Patent Application
20130095304
1. Field of the Invention
The present invention relates to an antistatic sheet and a manufacturing method thereof, and specifically, an antistatic sheet related to an antistatic mat to be laid on a floor and the like during maintenance or repair operations of electronic components or the like.
2. Description of the Related Art
During operations related to handling electronic components, it is necessary to protect the electric component from static electricity. However, mere sheets or mats conventionally used were not satisfying for this purpose. Therefore, an expensive antistatic mat equipped with a means (function) with electrically-conductive material impregnated therein, for example as is shown in Non-Patent Document 1 (http://www.mmm.co.jp/electrical/static/mat/lineup.html#f—9600), such as an electrically-conductive table mat, was normally used.
As is shown in Non-Patent Document 1, Non-Patent Document 2 (http://www.achilles.jp/product/03/01/04/01/index.html), and Non-Patent Document 3 (http://www.sigma-koki.com/pdf/jp/C090609.pdf), many mats have been commercially available; however, unit price per one mat was expensive. Therefore, when such mats have to be used in large volumes, such as in a maintenance service company of machines, antistatic mats (sheets) having a moderate price and expected to have an effect either equaling or surpassing the conventional mats are desired.
However, when such mats are to be used as protective sheets on which the electronic components or the like are temporarily placed and operated, the sheets must be superior in anti-fouling property, cushion property, lightweight property, handling property, durability and the like, in addition to having an antistatic function and a neutralization function. Further, in many cases, the sheets are laid on the floor to be operated thereon, so that it is necessary to prevent transition of static electricity from the floor side.
Patent Document 1 (Japanese Patent Laid-Open No. 2001-310383) discloses a technique related to “a manufacturing method of a film-non-woven fabric complex sheet characterized in melting and spinning a non-woven fabric made of thermoplastic fiber, superposing the non-woven fabric and a thermoplastic resin film within 30 minutes from spinning, and stretching the same, and the film-non-woven fabric complex sheet manufactured by the method”, aimed at providing a complex sheet of film and non-woven fabric and a manufacturing method thereof, which is capable of achieving stable film-forming and quality.
Patent Document 2 (Japanese Patent Laid-Open No. 2010-47857) discloses a technique related to “a short-fiber non-woven fabric consisting primarily of high-functional fiber and having a weight of 100 to 3000 g/m2, characterized in that the non-woven fabric has a puncture resistance value of 100 to 1000 g, a compression rate of 15 to 50%, and an air permeability of 0.1 to 30 cm3/cm2/sec”, aimed at providing the same as a protective non-woven fabric in glass factories and the like, because it has superior characteristics in anti-puncture resistance value, bulk property, and anti-air permeability.
Patent Document 3 (Japanese Patent Laid-Open No. 2007-39852) discloses a technique related to “an antielectric fiber cloth in which an antistatic composition including a polymer and/or polyamine resin of a quaternary ammonium salt type, a thermal reaction type blocked urethane having 2 or more block isocyanate group per one molecule, a surfactant having oleyl and two or more hydroxyl group, is applied to a fabric cloth”, aimed at providing an antielectric fiber cloth having superior wash resistance while preventing hardening of texture and the like, and having no need of a special device.
The present invention aims at providing an antistatic sheet superior in a neutralization function or an antistatic function.
Further, the present invention aims at providing an antistatic sheet superior in anti-fouling property, cushion property, lightweight property, handling property, durability and the like, in addition to the neutralization function or the antistatic function.
Still further, the present invention aims at providing a manufacturing method of the antistatic sheet superior in the neutralization function or the antistatic function.
At sites handling electronic devices (personal computers, servers, facsimiles, printers, security devices, measurement instruments, banking terminal devices, various vending machines and the like) or components thereof, it is necessary to temporary store the parts when performing maintenance/checking, repairing and the like of the respective parts. In doing so, conventionally, a temporary storage area of parts has been provided by laying a mat on a floor and the like. The present invention aims at providing a sheet to be used for protecting the parts temporarily stored from static electricity (neutralization function or antistatic effect), fouling (antifouling property), and moisture (water-absorbing property) and the like, and which has durability and good handling property.
More specifically, the present invention aims at providing an antistatic sheet having a superior neutralization function or the antistatic function and which is moderately priced. Further, the present invention aims at providing a manufacturing method of the configuration and the like of the antistatic sheet having a superior neutralization function or antistatic function.
