Whenever the vendor of personal property, at the time of selling and delivering such personal property, takes a mortgage or other security interest to secure the payment of the purchase money for such personal property, neither the surviving spouse nor the minor child or children of the vendee shall be entitled to year's support in the personal property as against the vendor or the vendor's heirs, personal representatives, or assigns until the purchase money of the personal property is fully paid; provided, however, that the mortgage or other security interest shall expressly state that the same is executed and delivered for the purpose of securing the debt for the purchase.