Tacky floor pad

Claim 2

A pad as in claim 1 wherein each said sheet is from 0.002 to 0.004 inch in thickness and said adhesive coating is about 0.00003 to 0.0003 inch in thickness.

Claim 3

A pad as in claim 3 wherein said adhesive coating is about 0.0001 inch in thickness.

Claim 4

A pad as in claim 1 wherein said adhesive is an intimate admixture of an acrylic resin and a surfactant in amount sufficient to effect wetting when said admixture is coated onto a polyethylene substrate, exhibits a Young''s modulus of -45* C. expressed as glass temperature; and has a tack angle of about 20* to 30* and an internal viscosity of from 5 to 24 hours as measured by the tests described herein by covering the steel cylinder described in said tests with a clean polyethylene surface, coating a polyethylene terephthalate strip with a layer of said adhesive mixture 0.001 inch thick, applying said coated strip over said polyethylene surface with 100 percent surface contact, hanging a 100 gram weight on a trailing edge of said strip to peel said strip from said surface to an equilibrium point, coming to a point within 5* of said equilibrium point within from 10 to 30 hours.

Claim 5

A pad as in claim 5 wherein said adhesive contains about 0.4 percent of said surfactant and about 99.60 percent of said acrylic resin.

Claim 6

A pad as in claim 1 wherein each said sheet has a corner area free of adhesive to enable grasping and removal of said sheet.

Claim 7

A pad as in claim 1 having beveled edges tapered inwardly by virture of each sheet being larger in both lengthwise and widthwise dimensions than the sheet above it, the area of a lower sheet which projects beyond the sheet above being non-adhesive.

Claim 8

A pad as in claim 1 wherein each said adhesive coating extends outwardly at least one-sixteenth inch farther than the next higher coating.

Claim 9

A pad as in claim 1 wherein the lowermost sheet is coated with the same adhesive on its bottom surface in a thicker coating.

Claim 10

A clean room entryway including in combination: a. an entrance doorway leading into said clean room, b. a corridor leading to said doorway and having a floor, and c. an unframed pad assembly having beveled edges, for cleaning shoes and wheels disposed adhesively directly to said floor just outside said doorway and large enough to receive the full perimeter of such wheel, and longer than a large step taken by a person walking, whereby to remove dust and dirt from wheels and shoes coming into contact therewith, d. said pad assembly comprising at least one stack of a plurality of sheets formed from a material selected from the group consisting of polyethylene and polypropylene, in detachably stacked arrangement, the upper surface only of each said sheet being corona-discharge treated to greatly improve adhesion, each said sheet having a thin layer of pressure-sensitive adhesive, substantially covering and adhered to said upper surface thereof and constituting the only material in between sheets, each downwardly succeeding layer of said adhesive extending outwardly farther than the next adjacent upper layer thereof to prevent peel and unwanted lamination being brought about by normal use.

Claim 11

A clean room entryway as in claim 11 wherein each said sheet is from 0.0002 to 0.004 inch in thickness and each said adhesive layer is about 0.0001 inch in thickness.

Claim 12

A clean room entryway as in claim 11 wherein said adhesive is an acrylic latex adhesive, has a Young''s modulus of from about -30* C. to about -50* C. expressed as glass temperature, a tack angle of from 20* to 30* and an internal viscosity of from 10 to 30 hours when measured by tests described in this specification.

Claim 13

A clean room entryway as in claim 11 wherein said pad is adhered to said floor by the same adhesive material in a thicker layer.

Claim 14

A clean room entryway as in claim 11 wherein each said sheet has a corner portion freed of adhesive to enable grasping and lifting.

Claim 15

A clean room entryway as in claim 15 wherein each said succeeding layEr of said adhesive extends at least 1/16 inch outwardly from said adjacent upper layer. 17 A clean room comprising walls, floor and ceiling defining a room, a doorway in one said wall, a hallway floor outside said doorway, and an unframed cleaning pad having beveled edges and adhesively and removably secured directly to said floor outside of said doorway and adapted to receive on its upper surface foot traffic and wheeled traffic, said pad being larger than a long step taken by a walking person and adapted to receive the full perimeter of the wheel of a wheeled cart, whereby to remove dust and dirt from wheels and shoes coming into contact therewith, said pad comprising a plurality of thin sheets formed from a material selected from the group consisting of polyethylene and polypropylene, in detachably stacked arrangement, each said sheet having a layer of pressure-sensitive adhesive substantially covering the upper face thereof, said upper face only having been corona-discharge pretreated to improve adhesion to an adhesive, each said sheet except the bottom being from 0.002 to 0.003 inch in thickness and said adhesive layer being from 0.00003 to 0.0003 inch in thickness, said pad having a thicker bottom sheet with a bottom surface and a thicker layer of adhesive disposed thereover to adhere said pad to said floor, each downwardly succeeding layer of said adhesive extending outwardly farther than the next adjacent upper layer of said adhesive in order to prevent undesired peeling upon normal use.

Claim 16

A clean room as in claim 17 wherein said first-mentioned adhesive layer is 0.001 inch in thickness.

Claim 17

A clean room as in claim 17 wherein said first mentioned adhesive has a Young''s modulus of from -30*C. to -55*C. expressed as glass temperature, a tack angle of from 20* to 30* and an internal viscosity of from 10 to 30 hours when measured by tests described in this specification.

Claim 18

A clean room as in claim 19 wherein the second-mentioned adhesive is the same as the first-mentioned adhesive.

Claim 19

A clean room as in claim 17 wherein each sheet has a corner portion freed of adhesive to enable grasping and lifting.

Claim 20

A clean room as in claim 17 wherein each said succeeding layer of said adhesive extends at least one-sixteenth inch outwardly from said adjacent upper layer.

Claim 21

A thin, throw-away cleansing pad adhesively and removably securable to a floor and adapted to form a substantially unobstructing portion of a pathway for foot or wheeled-cart traffic, comprising: a. a plurality of sheets formed from a material selected from the group consisting of polyethylene and polypropylene in detachably stacked arrangement, each said sheet having an upper surface and a lower surface, and b. a thin pressure-sensitive adhesive coating substantially covering and adhered to said upper surface of each said sheet and constituting the only material in between successive said sheets, c. said adhesive coating on each sheet extending further outwardly than such coating on the next higher sheet in said pad, to prevent peel and unwanted delamination from normal use.