RETROREFLECTIVE MATERIAL

• US 3,684,348 A
• Filed: 09/29/1970
• Issued: 08/15/1972
• Est. Priority Date: 09/29/1970
• Status: Expired due to Term

• Current Assignee: William P. Rowland
• Original Assignee: William P. Rowland
• Inventors: Rowland, William P.
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Tokar, Michael J.
• Application Number:
  US05/076,551
• Time in Patent Office: 686 Days
• Field of Search: 350/97-109
• US Class Current: 359/530
• CPC Class Codes: B29D 11/00605 Production of reflex reflectors
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: Y10T 428/1438 Metal containing

Abstract

Retroreflective material is provided by a composite synthetic plastic structure having a body portion with one smooth surface and another surface from which project a multiplicity of separately formed, minute cube corner formations having a side edge dimension of less than 0.025 inch. The cube corner formations may have a reflective coating thereon, and an adhesive layer and release paper to permit facile mounting on a support surface. Light rays entering through the smooth surface pass into the cube corner formations and are reflected back substantially parallel to the path of entry. In the method of making the composite material, a fluid molding material is deposited on a molding surface having cube corner recesses and a preformed body member is applied thereto. The molding material is then hardened and bonded to the body member.

Claims

2. The retroreflective material of claim 1 wherein each cube corner formation has one face parallel to one face of every other cube corner formation.

3. The retroreflective material of claim 1 wherein said cube corner formations are substantially equal in size and arranged in a pattern of rows and columns in which the center-to-center spacing between cube corner formations in every row and between cube corner formations in every column is in accordance with a uniform pattern.

4. The retroreflective material of claim 3 wherein the apex of each cube corner formation is in alignment with the apices of all of the cube-corner formations located in the pattern row and column in which it is disposed.

5. The retroreflective material of claim 1 wherein the apex of each cube corner formation is aligned with the center of its base.

6. The retroreflective material of claim 1 including a reflective coating on said faces of said cube corner formations.

7. The retroreflective material of claim 6 further including an adhesive layer on said reflective coating and a removable piece of sheet material loosely adhered to said adhesive layer whereby said sheet material may be removed to adhere said retroreflective sheet material to a substrate.

8. The retroreflective material of claim 6 wherein said reflective coating is metallic and including a layer of resin deposited on said reflective coating to provide protection therefor.

9. The retroreflective material of claim 1 wherein said body portion is flexible for mounting on surfaces of various configurations.

10. The retroreflective material of claim 9 wherein said body portions comprises flexible sheet material to which said cube corner formations are adhered.

11. The retroreflective material of claim 1 wherein said cube corner formations are less than 0.010 inch along the side edges.

12. Retroreflective composite synthetic plastic sheeting comprising:

a body portion of flexible synthetic resin sheet material having substantially parallel, smooth surfaces and a multiplicity of minute cube corner formations separately formed from synthetic resin and adhered to one of the surfaces of said body portion, said formations being closely spaced about and projecting from said surface so as to avoid any substantial smooth areas therebetween, said cube corner formations each having three faces and a base adjacent said body portion with a side edge dimension of not more than about 0.010 inch, the resins of said sheet material and said cube corner formations being essentially transparent, said cube corner formations being cast against said sheet material and bonded therewith into a composite structure, said cube corner formations being substantially equal in size and being arranged in a uniform pattern of rows and columns in which the center-to-center spacing between the cube corner formations in every row and the center-to-center spacing between the formations in every column are in accordance with a uniform pattern, the apex of each of said cube corner formations being vertically aligned with the center of its base to provide faces of equal size, said sheeting providing a structure wherein the light rays entering through the other of said surfaces of said body portion predominately pass through said body portion and into said cube corner formations by which they are reflected back through said body portion substantially parallel to the path of entry.

13. The retroreflective sheeting of claim 12 wherein there is included a reflective coating on the faces of said cube corner formations.

14. The retroreflective sheeting of claim 13 further including an adhesive layer on said reflective coating and a removable piece of sheet material loosely adhered to said adhesive layer whereby said sheet material may be removed to adhere said retroreflective sheet material to a substrate.

15. The retroreflective sheeting of claim 13, wherein said reflective coating is metallic and wherein there is included a layer of resin deposited on said metallic coating to provide protection therefor.

16. The retroreflective sheeting material of claim 12 wherein the resins of said cube corner formations and said sheet material are of essentially similar monomer composition.