Heat-curing foam-type binder composition, this magnetic pad and this wireless charging device

Abstract

A thermosetting foam-type binder composition comprising a main polymer resin and a foaming agent, having a foaming initiation temperature of 70 to 110°C, a foaming rate of 50 to 400%, and a viscosity of 3,000 to 100,000 cP. A magnetic pad may incorporate such a thermosetting foam-type binder composition, and a wireless charging device may incorporate such a magnetic pad.

Description

TECHNICAL AREA

[0001] The present invention relates to a heat-curing (e.g. thermosetting) foam-type binder composition, a magnetic pad comprising this composition, and a wireless charging device comprising this composition. BACKGROUND

[0002] Due to the increasing prevalence of electric vehicles, interest in wireless charging technologies is growing. These technologies allow for free battery charging without a wired charging device. Wireless charging technology essentially consists of a transmitter that sends power and a receiver that receives the transmitted power. This transmitter and receiver are composed of coils and magnetic materials. The magnetic material used is a key component determining the efficiency of wireless charging and is provided in the form of a pad within the wireless charging device. Ferrite tiles have been the primary material used for these magnetic pads, but the magnetic materials in ferrite tiles are very brittle due to the nature of ceramic tiles, which are susceptible to impact. Furthermore, they are difficult to manufacture in three-dimensional shapes.In the case of a receiver (vehicle) for a wireless charging system for electric vehicles, a particular disadvantage is that the magnetic material of the ferrite tiles can be easily damaged by vibrations and external impacts during driving. To overcome this disadvantage, efforts have been made to produce magnetic ferrite materials that are resistant to external impacts. Specifically, research has been conducted on flexible materials that can replace highly brittle ferrite tiles, and active research has also been carried out on binders optimized for these materials. BRIEF INVENTION EXPLANATION

[0003] The present invention relates to a thermosetting foam-type binder composition, a magnetic pad comprising therein and a wireless charging device comprising therein, and in particular to a thermosetting foam-type binder composition having thermosetting and foaming properties, comprising a main polymer resin and a foaming agent, a magnetic pad comprising therein and a wireless charging device comprising therein.

[0004] One embodiment of the present invention can solve the problems described above in the related technology, and one embodiment of the present invention can provide: a thermosetting foam-type binder composition comprising a polymer resin and a foaming agent to expand in volume and simultaneously cure when exposed to heat, thereby exhibiting excellent shock resistance and mechanical properties, a magnetic pad comprising this, and a wireless charging device comprising this.

[0005] One embodiment of the present invention can provide a thermosetting foam-type binder composition comprising a main polymer resin and a foaming agent, and having a foaming initiation temperature of 70 to 110°C, a foaming ratio of 50 to 400%, and a viscosity of 3000 to 100000 cP.

[0006] One embodiment of the present invention can provide a magnetic pad comprising 65 to 95 parts by weight of magnetic material pellets, 10 to 25 parts by weight of magnetic material powder, and 1.5 to 7 parts by weight of a thermosetting foam-type composition according to various embodiments of the present invention.

[0007] One embodiment of the present invention can provide a wireless charging device that has a magnetic pad according to one embodiment of the present invention.

[0008] According to one embodiment of the present invention, a magnetic pad comprising a binder composition can undergo volume expansion and a hardening reaction when shaped by pressing or heating. Accordingly, using one embodiment of the present invention, it may be possible to ensure excellent appearance, mechanical strength, and impact resistance.

[0009] A magnetic pad according to an embodiment of the present invention can have excellent electromagnetic properties and can be resistant to external shocks.

[0010] A binder composition according to one embodiment of the present invention can exhibit excellent formability to improve machinability when mixed with ferrite pellets or powder. Therefore, a magnetic pad incorporating such a binder composition can also offer a high degree of design freedom according to one embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and further features and advantages of exemplary embodiments of the present invention are evident from the detailed description of the exemplary embodiments in conjunction with the attached drawings.

[0012] They show: Fig. 1 Images of the appearances seen with the naked eye in Example 5-2 and Comparative Example 3-2 of exemplary embodiments of the present invention, Fig.2 Images of the appearances seen with the naked eye in Example 1-2 and Comparative Example 4-2 of exemplary embodiments of the present invention, and Fig. 3 a diagram in which the density and permeability of examples and comparative examples of exemplary embodiments of the present invention are compared. DETAILED DESCRIPTION OF EXAMPLE EXECUTION FORMS

[0013] The terms used herein, including technical or scientific terms, may have the same meaning as generally understood by experts unless otherwise defined. Terms defined in a commonly used reference work may be interpreted to have the same meanings as in the context of the related technology.

[0014] As used here, terms such as "first," "second," and the like can be used to describe different components, but the components are not necessarily limited by these terms. These terms can merely be used to distinguish one component from another. For example, a first component can be referred to as a second component, and likewise a second component can be referred to as a first component, without thereby departing from the scope of protection of the present invention.

[0015] The terms used herein may only be used to describe specific examples and are not necessarily intended to limit the present invention. A singular expression may have a plural expression unless otherwise defined in a context. It is noted that in the present invention, terms such as "including," "containing," or "having" indicate that a feature, number, step, process, component, part, or combination thereof described in the application is present, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, processes, components, parts, or combinations thereof.

