| JP2001353005 | SHOE INSOLE |
| WO/2001/089334 | THE SHOE WITH CUSHION FOR MASSAGE |
| WO/2007/144991 | BIOACTIVATOR, SOCK LINER AND METHOD OF PRODUCING SOCK LINER |
PARK, Jung Sik (1702 ho, 210 dong Samhwan Apt. 120-10,Dadae-dong, Saha-gu, Busan 604-757, KR)
JUNG, Jin Hyun (303 Geumhochunji Apt. 238-5, Munhyeon3-dong Nam-gu, Busan 608-823, KR)
KIM, Han Geun (1 Dongnae SK View Apt. 758-11, Oncheon-dong Dongnae-gu, Busan 607-835, 05-1702, KR)
PARK, Jung Sik (1702 ho, 210 dong Samhwan Apt. 120-10,Dadae-dong, Saha-gu, Busan 604-757, KR)
JUNG, Jin Hyun (303 Geumhochunji Apt. 238-5, Munhyeon3-dong Nam-gu, Busan 608-823, KR)
Claims
[I] An insole for eliminating static electricity, comprising: a top layer made of conductive synthetic fabric; a middle layer made of antistatic soft foam; and a bottom layer made of antistatic hard synthetic resin, wherein a pair of ferroelectric elements and an electric discharge net are inserted between the soft foam middle layer and the hard synthetic resin bottom layer.
[2] The insole of Claim 1, wherein the top layer is made of conductive synthetic fabric woven from synthetic fiber yarns having silver yarns arranged thereon at a given interval.
[3] The insole of Claim 1, wherein the soft foam middle layer is obtained by adding additives, including a foaming agent, zinc oxide and stearate, to a mixed base of 70-90 wt% ofethylene vinyl acetate (EVA) and 10-30 wt% of conductive carbon and foaming the mixture, such that the middle layer is electrically conductive.
[4] The insole of Claim 3, wherein the foaming agent, the zinc oxide and the stearate are used in amounts of 1-2 parts by weight, 2-2.5 parts by weight and 1-1.5 parts by weight, respectively, based on 100 parts by weight of the mixed base.
[5] The insole of Claim 1, wherein the ferroelectric elements are subjected to poling treatment so as to have positive (+) and negative (-) polarities, respectively, and are placed in a [H] -shaped groove formed in a convex arch portion protruding from the middle portion of the bottom layer, such that they can readily come into contact with the middle layer.
[6] The insole of Claim 5, wherein the ferroelectric elements are PZN-BT-PT[Pb(Zn
1/3 Nb 2Iϊ )O 3 J-BT[BaTiO 3 ]-PT[PbTiO 3 ] ferroelectric elements.
[7] The insole of Claim 6, wherein the PZN-BT-PT ferroelectric elements have a relative dielectric constant of 3000-6000. [8] The insole of Claim 7, wherein the electricity-receiving PZN-BT-PT ferroelectric elementsare made of a mixture of 0.55-0.65 mol PZN[Pb( V Zn 1/3 Nb 2K )O 3 ] ,
0.20-0.25 mol BT[BaTiO ] and 0.25-0.10 mol PT[PbTiO ].
[9] The insole of Claim 1, wherein the electric discharge net is made of a conductive foam material having a horseshoe-shaped network structure, and is placed in a [H] -shaped groove formed in the shoe heel portion of the hard synthetic resin bottom layer, such that it can come into contact with the middle layer.
[10] The insole of Claim 4, wherein the foaming agent is an azodicarbonamide foaming agent.
[I I] The insole of Claim 4, wherein the stearate is one selected from the group consisting of zinc stearate, calcium stearate, magnesium stearate and aluminum stearate. |
Description
INSOLE TO ELIMINATE ELECTROSTATICS
Technical Field
[1] The present invention relates to a shoe insole for eliminating static electricity, which comprises ferroelectric elements inserted therein, and thus can eliminate static electricity, and more particularly to aninsole for eliminating static electricity, which has the same external structure as that of general shoe insoles and can be applied to all kinds of shoes so as to efficiently eliminate static electricity generatedin the human body.
