CN105842765A - Retro-reflective product including optically active areas and optically inactive areas - Google Patents

Abstract

The invention generally relates to a retro-reflective product and a method for preparing the retro-reflective product.

Description

Including optically-active region and the retroreflective articles in optically inactive region

The application is filing date on April 15th, 2010, Application No. 201080066212.X, sends out The division Shen of the patent application of bright entitled " including optically-active region and the retroreflective articles in optically inactive region " Please.

Technical field

Present invention relates generally to retroreflective articles and the method preparing this goods.

Background technology

At the beginning of retroreflection material is characterised by be re-directed to make it be reflected back by the light inciding on material Beginning light source.This performance has made retroeflection sheet material be widely used in multiple traffic and personal security's application.Retroreflection sheet Material is usually used in various products, such as traffic sign, roadblock, licence plate, pavement markers and colored belt, with And vehicle and the reflective tape of clothing.

Optical element sheet material (such as, cube comer sheetings) and microballoon base sheet are two kinds of known types Retroeflection sheet material.Microballoon base sheet (being sometimes referred to as " microballon " sheet material) uses a large amount of microballoon, described micro- Ball embeds in adhesive phase typically at least in part, and has relevant specularly or diffusely material (such as, pigment particles, sheet metal or evaporation layer etc.) are with retroeflection incident light.Cube-corner retroreflective sheet Material (being sometimes referred to as " prism " sheet material) generally includes thin hyaline layer, and this hyaline layer has substantially Flat first surface and structured second surface, this structured second surface includes multiple geometry, Some or all of these geometries include three reflecting surfaces constituting solid angle element.

Generally, solid angle element is included in three orthogonal optical surfaces that single summit is intersected.Logical Often, send out from each of three vertical Cube-corner optical faces from the light of light source incidence to solid angle element Raw total internal reflection, and be redirected to be back to light source.The such as dust that is present on optical surface, Water and adhesive can suppress total internal reflection (TIR) and cause the reduction of retroreflection light intensity.So, air Interface is generally sealed film and is protected.But, diaphragm seal can reduce gross activity region, described gross activity Region is the region that retroeflection can occur on it.Additionally, diaphragm seal increases preparation cost.It addition, seal Method can produce visible pattern in retroeflection sheet material, and described visible pattern is unfavorable for multiple use, example As, the application in the business graphics purposes of licence plate and/or the most generally preferable more uniform outward appearance.Metal Change solid angle and do not rely on the TIR of retroreflection light, but they lead to for the observation in the daytime such as marking application Often it is insufficient to white.Additionally, the durability of metal coating may be insufficient.

Summary of the invention

The inventor of present patent application has been formed and there is not diaphragm seal and/or the retroeflection system of metallization solid angle Product.

Some embodiments of the retroreflective articles of the present invention include one or more optically-active region and one or many Individual optically inactive region, by including (such as) solid angle unit in the one or more optically-active region The patterned surface of part penetrates incident light back and forth, structuring table in the one or more optically inactive region Face substantially not retroeflection incident light.The one or more optically-active region includes proximity structure surface The low-index layer of a part or material.The one or more optically inactive region includes proximity structure The contact adhesive of the part on surface.Contact adhesive significantly destroys in patterned surface directly Adjacent part retroreflective.Low-index layer contributes to by patterned surface and contact adhesive Between formed " barrier " keep the retroreflective of adjacent structural surface.

Some embodiments of the retroreflective articles of the present invention include being positioned at contact adhesive and low-index layer it Between barrier layer.Barrier layer has enough structural intergrities and flows into be essentially prevented from contact adhesive In low-index layer.The exemplary materials being included in barrier layer includes resin, polymeric material, oil Ink, dyestuff and vinyl.In certain embodiments, barrier layer capture low-index layer in low Refraction materials.Low-index material is the material with the refractive index less than 1.3.

Some embodiments of the present invention relate generally to retroreflective articles, comprising: retroreflective layer, described retroeflection Layer includes that multiple solid angle element, the plurality of solid angle element are collectively forming the knot relative with first type surface Structure surface；Pressure sensitive adhesive layer, described pressure sensitive adhesive layer has first area and second area, Wherein said second area contacts described patterned surface；And described first and second regions have foot Enough different characteristics are to be formed between the patterned surface and described pressure sensitive adhesive layer of described retroreflective layer Low-index layer.

Some embodiments of the present invention relate generally to retroreflective articles, comprising: retroreflective layer, described retroeflection Layer includes the patterned surface relative with first type surface；Contact adhesive, described contact adhesive contacts institute State at least some of to form the optically inactive region of substantially not retroeflection incident light of patterned surface；With At least one low-index layer, at least one low-index layer described forms the optically-active district of retroeflection incident light Territory.

Some embodiments of the present invention relate generally to the method forming retroreflective articles, comprising: provide bag Include the retroreflective layer of the patterned surface relative with first type surface；And pressure sensitive adhesive layer is applied to described Patterned surface is to form first area and second area, and wherein said second area contacts described structure Change surface and described first area does not contact described patterned surface.

Accompanying drawing explanation

With reference to the accompanying drawings also with reference to the detailed description of the invention of the most multiple embodiments, can be more comprehensively geographical Solve and understand the present invention, wherein:

Figure 1A and 1B is the schematic side elevational of an exemplary embodiment of the retroreflective articles of the present invention Figure.

Fig. 2 is the schematic diagram of an exemplary intermediate steps of the retroreflective articles forming Fig. 1.

Fig. 3 is the schematic diagram of an exemplary embodiment of the retroreflective articles of the present invention.

Fig. 4 A and 4B is the schematic diagram of the pattern in example 11-13.

Fig. 5 is the schematic diagram of an exemplary embodiment of the retroreflective articles of the present invention.

Fig. 6 is the schematic diagram of the pattern in example 1-6.

Fig. 7 A and 7B is the figure of the distance of the left and right headlamp illustrating view angle relative standard's type car Line.

Fig. 8 is the schematic diagram of the pattern in example 14-19.

Fig. 9 is the schematic diagram of the pattern in example 14-19.