[0016] A thermosetting foam-type binder composition of an embodiment of the present invention may comprise a main polymer resin and a foaming agent.

[0017] In one embodiment of the present invention, the main polymer resin may comprise at least one selected from the group consisting of a silicone resin, a urethane resin, an epoxy resin, a polyester resin and an acrylic resin.

[0018] In various embodiments of the present invention, the main polymer resin can be a two-component polymer resin. In one example, the main polymer resin can be a two-component polymer resin comprising a first component that includes vinyldimethylpolysiloxane and a second component that includes organohydrogenpolysiloxane.

[0019] The first component may also contain dimethylpolysiloxane.

[0020] The first component can contain 25 to 35 parts by weight of vinyldimethylpolysiloxane and 1 to 10 parts by weight of dimethylpolysiloxane.

[0021] The second component may also contain vinyldimethylpolysiloxane.

[0022] The second component may contain 20 to 30 parts by weight of vinyldimethylpolysiloxane and 5 to 15 parts by weight of organohydrogenpolysiloxane.

[0023] In one embodiment of the present invention, the first component and the second component can be mixed or stirred and formed under thermocompression conditions. During such mixing or stirring, the polysiloxane (polymer) contained in the first component and the polysiloxane (polymer) contained in the second component can react with each other to cure. Therefore, the two-component polymer resin comprising the first and second components, and the binder comprising the two-component polymer resin, can be thermosetting.

[0024] As described above, the thermosetting foam-type binder composition of an embodiment of the present invention may include a foaming agent. The foaming agent can fill the pores of magnetic ferrite particles and powders, even at low binder content, by foaming during the manufacture of the magnetic pad, thereby improving its appearance and mechanical properties.

[0025] The foaming agent can be present in a quantity of 1 to 10 parts by weight or 3 to 7 parts by weight.

[0026] If the quantity is smaller than the area, it is possible that even with the application of heat, adequate foam formation will not occur.

[0027] If the quantity is larger than the area, over-foaming can cause a problem of reduced dimensional accuracy during molding.

[0028] The foaming agent may include at least one selected from the group consisting of azo-based, hydrazide-based, inorganic-based and microcapsule-based foaming agents.

[0029] In one example, the foaming agent can be a capsule-type foaming agent with a particle size of 10 to 30 µm. The thermosetting foam-type binder composition according to one embodiment of the present invention can include a foaming agent and can enable volume expansion by foaming upon application of heat. This can improve mechanical properties and result in excellent formability.

[0030] The mixing ratio of the main polymer resin and the foaming agent can be 80:1 to 10:1. In one embodiment, the mixing ratio can preferably be 45:1 to 15:1. Even more preferably, in another embodiment, the mixing ratio can be 35:1 to 15:1.

[0031] If the mixing weight ratio is less than 80:1, the foaming rate may be low, which can affect the appearance and mechanical strength of the magnetic pad.

[0032] At a mixing weight ratio of more than 10:1, the dimensional accuracy of a molded part may be impaired due to over-foaming.

[0033] The thermosetting foam-type binder composition according to various embodiments of the present invention can have a foaming initiation temperature of 70 to 110°C. The foaming initiation temperature of the thermosetting foam-type binder composition can be caused by the foaming initiation temperature of the foaming agent and can hardly be influenced by other components contained in the binder.

[0034] If the foaming initiation temperature is less than the range of 70 to 110°C, the formability and shelf life may be impaired due to early foaming during a thermocompression forming process in the manufacture of the magnetic pad according to an embodiment of the present invention.

[0035] If the foaming initiation temperature is greater than the range of 70 to 110°C, the foaming effect during the thermocompression forming process in the manufacture of the magnetic pad according to one embodiment of the invention may be minimal.

[0036] The thermosetting foam-type binder composition according to various embodiments of the present invention can exhibit a foaming rate of 50 to 400%. In one embodiment of the present invention, the foaming rate can refer to a volume increase rate when 10 g of the binder is injected into an aluminum cup and exposed to a temperature of 175°C for 10 minutes.

[0037] If the foaming rate is below the range of 50 to 400%, the foaming effect may be reduced and the formability and appearance may be impaired in the manufacture of the magnetic pad according to an embodiment of the present invention.

[0038] If the foaming rate exceeds the range of 50 to 400%, the density may be reduced and the dimensional stability may be impaired due to over-foaming during the manufacture of the magnetic pad according to an embodiment of the present invention.

[0039] The thermosetting foam-type binder composition according to various embodiments of the present invention can have a viscosity of 3000 to 100000 cP.

[0040] If the viscosity is below the specified range, the mixing stability of the binder, the magnetic material pellets and the powder may be impaired, resulting in binder sedimentation during the manufacture of the magnetic pad according to one embodiment of the present invention.

[0041] If the viscosity exceeds the specified range, the uniformity of the mixture of the binder, the magnetic material pellets and the powder may be impaired in the manufacture of the magnetic pad according to one embodiment of the present invention.

