PROBLEM TO BE SOLVED: To provide a thickener composition, which contains a synthetic paste, a natural paste, or a derivative thereof, which have been widely used for a long time, as a main thickening component and which, by being added a specific thickening component thereto, provides high viscosity with a small amount of use, which has been difficult to obtain with a conventional thickener alone, and to provide a method for greatly increasing viscosity of an aqueous solution using a small amount of the thickener composition, and a method for controlling viscosity of an aqueous solution using the thickening method.SOLUTION: The thickener composition comprises a first thickening component mixed to increase viscosity of water and a second thickening component obtained with plants of genus Corchorus as an origin, in which a weight ratio of the second thickening component, based on the total weight of the composition having the first thickening component and the second thickening component mixed, is set in a range of 1.5% to 60%. This enables viscosity of a mixed aqueous solution having the composition dissolved is increased two times or more compared to the viscosity of a single aqueous solution having only the first thickening component dissolved in the same concentration.COPYRIGHT: (C)2015,JPO&INPIT【課題】従来から広く使用されている合成糊剤、天然糊剤又はその誘導体を主たる増粘成分とし、これに特定の増粘成分を配合することにより、少量の使用量で単独では得られなかった高粘度を得ることのできる増粘剤組成物を提供する。また、少量の増粘剤組成物を利用して水溶液の粘度を大きく向上させる増粘方法、及び、この増粘方法を利用した水溶液の粘度調整方法を提供する。【解決手段】水の粘性を高めるために混入する第１増粘成分と、ツナソ属（Ｃｏｒｃｈｏｒｕｓ属）に属する植物を基原として得られる第２増粘成分とを含有し、第１増粘成分と第２増粘成分とを配合した組成物の総量に占める第２増粘成分の重量比率を１．５％～６０％の範囲内とする。このことにより、当該組成物を溶解した混合水溶液の粘度が、第１増粘成分のみを同じ濃度で溶解した単独水溶液の粘度に比べ、２倍以上に増粘される。【選択図】図４
