Retroreflective sheeting containing a validation image and methods of making the same

A retroreflective sheet with an image comprising a monolayer of transparent glass microsphere lenses, a polyvinylbutyral transparent polymeric spacing layer contacting and conforming to the bottom of the lenses, a reflective layer having a top surface in contact with the back surface of the spacing layer and a polyurethane topcoat and/or cover sheet overlying and conforming to the top surfaces of the lenses and having a flat top surface or face wherein the image is a non-conforming portion of the spacing layer and the reflective layer.

A method of preparing a retroreflective sheet with an image comprising the steps of (1) providing retroreflective sheeting having a spacing and reflective layer conforming to glass lenses, (2) heating the retroreflective sheeting and (3) pressing an image onto the spacing layer of the retroreflective sheet to form an image which is non-conforming to the lenses.

A method of making a retroreflective sheet with an image comprising the following steps:

• (1) pressing an image into a molding layer surface of a first assembly which comprises a molding layer and a substrate, (2) coating a transparent polymeric spacing layer on the imaged surface of the molding layer, (3) depositing a monolayer of transparent microsphere lenses onto the transparent polymeric spacing layer, (4) embedding by means of heat and pressure the monolayer of microsphere lenses into the transparent polymeric spacing layer which adheres to and conforms to the bottom surface of the monolayer of transparent microsphere lenses displacing the molding layer but substantially keeping the image intact, (5) covering the exposed transparent microsphere lenses with a transparent topcoat and/or transparent cover sheet, (6) removing the molding layer and substrate assembly, and (7) depositing a reflective layer over the exposed surface of the transparent polymeric spacing layer.

A method of making a retroreflective sheet with an image comprising the following steps:

• (1) printing an image using a transparent or transparently colored polymer onto a molding layer surface of a first assembly which comprises a molding layer and a substrate, (2) pressing the printed image into a molding layer surface of a first assembly which comprises a molding layer and a substrate, (3) coating a transparent polymeric spacing layer on the imaged surface of the molding layer, (4) depositing a monolayer of transparent microsphere lenses onto the transparent polymeric spacing layer, (5) embedding by means of heat and pressure the monolayer of microsphere lenses into the transparent polymeric spacing layer which adheres to and conforms to the bottom surface of the monolayer of transparent microsphere lenses displacing the molding layer but substantially keeping the image intact, (6) covering the exposed transparent microsphere lenses with a transparent topcoat and/or transparent cover sheet, (7) removing the molding layer and substrate assembly, and (8) depositing a reflective layer over the exposed surface of the transparent polymeric spacing layer.