KR20030078498A - Paint Composition for shielding or absorbing electromagnetic waves or providing metal or magnetic property and method for producing the composition - Google Patents

Abstract

PURPOSE: A metal magnetic composition and its preparation method are provided, to absorb and screen the electromagnetic wave by coating the composition on the surface of an electronic device. CONSTITUTION: The metal magnetic composition comprises 30-95 wt% of metal magnetic powder with a particle size of 0.03-100 micrometers; and 5-70 wt% of a binder resin. Preferably the metal magnetic powder is at least one selected from the group consisting of Sr-ferrite, Ba-ferrite, Mn-Zn-ferrite, Mg-Zn-ferrite, Ni-Zn-ferrite, permalloy, supermalloy, sendust, Fe, Cu, Ni, Al, NdFeB alloy, AlNiCo alloy and SmCo alloy; and the binder resin is at least one liquid resin selected from the group consisting of an acryl resin, a polyurethane resin, a polyester resin, an alkyd resin, a fluorinated resin, a silicone resin, a polycarbonate resin, a polyamide resin, an aldehyde resin and a poly(vinyl alcohol) resin.

Description

Paint Composition for shielding or absorbing electromagnetic waves or providing metal or magnetic property and method for producing the composition

The present invention relates to electromagnetic shielding, absorption, and to metal and magnetic paint compositions and methods of manufacturing the same. More specifically, the present invention relates to electromagnetic shielding, absorption, and metal and magnetic paint compositions including metal and magnetic powders and liquid binder resins, and methods of manufacturing the same. In modern times, the use of various electric and electronic devices such as TVs, computers, mobile phones, pagers, notebooks, and facsimiles is increasing in everyday life. By the way, most of these electrical and electronic devices emit electromagnetic waves, causing malfunction of electronic devices and impeding wireless communication. In addition, since electromagnetic waves emitted from the electrical and electronic devices have many harmful effects on the human body, efforts to reduce such electromagnetic waves have been continued. In order to reduce electromagnetic waves of electrical and electronic equipment, an ultrasonic oscillator using ferrite or nickel is usually mounted on the front of the electrical and electronic equipment, the apparatus is covered with copper, or the electrical and electronic equipment is packaged in a case composed of yttrium oxide. This is known. However, while the configuration of the device has become complicated and expensive, it has been difficult to achieve the desired degree of shielding effect. In addition, by shielding or separating electromagnetic waves by coating using a rolled plate such as Permalloy, the weight of the electrical and electronic equipment coated with the rolled plate is excessively disadvantageous. In addition, since the metal plate has to be cut or bent or welded, there is a problem that the work process is complicated and the cost is increased.

The present invention is to solve the above problems, an object of the present invention is to provide a paint composition that can easily shield the electromagnetic wave emitted from the electrical and electronic equipment by simply applying to the inner or outer walls of the electrical and electronic equipment. In addition, by applying a thickness of 0.05 to 5mm to a variety of materials, such as PET, PP, PE or PA film, paper, glass, wood, etc. to provide a paint composition that can easily exhibit the properties of the magnetic body.

