roller compactor. Thereafter, calcination temperature (calcination temperature): 1000 ° C., and calcination was performed in an air atmosphere rotary kiln.

Next, using a dry media mill (vibration mill, 1/8 inch diameter stainless steel beads), pulverize until the volume average particle size becomes about 4 μm, then add water, and further wet media mill (vertical type) Using a bead mill, 1/16 inch diameter stainless steel beads), the mixture was pulverized for 10 hours, and an aqueous solution of polyvinyl alcohol (PVA) as a binder was added thereto to obtain a slurry. The solid content in the slurry was 55.0% by mass, and the binder content was 1.0% by mass.
Next, the obtained slurry was spray-dried with a spray dryer to obtain a granulated product.

  Then, the particle size adjustment of the obtained granulated material was performed, and further, it heated at 650 degreeC for 2 hours with the rotary electric furnace, and the binder was removed.

  Then, using a fixed electric furnace, the obtained granulated material is fired (peak) at 1280 ° C. for 4 hours (main firing) in a nitrogen atmosphere, and further crushed and classified to collect soft ferrite particles. Got the body.

  The content of Mn in the soft ferrite particles thus obtained was 7.88% by mass, and the content of Fe was 64.13% by mass.

The volume average particle diameter of the soft ferrite particles was 45 μm.
Further, when the soft ferrite particles were measured using a vibrating sample type magnetometer, saturation magnetization: 92 A · m ² / kg, residual magnetization: 6.2 A · m ² / kg, coercive force: 1225 A / m Met.

The soft ferrite particles were measured at a Curie temperature and found to be 450 ° C. The Curie temperature of the soft ferrite particles was determined by measurement based on JIS C 2560-1.
In addition, it calculated | required similarly about each experimental example described later.

(Experimental example S2)
An aggregate of soft ferrite particles was produced in the same manner as in Experimental Example S1 except that the conditions for the pulverization treatment for the temporary sintered body, the conditions for spray drying using a spray dryer, and the conditions for adjusting the particle size for the granulated product were adjusted.

(Experimental example S3)
First, Fe ₂ O ₃ , Mn ₃ O ₄ and carbon black (C) were prepared, and these were charged into a Henschel mixer at a molar ratio of 8.0: 0.67: 1.1, Dry mixing and granulation for 10 minutes.

  The obtained granulated material was fired at 1000 ° C. for 4 hours (peak) in a nitrogen atmosphere using a fixed electric furnace.

  Furthermore, the fired product obtained by the firing was wet-ground using a bead mill at a solid content of 60% by mass for 30 minutes, washed, dehydrated, and dried to obtain an aggregate of soft ferrite particles.

(Experimental examples S4, S5)
An aggregate of soft ferrite particles was produced in the same manner as in Experimental Example S2 except that the ratio of Fe ₂ O ₃ and Mn ₃ O ₄ used as raw materials was as shown in Table 3.

  Regarding the above-described experimental examples S1 to S5, the production conditions of the aggregate of soft ferrite particles are summarized in Table 3, and the characteristics of the aggregate of soft ferrite particles are summarized in Table 4.

<Manufacture of ferrite powder>
(Example A1)
By mixing the aggregate of hard ferrite particles produced in the experimental example H1 and the aggregate of soft ferrite particles produced in the experimental example S3 at a predetermined ratio, hard ferrite particles and soft ferrite particles are mixed. A ferrite powder containing was obtained.

  The aggregate of the hard ferrite particles and the aggregate of the soft ferrite particles were mixed using a Henschel mixer.

(Examples A2 to A8)
Ferrite powder was produced in the same manner as in Example A1 except that the aggregate of hard ferrite particles, the combination of aggregates of soft ferrite particles, and the mixing ratio thereof were as shown in Table 5.

(Comparative Example A1)
The aggregate of hard ferrite particles produced in Experimental Example H2 was used as it was as ferrite powder without being mixed with other particles. That is, the ferrite powder of this comparative example consists of only a plurality of hard ferrite particles.

(Comparative Example A2)
The aggregate of soft ferrite particles produced in Experimental Example S2 was used as it was as ferrite powder without being mixed with other particles. That is, the ferrite powder of this comparative example consists only of a plurality of soft ferrite particles.

  Table 5 summarizes the configurations, magnetic characteristics, and the like of the ferrite powders of the examples and comparative examples described above.

<< 2 >> Production of Resin Composition Using each ferrite powder prepared as described above, a resin composition was produced as follows.

(Example B1)
Using a kneader and a pelletizer, the ferrite powder produced in Example A1 and polypropylene as a resin material were mixed, kneaded, and granulated at a mass ratio of 7.5: 92.5.
This obtained the resin composition as a pellet whose volume average particle diameter is 3 mm.

(Examples B2 and B3)
A resin composition as a pellet was obtained in the same manner as in Example B1 except that the blending ratio of ferrite powder and polypropylene was changed as shown in Table 6.

