Whenever the articles of incorporation of a foreign corporation authorized to conduct affairs in this state are amended, such foreign corporation shall, within thirty days after such amendment becomes effective, file in the office of the secretary of state a copy of such amendment duly authenticated by the proper officer designated under the laws of the state or country in which it is incorporated: PROVIDED, That the filing thereof shall not of itself enlarge or alter the purpose or purposes for which such corporation is authorized to pursue in conducting its affairs in this state, nor authorize such corporation to conduct affairs in this state under any other name than the name set forth in its certificate of authority.