Stock material or miscellaneous articles – Structurally defined web or sheet – Discontinuous or differential coating – impregnation or bond
Patent
1994-10-04
1997-10-14
Cannon, James C.
Stock material or miscellaneous articles
Structurally defined web or sheet
Discontinuous or differential coating, impregnation or bond
162135, 162136, 162138, 428207, 4285375, 451533, B24D 1102, B32B 516, B32B 3300, D21H 1944, D21H 1982, D21H 2114
Patent
active
056770391
DESCRIPTION:
BRIEF SUMMARY
Such a sheet can be used in various fields. It may be used to make articles for which there is a need to dissipate the electrostatic charges produced when they are used, or for articles whose primary or secondary function is to dissipate the electrostatic charges which develop and can be dangerous in a given environment.
Flexible abrasives are known that are made up of a substrate sheet onto which abrasive particles are glued with an adhesive, so that it is necessary to dissipate the electrostatic charges that arise during their use.
In effect, unless the abrasive is treated to dissipate the charges, the dust formed during the abrasion of an object is deposited and crushes the abrasive particles; this lowers the yield from the abrasion process. Moreover, workers can suffer electric shocks, which can cause uncontrollable gestures and put them in danger on the job.
Laminates are also known, which are currently used in making furniture, work tables, wall panels and the like.
The products obtained are used in particular in operating rooms, white rooms or computer rooms. In these rooms, there is a need to prevent dust from being retained, particularly as a result of the attraction exerted by electrostatic charges, and there is also a need to avoid sudden electrostatic discharge; hence the surfaces located in the room must be treated to provide for regular dissipation of the static electricity.
In the field of abrasives, the substrate or the adhesive layer, or the surface of the abrasive particles, is treated with a conductive product. Conductive products that have been employed are quaternary ammonium salts, carbon black, metal powders or fibers, metal alloys, metal salts, doped conductive polymers, or mineral pigments made conductive by coating them with an electroconductive layer of metal oxide.
It is known to use carbon black, either in bulk or on the surface, to make a conductive substrate.
In European Patent Application EP A 414 494, the abrasive is made conductive by incorporating carbon black in the adhesive used for gluing the abrasive particles.
In U.S. Pat. No. 3,942,959, the abrasive is made conductive by a layer of conductive compound, which may be a metal, metal alloy, metal pigment, salt or metal complex, this layer being deposited between two insulating layers. The conductive product may be placed on the back of the substrate, or on the face of the substrate (under the adhesive), or mixed with the adhesive or the particles.
In French Patent Application FR A 2276144, an abrasive is made conductive by depositing a conductive layer on top of the abrasive particles, the conductive product being graphite in particular.
In European Patent Application EP A 408 943, the abrasive is made conductive by treating the surface of the layer containing the abrasive particles with a solution containing a quaternary ammonium salt.
In European Patent Application EP A 398 580, the abrasive is made conductive by treating the surface of the layer containing the abrasive particles with a doped conjugated polymer, such as polythiophene, polyaniline, or polypyrrole.
In the field of laminates, the sheets of paper constituting them are treated with a conductive product.
First, Applicants wish to reiterate how laminates are manufactured in general, by distinguishing the two types of currently existing laminates, that is, those known as high-pressure laminates and those known as low-pressure laminates.
High-pressure laminates are produced from a core made up of a stack of sheets, generally of kraft paper, impregnated with heat-hardenable resin, in particular a phenolic resin.
Once the sheets of kraft paper have been impregnated with resin, they are dried and cut and then stacked on one another; the number of stacked sheets depends on the intended uses, and in general varies between 3 and 9.
Next, a decorative sheet is put in place; it may be combined with printed patterns or may be given an iridescent or metallic appearance and is impregnated with a heat-hardenable resin that does not darken when exposed to heat (a melamine-
REFERENCES:
patent: 4568609 (1986-02-01), Sato et al.
patent: 5071676 (1991-12-01), Jacobson
Database WPIL, Section Ch, Week 8314, Derwent Publications Ltd., London, GB .
Perrin Claude
Simon Christophe
Arjo Wiggins S.A.
Cannon James C.
LandOfFree
Antistatic sheet does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antistatic sheet, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antistatic sheet will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1553516