Laminate of optical elements having a layer of a pressure-sensitive adhesive, and a method for producing such laminate of optical elements

A laminate of optical elements comprising a transparent first optical element, a second optical element, and a transparent pressure-sensitive adhesive layer for bonding the first optical element to the second optical element, wherein the pressure-sensitive adhesive layer comprises:

• a base adhesive zone comprising a transparent base pressure-sensitive adhesive material and formed over a given range from a first principal surface of the pressure-sensitive adhesive layer facing the first optical element, in a thickness direction of the pressure-sensitive adhesive layer;
• and
• a transparent, adherent, refractive index-adjusting zone formed over a given range from a second principal surface of the pressure-sensitive adhesive layer facing the second optical element, in the thickness direction, the refractive index-adjusting zone having a refractive index greater than a refractive index of the base pressure-sensitive adhesive material,
• wherein
• a boundary between the base adhesive zone and the refractive index-adjusting zone is an undulating curve having irregular depths in the thickness direction of the pressure-sensitive adhesive layer with respect to at least one of the first principal surface or the second principal surface,
• the refractive index-adjusting zone comprises a pressure-sensitive adhesive material identical to the base pressure-sensitive adhesive material and particles having a refractive index greater than that of the pressure-sensitive adhesive material that increase an average refractive index of the refractive index-adjusting zone,
• the pressure-sensitive adhesive layer comprising the base adhesive zone and the refractive index-adjusting zone is a continuous layer of pressure-sensitive adhesive material,
• the particles included in the refractive index adjusting zone are distributed within the continuous layer of pressure-sensitive adhesive material such that at least 90% of the particles establish a pattern defining the boundary between the base adhesive zone and the refractive index-adjusting zone, and internal to the continuous layer of pressure-sensitive adhesive material,
• the particles are formed of one or more compounds selected from the group consisting of TiO2, ZrO2, CeO2, Al2O3, BaTiO3, Nb2O5 and SnO2,
• the second optical element is formed at a side facing the pressure-sensitive adhesive layer with a transparent conductive layer of a predetermined pattern,
• the refractive index-adjusting zone is in contact with both the transparent conductive layer and the second optical element, so as to fill spaces formed between the transparent conductive layer and the second optical element due to stepped shoulders of the pattern of the transparent conductive layer, and
• the refractive index of the refractive index-adjusting zone is less than that of the transparent conductive layer.