Provided is a hologram recording medium that can achieve suppression of deterioration of the storage stability in an unexposed state. The hologram recording medium includes a base material and a photosensitive layer. The oxygen permeability of the base material measured in an environment at 23? C. and 0% RH is more than 0.1 cm.sup.3.Math.(m.sup.2.Math.day.Math.atm).sup.?1 and 10000 cm.sup.3.Math.(m.sup.2.Math.day.Math.atm).sup.?1 or less. The photosensitive layer contains a polymerizable compound, and the polymerizable compound contains a compound represented by a specific general formula.

An optical device includes a first polarization selective reflector; and a second polarization selective reflector positioned relative to the first polarization selective reflector so that the first polarization selective reflector directs first light having a first polarization toward the second polarization selective reflector and the second polarization selective reflector directs second light having a second polarization toward the first polarization selective reflector. A first plane defined by the first polarization selective reflector intersects a second plane defined by the second polarization selective reflector at a first angle.

The disclosure belongs to the technical field of photopolymer materials, and more particularly relates to a dual image storage material as well as a preparation method and application thereof. The dual image storage material is obtained by selective photoreaction of 1 to 50 parts by weight of an organic fluorescent material, 7 to 50 parts by weight of liquid crystal, 0.2 to 10 parts by weight of a photoinitiator and 33 to 67 parts by weight of photopolymerizable monomers. The obtained dual image storage material can present a high-brightness holographic pattern under sunlight and a fluorescent pattern under ultraviolet light in the same spatial position. The presented holographic and fluorescent patterns may be the same or different. The obtained dual image storage material can be used in the field of optical anti-counterfeiting, optical information storage, displays or the like.

The invention relates to a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area. The invention furthermore relates to a method for the production of such a multilayer body, as well as a security element and security document with such a multilayer body.

A main object of the present invention is to provide a method of producing a volume hologram laminate which can regenerate a hologram image in an arbitrary wavelength by a simple process. To attain the object, the present invention provides a method of producing a volume hologram laminate using a volume hologram forming substrate which comprises: a substrate, a volume hologram layer formed on the substrate and containing a photopolymerizable material, a resin layer, formed on the substrate so as to contact to the volume hologram layer, containing a resin and a polymerizable compound, characterized in that the producing method comprises processes of: a hologram recording process to record a volume hologram to the volume hologram layer, a substance transit process of transiting the polymerizable compound to the volume hologram layer, and an after-treatment process of polymerizing the polymerizable compound.

A photopolymer composition comprising a polymer matrix or a precursor thereof including a reaction product between (i) a (meth)acrylate-based (co)polymer in which a silane-based functional group is located in a branched chain and an equivalent weight of the silane-based functional group is 300 g/eq to 2000 g/eq, and (ii) a linear silane crosslinking agent; a photoreactive monomer; and a photoinitiator, a hologram recording medium using the same, an optical element using the hologram recording medium, and a holographic recording method. The photopolymer composition can more easily provide a photopolymer layer having improved durability against temperature and humidity while having a large refractive index modulation value.

A hologram recording composition includes at least: a photopolymerizable compound containing at least a first photopolymerizable monomer; binder resin that is inactive to photopolymerization; and a photopolymerization initiator. A change in polarity of the first photopolymerizable monomer by photopolymerization reduces compatibility with the binder resin of the photopolymerizable compound than that before polymerization, the compatibility of the photopolymerizable compound before the polymerization being high.

The invention relates to a process for preparing triaryl organoborates proceeding from alkyl or cycloalkyl boronates in the presence of an n-valent cation 1/n K.sup.n+ and to the use of these substances as co-initiator in photopolymer formulations.

An optical device includes a first polarization selective reflector positioned relative to a spatial light modulator; and a first reflective assembly positioned relative to the first polarization selective reflector so that the first polarization selective reflector receives first light from the spatial light modulator and directs at least a portion of the first light having a first polarization toward the first reflective assembly as second light. The first reflective assembly receives the second light from the first polarization selective reflector and directs at least a portion of the second light toward the first polarization selective reflector as third light having a second polarization. The second polarization is distinct from the first polarization.

The present disclosure relates to a hologram recording medium having one surface with a higher surface energy than a polymer resin layer containing at least one polymer selected from the group consisting of triacetyl cellulose, alicyclic olefin polymer and polyethylene terephthalate, a hologram recording medium wherein the surface energy of any one surface is 50 mN/m or more, and an optical element comprising the hologram medium.