[2] In one embodiment,the present invention relates to an insole for eliminating static electricity, which comprises PZN-based ferroelectric elements included therein, and thus can eliminate static electricity generated in the human body. Background Art
[3] Generally, shoesfor eliminating static electricity, which function to eliminate static electricity generated in the human body, are mostly manufactured by adding a metal such as silver, copper or aluminum, or a conductive material such as conductive carbon, to a shoe insole made mainly of ethylene vinyl acetate (EVA). Such an insole for eliminating static electricity is technology of dissipating static electricity using a method of allowing electric charges generated in the human body to be naturally discharged through ethylene vinyl acetate (EVA) foam. This method allows static electricity to be eliminated to some extent, but when such a static electricity- eliminating insole is used to eliminate static electricity, there are problems in that it is difficult to efficiently eliminate static electricity due to a shoe midsole having insulating properties, and the risk of receiving an electric shock due to conductive phenomena can occur.
[4] In attempts to improve the above-described problems, Korean Utility Model Laid- open Publication No. 98-6316 (published on 30 April, 1998) and Korean Utility Model Registration Nos. 274092 (registered on 20 April, 2002), 320706 (registered on 8 July, 2003) and 424809 (registered on 21 August, 2006) disclose improvements in shoes for eliminating static electricity. Suchshoes have a structure as shown in FIG. 1, in which a grounding element 4 for discharging static electricity is included in the shoes, such that it comes into contact with a foot sole and a ground surface E, and thus electric charges generated in the human body can be discharged to the ground surface E through an insole 1, a miodsole 2 and an outsole 3. In order to eliminate static electricity generated in the human body using such prior methods, electric charges generated in the human body should be allowed to flow to the ground to dissipate static electricity. For this
reason, a portion of the shoe insole and midsole should be made of a material for eliminating static electricity, and the grounding element for discharging static electricity should be included in the shoe outsole, such that it can come into contact with the ground surface. This shoe structure for eliminating static electricity has a problem in that, when either the connection structure between the shoe insole, midsole and outsole or the structure of each of the insole, the midsole and the outsole becomes abnormal, this shoe structure cannot completely eliminate static electricity. Also, when the shoe structure is applied not only to general shoes, but also to industrial shoes, there is a problem in that a process for manufacturing the shoes becomes complicated due to the complex structure of the shoes, thus increasing the manufacturing cost of the shoes.
Disclosure of Invention Technical Problem
[5] The present invention has been solved in order to solve the above-described problems occurring in the prior art, and it is an object of the present invention to provide an insole for eliminating static electricity, which is a simple structure having the same appearance as a conventional shoe insole, as shown in FIG. 2, and can be applied to all kinds of shoes so as to efficiently eliminate static electricity generated in the human body.
[6] Accordingly, the insole for eliminating static electricity according to the present invention has a simple external structure, which can be simply used in all kinds of shoes, including not only general shoes, but also safety shoes for wearing in various industrial fields, and it can efficiently eliminate static electricity generated in the human body. Thus, the insole according to the present invention is characterized in that it can prevent not only various accidents, such as firing explosion and a fire, which occur due to the generation of static electricity in industrial fields, but also various safety accidents, such as electricshocks, body injuries, and unpleasant sensations by electric discharge sound, which occur due to the generation of static electricity in daily life. Technical Solution
[7] To achieve the above object, the present invention provides an insole having characteristics which will now be described in detail.
[8] The external structure of the inventive insole for eliminating static electricity has the same shape as conventional shoe insole, as shown in FIG. 2, such that the inventive insole can be simply used in not only general shoes, but also safety shoes for wearing in various industrial fields.
[9] The inventive insole for eliminating static electricity comprises: a top layer made of
conductive synthetic resin; a middle layer made of antistatic soft foam; and a bottom layer made of antistatic hard synthetic resin, wherein a pair of ferroelectric elements and an electric discharge net are inserted between the soft foam middle layer and the hard synthetic resin bottom layer.
[10] In the present invention, the top layer is a conductive synthetic fabric woven from synthetic resin yarns having silver yarns arranged thereon at a given interval and serves as a conducting material to conduct electric charges,generated in the human body, directly to the soft foam middle layer by means of the silver yarns. Also, because the silver yarns have excellent antibacterialand deodorant effects, the top layer also has an additional function to inhibit bacterial proliferation and the generation of offensive odors, which occur due to sweat released from a foot sole.