[0042] The thermosetting foam-type binder composition according to one embodiment of the present invention may further comprise an additive. The additive may include a (curing) catalyst, a curing retarder, a silane coupling agent, an inorganic filler, a lubricant, and the like. However, the additive is not limited to these, and the use of any additive suitable for improving the properties of the thermosetting foam-type binder composition is possible.

[0043] In one embodiment of the present invention, the (hardening) catalyst may comprise platinum (Pt). In one example, the catalyst may be contained in the first component. In another embodiment, the catalyst may be contained in an amount of 0.001 to 0.1 parts by weight.

[0044] In one embodiment of the present invention, the hardening retarder may be a compound having aliphatic unsaturated bonds. For example, the compound containing the aliphatic unsaturated bonds may have one, two, or more substances from the group consisting of 1-ethinyl-1-cyclohexanol, 3-methyl-1-penten-3-ol, 2-methyl-3-butyn-2-ol, 3-phenyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 1,5-hexadiyne, 1,6-heptadiyne, 3,5-dimethyl-1-hexyne, 2-ethyl-3-butyne, 2-phenyl-3-butyne, 1,3-divinyltetramethyldisiloxane, 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, and 1,3-Divinyl-1,3-diphenyldimethyldisiloxane are selected.

[0045] In one embodiment of the present invention, the curing retarder can be 1-ethynylcyclohexanol (ECH). However, the curing retarder is not limited to this, and any curing retarder available in this field can be used. The curing retarder can serve to improve preservation stability or to adjust the reactivity of a hydrosilylation reaction during the curing process.

[0046] In one example, the hardening retarder can be contained in the second component. The hardening retarder can be present in an amount ranging from 0.01 to 1 part by weight.

[0047] In one embodiment of the present invention, the silane coupling agent can be at least one selected from the group consisting of, for example, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, and methyltriacetoxysilane. However, the silane coupling agent is not limited thereto, and any silane coupling agent available in the field can be used. In one embodiment, the silane coupling agent can preferably be an epoxy-based silane or an amino-based silane.

[0048] The silane coupling agent can comprise both a reactive group that can bind to an organic functional group and a reactive group that can bind to an inorganic material within the molecule. This can improve the adhesion between different materials. The associated mechanical strength, water resistance, weather resistance, heat resistance, etc., can also be improved. In one embodiment of the present invention, the silane coupling agent can improve the interfacial adhesion between the thermosetting foam-type binder and a ferrite filler (powder or pellet).

[0049] In one embodiment of the present invention, the silane coupling agent can be contained in the first component or in the second component.

[0050] The inorganic filler according to one embodiment of the present invention can comprise at least one selected from the group consisting of talc, clay, calcium carbonate, mica, whiskers, silica dust, carbon fiber, barium sulfate, and wollastonite. The inorganic filler can impart excellent filling properties, elongation, heat resistance, cold resistance, and weather resistance. The inorganic filler can effectively repair cracks caused by various factors and improve fire resistance by increasing the flash point.

[0051] In one embodiment of the present invention, the inorganic filler can be silica dust (or pyrogenic silicon dioxide). However, the inorganic filler is not limited to this, and any inorganic filler that is available in this field can be used.

[0052] In one example, the inorganic filler can be present in both the first and second components. At this point, the inorganic filler in the first component can be present in an amount of 5 to 17 parts by weight. The inorganic filler in the second component can be present in an amount of 5 to 15 parts by weight.

[0053] In one embodiment of the present invention, the lubricant may comprise any lubricant selected from the group consisting of, for example, fatty acid-based lubricants such as stearic acid, hydroxystearic acid complex-stearic acid and oleic acid; lubricants based on aliphatic alcohols; lubricants based on aliphatic amides such as stearamide, oxystearamide, oleylamide, elsylamide, ricinolamide, behenamide, methylolamide, methylenebisstearamide, methylenebisstearbehenamide, bisamic acid of higher fatty acids and complex amides; lubricants based on aliphatic esters such as n-butylstearate, methylhydroxystearate, fatty acid esters of polyhydric alcohols, saturated fatty acid esters and ester waxes; lubricants based on fatty acid metal soap, and combinations thereof.The lubricant can be included in the thermosetting foam-type binder composition according to an embodiment of the present invention to reduce friction between particles, thereby improving density and preventing internal stresses.

[0054] In one embodiment of the present invention, the lubricant can be contained in the first component or in the second component.

[0055] The magnetic pad of an embodiment of the present invention can comprise magnetic material pellets, magnetic material powder and a thermosetting foam-type composition according to various embodiments of the present invention.

[0056] In one example, the magnetic pad can be produced by mixing magnetic material pellets, magnetic material powder and the thermosetting foam type composition according to various embodiments of the present invention to produce a paste, and subsequently thermocompressing the paste.

[0057] Thermocompression can cause volume expansion and heat hardening within the magnetic pad, resulting in excellent shock resistance and malleability.

[0058] The magnetic material pellet can be a MnZn ferrite pellet. For example, the magnetic material pellet could be a spherical MnZn ferrite pellet with a diameter of 2 mm to 5 mm.