(Example B4)
Using a kneader and a pelletizer, the ferrite powder produced in Example A1, polypropylene as a resin material, and silica (AEROSIL200, manufactured by Nippon Aerosil Co., Ltd.) as a white pigment in a mass ratio of 7.5: 87 .5: Mixed, kneaded and granulated at 5.0.
This obtained the resin composition as a pellet whose volume average particle diameter is 3 mm.

(Examples B5 and B6)
Except having changed the kind of ferrite powder as shown in Table 6, it carried out similarly to the said Example 1, and obtained the resin composition as a pellet.

(Examples B7 to B9)
A resin composition as a pellet was obtained in the same manner as in Example B1 except that the type of ferrite powder and the type of resin material were as shown in Table 6.

(Example B10)
Using a ball mill, the ferrite powder produced in Example A7 and the nylon powder as the resin material were mixed at a mass ratio of 7.5: 92.5.

  As a result, a resin composition as a mixed powder of ferrite powder and resin powder (nylon powder) was obtained.

(Example B11)
Using a ball mill, the ferrite powder produced in Example A8 and the fluororesin powder as a resin material were mixed at a mass ratio of 7.5: 92.5.

  As a result, a resin composition was obtained as a mixed powder of ferrite powder and resin powder (fluororesin powder).

(Comparative Example B1)
A resin composition as a pellet was obtained in the same manner as in Example B1, except that the type of ferrite powder was changed to the ferrite powder produced in Comparative Example A1.

(Comparative Example B2)
A resin composition as a pellet was obtained in the same manner as in Example B1, except that the type of ferrite powder was changed to the ferrite powder produced in Comparative Example A2.
Table 6 summarizes the conditions of the resin compositions of the respective Examples and Comparative Examples described above.

<< 3 >> Manufacture of molded body (Example C1)
Using a kneader and a T-die, the resin composition (pellet) produced in Example B1 was melted and molded to obtain a sheet-like molded body having a thickness of 100 μm.

(Examples C2 to C9)
A sheet-like molded body was produced in the same manner as in Example C1, except that the pellets produced in Examples B2 to B9 were used instead of the pellets produced in Example B1. did.

(Example C10)
As the resin composition, the mixed powder produced in Example B10 was put into a mold and subjected to pressure molding, and then heated at 180 ° C. for 4 hours to melt and cure the resin, and then cooled to obtain a diameter of 13 mm. A disc-shaped molded body having a thickness of 2.0 mm was produced.

(Example C11)
As a resin composition, a disc-shaped molded body was produced in the same manner as in Example C10 except that the mixed powder produced in Example B11 was used.

(Example C12)
The ferrite powder produced in Example A1 and SiO ₂ were dispersed in a PVA aqueous solution having a solid content of 10% by mass, and coated and dried using an applicator to obtain a sheet-like molded body having a thickness of 100 μm. At this time, the mass ratio of the solid content of PVA, ferrite powder, and SiO ₂ was 75.0 mass%, 20.0 mass%, and 5.0 mass%, respectively.

(Example C13)
The ferrite powder produced in Example A1, a liquid epoxy resin, a polymerization initiator, a boron trifluoride monoethylamine complex as a curing agent, and silica as a white pigment (Nihon Aerosil Co., Ltd., AEROSIL 200). After mixing, the mixture was poured into a mold made of silicone resin. Then, it heated at 120 degreeC, the epoxy resin was hardened, and the disk-shaped molded object of diameter: 13mm and thickness: 2.0mm was manufactured.

  The ferrite powder content in the obtained molded body was 20.0 mass%, the resin material content was 75.0 mass%, and the colorant content was 5.0 mass%.

(Example C14)
The ferrite powder produced in Example A1, the olefinic thermoplastic elastomer, and titanium dioxide particles as a white pigment were mixed, and this mixture was poured into a silicone resin mold. Then, the disk-shaped molded object of diameter: 13mm and thickness: 2.0mm was manufactured by heating at 120 degreeC and cooling after that.

  The ferrite powder content in the obtained molded body was 20.0 mass%, the resin material content was 75.0 mass%, and the colorant content was 5.0 mass%.

(Examples C15 to C18)
A disc-shaped molded body was produced in the same manner as in Example C14 except that the type of the resin material was changed as shown in Table 8.

  Examples C15 and C16 were poured into a mold and then melted and heated at 120 ° C. to produce a disk-shaped molded body having a diameter of 13 mm and a thickness of 2.0 mm.

  Further, the resin used in Examples C17 and C18 was obtained by diluting the resin solid content to 20% by mass with an organic solvent, and added so as to have the resin content described in Table 8 in terms of resin solid content. After pouring into a mold, the organic solvent was removed by heating at 65 ° C., and the resin was cured at 150 ° C.

(Example C19)
After mixing the resin composition (pellet) manufactured in the comparative example B1 and the resin composition (pellet) manufactured in the comparative example B2 at a weight ratio of 1: 1, the mixture is mixed with a kneader and a T-die. The resulting product was melted and molded to obtain a sheet-like molded product having a thickness of 100 μm.

(Comparative Examples C1, C2)
A sheet-like molded body was produced in the same manner as in Example C1, except that the pellets produced in Comparative Examples B1 and B2 were used instead of the pellets produced in Example B1. did.
Tables 7 and 8 collectively show the conditions and the like of the molded bodies of the above-described examples and comparative examples.

