Cleaning medium for removing contamination and method of making

Abstract

A cleaning medium that includes polyisobutylene (also sometimes referred to as polybutylene or as polybutene). Cleaning media include cleaning implements, polishers, and filters. Typically a substantial portion of the polyisobutylene has a molecular weight (MW) greater than 30,000 and in some particular applications the molecular weight is around 85,000. The polyisobutylene is generally adjacent to the surface of a substrate, such as a non-woven or woven fabric. A method of making a cleaning medium is provided. The method typically involves dissolving polyisobutylene in a solvent such as hexane to form a tackifier solution, soaking the substrate in the tackifier to produce a preform, and then drying the preform to produce the cleaning medium. The cleaning media are typically used dry, without any liquid cleaning agent. In embodiments where the cleaning medium is as cleaning implement or a polisher, the surface to be cleaned is wiped with a surface of the cleaning medium adjacent to which the polyisobutylene is disposed. Vigorous wiping may be used in applications where contamination is difficult to remove. In embodiments where the cleaning medium is a filter, a fluid is passed through the cleaning medium and the cleaning medium traps particles and aerosols entrained in the fluid.

1 . A cleaning medium comprising:
 a substrate having a bulk mass and a front surface having fibers; and   polyisobutylene disposed on the fibers adjacent to the front surface of the substrate, wherein a substantial portion of the polyisobutylene has a viscosity average molecular weight (M VA ) greater than approximately 30,000 and the relative weight ratio between the polyisobutylene and the fibers having polyisobutylene disposed thereon is between approximately 1 to 10 wt % polyisobutylene to approximately 90 to 99 wt % fibers.   
   
   
       2 . The cleaning medium of  claim 1  wherein a substantial portion of the polyisobutylene has a molecular weight that is between approximately 30,000 and 140,000 (M VA ). 
   
   
       3 . The cleaning medium of  claim 1  wherein the polyisobutylene is further disposed throughout the bulk mass of the substrate and the relative weight ratio between the polyisobutylene and the bulk mass of the substrate is between approximately 1 to 10 wt % polyisobutylene to approximately 90 to 99 wt % bulk mass of the substrate. 
   
   
       4 . The cleaning medium of  claim 1  wherein the polyisobutylene is further disposed through a permeated portion of the bulk mass of the substrate and the relative weight ratio between the polyisobutylene and the permeated portion of the bulk mass of the substrate is between approximately 1 to 10 wt % polyisobutylene to approximately 90 to 99 wt % permeated portion of the bulk mass of the substrate. 
   
   
       5 . The cleaning medium of  claim 1  wherein the substrate has a thickness and the bulk mass of the substrate has a reference portion, the reference portion of the bulk mass being a portion of the substrate to a depth of approximately the first one thousand micrometers of the thickness of the substrate, and the relative weight ratio between the polyisobutylene and the reference portion of the bulk mass of the substrate is between approximately 1 to 10 wt % polyisobutylene to approximately 90 to 99 wt % reference portion of the bulk mass of the substrate. 
   
   
       6 . The cleaning medium of  claim 1  wherein the substrate has a thickness and the bulk mass of the substrate has a reference portion, the reference portion of the bulk mass being a portion of the substrate to a depth of approximately the first one hundred micrometers of the thickness of the substrate, and the relative weight ratio between the polyisobutylene and the reference portion of the bulk mass of the substrate is between approximately 1 to 10 wt % polyisobutylene to approximately 90 to 99 wt % reference portion of the bulk mass of the substrate. 
   
   
       7 . The cleaning medium of  claim 1  further comprising at least a minimum detectable amount of solvent, the solvent selected from the group consisting of an alkane, an isoparaffin, an aliphatic compound, a cycloaliphatic compound, a terpene, and mixtures of two or more of the foregoing. 
   
   
       8 . The cleaning medium of  claim 8  wherein the amount of solvent does not exceed approximately 1000 ppm weight ratio of solvent to solvent plus polyisobutylene. 
   