Detailed description of the invention

Figure 1A and 1B shows an exemplary enforcement of the retroreflective articles 100 towards observer 102 Example.Retroreflective articles 100 includes that retroreflective layer 110, described retroreflective layer 110 include multiple solid angle element 112, the plurality of solid angle element 112 is collectively forming the patterned surface relative with first type surface 116 114.Retroreflective layer 110 also includes cover layer 118.Pressure sensitive adhesive layer 130 and retroreflective layer 110 phase Adjacent.Pressure sensitive adhesive layer 130 includes contact adhesive 132, one or more barrier layer 134 and lining Sheet 136.Barrier layer 134 has enough structural intergrities to prevent contact adhesive 132 inflow to be positioned at In low-index layer 138 between patterned surface 114 and barrier layer 134.Barrier layer 134 can be with The most advanced and sophisticated directly contact of solid angle element 112 or spaced apart or solid angle element can be pressed to slightly In the tip of 112.

When it is present, barrier layer 134 is formed between contact adhesive 130 and solid angle element 112 Physics " barrier ".Barrier layer can prevent contact adhesive during the initial preparation of retroreflective articles or Elapse in time and soak solid angle tip or surface because of the viscoelastic property of this adhesive.Pressure-sensitive adhesion Trapping layer between agent 130 and solid angle element 112 is low-index layer 138.Low-index layer thus For close.If it is used protective layer, then low-index layer is encapsulating.Low-index layer Encapsulating keeps and/or the integrality of protection low-index layer.The existence of barrier layer allows patterned surface The part retroeflection incident light 150 adjacent with low-index layer 138 and/or barrier layer 134 in 114.Screen Barrier layer 134 still prevents contact adhesive 130 and soaks cube comer sheetings.Do not contact with barrier layer 134 Contact adhesive 130 adhere to solid angle element, thus effectively seal against retroreflective regions to form rotation Light region or unit.Whole retroeflection structure is also kept together by contact adhesive 130, thus eliminates For independent diaphragm seal and the needs of seal process.In certain embodiments, contact adhesive closely connects Touch or be directly adjacent to the patterned surface of solid angle element.

As shown in Figure 1B, the light on the solid angle element 112 adjacent with low-index layer 138 is incided Line 150 is returned to observer 102 by retroeflection.For this reason, retroreflective articles 100 include low-refraction The region of layer 138 is referred to as optically-active region.By contrast, retroreflective articles 100 do not include low refraction The region of rate layer 138 is referred to as optically inactive region, because its substantially not retroeflection incident light.

Low-index layer 138 include refractive index be below about 1.30, below about 1.25, below about 1.2, low In about 1.15, below about 1.10 or the material of below about 1.05.Exemplary low-index material bag Include air and low-index material (e.g., U.S. Patent application No.61/324, the low folding described in 249 Penetrating rate material, this patent application is incorporated by reference herein).

Generally, prevent contact adhesive contact solid angle element 112 or flow into or wriggle to low refraction Any material in rate layer 138 can be used in barrier layer 134.Can be used for the example in barrier layer 134 Property material includes that resin, polymeric material, dyestuff, ink, vinyl, inorganic material, UV are solid Change type polymer, pigment, particle and globule.The size of barrier layer and spacing can be changed.? In some embodiments, barrier layer can form pattern on retroeflection sheet material.In certain embodiments, can wish Hope the visibility of the pattern reduced on sheet material.Generally, any required pattern can be by described technology Combination produce, including such as marking, such as letter, word, alphanumeric, symbol or even scheme Draw.Pattern is alternatively continuous print, discontinuous, dull, spiral type, the letter of any smooth change Number, longitudinally, laterally or the above-mentioned striped of change on both；Pattern can be formed image, logo, Or word, and pattern can include patterning coating and/or perforation.In certain embodiments, printing zone And/or non-printed areas can form security feature.Pattern can include (such as) irregular pattern, rule Pattern, grid, word, figure, image, lines and the intersection region of formation unit.

In at least some embodiments, pressure sensitive adhesive layer includes first area and second area.Second Region is directly or tight contact structure surface.First and second regions have the most different characteristics with Formed between pressure sensitive adhesive layer and the patterned surface of retroreflective layer and isolate low-index layer.? In some embodiments, second area includes that contact adhesive, first area have different from second area Composition.In certain embodiments, first area and second area have different polymer morphologies. In certain embodiments, first area and second area have different flow behaviors.Implement at some In example, first area and second area have different viscoelastic properties.In certain embodiments, One region and second area have different adhesion characteristics.In certain embodiments, retroreflective articles includes Form multiple second areas of pattern.In certain embodiments, pattern is irregular pattern, rule schema One in case, grid, word, figure and lines.

Can be used for the exemplary pressure-sensitive in the retroreflective articles of the present invention and include the adhesive propylene of crosslinking Acid fracturing sensitive adhesive.Other contact adhesives of presence or absence additive, such as, sky can be used So or synthetic rubber and the blend of resin, silicones or other polymeric systems.Contact adhesive PSTC (pressure-sensitive band association) be defined as the most permanent pressure tacky, available light and (refer to Pressure) adhere to kinds of surface and there is not the adhesive of phase transformation (liquid is to solid-state).

Acrylate and methyl (acrylic acid) ester: the existence range of acrylate is about 65 to about 99 weight Part, preferably from about 78 to about 98 weight portions and more preferably from about 90 to about 98 weight portions.Can use Acrylate includes at least one monomer selected from materials described below: the first simple function third of non-tert-alkyl alcochol Olefin(e) acid ester or methacrylate and their mixture, wherein said alkyl has 4 to about 12 Carbon atom.These acrylate or methacrylate are generally of below about-25 DEG C as homopolymers Glass transition temperature.This monomer provides relative to the high level of other comonomers to be had at low temperatures There is the PSA of relatively high adhesion.

Preferably acrylate or methacrylate monomers includes, but is not limited to selected from following substances Those: n-butyl acrylate (BA), n-BMA, isobutyl acrylate, acrylic acid 2-methylbutyl butenoate, 2-EHA, n-octyl, Isooctyl acrylate monomer (IOA), first Base Isooctyl acrylate monomer, acrylic acid different nonyl ester, isodecyl acrylate and their mixture.