<< 4 >> Evaluation of Molded Body << 4-1 >> Detection by Metal Detector With respect to the molded body manufactured in each of the above-described Examples and Comparative Examples, two types of metal detectors were used. Sensitivity (level meter, iron ball sensitivity) that can be detected was determined. That is, as a first metal detector, a belt conveyor type metal detector (manufactured by Nikka Densaku Co., Ltd., fine metal detector NT2-K4B) can be used to pass through the metal detector and detect a compact. While obtaining the sensitivity (level meter, iron ball sensitivity), using a belt conveyor type metal detector (made by System Square, META-HAWKII) as the second metal detector, let the metal detector pass, Sensitivity (level meter, iron ball sensitivity) capable of detecting the molded product was determined and evaluated according to the following criteria.

(First metal detector)
○: Sensitivity equivalent to or higher than 1% by mass of stainless fiber.
X: Sensitivity less than equivalent to 1% by mass of stainless fiber.

(Second metal detector)
○: Iron ball sensitivity diameter of 0.6 mm or more.
X: Iron ball sensitivity diameter less than 0.6 mm.

In addition, about Example C1-C9, C12, C19 and Comparative Example C1, C2 which shape | molded the molded object to the sheet form, it cut | disconnected to 80 mm x 60 mm size, and evaluated the section | slice. About Example C10, C11, C13-C18, the obtained molded object was used for evaluation as it was.
These results are shown in Table 9.

  As is apparent from Table 9, in the present invention, a molded body that can be stably detected by various metal detectors can be obtained. Moreover, in this invention, the surface property of a molded object can be controlled suitably and generation | occurrence | production of the unintentional unevenness | corrugation by containing powder was also prevented effectively. Moreover, in this invention, it was possible to adjust a molded object to various colors with a coloring agent. On the other hand, in the comparative example, a satisfactory result was not obtained.

  The ferrite powder of the present invention is a ferrite powder that can be detected by a metal detector, and includes hard ferrite particles and soft ferrite particles. Therefore, it is possible to provide a ferrite powder that can be suitably used for manufacturing a molded body that can be stably detected by various metal detectors. Therefore, the ferrite powder of the present invention has industrial applicability.

Claims (16)

  A ferrite powder that is detectable by a metal detector and includes hard ferrite particles and soft ferrite particles. Residual magnetization of 20 A · m ² / kg to 40 A · m ² / kg and saturation magnetization of 60 A · m ² / kg to 90 A · m ² according to VSM measurement when a magnetic field of 10 K · 1000 / 4πA / m is applied. The ferrite powder according to claim 1, which has a coercive force of 40 kA / m or more and 180 kA / m or less.   3. The ferrite according to claim 1, wherein the hard ferrite particles include particles containing Sr of 7.8% to 9.0% by mass and Fe of 61.0% to 65.0% by mass. 4. powder.   The soft ferrite particles include particles containing Mn in a range of 3.5 mass% to 20.0 mass% and Fe in a range of 50.0 mass% to 70.0 mass%. Ferrite powder according to item. Claims satisfying the relationship of 0.7 ≦ X _H / X _S ≦ 18, where X _H [mass%] is the hard ferrite particle content and X _S [mass%] is the soft ferrite particle content. Item 5. The ferrite powder according to any one of Items 1 to 4.   The ferrite powder according to any one of claims 1 to 5, wherein the volume average particle size of the hard ferrite particles is 0.1 µm or more and 60 µm or less.   The ferrite powder according to any one of claims 1 to 6, wherein the soft ferrite particles have a volume average particle diameter of 1 µm or more and 100 µm or less. Including hard ferrite particles, soft ferrite particles, and resin material,
A resin composition which can be detected by a metal detector. Ferrite powder according to any one of claims 1 to 7,
A resin composition comprising a resin material.   The resin composition according to claim 8 or 9, wherein the sum of the content of the hard ferrite particles and the content of the soft ferrite particles in the resin composition is 5.0 mass% or more and 90 mass% or less.   The resin material is selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol (PVA), fluororesin, silicone rubber, butadiene rubber, thermoplastic elastomer, epoxy resin, and silicone resin. The resin composition of any one of Claims 8 thru | or 10 containing a seed | species or 2 or more types. Including hard ferrite particles, soft ferrite particles and resin material,
A molded article, wherein the hard ferrite particles and the soft ferrite particles are fixed by a resin material.   The molded product according to claim 12, wherein the sum of the content of the hard ferrite particles and the content of the soft ferrite particles is 2.0 mass% or more and 20 mass% or less.   The molded body according to claim 12 or 13, wherein the molded body is used in food production, processing, and packaging sites.   The molded body according to claim 14, wherein the molded body is used for some or all of cooking utensils, cooking utensils, and food packaging members.   The molded body according to any one of claims 12 to 15, wherein the molded body includes the hard ferrite particles and the soft ferrite particles in a region within 1.0 mm in the thickness direction from the surface.