The patent protection period of R-4 10A refrigerant is 20 years, counting from 1996 65438+ 10/day, so the patent has been granted on 20 1 6 65438+1 0/month. At present, R-4 10A refrigerant has become a widely used refrigerant, which is used in many household and commercial air conditioning systems. As the patent expires, other companies can start to produce and sell R-4 10A refrigerant, which is easier to obtain and use, thus bringing more choices and competition.