In a sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a bottom surface of a non-woven fabric sheet, and an entire surface printing is implemented to an upper surface of the non-woven fabric sheet.
Further, in an antistatic sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a bottom surface of a non-woven fabric sheet, an entire surface printing is implemented to an upper surface of the non-woven fabric sheet, and an electrically-conductive paint is applied to an upper surface of the printed surface.
Further, in an antistatic sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a bottom surface of a non-woven fabric sheet, an entire surface printing is implemented to an upper surface of the non-woven fabric sheet, an electrically-conductive paint is applied to an upper surface of the printed surface, and an antistatic sheet is laminated on a bottom surface of the polyethylene sheet or the polypropylene sheet.
Further, in a manufacturing method of a sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a bottom surface of a non-woven fabric sheet, and an entire surface printing is implemented to an upper surface of the non-woven fabric sheet. In the manufacturing method of the sheet-like product of the present invention, an existing laminating machine and an existing printing machine may be used.
Further, in a manufacturing method of an antistatic sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a bottom surface of a non-woven fabric sheet, an entire surface printing is implemented to an upper surface of the non-woven fabric sheet, and an electrically-conductive paint is applied to an upper surface of the printed surface.
Further, in a manufacturing method of an antistatic sheet-like product of the present invention, an antistatic laminated polyethylene sheet in which a polyethylene sheet or a polypropylene sheet and an antistatic polyethylene sheet are laminated is laminated on a lower surface of a non-woven fabric, an entire surface printing is implemented to an upper surface of the non-woven fabric sheet, and an electrically-conductive paint is applied to an upper surface of the printed surface, so that an antistatic effect is obtained from a bottom surface of the antistatic laminated polyethylene sheet, and the antistatic effect from both sides are obtained.
Further, in a manufacturing method of an antistatic sheet-like product of the present invention, a polyethylene sheet or a polypropylene sheet is laminated on a lower surface of a non-woven fabric sheet, an entire surface printing is implemented to an upper surface of the non-woven fabric sheet, an electrically-conductive paint is applied to an upper surface of the printed surface, and an antistatic sheet is laminated to the bottom surface of the polyethylene sheet or the polypropylene sheet so as to obtain the antistatic effect from the both surfaces of the sheet.
The present invention provides an antistatic sheet which is light, superior in handling capability, has durability and is inexpensive. A first embodiment provides a polyethylene sheet laminated on a non-woven fabric sheet, and a print is implemented to entire upper surface of the non-woven fabric sheet. A second embodiment provides a polyethylene sheet laminated on the non-woven fabric sheet, wherein a print is laminated to whole upper surface of the non-woven fabric sheet, and an electrically-conductive paint layer is formed on the printed surface. A third embodiment provides a polyethylene sheet laminated on the non-woven fabric sheet, wherein a print is laminated to whole upper surface of the non-woven fabric sheet, the electrically-conductive paint layer is formed on the printed surface, and an antistatic polyethylene sheet is laminated at a lower surface of the polyethylene sheet.
Considering a case where operation is performed while placing electric components on a floor, it is said that an electrical resistance value is practically in antistatic region from 8th power of ten to 14th power of ten Q. However, practically, it is preferable that the value falls within the range of 7th power of ten to 10th power of ten Q. In this case, practical problems hardly arise. In the case where a sheet is laid on a floor and operation is performed thereon, tools, new components, and old components and the like will be placed on the sheet. There are many cases in which the parts are charged with static electricity. Especially, there are cases in which new parts are damaged by the static electricity charged to the old parts. What should not be overlooked is the point that, because the operation is performed on the sheet laid on the floor, depending on the material of the floor and the like, the static electricity from the floor may be the cause of damage. Further, the parts may receive influence from the static electricity charged to the human body.
In order to accurately achieve the effect with respect to such various static electricity, a third embodiment explained below is most preferred. It is preferable to give antistatic function to both surfaces of the sheet. A static electricity interrupting layer is configured from a non-woven fabric. As a countermeasure against static electricity, easiness of flow of static electricity becomes a problem. The easiness of flow of static electricity is ranked in order of antistatic property, antielectric property, conductive property, and current-carrying property.
For example, in order to prevent transition of the static electricity from the floor surface, it is preferable to laminate a sheet subjected to antistatic treatment on the surface contacting the floor surface. In this case, a thickness of the laminate sheet is preferably around 30 to 60μ. With the aim of saving cost for production, a commercially-available PE sheet, PP sheet or PET sheet and the like may be used.