Especially preferred acrylate includes those selected from following substances: Isooctyl acrylate monomer, propylene Acid N-butyl, acrylic acid 2-methylbutyl butenoate, 2-EHA and their mixture.

Polar monomer: the polar monomer (example of low content (normally about 1 to about 10 weight portion) can be used Such as carboxylic acid) increase the cohesive strength of contact adhesive.Under higher content, these polar monomers Tend to weakening adherence, increasing glass transition temperature and reduce low-temperature characteristics.

Available copolymerized acidic monomers includes, but is not limited to those selected from following substances: ethylenic Unsaturated carboxylic acid, ethylenic unsaturated sulfonic acid and ethylenic unsaturation phosphonic acids.The example of these monomers Including selected from those of following substances: acrylic acid (AA), methacrylic acid, itaconic acid, fumaric acid, Crotonic acid, citraconic acid, maleic acid, β .-propyloic acrylic ester, sulfoethyl methacrylate etc. Deng and their mixture.

Other available copolymerized polar monomer include, but is not limited to (methyl) acrylamide, N, N-bis- Alkyl substituted (methyl) acrylamide, N-vinyl lactam and (methyl) acrylic acid N, N-dialkyl group Aminoalkyl ester.Exemplary example includes, but is not limited to those selected from following substances: N, N- DMAA, N, N-dimethyl isobutyryl acrylamide, N, N-acrylamide, N, N-bis- Ethyl isobutyl acrylamide, N, N-dimethylaminoethyl methacrylate, N, N-dimethylamino-propyl first Base acrylate, N, N-dimethylamino ethyl acrylate, N, N-dimethylaminopropyl acrylate, NVP, N-caprolactam etc. and their mixture.

Nonpolar ethylenically unsaturated monomers: nonpolar ethylenically unsaturated monomers is following monomer, institute The homopolymers stating monomer (sees " the polymer hand of Bandrup and Immergut through Fedors method Volume " (Polymer Handbook)) measure and there is the solubility parameter of no more than 10.50 and more than 15 DEG C Tg.The non-polar character of this monomer tends to improving the low-energy surface bonding force of adhesive.These are non- Polarity ethylenically unsaturated monomers selected from (methyl) alkyl acrylate, (methyl) acrylic acid N-Arrcostab, And combinations thereof.Exemplary example includes, but is not limited to acrylic acid 3,3,5-3-methyl cyclohexanol Ester, methacrylic acid 3,3,5-3-methyl cyclohexanol ester, cyclohexyl acrylate, cyclohexyl methacrylate, Isobornyl acrylate, isobornyl methacrylate, n-octyl acrylamide, n-octyl isopropyl alkene Acid amides or combinations thereof.It is optional that, the nonpolar ethylenic of 0 to 25 weight portion can be added not Saturated monomer.

Tackifier: preferably tackifier include terpene phenolic resin, rosin, rosin ester, hydrogenated rosin Ester, synthesis hydrocarbon resin and combinations thereof.These tackifier provide good on low-energy surface Adhesion characteristic.Hydrogenated wood rosin glycerol ester and hydrogenation C9 aromatic resin are most preferred tackifier, this is because it There is following performance advantage, including high-caliber " adherence ", outdoor durable, anti-oxidant Limited interference effect in the rear crosslinking of property and acrylic acid PSA.

Can be at the monofunctional acrylate of every 100 parts of non-tert-alkyl alcochols or methacrylate, polarity list Body and nonpolar ethylenically unsaturated monomers add content and is about the tackifier of 1 to about 65 part with reality Existing required " adherence ".Preferably, tackifier have the softening point of about 65 to about 100 DEG C. But, adding tackifier and can reduce shearing or cohesive strength and increase the Tg of acrylic acid PSA, this is not It is beneficial to cold temperature characteristics.

Crosslinking agent: in order to increase shearing or the cohesive strength of acrylic pressure-sensitive adhesive, generally will crosslinking Additive is incorporated in PSA.Generally use two kinds of major type of crosslinking additives.The first kind cross-links Additive is heat cross-linking additive, such as polyfunctional aziridines.One example is for being referred to herein as The 1,1'-(1,3-phenylene dicarbonyl) of " bisamide "-bis--(2-methylaziridine) (CAS No.7652-64- 4).This chemical cross-linking agent can be added in solvent-borne type PSA after polymerization, and at baking oven This chemical cross-linking agent of thermal activation during drying coated adhesive.

In another embodiment, can use and depend on free radical and carry out the chemical crosslinking of cross-linking reaction Agent.The reagent of such as peroxide etc may act as radical source.When being fully heated, these precursors The free radical causing crosslinked polymer reaction will be generated.It is benzoyl peroxide that conventional free radical generates reagent Formyl.Only need a small amount of free-radical generating agent, but typically require compared with needed for bisamide reagent Higher temperature completes cross-linking reaction.

The chemical cross-linking agent of the second type is the photosensitive crosslinking by high intensity ultraviolet (UV) photoactivation Agent.Two kinds of conventional photosensitive crosslinker for heat fusing acrylic acid PSA are copolymerizable to PSA polymer Interior benzophenone and 4-acryloxybenzophenone.Add after can to solution polymer and by ultraviolet The another kind of photocrosslinking agent of photoactivation is triazine；Such as, 2,4-bis-(trichloromethyl)-6-(4-methoxyl group-benzene Base)-s-triazine.These crosslinking agents are by producing from artificial source's (such as medium pressure mercury lamp or ultraviolet backlight) UV-activated.

Additionally available crosslinking agent is hydrolyzable, the crosslinking agent of free redical copolymerization, such as monoene key Unsaturated monoalkoxy, dialkoxy and trialkoxy silane compound, include, but is not limited to first Base acryloxypropyl trimethoxy silane (derives from associating carbide chemical and plastics Co., Ltd The SILANE of (Union Carbide Chemicals and Plastics Co.)^TMA-174), vinyl two Methylethoxy base silane, vinyl methyl diethoxy silane, VTES, ethene Base trimethoxy silane, vinyltriphenoxysilane etc..

