The Answer

All of the words in the list are (were) brand names.  Interestingly, scotch tape is still called cellophane tape in Scotland.  Of course, we can add band-aid, Kleenex, Tylenol, and aspirin to the list, but that would have been too easy.

Several years ago, I had a class on language evolution in which we discussed the various means by which languages change.   We used the term metonymy for the use of a brand name to refer to the generic product.  I always thought of it as a high compliment to a company that its product and name could be so popular as to become the default word for said product.  Apparently, this phenomenon is now being called genericide, a decidedly negative term.  And companies are spending lots of money on advertising to remind us that their product brand is just that.  A notable exception is that Microsoft is actively trying to integrate "Bing" into our common lexicon just as Google has done unwillingly.

You can listen to an interesting show on the topic on The Age of Persuasion with Terry O'Reilly.