Google and IBM spokesmen wouldn't comment Friday on the purchase.
The patent transfers were recorded two weeks ago and cover a range of technologies, many of which have little to do with Google's Internet search and advertising business. One covers ways of automatically adjusting a clock, another deals with surface treatments for electrical contacts.
But even patents that have little do with Google's business can be useful ammunition in the hyper-litigious technology world.
If it's sued over patents by a company whose business relies on technologies covered by Google's patents, Google can file a retaliatory lawsuit.
Phone makers that use Google Inc.'s Android software are being sued by Apple Inc. and Microsoft Corp. As a young company, Google has few patents of its own to counter with.
Kent Walker, Google's general counsel, wrote in a blog post in April that the explosion in patent litigation threatens to stifle innovation.
"But as things stand today, one of a company's best defenses against this kind of litigation is (ironically) to have a formidable patent portfolio, as this helps maintain your freedom to develop new products and services," Walker wrote.
Earlier this month, Google participated in an auction for a collection of 6,000 patents from Nortel, a bankrupt Canadian maker of telecommunications equipment. It was outbid by a consortium including Apple that paid $4.5 billion.
In the past year, Google has also bought patents from Verizon Communications Inc. and Motorola Inc.
The patent sale was first reported by the blog SEO by the Sea, which follows Google.