[11] Also, in the present invention, the soft foam middle layer functions to conduct electric charges from the top layer, made of the conductive synthetic fabric woven using synthetic resin yarns and silver yarns, to the ferroelectric elements and the electric discharge net, which are inserted between the middle layer and the bottom. Moreover, the soft foam middle layer is made of antistatic soft foam and also functions as a cushion layer, which prevents the unpleasant sensations of the ferroelectric elements and the electric discharge net, which are inserted between the soft foam middle layer and the hard synthetic bottom layer, from being transferred to a foot sole.
[12] The soft foam middle layer is made of a soft foam material, which is obtained by foaming a mixture of ethylene vinyl acetate (EVA), conductive carbon and a foaming agent, such that shock absorption in the foaming process is increased. The soft foam material is preferably prepared by adding additives, including a foaming agent, zinc oxide and stearate, to a mixed base of 70-90 wt% of ethylene vinyl acetate (EVA) and 10-30 wt% of conductive carbon, and foaming the mixture, such that the soft foam material has antistatic performance.
[13] In the present invention, if the amount of ethylene vinyl acetate (EVA) added is less than 70 wt% or the amount of conductive carbon added is more than 30 wt%, the mechanical properties of the shoe insole can be reduced as a result of the reduction in the amount of addition of ethylene vinyl acetate (EVA), which is excellent in mechanical properties, including elasticity, elongation and tensile strength. Also, if the amount of ethylene vinyl acetate (EVA) added is more than 90 wt% or the amountof conductive carbon added is less than 10 wt%, electric charges generated in the human body cannot be smoothly conducted to the ferroelectric elements, such that static electricity generated in the human body cannot be smoothly eliminated, because the amount of conductive carbon added is relatively small compared to the amount of ethylene vinyl acetate (EVA) added.
[14] With respect to the additives, which are added to the mixed base, 1-2 parts by
weight of a foaming agent, 2-2.5 parts by weight of zinc oxide and 1-1.5 parts by weight of stearate are preferably added to 100 parts by weight of the mixed base for foaming.
[15] The foaming agent functions to expand ethylene vinyl acetate (EVA) to increase the impact resistance of the EVA. If the amount of foaming agent added is lower than the lower limit of the above- specified range, ethylene vinyl acetate (EVA) cannot be sufficiently foamed, and if it exceeds the upper limit of the above-specified range, ethylene vinyl acetate (EVA) can be excessively foamed, resulting in a reduction in the mechanical properties thereof.
[16] Also, a foaming agent usable in the present invention is a conventional foaming agent, and is preferably an azodicarbonamide foaming agent. However, because azodi- carbonamide has a relatively high decomposition temperature of 210 0 C it is required to add a decomposition promoter in order to lower the decomposition temperature of the azodicarbonamide foaming agent.
[17] Thus, in the present invention, zinc oxide is used as an active agent for lowering the decomposition temperature of azodicarbonamide, and when it is used in an amount within the above- specified range, it can lower the undesired high decompos ition- temperature of azodicarbonamide.
[18] Also, stearate, which is used in the present invention, is added in an amount within the above- specified range and is suitably coated with the foam material. Stearate, which can be used in the present invention, is preferably one selected from the group consisting of zinc stearate, calcium stearate, magnesium stearate and aluminum stearate.
[19] Meanwhile, the ferroelectric elements, which are used in the present invention, are piezoelectric elements and function to receive electric charges from the soft foam middle layer, andthen to discharge the electric charges to the hard synthetic resin bottom layer, thus eliminating the electric charges. Also, the ferroelectric elements are key parts, which function to absorb and neutralize positive (+) or negative (-) electric charges in positive (+) or negative (-) electrodes to dissipate electric charges, and the ferroelectric elements are subjected to poling treatment, such that they have positive (+) and negative (-) polarities, respectively.
[20] In the present invention, as the ferroelectric elements, it is preferable to use PZN-
BT-PT[Pb(Zn Nb )O J-BT[BaTiO ]-PT[PbTiO ] ferroelectric elements (hereinafter, referred to as "PZN-BT-PT ferroelectric element").