The present invention is to achieve the above object, the electromagnetic wave shielding, absorption and magnetic paint composition according to the present invention, comprising 30 to 95% by weight of the metal and magnetic powder and 5 to 70% by weight of the binder resin It is characterized by. In addition, the electromagnetic wave shielding, absorption and production method of the metal and magnetic paint composition according to the present invention, Sr-ferrite, Ba-ferrite, Mn-Zn ferrite, Mg-Zn ferrite, Ni-Zn ferrite, permalloy (permalloy), Supermalloy, sanddust, Fe, Cu, Ni, Al, neodymium-iron-boron alloys (NdFeB), aluminum-nickel-cobalt alloys (AlNiCo) or samarium-cobalt alloys (SmCo) powders 30 to 95% by weight of the metal and magnetic powder comprising at least one powder selected from the group consisting of acrylic resin, polyurethane resin, polyester resin, alkyd resin, fluorinated resin, silicone resin, polycarbonate resin, polyamide resin, aldehyde Mixing 5 to 70% by weight of one or more liquid resins selected from the group consisting of resins and polyvinyl alcohol resins; And dispersing the mixture formed by the mixing using a grinder. Hereinafter, the electromagnetic wave shielding, absorption, and metal and magnetic paint compositions according to the present invention will be described in detail. Preferred metals and magnetic powders for achieving the object of the present invention include ferrite powders such as Sr-ferrite, Ba-ferrite, Mn-Zn ferrite, Mg-Zn ferrite, Ni-Zn ferrite, permalloy, super High permeability alloys such as supermalloy and sanddust, metals such as Fe, Cu, Ni and Al, neodymium-iron-boron alloys (NdFeB), aluminum-nickel-cobalt alloys (AlNiCo) or samarium-cobalt It is a powder containing one or more of powders, such as an alloy (SmCo) powder. The metal and magnetic powders are materials for shielding, absorbing, and imparting magnetism to the metal and magnetic paint composition according to the present invention. In order to shield the electromagnetic waves, a part of the space must be surrounded by an electrical conductor to prevent the influence of the electromagnetic field from the outside, such as the electric and electronic equipment inside, or to prevent the influence of the electromagnetic field generated from the inside from reaching the outside. This requires magnetic materials with high permeability. Ferrite refers to a solid solution in which alloy elements or impurities are dissolved in iron of a stable body-centered cubic crystal below 900 ° C. As a metallographic term of steel, since it is a solid solution based on α iron, its appearance is the same as that of pure iron, but it is called strontium ferrite, barium ferrite or the like by naming the dissolved element. Ferrite powder can be prepared by various known methods. Taking Ni-Zn ferrite powder as an example, mixing carbonates and / or oxides based on Ni-Zn ferrite as a main component and firing the resulting mixture at high temperature to form Ni-Zn ferrite powder Powder mixing method consisting of, oxalic acid compounded with a mixed aqueous solution of water-soluble compounds of Ni, Zn and Fe to deposit oxalic acid, and the resulting oxalic acid calcined to produce Ni-Zn ferrite powder, and iron alkoxide Dissolving nickel acetylacetonate and zinc acetylacetonate in an organic solvent; It can be prepared by any of the methods consisting of adding water to the resulting solution to hydrolyze the alkoxide and acetyl acetonate and calcining the gel obtained therefrom to produce Ni-Zn ferrite powder. . Permaloy refers to a binary alloy of 78.5% nickel and 21.5% iron, originally a trade name for alloys with high permeability. At present, there are various kinds of nickel 75-90%, nickel 30-50%, and the like, and sometimes chromium, molybdenum, and titanium are added. Permalloy exhibits high magnetic permeability if properly heat treated. High magnetic permeability means high response in weak magnetic fields, making it an excellent magnetic material. It is produced by adding electrolytic nickel to molten iron called dark iron. The proper heat treatment to increase the magnetic permeability is to maintain at 900 to 950 ℃ for 1 hour and then to cool at a rate of 100 ℃ or less per hour, and then cooled to 600 ℃ and then quenched by placing it on a copper plate kept at room temperature in the air There is a way to. Sandust refers to a high permeability alloy having a composition of 5% aluminum, 10% silicon and 85% iron. Sandust has a high permeability because the magnetic anisotropy constant and the magnetic distortion constant are both zero from the composition of the three-element Al-Si-Fe system. It is made of fetish and soft. Neodymium-iron-boron alloy (NdFeB), aluminum-nickel-cobalt alloy (AlNiCo) or samarium-cobalt alloy (SmCo) powders may be prepared by any of several known methods. In order to achieve the object of the present invention, the binder resin used in the composition according to the present invention is an acrylic resin, polyurethane resin, polyester resin, alkyd resin, fluorinated resin, silicone resin, polycarbonate resin, polyamide resin, It is preferably at least one liquid resin selected from the group consisting of aldehyde resins and polyvinyl alcohol resins. The acrylic resin contained in the paint composition according to the present invention may be a homopolymerization of methacrylate monomers such as methyl methacrylate, ethyl methacrylate or ethyl acrylate, or