A vacuum heat insulating material includes a sheath material and a core material that is sealed inside the sheath material in a hermetically sealed decompressed state. The sheath material comprises a gas barrier layer and heat sealing layer. Heat sealing layer contains a heat sealing resin and filler with an aspect ratio exceeding 1. In heat sealing layer, at least some of filler is oriented, with a long-axis direction intersecting with a direction in which heat sealing layer spreads. Accordingly, there is provided a vacuum heat insulating material capable of preventing entry of a gas to the inside and favorably ensuring the hermetically sealed decompressed state on the inside.

Provided is an insulating sheet capable of effectively enhancing thermal conduction and adhesiveness and effectively suppressing generation of voids. The insulating sheet according to the present invention contains a thermosetting component and boron nitride, the insulating sheet has a first surface on one side in a thickness direction and a second surface on the other side in the thickness direction, and a first average major diameter of the boron nitride in a region having a thickness of 10% of a thickness of the sheet, from the first surface toward the second surface is smaller than a second average major diameter of the boron nitride in a region having a thickness of 90% of a thickness of the sheet, from the second surface toward the first surface.

Provided is an insulating sheet capable of effectively enhancing thermal conduction and adhesiveness and effectively suppressing variation in the adhesiveness. The insulating sheet according to the present invention contains a thermosetting component and boron nitride, the insulating sheet has a first surface on one side in a thickness direction and a second surface on the other side in the thickness direction, and a first average aspect ratio of the boron nitride in a region having a thickness of 10% of a thickness of the sheet, from the first surface toward the second surface is smaller than a second average aspect ratio of the boron nitride in a region having a thickness of 90% of a thickness of the sheet, from the second surface toward the first surface.

Provided is a PSA sheet having limited light transmission, an increased refractive index and good adhesive properties. The PSA sheet provided by this invention has a PSA layer. The PSA sheet has a total light transmittance below 80%. The PSA layer has a first face and a second face on the opposite side to the first face. The PSA layer comprises high-refractive-index particles. In the PSA layer, the high-refractive-index particles are concentrated in a range that extends from the first face towards the second face side and has a thickness of at least 100 nm, accounting for less than 50% of the PSA layer thickness.

A security tag that includes a resin layer, and a plurality of colloidal particles. The plurality of colloidal particles are embedded in the resin layer and arranged, spaced apart from one another, along a planar direction perpendicular to a thickness direction. The plurality of colloidal particles constitute at least one type of two-dimensional crystal.