Any 5 or more persons who are at present members of the Michigan dairymen’s association, who may desire to become incorporated for the purposes set forth in section 1, may execute under their hands and acknowledge before some person within this state authorized to take acknowledgment of deeds, 1 or more duplicate articles of agreement, as hereinafter specified, 1 copy whereof shall be filed and recorded in the office of the secretary of state, and upon the execution and acknowledgment of such articles, the signers thereof and those who may thereafter become associated with them, shall become a body politic and corporate for the purposes set forth in said articles.