monomers capable of reacting with the monomers such as acrylic. Ronitrile, methacrylamide, maleic anhydride, aliphatic chains with acrylate end groups, methacrylic acid, vinylacetate or styrene and the like and copolymerization with the monomers. Methods for preparing polyacrylic resins are disclosed in "Surface coatings, vol. 1-Raw materials and their usage, chapman and Hall Ltd., 1983, pages 144-157" by the Oil and Color Chemist 'Association of Australia. Suitable polyurethane resins for the paint compositions according to the invention include the reaction products of isocyanates and polyols. Isocyanates are for example 1,6-hexamethylene diisocyanate, polymethylene polyphenylisocyanate, 4,4'-methylenebis- (phenylisocyanate), 1,5-naphthalene diisocyanate, bitolylene, diisocyanate, methylene-bis (Cyclohexyl isocyanate), isophorone diisocyanate, trimethylhexamethylene diisocyanate, m-xylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and 1,4-bis (isocyanatomethyl) Selected from the group consisting of cyclohexane. Generally the polyol is selected from the group consisting of polyether polyols and polyester polyols. Methods for preparing polyurethane resins are disclosed, for example, in Kirk Othmer's Encyclopedia of Chemical Technology, 1982, Vol. 23, pages 576-608. Dispersions of polyurethane resins are described, for example, in "Advances in Urethane Science and Technology, 1987, Stanford, Vol. 10, pages 121-162" by JWRosthauser et al. And in "Progress in Organic Coatings, 1981, Vo. 9, pages 291-332 ", it can be stabilized by adding polyoxyethylene segments to the polyurethane chain. The segments may be caustic in modified diol or isocyanate units, and monohydroxyl-functional polyoxyethylene polyethers may be added directly to the polyurethane chain. Suitable polyester resins for use in the present invention include dicarboxylic acid units or derivatives thereof selected from the group consisting of maleic anhydride, fumaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, and tetrachlorophthalic acid, And diol units selected from the group consisting of 1,2-propanol, 1,3-butanol, ethylene glycol, neopentyl glycol, diethylene glycol, bisphenol-A and tricyclodecane dimethanol. The manufacturing method of a polyester resin is known to those skilled in the art. See, eg, "Surface coatings, Vol. 1- Raw material and their usage" by the Oil and Color Chemists Association of Australia, Chapman and Hall Ltd, 1983, pages 78-87. Alkyd resins that can be used in the present invention are selected from the group consisting of glycerol, pentaerythritol, ethylene glycol, sorbitol, trimethylolethane, trimethylolpropane, dipentaerythritol, tripentaerythritol, neopentyl glycol and dimethylene glycol Polyols and phthalic anhydrides, phthalic acid, isophthalic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride and polycarboxylic acids or derivatives thereof and fatty acids such as linoleic acid or oleic acid. Methods of preparing alkyd resins are known to those of ordinary skill in the art. For example, H.F. Mark et al., "The Encyclopedia of Chemical Technology, 1978, Vol. 2, pages 18-50". Examples of the fluorinated resins include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride. The production method is known in the art several methods according to each type. As silicone resin, the hydrolysis product of bifunctional or trifunctional chlorosilane is mentioned, for example. Chlorosilane is dissolved in an organic solvent such as toluene or xylene and then hydrolyzed. Silicone resins can also be prepared by treating alkoxysilanes such as ethoxy, ethoxy and / or propoxysilane with a strong acid in an aqueous medium and then inducing a polymerization reaction. The manufacturing method of silicone resin is surface coating, Vol. 1- Raw material and their use ", Chapman and Hall Ltd, 1983, pages 134-143. Examples of the polycarbonate resin include polycarbonate esters of bisphenol A, which is a commercially available thermoplastic resin. It can be prepared by two preparation methods, a solvent method by interfacial polycondensation of phosgene, and a melting method by transesterification of bisphenol A and diphenyl carbonate, and polyamide resins include melamine, benzoguanamine, glycoluril and And reaction products of formaldehyde with compounds containing amino groups such as urea, etc. The preparation method is described in Surface coating, Vol. 1-Raw material and their usage ", Chapman and Hall Ltd, 1983, pages 87-98. It is. Aldehyde resins include urea resins, melamine resins and the like. The urea resin combines urea and formalin, sometimes with a slight amount of ammonia to make it weakly alkaline, and when heated to about 70 ° C, it becomes urea resin. The melamine resin is warmed by adding an appropriate amount of melamine to weakly alkaline formalin to obtain a syrup-like resin. The polyvinyl alcohol resin can be obtained by hydrolyzing polyvinyl acetate (vinyl acetate resin). The paint composition according to the present invention may further comprise a curing agent. It is preferable that a hardening | curing agent is a heat hardening | curing agent. Hereinafter, the magnetic paint invention will be described in more detail with reference to the accompanying drawings, examples 1, 2 and 3 of the present invention for electromagnetic shielding, absorption, and method for producing metal and magnetic paint compositions according to the present invention. The scope of is not limited.

