Laminar thermal imaging medium containing photohardenable adhesive layer and polymeric elastic and non-brittle barrier layer
AssigneePolaroid Corporation
InventorsKenneth J. McCarthy, Robert J. Pusateri
Life of this patent
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Abstract
A laminar thermal imaging medium, and a method of preparing same, are disclosed and include a photohardenable adhesive layer containing a photopolymerizable ethythenically unsaturated monomer, and a barrier layer for providing resistance to the diffusion of the polymerizable monomer therethrough to other layers of the thermal imaging medium. The barrier layer increases substantially the time period before which photohardening of the adhesive layer need be performed, during which time cutting and other manufacturing operations can be performed. The elastic and non-brittle character of the barrier layer provides improved durability of images prepared from the thermal imaging medium.
Claims20
A laminar thermal imaging medium comprising an image-forming substance confined between a pair of sheets, said laminar medium comprising in order:
- a first sheet transparent to said image-forming radiation and having at least a surface zone or layer of polymeric material heat-activatable upon subjection of said thermal imaging medium to brief and intense radiation;
- a layer of porous or particulate image-forming substance having cohesivity in excess of its adhesivity for said polymeric heat-activatable layer;
- a release layer to facilitate separation of the thermal imaging medium into first and second images, each in said porous or particulate image-forming substance, upon subjection of the thermal imaging medium to brief and intense radiation and separation of the respective sheets of the medium;
- a polymeric elastic and non-brittle layer;
- a photohardenable adhesive layer comprising a macromolecular organic binder and a photopolymerizable ethylenically unsaturated monomer, said layer being hardenable to a layer of sufficient hardness to provide a durable base for an image thereon in said porous or particulate image-forming substance;
- and
- a second sheet adhesively bonded to said laminar thermal imaging medium by said photohardenable adhesive layer;
- said polymeric elastic and non-brittle layer having resistance to diffusion therethrough to said release layer of said photopolymerizable ethylenically unsaturated monomer of said photohardenable adhesive layer;
- said imaging medium being imageable upon subjection to said brief and intense radiation and being capable of absorbing said radiation and of converting said radiation to heat sufficient in intensity to activate said heat-activatable polymeric material for attachment of said porous or particulate image-forming substance firmly to said first sheet in areas of exposure to said radiation, said polymeric material upon being heated and subsequently cooled being effective to attach said porous or particulate image-forming substance in said areas to or through an intermediate layer to said first sheet.
A laminar thermal imaging medium comprising an image-forming substance confined between a pair of sheets, said laminar medium comprising in order:
- a first sheet transparent to said image-forming radiation and having at least a surface zone or layer of polymeric material heat-activatable upon subjection of said thermal imaging medium to brief and intense radiation;
- a layer of porous or particulate image-forming substance having cohesivity in excess of its adhesivity for said polymeric heat-activatable layer;
- a release layer to facilitate separation of the thermal imaging medium into first and second images, each in said porous or particulate image-forming substance, upon subjection of the thermal imaging medium to brief and intense radiation and separation of the respective sheets of the medium;
- a polymeric elastic and non-brittle layer;
- a photohardened adhesive layer obtained by photohardening a photohardenable layer comprising a macromolecular organic binder and a photopolymerizable ethylenically unsaturated monomer, said photohardened adhesive layer being of sufficient hardness to provide a durable base for an image thereon in said porous or particulate image-forming substance;
- and
- a second sheet adhesively bonded to said laminar thermal imaging medium by said photohardenable adhesive layer;
- said polymeric elastic and non-brittle layer having resistance, prior to said photohardening, to diffusion therethrough to said release layer of said photopolymerizable ethylenically unsaturated monomer of said polyhardenable layer;
- said imaging medium being imageable upon subjection to said brief and intense radiation and being capable of absorbing said radiation and of converting said radiation to heat sufficient in intensity to activate said heat-activatable polymeric material for attachment of said porous or particulate image-forming substance firmly to said first sheet in areas of exposure to said radiation, said polymeric material upon being heated and subsequently cooled being effective to attach said porous or particulate image-forming substance in said areas to or through an intermediate layer to said first sheet.
Dependencies are inferred from the claim text.