In any embodiment, the non-woven fabric used constitutes a static electricity interrupting layer. From the viewpoint of cushion property, folding property and durability, a non-woven fabric with the weight of about 40 to 100 g/m2 is appropriate. However, the thickness may be varied according to need. Commercially-available materials exert no problem. However, it is widely known that static electricity is hardly generated when humidity is high. Therefore, materials having some hygroscopic ability are preferred. For example, a pulp non-woven fabric and a polyester non-woven fabric are preferred.
In order to prevent scuffing, and to obtain uniformity of conductive paint, it is preferable to implement solid printing on the entire surface of the upper surface of the non-woven fabric. Also, from the viewpoint of design, a color printing and the like may be implemented thereon. Subsequently, the electrically-conductive paint is coated on the whole surface of the printed surface. The purpose of the entire surface printing is to enhance the effect of the conductive polymer. By applying the conductive polymer after the entire surface printing on the upper surface of the non-woven fabric, the consumed quantity of the conductive polymer decreases greatly. In any event, the entire surface printing of the non-woven fabric is a novel idea in the printing field.
Hereinafter, explanation will be given on the embodiments of the present invention with reference to the drawings.
As is shown in
It is preferable that the thickness of the non-woven fabric sheet 10 is around 40 to 100μ, the thickness of the PE sheet 20 is around 30 to 60μ, and a print film of the entire surface printing of the upper surface of the non-woven fabric sheet 10 is around 1 to 10μ. The entire surface printing of the non-woven fabric is a novel idea in a field of printing.
A specific manufacturing method of the antistatic sheet according to the first embodiment is shown in
The non-woven fabric sheet 10 is unwound from a non-woven fabric sheet roll 110, and is supplied to the process. On the other hand, the PE sheet or the PP sheet 20 is unwound from a PE sheet roll or a PP sheet roll 120 and is supplied to the process. To a surface of the PE sheet or the PP sheet 20, an adhesive 70 is applied from an adhesive application roll 130. Thereafter, the non-woven fabric sheet 10 and the PE sheet or the PP sheet 20 are introduced into a laminating roll 140, press-bonded and laminated therein. Thereafter, a laminated sheet 60 is introduced into a printing roll 150, and a surface on the non-woven fabric sheet 10 side of the laminated sheet 60 is entirely printed (an ink tank 35), so that the entire surface printing surface 30 is formed. Thereafter, the laminated sheet 60 with the surface on the non-woven fabric sheet 10 side entirely printed is introduced into a cutting roll 160, and is cut into a predetermined shape.
A second embodiment of the present invention is, as is shown in
It is preferable that the thickness of the non-woven fabric sheet 10 is around 40 to 100μ, the thickness of the PE sheet 20 is around 30 to 60μ, a print film of the entire surface of the upper surface of the non-woven fabric sheet 10 is around 1 to 10μ, and an application thickness of the electrically-conductive paint is around 0.1 to 10μ. The entire surface printing of the non-woven fabric is a novel idea in a field of printing. Further, in the case of forming the electrically-conductive paint surface 40 by applying the electrically-conductive paint after entire surface printing of the non-woven fabric, the consumed quantity of the electrically-conductive paint is dramatically small.
A specific manufacturing method of the antistatic sheet of the second embodiment is shown in
Similar to the first embodiment, the non-woven fabric sheet 10 is unwound from the non-woven fabric sheet roll 110, and is supplied to the process. On the other hand, the PE sheet or the PP sheet 20 is unwound from the PE sheet roll or the PP sheet roll 120 and is supplied to the process. To the surface of the PE sheet or the PP sheet 20, the adhesive 70 is applied from the adhesive application roll 130. Thereafter, the non-woven fabric sheet 10 and the PE sheet or the PP sheet 20 are introduced into the laminating roll 140, press-bonded and laminated therein. Thereafter, the laminated sheet 60 is introduced into the printing roll 150, and the surface on the non-woven fabric sheet 10 side of the laminated sheet 60 is entirely printed (the ink tank 35), so that the entire surface printing surface 30 is formed. Thereafter, the laminated sheet 60 with the non-woven fabric sheet 10 side surface entirely printed is introduced into an electrically-conductive paint application roll 155, an electrically-conductive paint (an electrically-conductive paint tank 45) is applied to the entire surface printing surface, so that the electrically-conductive paint surface 40 is formed. Thereafter, the laminated sheet 60 is introduced into the cutting roll 160, and is cut into a predetermined shape.
