Retroreflective sheet material and method of making same
First Claim
1. In a process for producing a retroflective sheeting having microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them, the steps comprising:
- (a) forming a retroreflective sheeting having microretroreflective formations closely spaced on one surface thereof, said formations being configured to retroreflect light entering the other surface of said sheeting and impinging upon the surface of said formations;
(b) forming a coating on said one surface comprising a thin metallic deposit providing a first coating material over substantially the entire surface of said formations and a second coating material over only a portion of said formations, said metallic deposit and second coating material being superposed over a portion of said one surface;
(c) applying a solvent to said one surface to remove said metallic deposit from the major portion of the surface area of said formations and thereby expose the surface thereof where said metallic deposit is removed while leaving a partial coating of said metallic deposit on the surface of said formations over a minor portion of the surface area; and
(d) adhering a backing element to said one surface, said backing element extending in a plane generally above said formations and being spaced from said major portion of said surface area of said formations to leave said surface area exposed to the atmosphere thereabout, whereby light rays entering the said other surface of said sheeting and impinging upon said residual coating are reflected thereby and those impinging upon said exposed surface area are reflected by the interface with the atmosphere.
4 Assignments
0 Petitions
Accused Products
Abstract
A retroreflective sheeting has microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them. It is produced by forming a coating on microprism surface, and this coating includes a thin metallic deposit over substantially the entire surface and a second coating material over only a portion of the surface. The coated surface is then exposed to a solvent to remove the coating from its predominant area and leave the metal deposit on only a minor portion of the area. A backing sheet is then applied over the microprisms and bonded to the retroreflective sheeting so as to leave an air interface about the predominant area of the microprisms. As a result, some light rays are retroreflected by the metal deposit and some are retroreflected by the atmosphere interface. The sheeting exhibits daytime whiteness over the bulk of its surface area.
182 Citations
24 Claims
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1. In a process for producing a retroflective sheeting having microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them, the steps comprising:
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(a) forming a retroreflective sheeting having microretroreflective formations closely spaced on one surface thereof, said formations being configured to retroreflect light entering the other surface of said sheeting and impinging upon the surface of said formations; (b) forming a coating on said one surface comprising a thin metallic deposit providing a first coating material over substantially the entire surface of said formations and a second coating material over only a portion of said formations, said metallic deposit and second coating material being superposed over a portion of said one surface; (c) applying a solvent to said one surface to remove said metallic deposit from the major portion of the surface area of said formations and thereby expose the surface thereof where said metallic deposit is removed while leaving a partial coating of said metallic deposit on the surface of said formations over a minor portion of the surface area; and (d) adhering a backing element to said one surface, said backing element extending in a plane generally above said formations and being spaced from said major portion of said surface area of said formations to leave said surface area exposed to the atmosphere thereabout, whereby light rays entering the said other surface of said sheeting and impinging upon said residual coating are reflected thereby and those impinging upon said exposed surface area are reflected by the interface with the atmosphere. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A retroreflective sheet material comprising:
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(a) retroreflective sheeting having a multiplicity of closely spaced microretroreflective formations on one surface thereof with a coating on a minor portion of said one surface, said coating including a reflective metallic deposit on a minor portion of the area of said one surface; and (b) backing sheeting adhered to said one surface of said reflective sheeting, and extending in a plane generally above the formations and spaced from the predominant surface area exposed to the atmosphere, the major portion of the area of said one surface being free from said coating and from contact with said backing sheeting to provide an atmosphere interface thereat, whereby light rays entering the said other surface of said sheeting and impinging upon said metallic deposit are reflected thereby and those impinging upon said metal free surface area are reflected by the atmospheric interface. - View Dependent Claims (16, 17, 18, 19, 20)
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21. In a process for producing a retroflective sheeting having microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them, the steps comprising:
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(a) forming a retroreflective sheeting having microretroreflective formations closely spaced on one surface thereof, said formations being configured to retroreflect light entering the other surface of said sheeting and impinging upon the surface of said formations; (b) forming a coating on said one surface by first depositing a thin metallic deposit providing a first coating material over substantially the entire surface of said formations and thereafter depositing a second coating material on said metallic deposit over only a minor portion of said formations, said second coating material comprising a protective organic adhesive; (c) applying a solvent for the metal of said metallic deposit to said one surface to remove said metallic deposit in the areas unprotected by said second coating material and thereby from the major portion of the surface area of said formations to expose the surface thereof, said removal leaving a partial coating of said metallic deposit and second coating material on the surface of said formations over a minor portion of the surface area; and (d) adhering a backing element to said second coating material on said one surface, said backing element extending in a plane generally above said formations and being spaced from said major portion of said surface area of said formations to leave said surface area exposed to the atmosphere thereabout, whereby light rays entering the said other surface of said sheeting and impinging upon said residual coating are reflected thereby and those impinging upon said exposed surface area are reflected by the interface with the atmosphere.