   
       9 . A cleaning medium comprising:
 (a) a substrate comprising a plurality of fibers each having a surface; and   (b) polyisobutylene disposed adjacent to the surface of the fibers to form treated fibers having a treated thickness; wherein the polyisobutylene comprises droplets disposed on the treated fibers, the droplets having a length that is between approximately one and five times the treated thickness of the treated fibers and the droplets having a width that is between approximately 110% and 150% of the treated thickness of the treated fibers.   
   
   
       10 . The cleaning medium of  claim 9  wherein the substrate has a front surface and substantially all of the polyisobutylene is disposed adjacent to the front surface. 
   
   
       11 . The cleaning medium of  claim 9  wherein a substantial portion of the polyisobutylene has a viscosity average molecular weight (M VA ) of approximately 85,000. 
   
   
       12 . The cleaning medium of  claim 9  wherein a substantial portion of the polyisobutylene has a viscosity average molecular weight (M VA ) that is greater than approximately 30,000. 
   
   
       13 . The cleaning medium of  claim 9  wherein the substrate embodies between approximately 94% and 99.5% of the total dry weight of the cleaning medium. 
   
   
       14 . The cleaning medium of  claim 9  wherein the substrate embodies between approximately 6% and 94% of the total dry weight of the cleaning medium. 
   
   
       15 . The cleaning medium of  claim 9  wherein the substrate embodies between approximately 0.5% and 6% of the total dry weight of the cleaning medium. 
   
   
       16 . The cleaning medium of  claim 9  further comprising at least a minimum detectable amount of solvent, the solvent selected from the group consisting of an alkane, an isoparaffin, an aliphatic compound, a cycloaliphatic compound, a terpene, and mixtures of two or more of the foregoing. 
   
   
       17 . The cleaning medium of  claim 16  wherein the detectable amount of solvent does not exceed approximately 200 ppm at a 95% confidence level. 
   
   
       18 . A cleaning medium comprising:
 a substantially impervious substrate having a front surface; and   polyisobutylene disposed on the front surface of the substrate, wherein a substantial portion of the polyisobutylene has a viscosity average molecular weight (M VA ) greater than approximately 30,000.   
   
   
       19 . The cleaning medium of  claim 18  wherein a substantial portion of the polyisobutylene has a molecular weight that is between approximately 30,000 and 140,000 (M VA ). 
   
   
       20 . A method of making a cleaning medium, the method comprising:
 (a) dissolving polyisobutylene having a viscosity average molecular weight (M VA ) over 30,000 in a solvent selected from the group consisting of an alkane, an isoparaffin, an aliphatic compound, a cycloaliphatic compound, a terpene, and mixtures of two or more of the foregoing to form a tackifier solution of approximately 0.5 wt % to approximately 10 wt % polyisobutylene;   (b) applying the tackifier solution to a substrate to produce a preform; and   (c) drying the preform to form the cleaning medium.   
   
   
       21 . The method of making a cleaning medium of  claim 20  wherein step (a) comprises dissolving the polyisobutylene in the solvent to form a tackifier solution of approximately 0.5 wt % to approximately 1.5 wt % polyisobutylene. 
   
   
       22 . The method of making a cleaning medium of  claim 20  wherein step (a) comprises dissolving the polyisobutylene in the solvent to form a tackifier solution of approximately 1.5 wt % to approximately 2.0 wt % polyisobutylene. 
   
   
       23 . The method of making a cleaning medium of  claim 20  wherein step (a) comprises dissolving the polyisobutylene in the solvent to form a tackifier solution of approximately 2 wt % to approximately 3 wt % polyisobutylene. 
   
   
       24 . The method of making a cleaning medium of  claim 20  wherein step (a) comprises dissolving the polyisobutylene in the solvent to form a tackifier solution of approximately 4 wt % to approximately 6 wt % polyisobutylene. 
   
   
       25 . A cleaning wipe having a total dry weight, the cleaning wipe comprising:
 (a) a porous substrate, the porous substrate having a bulk mass with a plurality of voids and the porous substrate embodying a percentage of the total dry weight of the cleaning wipe, leaving a remaining percentage of dry weight; and   (b) polyisobutylene disposed within at least a portion of the plurality of voids, the polyisobutylene embodying substantially all of the remaining percentage of dry weight of the cleaning wipe