In the antistatic sheet of the second embodiment, the electrically-conductive paint surface 40 as the conductive layer is provided only on the surface thereof. As such, in the case where the electronic component or the like is placed on the antistatic sheet, the static electricity charged to the electronic component or the like is rapidly neutralized.
A third embodiment of the present invention is, as is shown in
In the third embodiment, the sheet-like product may, in place of laminating the PE sheet 20 or the PP sheet 20 to the lower surface of the non-woven fabric sheet 10 and then laminating the antistatic PE sheet 50 to the lower surface thereof, laminate an antistatic laminated PE sheet 80, which is obtained by laminating the antistatic PE sheet 50 to the lower surface of the PE sheet 20 or the PP sheet 20, to the lower surface of the non-woven fabric sheet 10.
It is preferable that the thickness of the non-woven fabric sheet 10 is around 40 to 100μ, the thickness of the antistatic PE sheet 50 is around 20 to 60μ, the thickness of the print film of the whole surface of the upper surface of the non-woven fabric sheet 10 is around 1 to 10μ, and an application thickness of the electrically-conductive paint is around 0.1 to 10μ. The thickness of the PE sheet 20 alone may be, as is in the second embodiment, 30 to 60μ.
A specific manufacturing method of the antistatic sheet of the third embodiment is shown in
Similar to the first and the second embodiment, the non-woven fabric sheet 10 is unwound from the non-woven fabric sheet roll 110, and is supplied to the process. On the other hand, the antistatic laminated PE sheet 80 is unwound from an antistatic laminated PE sheet roll 180 and is supplied to the process. To the surface of the antistatic laminated PE sheet 80, the adhesive 70 is applied by the adhesive application roll 130. Thereafter, the non-woven fabric sheet 10 and the antistatic laminated PE sheet 80 are introduced into the laminating roll 140, press-bonded and laminated therein. Thereafter, the laminated sheet 60 is introduced into the printing roll 150, and the surface on the non-woven fabric sheet 10 side of the laminated sheet 60 is entirely printed (the ink tank 35), so that the entire surface printing surface 30 is formed. Thereafter, the laminated sheet 60 with the non-woven fabric sheet 10 side surface entirely printed is introduced into the electrically-conductive paint application roll 155, the electrically-conductive paint (the electrically-conductive paint tank 45) is applied to the entire surface printing surface, so that the electrically-conductive paint surface 40 is formed. Thereafter, the laminated sheet 60 is introduced into the cutting roll 160, and is cut into a predetermined shape.
In the specific manufacturing method (
Similar to the first and the second embodiment, the non-woven fabric sheet 10 is unwound from the non-woven fabric sheet roll 110, and is supplied to the process. On the other hand, the PE sheet or the PP sheet 20 is unwound from the PE sheet roll or the PP sheet roll 120 and is supplied to the process. To the surface of the PE sheet or the PP sheet 20, the adhesive 70 is applied by the adhesive application roll 130. Thereafter, the non-woven fabric sheet 10 and the PE sheet or the PP sheet 20 are introduced into the laminating roll 140, press-bonded and laminated therein. Thereafter, the laminated sheet 60 is introduced into the printing roll 150, and the surface on the non-woven fabric sheet 10 side of the laminated sheet 60 is entirely printed (the ink tank 35), so that the entire surface printing surface 30 is formed. Thereafter, the laminated sheet 60 with the non-woven fabric sheet 10 side entirely printed is introduced into the electrically-conductive paint application roll 155, the electrically-conductive paint (the electrically-conductive paint tank 45) is applied to the entire surface printing surface, so that the electrically-conductive paint surface 40 is formed. Thereafter, the laminated sheet 60 is introduced into a laminating roll 170, and the antistatic PE sheet 50 is laminated on the side of the PE sheet 20 or the PP sheet 20. Thereafter, the laminated sheet 60 is introduced into the cutting roll 160, and is cut into a predetermined shape.
As is explained above, in the third embodiment, the electrically-conductive paint surface 40 having the highest (easier to flow the static electricity) conductivity in the order of easiness of flowing the static electricity is formed to the upper surface (the surface on which the electronic component or the like charged with the static electricity is placed) of the non-woven fabric which functions as the static electricity interrupting layer, and the antistatic PE sheet 50 with antistatic ability lower in the order is formed to the lower surface on the opposite side (the surface contacting the floor). By doing so, the neutralization of the static electricity of the electronic component or the like placed on the antistatic sheet of the present invention is performed promptly, and the transition of the static electricity from the floor may be inhibited.