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22. In a process for producing a retroreflective sheeting having microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them, the steps comprising:
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(a) forming a retroreflective sheeting having microretroreflective formations closely spaced on one surface thereof, said formations being configured to retroreflect light entering the other surface of said sheeting and impinging upon the surface of said formations; (b) forming a coating on said one surface by first depositing a second coating material over the major portion of said formations, and thereafter forming a thin metallic deposit comprising a first coating material over substantially the entire surface of said formations, said metallic deposit and second coating material being superposed over only a minor portion of said one surface; (c) applying a solvent for said second coating material to said one surface to remove said second coating material and the overlying metallic deposit from the major portion of the surface area of said formations and thereby to expose the surface thereof, said metallic deposit remaining on the surface of said formations over a minor portion of the surface area; (d) depositing an adhesive upon said one surface in a grid-like pattern; and (e) adhering a backing element to said adhesive on said one surface, said backing element extending in a plane generally above said formations and being spaced from said major portion of said surface area of said formations to leave said surface area exposed to the atmosphere thereabout, whereby light rays entering the said other surface of said sheeting and impinging upon said residual metallic deposit are reflected thereby and those impinging upon said exposed surface area are reflected by the interface with the atmosphere.
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23. A retroreflective sheet material comprising:
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(a) retroreflective sheeting having a multiplicity of closely spaced microretroreflective formations on one surface thereof with a coating on a minor portion of said one surface, said coating including a reflective metallic deposit on a minor portion of the area of said one surface and an adhesive superposed on said metallic deposit; and (b) backing sheeting adhered to said adhesive on said one surface of said reflective sheeting, and extending in a plane generally above the formations and spaced from the predominant surface area exposed to the atmosphere, the major portion of the area of said one surface being free from said coating and from contact with said backing sheeting to provide an atmosphere interface thereat, whereby light rays entering the said other surface of said sheeting and impinging upon said metallic deposit are reflected thereby and those impinging upon said metal free surface area are reflected by the atmospheric interface.
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24. A retroreflective sheet material comprising:
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(a) retroreflective sheeting having a multiplicity of closely spaced microretroreflective formations on one surface thereof with a coating on a minor portion of said one surface, said coating including a reflective metallic deposit and an adhesive disposed in a grid-like pattern, only a minor portion of the surface area of the formations between the lines of said grid-like pattern having said metallic deposit thereon, the major portion of the surface area of said one surface being free from said metallic deposit and said adhesive; and (b) backing sheeting adhered to said adhesive on said one surface of said reflective sheeting, and extending in a plane generally above the formations and spaced from the predominant surface area exposed to the atmosphere, the major portion of the area of said one surface being free from said coating and from contact with said backing sheeting to provide an atmosphere interface thereat, whereby light rays entering the said other surface of said sheeting and impinging upon said metallic deposit are reflected thereby and those impinging upon said metal free surface area are reflected by the atmospheric interface.
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Specification