Crosslinking agent be typically based on 100 parts by weight propylene acid esters or methacrylate, polar monomer and Nonpolar ethylenically unsaturated monomers meter exists with 0 to about 1 weight portion.

In addition to thermal cross-linking agent, moisture-crosslinking agent or photosensitive crosslinker, it is possible to use High energy electromagnetic spoke Penetrate (such as γ or electron beam irradiation) and realize crosslinking.In such a case, it is possible to need not crosslinking agent.

Other additives: owing to acrylic pressure-sensitive adhesive has the non-oxidizability of excellence, be generally not required to Will the additive of such as antioxidant and UV light absorber etc.Can in heat fusing acrylic acid PSA Use a small amount of heat stabilizer to improve the heat endurance during being heat-treated.

Plasticizer: be optional that, can by the plasticizer (e.g., below about 10 weight portion) of low content with Tackifier carry out mixing to adjust Tg, in order to optimize stripping and the low-temperature characteristics of adhesive.Can be added this Plasticizer in the adhesive of invention is selected from various commercially available material.In all cases, add The plasticizer entered must be compatible with the thickening acrylic acid PSA in preparation.Representational plasticizer includes gathering Oxygen vinyl aryl ether, hexanedioic acid dialkyl ester, phosphoric acid 2-ethylhexyl diphenyl ester, phosphoric acid tert-butyl benzene Base diphenyl ester, adipic acid two (2-ethylhexyl) ester, toluenesulfonamide, dibenzoic acid DPG ester, Polyethylene glycol dibenzoate, polyoxypropylene aryl ether, dibutoxy ethoxyethyl group formal and Di butoxyethoxyethyl adipate.

The various polymer film substrate being made up of various thermosettings or thermoplastic polymer are suitable as covering Layer and body layer.Body layer can be single or multiple lift film.Can be used as the body layer of flexible retroreflective article The illustrative examples of the polymer of film includes: (1) fluorinated polymer, the most poly-(CTFE), poly- (tetrafluoraoethylene-hexafluoropropylene copolymer), poly-(tetrafluoroethylene-perfluoro (alkyl) vinyl ether co-polymer), Poly-(vinylidene difluoride-hexafluoropropylene copolymer)；(2) there is the poly-(ethene-methyl of sodium ion or zinc ion Acrylic copolymer) ionomeric ethylene compolymers, such as it is available from the Du Pont in Wilmington city, the Delaware State The SURLYN-8920 board of company (E.I.duPont Nemours, Wilmington, Del.) and SURLYN-9910 board；(3) low density polyethylene (LDPE), such as low density polyethylene (LDPE)；Linear low density polyethylene Alkene；And very low density polyethylene；Plasticising type halogenated vinyl polymer, such as plasticising type poly-(vinyl chloride)； (4) polyethylene and ethylene copolymers, including acid-functionalized polymer, the most poly-(ethylene-acrylic acid copolymer) " EAA ", poly-(ethylene-methacrylic acid copolymer) " EMA ", poly-(ethylene maleic acid copolymerization Thing) and poly-(ethene-fumaric acid copolymer)；Acrylic acid functionalized polymer, the most poly-(ethene-the third Olefin(e) acid alkyl ester copolymer), wherein alkyl is methyl, ethyl, propyl group, butyl etc., or CH3 (CH2) n-, wherein n is 0 to 12, and poly-(ethylene-vinyl acetate copolymer) " EVA "； (5) (such as) aliphatic urethane.Body layer is preferably olefinic polymeric material, and it generally comprises The olefin(e) with 2 to 8 carbon atoms of at least 50 weight %, most common of which is ethene and third Alkene.Other body layer includes (such as) poly-(polyethylene naphthalate), Merlon, poly-(methyl) third Olefin(e) acid ester (such as, polymethyl methacrylate or " PMMA "), polyolefin (such as, poly-third Alkene or " PP "), polyester (such as, polyethylene terephthalate or " PET "), polyamides Amine, polyimides, phenolic resin, cellulose diacetate, cellulose triacetate, polystyrene, benzene Ethylene-propylene lonitrile copolymer, cyclic olefine copolymer, epoxy resin etc..

The exemplary liner that can be used in the retroreflective articles of the present invention includes the material that silicones is coated with, example Such as paper and polymer film (including plastics).Liner base material can be individual layer or multilayer.Concrete Example includes that polyester (such as polyethylene terephthalate), polyethylene, polypropylene (include stream Prolong the polypropylene with biaxial orientation) and paper (include the paper of clay coated, the paper of polyethylene coated or Poly-(ethylene glycol terephthalate) film of polyethylene coated).

In certain embodiments, such as in retroreflective articles 100, solid angle element 112 is tetrahedron Or pyramid form.Dihedral angle between any two facet all can be according to characteristic required in application Change.In some embodiments (including the embodiment shown in Figure 1A and 1B), any two is little flat Dihedral angle between face is 90 degree.In such an embodiment, facet be substantially perpendicular to each other (as In the corner in room), and this optical element can be described as solid angle.Alternatively, adjacent Dihedral angle between facet can deviate 90 °, such as (e.g.) in United States Patent (USP) No.4, in 775,219 Described, the disclosure of which is incorporated by reference in its entirety herein.Alternatively, Optical element in retroreflective articles can be butt solid angle.Optical element can be complete solid angle, butt Solid angle or the solid angle of preferred geometries (PG), such as (e.g.) United States Patent (USP) No. Described in 7,422,334, the disclosure of which is incorporated by reference in its entirety herein.Each retroeflection Optical element includes the symmetry axis becoming isogonism with facet.In certain embodiments, symmetry axis is perpendicular to Base portion or anterior face.In certain embodiments, symmetry axis be not orthogonal to base portion or anterior face and Summit or optical element are tilt, such as (e.g.) United States Patent (USP) No.4, described in 588,258, and should Disclosure is incorporated by reference in its entirety herein.The retroreflective layer 110 of Figure 1A and 1B is shown as Including cover layer 118 and do not include base layer or body portion.Base layer may be defined as and solid angle Element is coextensive and the continuous layer of material that is constructed from the same material.This structure is permissible for embodiment flexibly It is preferable.Those skilled in the art is it will be recognized that retroreflective layer 110 can include base layer or matrix part Point.

