A mutual savings bank may invest its funds:
No law of this state prescribing the nature, amount, or form of security or requiring security or prescribing or limiting interest rates or prescribing or limiting the term, shall be deemed to apply to loans, contracts, advances of credit or purchases made pursuant to the foregoing subdivisions (1), (2), (3), (4), (5), and (6).
RCW 32.20.040