Fluorine resin surface modification method, surface-modified fluorine resin production method, joining method, material having surface-modified fluorine resin, and joined body

A material having a surface-modified fluorine resin,

• the material comprising:
• a fluorine resin provided on a surface of the material;
• and
• a hydrophilized layer provided on at least a part of a surface of the fluorine resin, the hydrophilized layer composed of a functional group composed of a carbon atom, a hydrogen atom, and an oxygen atom,
• wherein the hydrophilized layer is made by a method comprising:
• irradiating an organic compound containing an oxygen atom with ultraviolet light having at least an intensity in a wavelength range of 205 nm or less, while the organic compound containing the oxygen atom is continuously supplied in gaseous form, to generate a radical, and
• bringing the radical into contact with the surface of the fluorine resin to form the hydrophilized layer on the at least the part of the surface of the fluorine resin;
• and
• wherein the at least the part of the surface of the fluorine resin including the hydrophilized layer provided thereon has a peak intensity of carbon atoms and a peak intensity of oxygen atoms that are higher than a peak intensity of fluorine atoms in a photoelectron spectrum by XPS survey analysis.