[21] Also, the PZN-BT-PT ferroelectric element preferably has a relative dielectric constant of 3,000-6,000. If the PZN-BT-PT ferroelectric elements have a relative dielectric constant of less than 3,000, static electricity generated in the human body will not be rapidly conducted to the antistatic hard synthetic bottom layer, such that
electric potential enough to stimulate the human body will remain in the insole so as to give electrostatic stimulation to the human body. On the other hand, the PZN-BT-PT ferroelectric elements have a relative dielectric constant of more than 6,000, it will be difficult to fabricate and can be readily damaged. [22] Also, the PZN-BT-PT ferroelectric element 20, which is used in the present invention, is preferably made of a mixture of 0.55-0.65 mol PZN[Pb(Zn Nb )O 1, r J 1/3 2/3 3
0.20-0.25 mol BT[BaTiO ] and 0.25-1.0 mol PT[PbTiO ] in order to maintain the above-specified relative dielectric constant. If each of the compounds forming the ferroelectric element deviates from the above- specified mol range, the relative dielectric constant required in the present invention will not be shown.
[23] In the case where the ferroelectric element is inserted between the middle layer and the bottom layer, it is included in a [H] -shaped groove formed in a convex arch portion protruding from the middle of the bottom, such that it can readily come into contact with a foot sole and the middle layer, whereby electric charges generated in the human body are discharged.
[24] As used herein, the term "arch portion (A)" refers to the convex arch-shaped portion of the insole, which can support the concave arch portion (indicated by a dotted line in FIG. 3) of the human foot sole.
[25] Meanwhile, the electric discharge net is made of a conductive foam material having a horseshoe-shaped network structure, and is included in a [H] -shaped groove formed in the shoe heel portion of the hard synthetic resin bottom layer, such that it can come into contact with the middle layer. Thus, it functions to discharge electric charges from the soft foam middle layer to the hard synthetic resin bottom layer. The electric discharge net is made of the same material as the material of the soft foam middle layer, and the detailed description of said material has been already made, and thus will be omitted herein.
[26] Meanwhile, the hard synthetic resin bottom layer in the present invention is a layer for dissipating the electric charges charged in the ferroelectric elements and the electric charges discharged through the electric discharge net. It is made of a mixture of hard ethylene vinyl acetate (EVA) and conductive carbon and functions to relieve local pressure applied externally from a road surface through the outsole and midsole when a person walks.
[27] The hard synthetic resin bottom layer consists of an antistatic hard synthetic resin layer obtained by foaming a mixture of 70-90 wt% of ethylene vinyl acetate (EVA) and 10-30 wt% of conductive carbon. If the amount of ethylene vinyl acetate (EVA) added is less than 70 wt% or the amount of conductive carbon added is more than 30 wt%, the mechanical properties of the shoe insole can be reduced as a resultof the reduction in the amount of addition of ethylene vinyl acetate (EVA), which is excellent
in mechanical properties such as elasticity, elongation and tensile strength. On the other hand, the amount of ethylene vinyl acetate (EVA) added is more than 90 wt% or the amount of conductive carbon added is less than 10 wt%, electric charges generated in the human body cannot be smoothly conducted to the ferroelectric elements, such that static electricity generated in the human body cannot be smoothly eliminated, because the amount of conductive carbon added is relatively small compared to the amount of ethylene vinyl acetate (EVA) added.
[28] Accordingly, the present invention having the above-described construction is based on the principle according to which electric charges generated in the human body are conducted through the top layer and the middle layer, and then charged in the ferroelectric elements, and the remaining electric charges are discharged to the antistatic hard synthetic resin bottom layer through the electric discharge net, thus dissipating electric charges.
[29] The insole for eliminating static electricity according to the present invention is structured such that a potential of more than 2 kV, generatedin the human body, will be dissipated in the insole within a time of 1-2 seconds, so that static electricity will be eliminated, and finally a potential of less than 0.5 kV, which causes no damage to the human body, will remain.