[0059] The magnetic pad of an embodiment of the present invention can contain the magnetic material pellets in an amount of 65 to 95 parts by weight. Preferably, in one embodiment, the magnetic material pellets can be contained in an amount of 70 to 80 parts by weight. If the magnetic material pellets are contained in an amount of less than 65 parts by weight, the magnetic properties of the magnetic pad may be impaired. If the magnetic material pellets are contained in an amount greater than 95 parts by weight, the formability of the magnetic pad may be impaired. Therefore, the aforementioned range may be preferred for an embodiment.

[0060] The magnetic material powder can be MnZn ferrite powder. For example, the magnetic material powder could be an MnZn ferrite powder with a diameter of 75 µm to 85 µm.

[0061] The magnetic pad of an embodiment of the present invention may contain the magnetic material powder in an amount of 10 to 25 parts by weight. Preferably, in one embodiment, the magnetic material powder may be contained in an amount of 15 to 21 parts by weight. If the magnetic material powder is contained in an amount of less than 10 parts by weight, the formability of the magnetic pad may be impaired. If the magnetic material powder is contained in an amount of more than 25 parts by weight, the magnetic properties of the magnetic pad may be impaired. Therefore, the aforementioned range may be preferred for one embodiment.

[0062] The magnetic pad of an embodiment of the present invention can comprise 1.5 to 7 parts by weight of the thermosetting foam-type composition according to various embodiments of the present invention described above. Preferably, in one embodiment, the thermosetting foam-type composition may be present in an amount of 2 to 5 parts by weight. If the thermosetting foam-type composition is present in an amount of less than 1.5 parts by weight, the formability of the magnetic pad may be impaired. If the thermosetting foam-type composition is present in an amount of more than 7 parts by weight, the magnetic properties of the magnetic pad may be impaired. Therefore, the aforementioned range may be preferred in one embodiment.

[0063] Since the thermosetting foam type composition can be the same as the thermosetting foam type composition according to various embodiments described above, a description of the same is omitted.

[0064] The wireless charging device of an embodiment of the present invention can comprise the magnetic pad according to various embodiments of the present invention as described above. In one example, the wireless charging device can be a wireless charging device for an electric vehicle.

[0065] The present invention is described in more detail below with reference to examples. However, the following examples and experimental examples serve only to describe the present invention in more detail, and the scope of application of the present invention is not necessarily limited by the following examples and experimental examples. Example 1 Example 1-1

[0066] To produce a two-component, thermosetting foam-type binder, a first component and a second component were prepared. The first component was prepared by mixing 31.3 parts by weight of vinyldimethylpolysiloxane (viscosity 7000 cP), 4.9 parts by weight of dimethylpolysiloxane (viscosity 6000 cP), 12.2 parts by weight of pyrogenic silicon dioxide, and 0.039 parts by weight of a platinum catalyst (Pt 1%).

[0067] The second component was prepared by mixing 24.3 parts by weight of vinyldimethylpolysiloxane (viscosity 7000 cP), 10.7 parts by weight of organohydrogenpolysiloxane (viscosity 5000 cP), 10.3 parts by weight of pyrogenic silicon dioxide and 0.029 parts by weight of a hardening retarder (ECH, 1-Ethinyl-1-cyclohexanol).

[0068] After mixing the prepared first and second components, an additional 3.0 parts by weight of a capsule-type foaming agent (foaming initiation temperature of 90°C, particle size of 15 µm) was added. The mixture was stirred and degassed to produce a binder. Example 1-2

[0069] A magnetic pad incorporating a thermosetting foam-type binder was manufactured.

[0070] First, 76.2 g (3 mm diameter) of MnZn ferrite pellets, 19.0 g (80 µm diameter) of MnZn ferrite powder, and 4.8 g of the binder according to Example 1-1 were mixed in a horizontal rotary mixer for 1 hour to produce a paste. The resulting paste was filled into a mold measuring 100 mm wide x 100 mm long x 5 mm high and then compressed at a pressure of 0.35 t / cm². 2 Compressed for 10 minutes using a press preheated to 120°C to produce a magnetic pad. Example 2 Example 2-1

[0071] A binder was prepared in the same manner as in Example 1-1, except that vinyldimethylpolysiloxane (viscosity 4000 cP) and dimethylpolysiloxane (viscosity 3000 cP) were used as the first component and vinyldimethylpolysiloxane (viscosity 4000 cP) and organohydrogen polysiloxane (viscosity 2500 cP) were used as the second component. Example 2-2

[0072] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 2-1. Example 3 Example 3-1

[0073] A binder was prepared in the same manner as in Example 1-1, except that vinyldimethylpolysiloxane (viscosity 30000 cP) and dimethylpolysiloxane (viscosity 25000 cP) were used as the first component and vinyldimethylpolysiloxane (viscosity 30000 cP) and organohydrogen polysiloxane (viscosity 20000 cP) were used as the second component. Example 3-2

[0074] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 3-1. Example 4 Example 4-1

[0075] A binder was prepared in the same manner as in Example 1-1, except that 1.5 parts by weight of a capsule-type foaming agent were added. Example 4-2

