Tin-doped indium oxide fine particle dispersion, method for manufacturing the same, interlayer film for laminated glass with heat ray blocking properties formed by using said dispersion, and laminated glass therewith

An interlayer film for heat shield laminated glass, which is formed by using a resin composition of a mixture of a dispersion of tin-doped indium oxide fine particles and a polyvinyl acetal resin,

• wherein, under measuring conditions in which the interlayer film having a thickness of 0.76 mm is interposed between clear glass sheets having a thickness of 2.5 mm,
• electromagnetic wave shield properties at a frequency of 0.1 MHz to 26.5 GHz is 10 dB or less,
• a haze value is 1.0% or less,
• a visible light transmittance is 70% or more,
• a solar radiation transmittance at a wavelength within a range from 300 to 2100 nm is 80% or less of the visible light transmittance, and
• a reflection yellow index is −12 or more,
• wherein, the dispersion of tin-doped indium oxide fine particles comprises (1) tin-doped indium oxide fine particles having a primary average particle size of 0.2 μm or less, (2) a plasticizer for an interlayer film, (3) an organic solvent containing at least one alcohol as a main component, and (4) a dispersion stabilizer,
• wherein, under measuring conditions of a content of the tin-doped indium oxide fine particles of 0.7% by weight based on the total weight of the dispersion and an optical path length of a glass cell of 1 mm,
• a visible light transmittance of the dispersion is 80% or more,
• a solar radiation transmittance of the dispersion at a wavelength within a range from 300 nm to 2100 nm is ¾ or less of the visible light transmittance,
• a haze value of the dispersion is 1.0% or less,
• a reflection yellow index of the dispersion is −20 or more,
• the dispersion stabilizer comprises a chelate, an organic acid, and a phosphate ester-based compound,
• a content of the tin-doped indium oxide fine particles is from 10% to 60% by weight based on a total weight of the dispersion,
• in the dispersion, a content of the organic acid is in a range of 2% to 8% by weight based on the total weight of the dispersion, a content of the phosphate ester-based compound is in a range of 1% to 6% by weight based on the total weight of the dispersion, a content of the chelate is in a range of 1% to 10.3% by weight based on the total weight of the dispersion, a content of the alcohol is from 4% to 13.8% by weight based on the total weight of the dispersion, and a content of the plasticizer is from 10% to 80% by weight based on the total weight of the dispersion, respectively.