Static electricity is a form of dc electricity or better a dc charge. The container of this charge usually is an isolator with negative or positive charged molecules on the surface. This charge is steady and not alternating in polarity. On the same isolating surface however there can be multiple “spots” that contain a charge with a different polarity. So on a surface there can be both one or more negative and one or more positive polarity charges but the charge itself does not change in polarity in time and is therefor a dc charge.