unity - How to tilt an object(2D) after collision and the rotate continuously

I am having trouble rotating and object after collision. The object only transforms to the given angle of rotation once and stops. I would like to achieve in a way that after it has collided with the player object it rotates continuously till its killed after exiting the screen. The OnCollisionEnter2D(Collision2D collision) can't achieve this.

How can I achieve it using the FixedUpdate function?

Here is the code:

namespace Assets.scripts
{
    public class Barmovementscript : MonoBehaviour
    {
        public float Tilt;


        private void FixedUpdate()
        {
        }

        // upon collision the object rotates in a clockwise direction.
        void OnCollisionEnter2D(Collision2D collision)
        {
            if (collision.collider.tag == "Player")
            {
                Tilt += Time.deltaTime * -10;

                gameObject.transform.rotation = Quaternion.Euler(0, 0, Tilt);
            }
        }
    }
}