Patent ID: 11912054
Assignee: SUMITOMO METAL MINING CO., LTD.
Field: Surface technology, coating (Chemistry)
Classification: CPC B  G  H | IPC B

Claim 8:
9. A method for producing a light to heat conversion layer comprising infrared absorbing particles and a binder component,
wherein the infrared absorbing particles are composite tungsten oxide fine particles including a hexagonal crystal structure and are represented by general formula MxWyOz in which M is one or more elements selected from alkali metals, W is tungsten, O is oxygen, and x, y, and z satisfy 0.001≤x/y≤1 and 2.0≤z/y≤3.0, and wherein a light transmittance at a wavelength of 1,000 nm of the light to heat conversion layer is 1% or more and 5% or less, and a visible light transmittance of the light to heat conversion layer is 62.1% or more and 70.3% or less,
the method comprising:
producing the composite tungsten oxide fine particles so that their lattice constant is in a range of 7.3850 Å or more and 7.4186 Å or less for a-axis, and 7.5600 Å or more and 7.6240 Å or less for c-axis, a particle size of the composite tungsten oxide fine particles is 10 nm or more and 100 nm or less, and a crystallite size of the composite tungsten oxide fine particles is 10 nm or more and 100 nm or less; and
performing a pulverization and dispersion step so that an average particle size is 100 nm or less while maintaining the range of the lattice constant in the composite tungsten oxide fine particles.