As illustrated schematically in fig. 2, at least some of method in the retroreflective articles of the preparation present invention Including barrier layer material 134 being arranged in pressure sensitive adhesive material 132 and subsequently by the pressure of gained Sensitive adhesive layer 130 is laminated to retroreflective layer 110.Pressure sensitive adhesive layer 130 can shape in many ways Become, include, but is not limited to following illustrative methods.In one exemplary embodiment, will be formed The material of barrier layer is printed onto on contact adhesive.Printing process can be non-contact method, such as, makes Print with ink-jet printer.Printing process can be method of contact printing, such as flexographic printing.Separately In one exemplary embodiment, material use (such as) ink-jet or the screen painting of barrier layer will be formed Method is printed onto in smooth insulation surfaces and transfers to pressure-sensitive adhesion followed by from smooth insulation surfaces In agent.In another exemplary embodiment, the material filling forming barrier layer is coated onto micro-structural and glues Mixture surface (e.g., is manufactured by the 3M company of Paul, MN (St.Paul, MN) Comply liner) on.Pass through (such as) lamination subsequently by barrier layer material from microstructured liner It is transferred to contact adhesive.Then retroreflective articles adhesively can be bonded to substrate (e.g., aluminium base The end) to form (such as) licence plate or label.

Fig. 3 and 5 shows some alternative exemplary retroreflective goods of the present invention.Specifically Saying, Fig. 3 and 5 shows the retroreflective articles including structuring sealant.In certain embodiments, close Sealing includes in (such as) thermoplastic polymer, crosslinkable materials and radiation curable material extremely Few one.In certain embodiments, sealant includes adhesive, such as, heat-activatable adhesive and/ Or contact adhesive.These structures are characterized by that be laminated to the impressing at retroreflective layer back, multiple Sealant that is that make or that formed in a similar manner.Sealant can be available duplication, hot padding, squeeze Go out contact adhesive, heat-activatable adhesive or other materials that duplication etc. is formed.

Fig. 3 is the signal of an exemplary embodiment of the retroreflective articles 300 towards observer 302 Figure.Retroreflective articles 300 includes that retroreflective layer 310, described retroreflective layer 310 include multiple solid angle element 312, the plurality of solid angle element 312 is collectively forming the patterned surface relative with first type surface 316 314.Retroreflective layer 310 also includes cover layer 318.Retroreflective layer 310 is shown as and there is not base layer or matrix The flexible substrates of part, but as described above, retroreflective layer 310 can include base layer and/or any type Optical element.Structured adhesive layer 330 is adjacent with retroreflective layer 310.Structured adhesive layer 330 Elevated regions (relative peripheral region including the adhesive of (such as, hexagonal array) in closed pattern The region that territory is protruding).Structured adhesive layer includes that structured adhesive liner 340 and heat fusing glue Mixture layer 350.Structured adhesive layer 330 limits low-index layer when being bonded to retroreflective layer 310 338, described low-index layer 338 keeps the retroreflection characteristics of patterned surface 314.More particularly, The existence of low-index layer 338 allows the portion adjacent with low-index layer 338 of patterned surface 314 Divide retroeflection incident light 150.Thus, including the solid angle element 312 adjacent with low-index layer 338 Retroreflective articles 300 part is optically-active, because its retroeflection incident light.By contrast, have with three-dimensional Retroreflective articles 300 part of structured adhesive layer 330 part that angle element 312 is adjacent is optically inactive Region, because they substantially not retroeflection incident lights.The not contact structures of structured adhesive layer 330 That changes surface 314 is partially adhered to solid angle element 312, thus effectively seals against retroreflective regions to be formed Optically-active region or unit.Whole retroeflection structure is also kept together by structured adhesive layer 330, by This eliminates for independent sealant and the needs of seal process.In the embodiment shown in fig. 3, retroeflection Goods 300 are adhesively bonded to aluminium substrate 360 to form licence plate.

Structured adhesive layer can be formed in several different ways.Structured adhesive layer can include (such as) multiple layers that are that concurrently form or that can be built by repetition step.One exemplary side Method starts from the flat film of adhesive being optionally disposed in carrier web.By adhesive clip at smooth roller and tool Have between the roller of required embossing pattern.By applying temperature and pressure, embossing pattern is transferred to bonding Agent.Second illustrative methods needs can be cast or extrudable adhesive material.By material is extruded Binder film is formed on the roller have required embossing pattern.When adhesive material is removed from roller Time, the embossing pattern that its holding is relevant to this roller.Then structured adhesive layer is laminated to retroeflection Layer.

In alternative embodiment, structured adhesive layer can include (such as) materials described below, Described material is not for adhesive but utilizes adhesive to be applied on the tip of structure.

The illustrative methods preparing this retroreflective articles 400 starts from smooth non-adhesive film, example As, polyethylene.Polyethylene film is clipped between smooth roller and the roller with required embossing pattern.Pass through Apply temperature and pressure, embossing pattern is transferred to polyethylene film.Then (such as) is utilized to touch painting Cloth or another kind of suitably method transfer the adhesive to the tip of duplicating film.Then adhesive is coated with Structured liner be laminated to retroreflector.

No matter use above-mentioned any preparation method, the most subsequently by following manner by structured adhesive It is bonded to retroreflective layer layer by layer: clipped together in the roll gap being made up of two smooth rollers by the two film.Logical Cross applying temperature and pressure and adhesively bond described film, be consequently formed and keep returning of solid angle element The air pit of penetrating property.

Being optional that, available materials described below comes the first area of patterned adhesives or non-lug boss Point, described material for reduce structured adhesive layer seal leg creep, additionally minimize process or Touched, by the bottom of groove, the unfavorable effect that the tip of solid angle element is caused during use.Fig. 5 illustrates Retroreflective articles 500, wherein barrier layer 580 is limited at the bottom of structured adhesive layer, but barrier Layer 580 can be located at any position in groove, and precondition is that it will not significantly reduce sealing leg to returning Penetrate the bonding force of layer 310.

