Adsorbent Articles for Disk Drives
An improved activated carbon adsorbent for disk drives that has improved or increased adsorption capacity for moisture between 25% RH and 45% RH while optionally maintaining good capacity for organic vapors, acid gasses and moisture at 95% RH.
1 . An adsorbent article for a disk drive comprising carbon adsorbent, said carbon adsorbent having functional end groups comprising oxygen such that the carbon adsorbent comprises at least about 13.5 percent oxygen by weight.
2 . The adsorbent article of claim 1 in which said carbon adsorbent comprises at least 15.0 percent oxygen by weight.
3 . The adsorbent article of claim 1 in which the functional end groups are selected from the group consisting of anhydrides, carboxyls, carbonyls, carboxylic acids, phenols, quinones, ethers and lactones.
4 . The adsorbent article of claim 1 in which the functional end groups are covalently bonded to the carbon adsorbent such that the end groups impart new chemical functionality to the carbon adsorbent.
5 . The adsorbent article of claim 1 , in which said carbon adsorbent is in a form selected from the group of a tablet, filled tape adsorbent embedded fabric, adsorbent beads and adsorbent granules.
6 . An adsorbent article for a disk drive comprising carbon adsorbent, said carbon adsorbent having functional end groups such that said carbon adsorbent comprises at least about 6.0 percent of an element selected from the group consisting of nitrogen, sulfur, phosphorous, bromine, chlorine, and fluorine.
7 . The adsorbent article of claim 6 , in which the functional end groups are selected from the group consisting of amines, phosphates, sulfates, chlorides, fluorides.
8 . An adsorbent article for a disk drive comprising carbon adsorbent, said carbon adsorbent having more than about 40 meq/100 grams of total acidity as determined by Boehm titration.
9 . The adsorbent article of claim 8 in which said carbon adsorbent has more than 50 meq/100 grams of total acidity as determined by Boehm titration.
10 . The adsorbent article of claim 8 in which said carbon adsorbent has more than 70 meq/100 grams of total acidity as determined by Boehm titration.
11 . The adsorbent article of claim 8 in which said carbon adsorbent has more than 90 meq/100 grams of total acidity as determined by Boehm titration.
12 . An adsorbent device for a disk drive comprising carbon adsorbent, said carbon adsorbent adapted to have a moisture capacity at moderate RH of greater 14%.
13 . The adsorbent device of claim 12 in which the carbon adsorbent is adapted to have a moisture capacity at moderate RH of greater than 17%.
14 . The adsorbent device of claim 12 in which the carbon adsorbent is adapted to have a moisture capacity at moderate RH of greater than 20%.
15 . An adsorbent device for a disc drive comprising carbon adsorbent, said carbon adsorbent adapted to absorb moisture such that the adsorbent device adsorbs at least 0.08 g water per cubic centimeter of adsorbent device volume at moderate RH.
16 . The adsorbent device of claim 15 in which said carbon adsorbent is adapted to adsorb at least 0.10 g water per cubic centimeter of adsorbent device volume at moderate RH.
17 . An adsorbent device for a disk drive comprising carbon adsorbent adapted such that the adsorbent has a moisture capacity of at least 14% at moderate RH and a TMP capacity of at least about 17.5 percent by weight.