[0076] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 4-1. Example 5 Example 5-1

[0077] A binder was prepared in the same manner as in Example 1-1, except that 5.0 parts by weight of the capsule-type foaming agent were added. Example 5-2

[0078] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 5-1. Example 6 Example 6-1

[0079] A binder was prepared in the same manner as in Example 1-1, except that a capsule-type foaming agent with a foaming initiation temperature of 75°C was used. Example 6-2

[0080] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 6-1. Example 7 Example 7-1

[0081] A binder was prepared in the same manner as in Example 1-1, except that a capsule-type foaming agent with a foaming initiation temperature of 105°C was used. Example 7-2

[0082] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Example 7-1. Comparison example 1 Comparison example 1-1

[0083] A binder was prepared in the same manner as in Example 1-1, except that vinyldimethylpolysiloxane (viscosity 1000 cP) and dimethylpolysiloxane (viscosity 800 cP) were used as the first component and vinyldimethylpolysiloxane (viscosity 1000 cP) and organohydrogen polysiloxane (viscosity 800 cP) were used as the second component. Comparison example 1-2

[0084] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 1-1. Comparison example 2 Comparison example 2-1

[0085] A binder was prepared in the same manner as in Example 1-1, except that vinyldimethylpolysiloxane (viscosity 90000 cP) and dimethylpolysiloxane (viscosity 80000 cP) were used as the first component and vinyldimethylpolysiloxane (viscosity 90000 cP) and organohydrogen polysiloxane (viscosity 85000 cP) were used as the second component. Comparative example 2-2

[0086] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 2-1. Comparison example 3 Comparison example 3-1

[0087] A binder was prepared in the same way as in Example 1-1, except that no foaming agent was added. Comparison example 3-2

[0088] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 3-1. Comparison example 4 Comparison example 4-1

[0089] A binder was prepared in the same manner as in Example 1-1, except that 0.5 parts by weight of a capsule-type foaming agent were added. Comparison example 4-2

[0090] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 4-1. Comparison example 5 Comparison example 5-1

[0091] A binder was prepared in the same manner as in Example 1-1, except that 10.0 parts by weight of a capsule-type foaming agent were added. Comparative example 5-2

[0092] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 5-1. Comparison example 6 Comparison example 6-1

[0093] A binder was prepared in the same manner as in Example 1-1, except that a capsule-type foaming agent with a foaming initiation temperature of 60°C was used. Comparative example 6-2

[0094] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 6-1. Comparison example 7 Comparison example 7-1

[0095] A binder was prepared in the same manner as in Example 1-1, except that a capsule-type foaming agent with a foaming initiation temperature of 125°C was used. Comparative example 7-2

[0096] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 7-1. Comparison example 8 Comparison example 8-1

[0097] A conventional QS119F two-component silicone foam with a foaming initiation temperature of room temperature was used as the binder. Comparative example 8-2

[0098] A magnetic pad was produced in the same way as in Example 1-2, except that the binder was used according to Comparative Example 8-1.

[0099] The binder compositions of the above examples and comparison examples have been summarized in the following Table 1. [Table 1] First component Second component Foaming agents (foaming initiation temperature, particle size) Vinyldimethylpolysiloxane (viscosity) Dimethylpolysiloxane (viscosity) Extender catalyst Vinyldimethylpolysiloxane (viscosity) Organohydrogen polysiloxane (viscosity) Extender Hardening retarder Example 1-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 3.0 (90°C, 15 µm) Example 2-1 31.3 (4000 cP) 4.9 (3000 cP) 12,2 0,039 24.3 (4000 cP) 10.7 (2500 cP) 10,3 0,029 3.0 (90°C, 15 µm) Example 3-1 31.3 (30000 cP) 4.9 (25000 cP) 12,2 0,039 24.3 (30000 cP) 10.7 (20000 cP) 10,3 0,029 3.0 (90°C, 15 µm) Example 4-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 1.5 (90°C, 15 µm) Example 5-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 5.0 (90°C, 15 µm) Example 6-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 3.0 (75°C, 15 µm) Example 7-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 3.0 (105°C, 15 µm) See example 1-1 31.3 (1000 cP) 4.9 (800cP) 12,2 0,039 24.3 (1000 cP) 10.7 (800cP) 10,3 0,029 3.0 (90°C, 15 µm) See example 2-1 31.3 (90000 cP) 4.9 (80,000 cP) 12,2 0,039 24.3 (90000 cP) 10.7 (85000 cP) 10,3 0,029 3.0 (90°C, 15 µm) See example 3-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 - See example 4-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 0.5 (90°C, 15 µm) See example 5-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 10.0 (90°C, 15 µm) See example. 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24,3(7000 10.7 (5000 cP) 10,3 0,029 3.0 (60°C, 15 µm) 6-1 cP) See example 7-1 31.3 (7000 cP) 4.9 (6000cP) 12,2 0,039 24.3 (7000 cP) 10.7 (5000 cP) 10,3 0,029 3.0 (125°C, 15 µm) See example 8-1 QS119F 2-component silicone foam Experiment 1: Measurement of binder properties