Example 1

Aqueous binder (35% by weight) and additives (4% by weight) are added to the container and stirred for 70 minutes with a stirrer, Sr-ferrite (61% by weight) is added and the raw materials are mixed with a stirrer. After stirring is complete, put into a 3roll mill to disperse the agglomeration of particles and particles of ferrite. The 3roll mill was completed and the paper substrate was coated with a thickness of 0.6 mm. After coating, the drying temperature was performed at 140 ° C., and the magnetization was carried out under a voltage of 3000 V and a capacitance of 2500 kV. The coated paint was measured with a surface Gauss using a Gaussian to obtain 350G.

Example 2

The manufacturing process was the same as in Example 1, the coating thickness of the paint to 0.2mm to obtain 180G.

Example 3

The manufacturing process was the same as in Example 1 above, and the thickness of the paint was coated to 0.05 mm to obtain 70 G. Examples 4, 5 and 6 illustrate electromagnetic shielding paints, but the examples do not limit the scope of the present invention.

Example 4

Aqueous binder (12% by weight) and additives (2% by weight) were added to the container and stirred for 150 minutes with a stirrer. Then, a powder (86% by weight) containing 50 to 50 Cu and Al powders having an average of 1.5 μm was added thereto, followed by stirring. Mix raw materials with After the stirring is completed, put into a 3 roll mill to disperse the particles and aggregates of permalloy. 3roll mill was completed and the paper substrate was coated with a thickness of 0.05mm and dried at a temperature of 160 ℃. As a result of electromagnetic wave absorption experiment, the shielding effect of 28dB was obtained.

Example 5

The manufacturing process was the same as in Example 4, the coating thickness of the paint 0.3mm to obtain a shielding effect of 45dB.

Example 6

The manufacturing process was the same as in Example 4, the coating thickness of the paint to 0.8mm to obtain a shielding effect of 70dBd.

Examples 7, 8, and 9 describe electromagnetic wave absorbing paints, but the examples do not limit the scope of the present invention.

Example 7

Aqueous binder (14% by weight) and additives (3% by weight) are added to the container and stirred for 150 minutes with a stirrer, a permalloy (83% by weight) is added and the raw materials are mixed with a stirrer. After the stirring is completed, put into a 3 roll mill to disperse the particles and aggregates of permalloy. 3roll mill was completed and the paper substrate was coated with a thickness of 0.3mm and dried at a temperature of 160 ℃. As a result of the electromagnetic wave absorption test, the absorption capacity was 8dB.

Example 8

The manufacturing process was the same as in Example 7, the coating thickness of the paint to 0.8mm to obtain 14dB.