The structured adhesive layer of Fig. 3-5 can include (such as) thermoplastic polymer, heat activated adhesive The EVA of agent, such as acid/acrylate or acid anhydrides/acrylate modified is (such as, as in United States Patent (USP) No.7, the Bynel 3101 described in 611,251, this full patent texts is incorporated by reference herein). The structured adhesive layer of Fig. 3-5 can include (such as) acrylic acid PSA or any other is imprintable Material, described imprintable material has will adhere to the adhesion characteristic of solid angle element.Diaphragm seal layer and Interface between (such as solid angle) microstructured layer generally includes the surface process improving bonding force.Many The surface process planting raising bonding force is known, and includes that (such as) is mechanically roughened, chemical Process (inert gas of air or such as nitrogen etc), sided corona treatment (such as Described in US2006/0003178A1), plasma treatment, flame treatment and actinic radiation.

Retroeflection coefficients R_A(being sometimes referred to as the retroeflection rate of the retroreflective articles of the present invention) can be according to institute in application The characteristic needed is modified.In certain embodiments, R_AMeet under 0 degree and 90 degree of angles of orientation ASTM D4956-07e1 standard.In certain embodiments, when according to ASTM E-810 method of testing Or CIE 54.2；2001 method of testings 0.2 degree of view angle and+5 degree incidence angles measure time, R_AAbout 5cd/(lux·m²) to about 1500cd/ (lux m²In the range of).In certain embodiments, as returned wherein Penetrate goods in the embodiment of traffic control signals, plotter or roadblock, as according to ASTM E- 810 method of testings or CIE 54.2；2001 method of testings are surveyed in 0.2 degree of view angle and+5 degree incidence angles , R_AIt is at least about 330cd/ (lux m²) or at least about 500cd/ (lux m²) or at least about 700cd/(lux·m²).In certain embodiments, in the application relevant at motor vehicles, such as basis ASTM E-810 method of testing or CIE 54.2；2001 method of testings 0.2 degree of view angle and+5 spend into Firing angle records, R_AIt is at least about 60cd/ (lux m²) or at least about 80cd/ (lux m²) or at least about 100cd/(lux·m²)。

The another kind of method of these distinct optical features measuring the sheet material of present patent application relates to measuring and divides Number retroeflection rate R_T.Mark retroeflection rate (R_T) it is another the useful parameter for characterizing retroeflection.R_T, ASTM E808-01 is described in detail, is to be irradiated in retroreflector, less than specified maximums α_max View angle in the ratio of Unidirectional light flux that receives.Therefore, R_TRepresentative reflexes to given grand sight Angle measurement α_maxInterior part light.Follow ASTM E808-01, R_TCan calculate according to the following formula:

$R_T=\underset{\mathrm{\α}=0}{\overset{{\mathrm{\α}}_{max}}{\∫}}\underset{\mathrm{\γ}=-\mathrm{\π}}{\overset{\mathrm{\π}}{\∫}}\left(\frac{R_a}{cos\left(\mathrm{\β}\right)}\right)\left(\mathrm{\α}\right)d\mathrm{\γ}d\mathrm{\α},$

Wherein α is view angle (representing with radian), and γ is apparent angle (also representing with radian), and β is incident Angle, and R_aFor conventional retroeflection coefficient, with unit candela/lux/square metre represent.Just this is special For the purpose of profit application, R_TRefer to the mark retroeflection rate with fractional representation, and %R_TRefer to hundred The mark retroeflection rate of fraction representation, i.e. %R_T=R_T× 100%.In either case, mark returns The equal dimensionless of rate of penetrating.Because chart contributes to understanding that the view angle of retroeflection sheet material, mark retroeflection rate can be painted It is made as maximum view angle α_maxFunction.Herein this figure line is referred to as R_T-α_maxCurve or %R_T- α_maxCurve.

It is R for characterizing another useful parameter of retroeflection_TSlope, it may be defined as observing for maximum The little change at angle or increment Delta α_max, R_TChange.Relevant parameter %R_TSlope may be defined as maximum Little changes delta α of view angle_max, %R_TChange.Therefore, R_TSlope (or %R_TSlope) represent R_T-α_maxCurve (or %R_T-α_maxCurve) slope or rate of change.For discontinuous data point, This tittle can be estimated by the following method: calculates two different maximum view angle α_maxCorresponding R_T (or %R_T) difference, and by this difference divided by increment Delta α of maximum view angle_max(with radian table Show).As Δ α_maxWhen representing with radian, R_TSlope (or %R_TSlope) it is the rate of change of every radian. Alternatively and as used herein, as Δ α_maxWhen representing with degree, R_TSlope (or %R_T Slope) for often spending the rate of change of view angle.

R given above_TFormula relates to retroeflection coefficients R_AWith other factors in whole apparent angle (γ=-π to+π) scope and view angle scope (α=0 to α_max) interior integration.Discontinuous processing During data point, this integration is usable in discontinuous view angle α_maxValue (0.1 degree) is (with increment Δα_maxSeparate) place measure R_APerform.

In at least some embodiments of the invention, for the incidence visible light that incidence angle is-4 degree, knot Structure surface show the total light return rate not less than about 5% having, not less than 8%, not less than 10%, Not less than 12%, not less than 15%.In at least some embodiments of the invention, for 0.2 degree View angle and the incidence angle of-4 degree, the patterned surface of retroreflective articles shows retroeflection coefficients R A having Not less than about 40cd/ (lux m2), not less than 50cd/ (lux m2), not less than 60cd/ (lux m2), no Less than 70cd/ (lux m2) and not less than 80cd/ (lux m2).

By properly selecting barrier layer material, size and/or spacing, the retroreflective articles tool of the present invention Ratio is had to use the obtained outward appearance of conventional retroreflective articles including sealant outward appearance evenly.It addition, this The retroreflective articles of invention need not include or use sealant, thus reduces their cost.