[0100] In Experiment 1, the properties (viscosity, foaming rate, foaming initiation temperature, and working time) of the binders were measured according to the examples and comparison examples and summarized in Table 2 below. Viscosity was measured using a Brookfield viscometer, foaming rate was measured by exposing 10 g of the binder to 175°C in an aluminum beaker for 10 minutes to measure the rate of volume increase, and working time referred to the point at which machinability deteriorated due to an increase in viscosity caused by a curing reaction at room temperature. [Table 2] viscosity Binder properties Viscosity (cP) Foaming rate (%) Foaming initiation temperature (°C) Processing time (25°C) Example 1-1 10000 150 90 After 3 days Example 2-1 5000 150 90 After 3 days Example 3-1 40000 150 90 After 3 days Example 4-1 10000 80 90 After 3 days Example 5-1 10000 250 90 After 3 days Example 6-1 10000 150 75 After 3 days Example 7-1 10000 150 105 After 3 days Comparison example 1-1 1500 150 90 After 3 days Comparative example 2-1 150000 80 90 After 3 days Comparative example 3-1 10000 0 n / a After 3 days Comparative example 4-1 10000 30 90 After 3 days Comparative example 5-1 10000 500 90 After 3 days Comparative example 6-1 10000 420 60 After 3 days Comparative example 7-1 10000 20 125 After 3 days Comparative example 8-1 8000 350 25 Within 10 minutes

[0101] Referring to Table 2, it can be seen that the binders in the examples all have a foaming initiation temperature of 70 to 110°C, a foaming rate of 50 to 400%, and a viscosity of 3,000 to 100,000 cP. On the other hand, it can be seen that the viscosity of comparison examples 1 and 2 is outside the range, the foaming initiation temperature of comparison examples 3, 6 to 8 is outside the range, and the foaming rate of comparison examples 3 to 7 is outside the range. It can therefore be concluded that the binders in the examples are superior to the binders in the comparison examples with regard to formability and magnetic properties in the production of the magnetic pads. Experimental Example 2: Evaluation of Miscibility

[0102] In experimental example 2, the following experiment was carried out to measure and evaluate the miscibility of the magnetic pads according to the examples and comparison examples.

[0103] During the production of the magnetic pads according to the examples and comparative examples, the mixing state of a paste prepared as an intermediate product was visually inspected. If the MnZn ferrite pellets, powder, and binder were observed to be uniformly mixed, the miscibility was rated 5. Conversely, if the binder was not uniformly applied, if there was significant clumping between the MnZn ferrite pellets and the powder, or if the binder was unstable, the miscibility was rated 1. The results are presented in Table 3 below. [Table 3] Magnetic pad properties Paste miscibility Example 1-2 4 Example 2-2 5 Example 3-2 4 Example 4-2 4 Example 5-2 4 Example 6-2 4 Example 7-2 4 Comparison example 1-2 2 Comparative example 2-2 1 Comparison example 3-2 4 Comparison example 4-2 4 Comparative example 5-2 4 Comparative example 6-2 4 Comparative example 7-2 4 Comparative example 8-2 1

[0104] Referring to Table 3, it can be seen that in the examples, the MnZn ferrite pellets, the powder, and the binder were observed to be uniform, and the evaluation values ​​were therefore 4 or higher, whereas in the comparison examples, the evaluation values ​​were 1 to 4, indicating lower uniformity than in the examples. It can therefore be concluded that the magnetic pads in the examples are superior with respect to their mechanical properties. Experiment 3: Measurement of mechanical strength and impact resistance

[0105] In Experiment 3, the mechanical strength, e.g., impact resistance, of the magnetic pads according to the examples and comparison examples was evaluated. The magnetic pads of the examples and comparison examples were manufactured and then dropped three times from a height of 1.5 m to observe whether the magnetic pads broke or the pellets detached. If the magnetic pads broke or cracked, or if some of the pellets detached at the corners, the appearance of the pads was rated as "poor," and if there was no deformation after the drop, the appearance of the pads was rated as "good." The results are presented in Table 4 below. [Table 4] Magnetic pad properties Pad appearance Impact resistance (three drops from a height of 1.5 m) Example 1-2 Good Passed Example 2-2 Good Passed Example 3-2 Good Passed Example 4-2 Good Passed Example 5-2 Good Passed Example 6-2 Good Passed Example 7-2 Good Passed Comparison example 1-2 Poor (unevenness of the binder) NG (replacement of pellets) Comparative example 2-2 Poor (unevenness of the binder) NG (replacement of pellets) Comparison example 3-2 Poor (unevenness of dimensions) NG (replacement of pellets) Comparison example 4-2 Poor (unevenness of dimensions) NG (replacement of pellets) Comparative example 5-2 Poor (unevenness of dimensions) Passed Comparative example 6-2 Poor (unevenness of dimensions) Passed Comparative example 7-2 Poor (unevenness of dimensions) NG (replacement of pellets) Comparative example 8-2 Poor shaping Poor shaping

[0106] As shown in Table 4, all magnetic pads in the comparison examples were rated as "poor" in terms of pad appearance after the drop test, as the pads broke, for example. Furthermore, pellet detachment was observed in comparison examples 1-2 to 4-2 and 7-2 to 8-2. Conversely, no pellet detachment was observed in any of the magnetic pads in the examples, none of which broke or cracked, resulting in a "good" rating for pad appearance. This demonstrates that the magnetic pads in the examples exhibit excellent impact resistance and superior mechanical properties compared to the magnetic pads in the comparison examples.

