There are no patented products in China, but there are patents abroad. Will the sale of our products in China be infringing in that country?

Patents are regional, and they are protected in which country they are applied for.

For example:

A applied for a patent in Japan, but it is not infringement for B to produce the patented product in China.

However, if Party B transports the products produced in China to Japan for sale, it will infringe Party A's patent right in Japan, and the specific liability and amount of compensation for infringement will be determined according to relevant Japanese laws.