Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Cheryl M Frey

Bruce Brandon Wilson

Kenneth L Smith

Olester Benson, Jr

Jeanine M Shusta

Gerald M Benson

Paul E Marecki

Matthew R Atkinson

James C Coderre

Susan K Nestegard

James E Lasch

John C Kelliher

Theodore J Szczech

Chester A Bacon, Jr

Michele A Craton

Vera L Lightle

Michael P Daniels

Harlan L Krinke

Joseph R Zwack

Roger E Luehrs

Retroreflective sheeting includes a body layer having a structured surface with recessed faces forming cube corner cavities. A reflective film is disposed at least on the recessed faces, and a fill material fills the cube corner cavities. The fill material comprises radiation-curable materials, adhesives, or both, and preferably transparent radiation-curable pressure-sensitive adhesives. The fill material preferably forms a continuous layer covering both the recessed faces and upper portions of the structured surface. A transparent cover layer preferably contacts the fill material layer.

Cube corner cavity based retroreflectors with transparent fill material

Cube corner cavity based retroeflectors with transparent fill material

A glittering non-retroreflective sheeting 60 includes an array of cube-corner elements 30 that are arranged in the array such that the sheeting glitters when light is incident thereon. The glitter is in the form of many discrete points of light 68 that tend to blink off and on. The array may be configured such that a dihedral angle .alpha. varies between adjacent cube faces 31 of adjacent cube-corner elements 30 in each groove in one of the groove sets 45, 46, or 47 and such that the base plane 36 are not parallel to each other when the sheeting 60 is laid flat. Preferably, the dihedral angle .alpha. between faces 31 of adjacent cube-corner elements 30 varies in essentially all of the grooves such that the cube-corner elements are randomly tilted throughout the array. The glitter can make the sheeting very useful for aesthetic or decorative applications.

Glittering cube-corner article

A cube corner retroreflective sheeting construction comprising alternating zones of cube corner element arrays disposed at approximately ninety degrees orientations to provide exactly two principal plane of improved retroreflective performance in response to light incident on the sheeting at high entrance angles is disclosed. According to one embodiment the sheeting includes a body layer which has an elastic modulus less than 7.times.10.sup.8 pascals and cube corner elements formed from a material which has an elastic modulus greater than 16.times.10.sup.8 pascals. According to a second embodiment the sheeting includes an overlay film having two major surfaces and comprising a first polymeric material and a plurality of arrays of substantially independent cube corner elements bonded to a major surface of the overlay film having a minimal, fractured land.

Dual orientation retroreflective sheeting

The present invention provides a retroreflective sheeting having a front surface and a back surface, the retroreflective sheeting retroreflecting light entering through the front surface, wherein the retroreflective sheeting comprises encapsulated-lens retroreflectors. The retroreflective sheeting includes a plurality of indentations in the back surface of the retroreflective sheeting and seal coat at least partially filling the indentations.

Retroreflective sheeting with coated back surface

The present invention provides a retroreflective sheeting including a structured retroreflective film including an array of structured retroreflective elements, a thermoplastic sealing film located proximate the structured elements, and bonding agent between the sealing film and the structured retroreflective elements, wherein the bonding agent bonds the sealing film to the structured retroreflective film.

Bonded structured retroreflective sheeting

A cube-corner retroreflective sheeting 60 includes an array of cube-corner elements 30 that are defined by three sets of intersecting parallel grooves 45, 46, 47. The cube-corner elements 30 are arranged in the array such that the sheeting 60 glitters when exposed to light. The glitter is in the form of many discreet points of light that tend to blink on and off when viewed by the naked eye. The array may be configured such that a dihedral angle .alpha. varies between adjacent cube faces 31 of adjacent cube-corner elements 30 in each groove in one of the groove sets 45, 46, or 47 and such that base planes are not parallel to each other when the sheeting 60 is laid flat. Preferably, the dihedral angle .alpha. between faces 31 of adjacent cube-corner elements 30 varies in essentially all of the grooves such that the cube-corner elements are randomly tilted throughout the array. The sheeting glitters very well under daytime viewing conditions and also to some extent under nighttime or retroreflective conditions. The glittering effect can enhance the sheeting's conspicuity, and hence highlight a person's presence to give them improved safety and security.

Glittering cube-corner retroreflective sheeting

A mold 79 that includes an array of cube-corner elements 80 that are arranged in the array such that a retroreflective cube-corner sheeting 60 that is formed thereon is capable of glittering when light is incident on the sheeting. The array may be defined by three sets of intersecting grooves 25, 26, 27 where each groove set includes two or more generally parallel grooves. At least one groove in at least one of the sets has faces 22 of adjacent cube-corner elements 30a, 30b arranged such that a dihedral angle .alpha. located between adjacent faces varies along the groove(s) in the set.

Mold for producing glittering cube-corner retroreflective sheeting

A retroreflective article comprising an ultra-flexible structured retroreflective sheeting having a front surface and a back surface, the sheeting retroreflecting light entering through the front surface, wherein the sheeting comprises an overlay film, a two-dimensional array of substantially independent structured elements, the structured elements bonded to the overlay film, and a sealing film forming the back surface of the sheeting and bonded to the overlay film between the structured elements; a plurality of indentations in the sealing film; and a seal coat located on the sealing film, wherein the seal coat at least partially fills the indentations in the sealing film.

Ultra-flexible retroreflective sheeting with coated back surface

A method of making a glittering cube-corner sheeting, which method includes: (a) providing a first retroreflective sheeting that includes an array of cube-corner elements arranged in a repeating pattern; and (b) exposing the first retroreflective sheeting to heat, pressure, or a combination thereof to produce a second retroreflective sheeting that comprises an array of cube-corner elements that are randomly tilted; or which method may comprise: (a) providing a mold that has a structured surface that includes a multiplicity of cube-comer elements, the cube-corner elements each including a base plane and three faces, the cube-corner elements being arranged such that the base planes do not reside in the same plane when the sheeting is laid flat; and (b) forming a cube-corner sheeting from the mold.

Method of making glittering cube-corner retroreflective sheeting

A retroreflective sheeting having a multiplicity of discrete, cube-corner elements cured in situ on a transparent, polymeric overlay film deformed into a three-dimensional structure so that base edges of a plurality of cube-corner elements are non-planar with respect to one another. The retroreflective article preferably has at least one target optical property. The present invention is also directed to a method of deforming the retroreflective sheeting to form a retroreflective article in which the base edges of a plurality of cube-corner elements are non-planar with respect to one another.

Formed ultra-flexible retroreflective cube-corner composite sheeting

The present invention provides a retroreflective sheeting including a structured film having an array of structured elements and a sealing film attached to the structured film by a plurality of rivet-like connections perforating the sealing film. Preferably, the rivet-like connections form flanges. The preferred sealing film is a thermoplastic polymer with a ductile yield of at least about 20%. The retroreflective sheetings according to the present invention can also include a seal coat located on the sealing film. In some embodiments, the seal coat can be prepared from a seal coat precursor comprising radiation curable components. The present invention also includes methods of manufacturing the various embodiments of the retroreflective sheetings.

Structured retroreflective sheeting having a rivet-like connection

A method for manufacturing flexible cube corner retroreflective sheeting comprising the steps of:

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White Bear Lake, MN, United States of America

Cheryl M Frey