As the antistatic agent used in the embodiment of the present invention, it is preferable to use an antistatic polymer paint manufactured by Shin-Etsu Polymer Co., Ltd., or an antistatic agent manufactured by Nissan Chemical Industries, Ltd. or Marubishi Oil Chemical Co., Ltd.
The following experiment had been conducted to verify the effect with the antistatic sheet of the present invention. As the object of the experiment, (1) non-woven fabric/PE sheet (with antistatic agent), and (2) non-woven fabric/PE sheet (without antistatic agent), were used, and as the material for charging the static electricity, (3) nylon 100%, (4) polyethylene 100%, and (5) bubble sheet, were used.
First, in order to study a charge amount of the static electricity of (1) through (5) mentioned above, a value measured as an initial value 1 is measured by rubbing a friction cloth of 100% rayon 20 times in a horizontal direction against test pieces of (1) to (5) above by manpower, and then measuring the static electricity. Measurement was performed using a surface potential measurement instrument STATIRON TYPE-TL, a tuning fork vibrator type, manufactured by Shishido Electrostatic, Co., Ltd, as a measuring instrument. The measurement distance was 50 mm.
As a result, the initial values 1 of the static electricity of the above-mentioned test pieces were as follows (unit: V).
(1) Non-woven fabric/PE sheet (with antistatic agent) non-woven fabric surface: 0, PE surface: −10
(2) Non-woven fabric/PE sheet (without antistatic agent) non-woven fabric surface: 0, PE surface: −100
(3) Nylon 100% −5,000
(4) Polyethylene 100% −8,000
(5) Bubble sheet −7,000
Next, in order to verify the neutralization effect of (1) and (2) above, the static electricity were charged to the test pieces of (3) to (5) above by rubbing the friction cloth of 100% rayon 20 times in the horizontal direction, then the test pieces were placed on (1) non-woven fabric/PE sheet (with antistatic agent), and (2) non-woven fabric/PE sheet (without antistatic agent), and the change in the static electricity were measured.
First, the neutralization effect in the case where the charged test piece was placed was measured, and thereafter, the static electricity of each test piece was measured after removing the test piece. The results are shown in Table 1. According thereto, it is proven that the neutralization effect when an object charged with static electricity is placed thereon is extremely high in both (1) non-woven fabric/PE sheet (with antistatic agent) and (2) non-woven fabric/PE sheet (without antistatic agent), and it is proven that the static electricity charged is reduced to approximately half the value when the object is removed therefrom.
From the present experiment, the following was proven.
(1) There was hardly any charging in the non-woven fabric/PE laminate material.
(2) In the case where the antistatic agent was applied to the non-woven fabric surface of the non-woven fabric/PE laminate material with a technique of solid printing, there was also an effect on the PE surface on the rear side.
(3) There is a neutralization effect when a material easily charged and storing electricity, such as PE and nylon, is attached to the non-woven fabric/PE laminate material, and the effect is increased when the antistatic agent was applied to the non-woven fabric surface with a technique of solid printing.
(4) As is explained above, in the third embodiment in which solid printing of the antistatic agent is performed on the non-woven fabric, and the PE laminate material for antistatic is used, it becomes possible to achieve extremely high antistatic effect and neutralization effect without fail.
The effects of the present invention are as follows.
With the configuration explained above, the present invention provides an antistatic sheet capable of exerting the neutralization effect and the antistatic effect of electronic devices.
Further, the present invention provides an antistatic sheet exerting superior effect in anti-fouling property, cushion property, lightweight property, handling property, durability and the like, in addition to the neutralization effect and the antistatic effect.
A general electrically-conductive mat conventionally used has a thickness of about 2 mm and about 3 kg/m2, however, the antistatic sheet of the present invention is capable of achieving a thickness of about 0.2 mm and about 80 g/m2. Further, the same can be provided inexpensively.
Further, the present invention is capable of manufacturing the antistatic sheet equipped with the neutralization function and the antistatic function easily.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-130453 | Jun 2010 | JP | national |
This application is a continuation of International application No. PCT/JP2011/063052, filed on Jun. 7, 2011, the contents of which are incorporated herein by reference. The present application is based on and claims priority of Japanese patent application No. 2010-130453 filed on Jun. 7, 2010, the entire contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2011/063052 | Jun 2011 | US |
| Child | 13693641 | US |
