Tri-County Materials, Inc. (Tri-County) (plaintiff) entered into a contract with Ladd Construction Company (Ladd) for the sale of sand and gravel. Tri-County then entered into an agreement with KMB, Inc. (KMB) to lease certain equipment to transport the material. As security for Tri-County’s payment obligations under the lease agreement, Tri-County granted a security interest to KMB in a portion of the Ladd account. KMB did not file a financing statement. Neither KMB nor Tri-County had previously entered into this type of security agreement. The lease payments amounted to approximately 12 percent of the total Ladd account. Tri-County filed for bankruptcy. The bankruptcy court determined that Tri-County assigned a significant portion of its account, and the transaction was not casual and isolated. The bankruptcy court, therefore, ruled that KMB did not have a priority in its security, interest because the interest was not perfected.