Advantageous Effects
[30] As described above, the present inventionprovides the shoe insole for eliminating static electricity, which comprises ferroelectric elements inserted therein, and thus can eliminate static electricity. More particularly, the present invention provides the shoe insole for eliminating static electricity, which has the same external structure as that of general shoe insoles and can be applied to all kinds of shoes so as to efficiently eliminate static electricity generated in the human body. Brief Description of the Drawings
[31] FIG. 1 is a cross-sectional view of a prior general shoe for eliminating static electricity;
[32] FIG. 2 shows a shoe for eliminating static electricity according to the present invention;
[33] FIG. 3 shows the arch portion (dotted line) of a normal person;
[34] FIGS. 4 to 6 show a process of assembling the parts of the static electricity- eliminating shoe according to the present invention;
[35] FIG. 7 is a cross-sectional view taken along line C-C in the hard synthetic resin bottom layer of FIG. 5; and
[36] FIG. 8 is a cross-sectional view taken along line D-D' in the hard synthetic resin bottom layer of FIG. 5.
Best Mode for Carrying Out the Invention
[37] Hereinafter, the present invention will be descried in further detail with reference to examples. It is to be understood, however, that these examples are not to be construed to limit the scope of the present invention.
[38] 1. Manufacturing of insole for eliminating static electricity
[39] (Example 1)
[40] An insole for eliminating static electricity, which consists of the following parts, was manufactured: a top layer made of a conductive synthetic fabric woven from synthetic resin yarns having silver yarns arranged thereon at a given interval; a middle layer made of a soft foam material obtained by adding 1 part by weight of an azodi- carbonamide foaming agent, 2 parts by weight of zinc oxide and 1 part by weight of magnesium stearate to 100 parts by weight of a mixed base of 70 wt% of ethylene vinyl acetate (EVA) and 30 wt% of conductive carbon and foaming the mixture; and a bottom layer consisting of a hard synthetic resin layer obtained by extruding a mixture of 70 wt% of ethylene vinyl acetate (EVA) and 30 wt% of conductive carbon, wherein a pair of PZN-BT-PT ferroelectric elements and an electric discharge net are inserted between the middle layer and the bottom layer.
[41] The electric discharge net was formed using a material having the same composition as that of the soft foam middle layer.
[42] (Example 2)
[43] An insole for eliminating static electricity, which consists of the following parts, was manufactured: a top layer made of a conductive synthetic fabric woven from synthetic resin yarns having silver nanoparticle-coated yarns arranged thereon at a given interval; a middle layer made of a soft foam material obtained by adding 2 parts by weight of an azodicarbonamide foaming agent, 2.5 parts by weight of zinc oxide and 1.5 parts by weight of magnesium stearate to 100 parts by weight of a mixed base of 90 wt% of ethylene vinyl acetate (EVA) and 10 wt% of conductivecarbon and foaming the mixture; and a bottom layer consisting of a hard synthetic resin layer obtained by extruding a mixture of 90 wt% of ethylene vinyl acetate (EVA) and 10 wt% of conductive carbon, wherein a pair of PZN-BT-PT ferroelectric elements and an electric discharge net are inserted between the middle layer and the bottom layer.
[44] The electric discharge net was formed using a material having the same composition as that of the soft foam middle layer.
[45] 2. Test of static electricity elimination
[46] Each of the static electricity-eliminating insoles manufactured in Examples 1 and 2 was placed in a conventional safety shoe and charged to a constant voltage of 6.4 kV. The shoes comprising the antistatic insole were brought into contact with the plate of a
charged plate analyzer (CPA), and in this state, the remaining potential was measured using a device for measuring human static electricity.
[47] 3. Test results
[48] In the results of the test according to the above section 2, the static electricity- eliminating insoles of Examples 1 and 2 showed the remaining potentials of only 350V and 360V, respectively. Also, the time taken for a static electricity of 6.4 kV to be reduced to less than 1.0 kV, which causes no static electricity phenomenon in the human body, and, as a result, the time was shorter than 2 seconds in both Examples 1 and 2, suggesting that no electrostatic damage to the human body would occurred.
[49] As described above, the static electricity-eliminating insole according to the present invention is characterized in that it allows static electricity generated in the human body to be dissipated in the shoe insole, such that the static electricity generated causes no damage to the human body.
[50] While the embodiment of the present invention has been described in detail with reference to the accompanying drawings, the scope of the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and sprit of the present invention as disclosed in the accompanying claims. Mode for the Invention
[51] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 4 to 6, which show the process in which the parts of the static electricity-eliminating insole are bonded with each other. However, the scope of the present invention is not limited only to the accompanying drawings.