[0107] Meanwhile, the forming states and detachment of the magnetic pads were visually observed according to the examples and comparison examples. The appearances of the magnetic pad from Example 5-2 and the magnetic pad from Comparison Example 3-2 were visually examined and are shown in Fig. 1 shown, and the appearances of the magnetic pad from Example 1-2 and the magnetic pad from Comparison Example 4-2 were visually examined and are in Fig. 2 shown.

[0108] Referring to Fig. It can be confirmed that the magnetic pad from comparison example 3-2 has an uneven surface. This may be because the magnetic pad in comparison example 3-2 does not contain a foaming agent, resulting in low dimensional stability and poor malleability.

[0109] Referring to Fig.Figure 2 shows that the magnetic pad of comparison example 4-2 has a poor pad appearance and pellets are detaching. The reason for this could be that comparison example 4-2 contains a low amount of foaming agent and therefore has insufficient foaming properties. Experiment 4: Measuring density

[0110] In experimental example 4, the densities of the magnetic pads were measured according to the examples and comparison examples. The densities were calculated using the following equation 1. Density (%) = Weight of the magnetic pad / Volume of the magnetic pad × 100

[0111] The results are listed in Table 5 below. [Table 5] Magnetic pad properties Density (g / cm³) 3 ) Example 1-2 3,85 Example 2-2 3,80 Example 3-2 3,89 Example 4-2 3,78 Example 5-2 3,90 Example 6-2 3,88 Example 7-2 3,85 Comparison example 1-2 3,82 Comparative example 2-2 3,55 Comparison example 3-2 3,75 Comparison example 4-2 3,77 Comparative example 5-2 3,55 Comparative example 6-2 3,65 Comparative example 7-2 3,75 Comparative example 8-2 3,45

[0112] Referring to Table 5, it can be seen that the densities of the magnetic pads according to the comparison examples are 3.45 to 3.82, while the densities of the magnetic pads according to the examples are 3.78 to 3.90. From this, it can be deduced that the magnetic pads in the examples have relatively high densities and are therefore superior in terms of dimensional stability. Experiment 5: Measurement of dimensional accuracy

[0113] In experimental example 5, the dimensional accuracy of the magnetic pads was measured according to the examples and comparison examples. The dimensional accuracy was evaluated by defining (actual sample volume / mold volume × 100 (%)). The actual sample volume was measured using a hydrometer to determine the actual volume of the produced magnetic pad. The results are shown in Table 6 below. [Table 6] Magnetic pad properties Dimensional accuracy (%) Example 1-2 98,5 % Example 2-2 98,2 % Example 3-2 98,3 % Example 4-2 98,1 % Example 5-2 99,3 % Example 6-2 99,2 % Example 7-2 98,1 % Comparison example 1-2 96,5 % Comparative example 2-2 91,5 % Comparison example 3-2 92,1 % Comparison example 4-2 94,2 % Comparative example 5-2 103,0 % Comparative example 6-2 102,1 % Comparative example 7-2 93,1 % Comparative example 8-2 Poor design

[0114] Referring to Table 6, it can be seen that the magnetic pads in the examples all exhibited a dimensional accuracy of 98 to 100%. In contrast, the magnetic pads in the comparison examples often had a dimensional accuracy of 91 to 95%, and it was particularly confirmed that the magnetic pad in comparison example 8-2 itself had poor shape. This further confirmed that the magnetic pads in the examples exhibited better formability. Experiment 6: Measurement of magnetic properties

[0115] In Experiment 6, the permeability of the magnetic pads was measured according to the examples and comparison examples. The magnetic pads from the examples and comparison examples were formed into a toroidal shape with an outer diameter of 39 mm × inner diameter of 17 mm × height of 5 mm, and then 10 turns of Φ 0.5 (e.g., Ø 0.5) copper wire were wound to measure the inductance using an LCR meter, and the permeability was converted based on the following Equation 2. μ(Permeability)=(L×l)(0.4×π×N2×A×0.01) (L: Inductance (uH) (e.g. µH), I: Mean free path (cm), N: Number of turns, A: Cross-sectional area (cm²) 2 )

[0116] The results are listed in Table 7 below. [Table 7] Magnetic pad properties permeability Example 1-2 58,3 Example 2-2 54,5 Example 3-2 56,9 Example 4-2 53,9 Example 5-2 56,6 Example 6-2 54,3 Example 7-2 56,8 Comparison example 1-2 51,9 Comparative example 2-2 37,7 Comparison example 3-2 50,5 Comparison example 4-2 50,9 Comparative example 5-2 41,1 Comparative example 6-2 44,1 Comparative example 7-2 50,8 Comparative example 8-2 35,6

[0117] Referring to Table 7, it can be seen that the magnetic pads of the examples exhibit permeability values ​​of 53.9 to 58.3, while the magnetic pads of the comparison examples exhibit permeability values ​​of 35.6 to 51.9. This demonstrates that the magnetic pads of the examples are superior to the magnetic pads of the comparison examples with respect to their magnetic properties. Meanwhile, a graph was created to establish a relationship between the densities of the examples and the comparison examples measured in Experiment 4 and the permeability measured in Experiment 6, as shown in [reference to graph]. Fig. 3 shown. As from Fig. As can be seen in Figure 3, the examples show higher values ​​than the comparison examples in terms of both density and permeability.