Embodiment including the sealing structure shown in (such as) Fig. 3 and 5 has some extra spies Determine advantage.Such as, seal leg and can be prepared as sufficiently small, so that they can not adversely affect printing Handicraft on the surface of retroreflective articles or structure or the aesthetic property of design.Additionally, these sealing sides Method not substantially changes the angle distribution of the retroreflection light deriving from naked retroreflective layer.These methods also allow for being formed appoints Meaning shape and the sealing leg of color.Therefore, can be formed and there is the retroreflective articles of white appearance and have Anti-ripple effect and/or the goods of security feature.Finally, manufacture method is streamlined, because from method In eliminate steam application step.

Additionally, when compared to pearl sheet material, the retroreflective articles of the present invention has the performance of improvement.Logical Often it is known that prism sheet material compared with bead matrix material the incident light of retroeflection higher percent to return Light echo source.(see, e.g., " the Driver-Focused Design of of Kenneth Smith The Retroreflective Sheeting for Traffic Signs (driver for the retroeflection sheet material of traffic sign Be main design) " Fig. 2 and 3 (13-17 day in January, 2008 is in Washington DC The 87th transportation research report annual meeting (the 87th Annual Meeting that (Washington, D.C.) holds of Transportation Research Board)).When retroreflection light is appropriately arranged with relative to view angle, Result is to have the product of excellent brightness and performance.

The geometry of microsealing unit, shape, size and structure can be uniform on whole sheet material, or Can change in a controlled manner.The change of cell geometry (such as size, shape and cell width) can For being deliberately introduced on the visual appearance closely with (less than 20 feet, preferably shorter than 5 feet) Slight fluctuations.Between this fluctuation can have or the effect that conceals defects, described defect can random distribution In sheet material (pollutant, coating crack etc.), or may originate from the periodic structure in mould or product (such as, proportional amplification or sealing wire).

Microsealing prism sheet material is particularly suited in the application of such as licence plate and figure etc.When replacing glass During glass sequin material, prism sheet material provides following beneficial effect, such as, significantly lower manufacturing cost, The circulation timei and the refuse that reduce (especially include solvent and CO₂) elimination.Additionally, work as and glass When glass pearl retroreflector is compared, prism structure returns the light dramatically increased.Suitable design also allows for making this Light is arranged at the view angle being even more important licence plate, e.g., and 1.0 to 4.0 degree scopes.Finally, micro-close Mounting material close up needed for these products application is examined distance and is provided brilliant white and uniform outward appearance.

The feature of sealing unit may be in unit size size and sealing unit leg or line thickness.For The unit size of 3M HIP and 3M flexibility prism product is about 0.143 inch and 0.195 inch respectively. Sealing leg width for same sample is about 0.018 inch and 0.025 inch respectively.Characteristic feature list The another way of elemental size is for using cellar area divided by girth.This feature unit dimension D_cCan be used for The most different cell geometries.These relatively large sealing unit sizes are completely suitable for wherein Generally use their application.But when close-ups (e.g., several feet distance or at hand Hold or handle official business in indoor environment) time, the uneven outward appearance of the retroeflection sheet material with these unit sizes is Significantly.But, the actual range using this sheet material is the biggest.Such as, for right wing For the direction board that shoulder is installed, critical direction board distance (depend on following factor, such as, first and Last viewing distance, direction board position and barrier and definition) it is about 50 to 150 meters.This A little critical distances represent that driver the most actually obtains the region of information from motorway guide planks.According to visual acuity Threshold value, each sealing unit at these critical distances is the most sightless.

The distance of a foot, the normal visual acuity of human eye is about 0.0035 inch, and (88.9 is micro- Rice).This means that then most people is seen if having the alternately black and white line being all about 89 microns wide Get up for entity ash block.(see, As,http://www.ndted.org/EducationResources/CommunityCollege/PenetrantTe st/Introduction/visualacuity.htm).Alternatively, 20/20 eyesight is 20 At Ying Chi distinguish spaced apart 1 arc divide-about 1 inch 1/16 two points needed for visual acuity (see, As,http://en.wikipedia.org/wiki/Visual_acuity#Visual_acuity_expression)。 Therefore for the minimum viewing distance of approximation expection of about two feet, it is impossible to tell less than about 180 micro- Any feature of rice.For human eye, the sheet material with the discrete characteristic size less than this level will Appear as uniform.

Compared to various roads signage purposes, in licence plate, include that word is phase with the letter of numeral To less.Such as, the letter height of about 2.75 inches and stroke width (the letter number of 0.35 inch The rugosity of word) it is common in the U.S..Similarly, the letter height of about 3.0 inches and 0.45 inch Stroke width be common in the U.S..As described above, the black and white visual acuity limit under ideal conditions It is about 0.0035 inch/foot distance.Therefore, if the stroke width on US plate is about 0.35 English Very little, then it can be seen that the ultimate range of these strokes is about 100 feet.Between alphanumeric and background Contrast ratio (can abandon the black in white background because of the factor of such as dust absorption or graphic designs etc Letter) and reduce.In this case, the ultimate range being used for reading this plate will drop further Low.The real world of such as poor lighting, mobile vehicle, bad weather and bad eyesight etc becomes Amount can further and significantly decrease utmost sharpness distance.Therefore usually study in licence plate market (specifically) licence plate is in the critical licence plate distance of about 50 to about 125 feet (15.2 to 38.1 meters) In the range of definition.The view angle being even more important licence plate is located substantially at the model of about 1.0 to about 4.0 degree In enclosing, as shown in figs. 7 a-b.Compared to standard car, at such as SUV or truck etc Bigger vehicle in, driver's eyes even more add away from headlamp.Therefore, the most relatively In big vehicle, view angle will be the biggest.

Exemplary retroreflective articles includes that (such as) retroeflection sheet material, retroeflection label (include (such as) Traffic control signals, street sign indicator, highway sign, lane markings etc.), licence plate, plotter, Roadblock, personal security's product, figure sheet material, safety vest, vehicle graphic and display sign.

