Arylalkanoylpyridazine derivatives of the formula I and their physiologically acceptable salts and solvates, in which R1, R2, Q and B have the meanings indicated in Claim 1, show an inhibition of phosphodiesterase IV and can be employed for the treatment of asthma, chronic bronchitis, atopic dermatitis, psoriasis and other skin diseases, inflammatory diseases, autoimmune disorders, such as, for example, rheumatoid arthritis, multiple sclerosis, Crohns disease, diabetes mellitus or ulcerative colitis, osteoporosis, transplant rejection reactions, cachexia, tumour growth or tumour metastases, sepsis, memory disorders, atherosclerosis and AIDS.