[0118] The present invention has been described above with reference to preferred embodiments thereof. Those skilled in the field will recognize that the present invention can be implemented in modified form without departing from the scope of protection of the present invention. Therefore, the disclosed examples should be considered from an illustrative rather than a necessarily limiting perspective. The scope of the present invention can be described by the attached claims, and differences within the scope of equivalents thereof may be considered as being contained in the present invention.

Claims

[1] Thermosetting foam-type binder composition comprising: a main polymer resin and a foaming agent that achieves a foaming initiation temperature of 70 to 110°C, has a foaming rate of 50 to 400% and a viscosity of 3000 to 100000 cP. [2] Composition according to claim 1, wherein the main polymer resin and the foaming agent are mixed in a weight ratio of the main polymer resin to the foaming agent in a mixing ratio range of 80:1 to 10:

1. [3] Composition according to claim 1 or 2, wherein the main polymer resin is a two-component type polymer resin, comprising: a first component comprising vinyldimethylpolysiloxane, and a second component comprising organohydrogen polysiloxane. [4] Composition according to claim 3, wherein the first component further comprises dimethylpolysiloxane, and wherein the second component further comprises vinyldimethylpolysiloxane. [5] Composition according to claim 4, wherein the first component comprises: 25 to 35 parts by weight of vinyldimethylpolysiloxane and 1 to 10 parts by weight of dimethylpolysiloxane, and where the second component exhibits: 20 to 30 parts by weight of vinyldimethylpolysiloxane and 5 to 15 parts by weight of organohydrogen polysiloxane. [6] Composition according to any one of claims 1 to 5, wherein the foaming agent comprises at least one selected from the group consisting of azo-based, hydrazide-based, inorganic-based and microcapsule-based foaming agents. [7] Composition according to any one of claims 1 to 6, wherein the foaming agent is a capsule-type foaming agent having a particle size of 10 to 30 µm. [8] Magnetic pad, comprising: comprising 1.5 to 7 parts by weight of a thermosetting foam-type binder composition: a main polymer resin and a foaming agent that has a foaming initiation temperature of 70 to 110°C, a foaming rate of 50 to 400% and a viscosity of 3000 to 100000 cP. [9] Magnetic pad according to claim 8, wherein the main polymer resin is a two-component type polymer resin, comprising: a first component comprising vinyldimethylpolysiloxane, wherein the first component further comprises dimethylpolysiloxane, and wherein the first component comprises: 25 to 35 parts by weight of vinyldimethylpolysiloxane and 1 to 10 parts by weight of dimethylpolysiloxane, and a second component comprising organohydrogen polysiloxane, wherein the second component further comprises vinyldimethyl polysiloxane, and wherein the second component comprises: 20 to 30 parts by weight of vinyldimethylpolysiloxane and 5 to 15 parts by weight of organohydrogen polysiloxane. [10] Magnetic pad according to claim 9, wherein the foaming agent comprises at least one selected from the group consisting of azo-based, hydrazide-based, inorganic-based and microcapsule-based foaming agents, wherein the foaming agent is a capsule-type foaming agent with a particle size of 10 to 30 µm, wherein the main polymer resin and the foaming agent are mixed in a weight ratio of the main polymer resin to the foaming agent in a mixing ratio range of 80:1 to 10:

1. [11] Wireless charging device comprising the magnetic pad according to any one of claims 8 to 10. [12] Wireless charging device according to claim 11, wherein the main polymer resin is a two-component type polymer resin, comprising: a first component comprising vinyldimethylpolysiloxane, wherein the first component further comprises dimethylpolysiloxane and wherein the first component comprises: 25 to 35 parts by weight of vinyldimethylpolysiloxane and 1 to 10 parts by weight of dimethylpolysiloxane, and a second component comprising organohydrogen polysiloxane, wherein the second component further comprises vinyldimethyl polysiloxane, and wherein the second component comprises: 20 to 30 parts by weight of vinyldimethylpolysiloxane and 5 to 15 parts by weight of organohydrogen polysiloxane. [13] Wireless charging device according to claim 12, wherein the foaming agent comprises at least one selected from the group consisting of azo-based, hydrazide-based, inorganic-based and microcapsule-based foaming agents, wherein the foaming agent is a capsule-type foaming agent having a particle size of 10 to 30 µm, and wherein the main polymer resin and the foaming agent are mixed in a weight ratio of 80:1 to 10:1.

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