all the companies in the world are beginning to use the blockchain technology but none of those companies have bought bitcoin
Don't say that "all" as there's still no basis that all of them are adopting blockchain technology soon. Let's use the term "many" are adopting it and has expressed their interest on it. They are not saying that they have bought bitcoin but there's no protocol or need to say that they did.
and other companies create their own blockchain, this would affect the price of bitcoin in the near future?
It's necessary for those companies to create their own blockchain and that's how they are adopting the technology. They are using bitcoin's blockchain but it's not bitcoin itself.