Wiper blade

A wiper blade, comprising:

• a hand grip portion;
• and
• an elastic portion supported by the hand grip portion, a part of the elastic portion being configured to be pressed against a surface of a member to be cleaned in order to clean the surface of the member, the hand grip portion extending in a direction perpendicular to a direction in which the elastic portion extends;
• and
• the elastic portion comprising a polyurethane which is a reaction product of a composition comprising an isocyanate compound including a diisocyanate and a trifunctional or higher polyfunctional isocyanate, and an alcohol including a trifunctional or higher polyfunctional alcohol, wherein
• when defining a side of the elastic portion farthest away from the hand grip portion as a tip side of the wiper blade, the elastic portion has, on the tip side, a main surface opposing the member to be cleaned, and a tip surface that forms a tip side edge together with the main surface,
• when defining a length of a first line segment drawn on the tip surface parallelly to the tip side edge at a distance of 10 μm from the tip side edge as L1, and respectively defining points at (⅛)L1, (½)L1 and (⅞)L1 from one end side on the first line segment as P0, P1 and P2, and when measuring, using a scanning probe microscope, an elastic modulus at 70000 points at a 0.1 μm pitch in each of three rectangular observation regions on the tip surface, each of the rectangular observation regions having respective centroids at P0, P1 and P2, and having a 70 μm-long side parallel to the first line segment and a 10 μm-long side perpendicularly intersecting the first line segment, a mean value of the 210000 obtained elastic modulus values is 15 to 470 MPa, and a coefficient of variation of elastic modulus is 17.6% or lower,
• when defining a length of a second line segment drawn on the main surface parallelly to the tip side edge at a distance of 10 μm from the tip side edge as L2 and respectively defining points at (⅛)L2, (½)L2 and (⅞)L2 from one end side on the second line segment as P3, P4 and P5, and when measuring, using a scanning probe microscope at 70000 points at a 0.1 μm pitch in each of three rectangular observation regions on the main surface, each of the rectangular observation regions having centroids at P3, P4 and P5, and having a 70 μm-long side parallel to the second line segment and a 10 μm-long side perpendicularly intersecting the second line segment, a mean value of the 210000 obtained elastic modulus values is 15 to 470 MPa, and a coefficient of variation of elastic modulus is 17.6% or lower,
• in a measurement of elastic modulus on the tip surface, the coefficient of variation of elastic modulus is 6.0% or lower, and
• in a measurement of elastic modulus on the main surface, the coefficient of variation of elastic modulus is 6.0% or lower.