[52] As shown in FIG. 4, the static electricity-eliminating insole according to the present invention comprises: a top layer 10 made of a conductive synthetic fabric; a middle layer 20 made of an antistatic soft foam material; and a bottom layer made of an antistatic hard synthetic resin material. Between the soft foam middle layer 20 and the hard synthetic resin bottom layer 50, there are a pair of PZN-BT-PTferroelectric elements 30, which are placed in a [H] -shaped groove formed in anarch portion A protruding from the middle portion of the hard synthetic resin bottom layer 50, and an electric discharge net 40, which is placed in a [H] -shaped groove formed in the shoe heel portion B of the hard synthetic resin bottom layer 50.
[53] The PZN-BT-PT ferroelectric elements are circular elements having a circular shape like a coin. The ferroelectric elements are subjected to poling treatment, such that the two ferroelectric elements have positive (+) and negative (-) polarities, respectively, whereby the the positive (+) or negative (-) electrode of the ferroelectric elements can absorb and neutralize positive (+) or negative (-) electric charges
generated in the human body, and then discharge the electric charges slowly to the hard synthetic resin so as to dissipate the electric charges. Also, the electric discharge net 40 is made of a conductive foam material having a horseshoe-shaped network structure, and functions to discharge electric charges from the soft foam middle layer 20 to the hard synthetic resin bottom layer 50.
[54] As shown in FIG. 5, a pair of the PZN-BT-PT ferroelectric elements 30 is placed in the [H] -shaped groove formed in the convex arch portion A protruding from the middle portion of the hard synthetic resin bottom layer 50, and the electric discharge net 40 is placed in the [H] -shaped groove formed in the shoe heel portion B of the hard synthetic resin bottom layer 50.
[55] As shown in FIG. 6, the PZN-BT-PTferroelectric element pair and the electric discharge net are placed in the hard synthetic resin bottom layer 50, and then the soft foam middle layer 20 is bonded to the upper surface of the bottom layer 50. When the top layer 10 is bonded to the upper surface of the middle layer 20, as shown in FIG. 2, a static electricity-eliminating shoe, which has a simple shape and the same structure as that of general shoe insoles, is obtained.
[56] For reference, FIG. 7 is a cross-sectional view taken along line C-C in the hard synthetic resin bottom layer of FIG. 5. Specifically, FIG. 7 is a cross-sectional side view, which shows a pair of the PZN-BT-PT ferroelectric elements30 placed in the arch portion A of the hard synthetic resin bottom layer 50, and the electric discharge net 40 placed in the shoe heel portion B.
[57] FIG. 8 is a cross-sectional view taken along line D-D in the hard synthetic resin bottom layer of FIG. 5.
[58] Hereinafter, the process, in which static electricity generated in the human body is eliminated by the static electricity-eliminating shoe according to the present invention, will be described with reference to FIG. 4.
[59] When a electrostatic phenomenon occurs in the human body, the top layer 10 made of the synthetic fiber woven from the silver nanoparticle-coated yarns will receive electric charges generated in the human body and conduct the electric charges to the soft foam middle layer 20. Then, the soft foam middle layer 20 will conduct the electric charges to the PZN-BT-PTferroelectric elements 20 and, at the same time, discharge the remaining electric charges to the antistatic hard syntheticresin bottom layer 50 through the electric discharge net 40, whereby the electric charges generated in the human body will be dissipated in the static electricity-eliminating insole.
[60] Herein, a pair of the PZN-BT-PT ferroelectric elements 20, the surfaces of which were treated to serve as positive (+) and negative (-) electrodes, functions to receive and neutralize the electric charges, and then to discharge the electric charges to the hard synthetic resin bottom layer 50.
Industrial Applicability
[61] As described above, the present invention provides theshoe insole for eliminating static electricity, which comprises ferroelectric elements inserted therein, and thus can eliminate static electricity. More specifically, the present invention provides the shoe insole for eliminating static electricity, which has the same external structure as that of general shoe insoles and can be applied to all kinds of shoes so as to efficiently eliminate static electricity generated in the human body.
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