Example 9

The manufacturing process was the same as in Example 7, and the coating thickness was 1.2 mm to obtain 20 dB. First, Sr-ferrite, Ba-ferrite, Mn-Zn ferrite, Mg-Zn ferrite, Ni-Zn ferrite, and permalloy (permalloy), supermalloy, sanddust, Fe, Cu, Ni, Al, neodymium-iron-boron alloys (NdFeB), aluminum-nickel-cobalt alloys (AlNiCo) and samarium-cobalt alloys (SmCo 80 weight% of the powder (1) which consists of) was injected into 18 weight% of polyurethane liquid resin (2). Furthermore, 2 weight% of heating hardening | curing agents were added. Thereafter, the mixture was stirred and mixed at 100 to 10,000 rpm. As shown in Fig. 1, the screw type of mixing is preferably a grate shape. The mixture formed by the mixing was dispersed in 3 mils (3). The dispersed mixture was placed in a container and stored as paint composition product 4. In addition, the dispersed mixture was directly applied to a substrate 5 such as PET, PP, PE, PA, paper, glass, nonferrous metal, metal or wood in a thickness of 0.05 to 10 mm.

By using the electromagnetic wave shielding, absorption and metal and magnetic paint compositions according to the present invention, the electromagnetic wave emitted from the electrical and electronic device can be easily shielded by simply applying to the inner wall or the outer wall of the electrical and electronic device. As a result, by suppressing electromagnetic waves emitted from various electrical and electronic devices, it is possible to prevent malfunctions of electrical and electronic devices and to remove obstacles to wireless communication, and to prevent many harmful effects of electromagnetic waves on the human body. In addition, by applying to a variety of materials, such as PET, PP, PE or PA film, paper, glass, wood, etc., there is an effect that can easily shield and absorb electromagnetic waves and properties of the magnetic material.

Claims (5)

An electromagnetic shielding, absorption and metal and magnetic paint composition comprising 30 to 95% by weight of metal and magnetic powder and 5 to 70% by weight of binder resin having a particle size of 0.03-100 μm. According to claim 1, wherein the metal and magnetic powder, Sr-ferrite, Ba-ferrite, Mn-Zn ferrite, Mg-Zn ferrite, Ni-Zn ferrite, permalloy, supermalloy, sanddust (sendust), Fe, Cu, Ni, Al, neodymium-iron-boron alloys (NdFeB), aluminum-nickel-cobalt alloys (AlNiCo) or samarium-cobalt alloys (SmCo) powders Electromagnetic shielding, absorption and metal and magnetic paint composition, characterized in that. The said binder resin is an acrylic resin, a polyurethane resin, a polyester resin, an alkyd resin, a fluorinated resin, a silicone resin, a polycarbonate resin, a polyamide resin, an aldehyde resin, and polyvinyl alcohol of Claim 1 or 2 Electromagnetic shielding, absorption and metal and magnetic paint composition, characterized in that at least one liquid resin selected from the group consisting of resins. Sr-ferrite, Ba-ferrite, Mn-Zn ferrite, Mg-Zn ferrite, Ni-Zn ferrite, permalloy, supermalloy, sanddust, Fe, Cu, Ni, Al, neodymium 30-95% by weight of metal and magnetic powder comprising at least one powder selected from the group consisting of iron-boron alloy (NdFeB), aluminum-nickel-cobalt alloy (AlNiCo) or samarium-cobalt alloy (SmCo) powder 5 to 70% by weight of at least one liquid resin selected from the group consisting of resins, polyurethane resins, polyester resins, alkyd resins, fluorinated resins, silicone resins, polycarbonate resins, polyamide resins, aldehyde resins and polyvinyl alcohol resins; Method for producing electromagnetic shielding, absorption and metal and magnetic paint composition comprising the step of mixing. The electromagnetic wave shielding and absorption for coating the paint composition prepared according to the method of claim 1 to a substrate such as PET, PP, PE, PA, paper, glass, non-ferrous metal, metal or wood in a thickness of 0.05 to 10mm And metal and magnetic paint compositions.