Water-resistant organic thin-film, method for producing water-resistant organic thin-film, and image display device including water-resistant organic thin-film

A method for producing a water-resistant organic thin film, comprising the step of bringing a waterproofing treatment liquid into contact with one or both surfaces of an organic thin film comprising an organic dye having an anionic group, wherein the waterproofing treatment liquid contains organic nitrogen compounds, wherein

• the organic nitrogen compounds are first, second, and third acyclic organic nitrogen compounds each having two or more nitrogen atoms per molecule, wherein
• the nitrogen atoms of each of the first, second, and third organic nitrogen compounds are each in a cationic group, and
• the relation A≤0.4 nm<B<C is satisfied, wherein A represents a distance (nm) between adjacent nitrogen atoms in the first organic nitrogen compound, B represents a distance (nm) between adjacent nitrogen atoms in the second organic nitrogen compound, and C represents a distance (nm) between adjacent nitrogen atoms in the third organic nitrogen compound, wherein
• the distance A (nm) between nitrogen atoms in the first organic nitrogen compound is from 0.30 nm to 0.40 nm,
• the distance B (nm) between nitrogen atoms in the second organic nitrogen compound is more than 0.40 nm to 0.70 nm, and
• the distance C (nm) between nitrogen atoms in the third organic nitrogen compound is more than 0.70 nm to 1.80 nm, wherein
• the waterproofing treatment liquid contains 5 to 40% by mass of the first organic nitrogen compound, 30 to 70% by mass of the second organic nitrogen compound, and 10 to 50% by mass of the third organic nitrogen compound based on the total mass of the first, second, and third organic nitrogen compounds, and
• a content of the first organic nitrogen compound is less than a content of the second organic nitrogen compound in the water-resistant organic thin film.