Following example describes some representative configuration of the various embodiments of retroreflective articles, and preparation The method of heretofore described retroreflective articles.Following example is it is intended that illustrative, but is not intended to limit The scope of the present invention processed.

Example

The preparation of retroreflective layer:

By hexenoic acid acrylate (EAA) (can be purchased from close with trade name " Primacor 3440 " Have a rest the Dow Chemical Company (Dow Company) of Midland, root state (Midland, MI)) with thickness be The film of 0.01cm (4mil) is cast to the corona that about 53in (134.6cm) is wide and 0.05mm (0.002in) is thick Cover layer is prepared on polyethylene terephthalate (PET) carrier processed.By the globule of EAA Sending in the single screw extrusion machine of 1.9cm (3/4in), described single screw extrusion machine is available from south, New Jersey The C.W. Brabender instrument company (C.W. in Ha Kensake city (South Hackensack, N.J.) Brabender Instruments Inc.)).The Temperature Distribution of this extruder be 140 DEG C (284) extremely 175 DEG C (347) so that melt temperature is about 175 DEG C (347).Along with molten resin leaves extrusion Machine, it (can be with trade name " Ultraflex-40 " purchased from Wisconsin State Qi Powa by horizontal die head Extrusion die industrial group (the Extrusion Dies Industries in Fu Ersi city (Chippewa Falls, WI) ) and be poured on pet vector mentioned above LLC).Pet vector is with about 36 meters/min (120ft/min) advance.Make the gained on pet vector melt cover layer to support with hardened steel in rubber rollers Move between roller, so that molten resin is solidified stratification.With 1.5J/cm²Energy carry out sided corona treatment EAA Surface.

Cube corner structures has spacing or three groups of phases that major trough spacing is 81.3 microns (0.0032 inches) The groove handed over.The groove intersected forms the solid angle bottom triangle that angle is 61,61,58 degree, so that The height of solid angle element is 37.6 microns (0.00148 inches).Major trough spacing is defined as forming the end Separation between the groove at two 61 degree of base angles of portion's triangle.

Use (can be with trade name by combining the bisphenol A epoxy diacrylate of 25 weight % " Ebecryl 3720 " is purchased from Wood orchid Parker city, New Jersey (Woodland Park, NJ) Cytek), the dimethylaminoethyl acrylate (" DMAEA ") of 12 weight %, 38 weight % TMPTA (trimethylolpropane trimethacrylate) and the 1,6HDDA (diacrylate of 25 weight % Hexylene glycol ester) and the resin combination that formed to prepare Cube corner microstructures.This formulation contains TPO (the 2,4,6-trimethylbenzoyl diphenyl phosphine oxide) light trigger of 0.5pph.

At room temperature it is cast to be heated to 77 DEG C (7.6m/min) (170) by resin combination with 25fpm Metal tools on.By having the rubber roller in gap, resin combination is filled up instrument neutral body angle The hole of micro-structural, described gap is set so that resin combination fills up the embossing figure on instrument The hole of case, and make the amount of resin being positioned on the matrix region of instrument minimum.By making through corona EAA film/the pet vector processed contacts with the Cube corner microstructures of resin and prepares retroreflective layer.Use 12 Fusion D UV lamps being set as 600W/in (are available from Rockville, MD city The Fusion Systems of (Rockville, MD)) solidified by the pet vector on instrument/EAA film Cube corner microstructures resin.At uviol lamp dichroism used above wave filter, so that red to construct External heat minimizes.When completing solidification process and from instrument removal retroreflective layer, utilize 50% time fortune The Fusion D UV light irradiation Cube corner microstructures of row is with UV radiation curing after providing.Make retroreflective layer warp Cross the baking oven being set under 127 DEG C (260) to relax the stress in film.

Example 1-15:

Structured layer is prepared by producing structure on the base layer.In certain embodiments, by inciting somebody to action Barrier material (can be used for the material in barrier layer) optionally uses (e.g., pattern printing, pattern Coating) on basalis, produce structure.Alternatively, barrier material is administered to every On absciss layer, subsequently the separation layer comprising barrier material is laminated to basalis.In certain embodiments, Utilize mould to be applied on basalis by pattern, thus prepare structured layer.In some embodiments In, basalis is adhesive phase.Retroreflection optical structure is prepared by structured layer being laminated to retroreflective layer Make, wherein barrier material contacts Cube corner microstructures.

Comparative examples A 1 and A2:

Prepare retroreflective layer as described above, except for the difference that use the material of difference batch.

Example 1-5:

Radiation polymerization contact adhesive is prepared described in United States Patent (USP) No.5,804,610 (Hamer) (PSA), this patent is hereby incorporated herein by.By mixing the 95 different monooctyl esters of parts by weight of acrylic acid (IOA), 5 parts by weight of acrylic acid (AA), 0.15 weight portion Irgacure 651 (are purchased from New Jersey Ciba (Ciba Corporation), is now BASF AG), 0.10 weight portion 4-acryloyl-oxygen Generation-benzophenone (ABP), 0.05 weight portion isooctyl thioglycolate (IOTG) and 0.4 weight portion Irganox 1076 (being purchased from Ciba (Ciba Corporation)) prepares PSA composition.Will The EVAc film that PSA composition is placed in by thickness is 0.0635mm (can be with business The name of an article " VA-24 " is purchased from the Pliant company in city of Dallas of Texas (Dallas, TX)) make In packaging and seal, described film is measured as about 10cm × 5cm.Then PSA composition is gathered Close.After polymerization, by PSA composition and the TiO of 10%₂Pigment is blended and is about 27 with thickness Grain/4 inch × 6 inch sample (11.3mg/cm²) film be poured on silicones release liner, as Substantially described in United States Patent (USP) No.5,804,610.Then PSA film is made to stand radiation crosslinking step.

Utilize UV ink-jet printer (Georgia State can be purchased from trade name " Mimaki JF-1631 " The Mimaki in Su Wanni city (Suwanee, GA)) barrier material is optionally printed onto PSA film On.Yellow inkjet ink (being purchased from Mimaki) is used as barrier material.Use the 8 unidirectional prints of journey Brush, with being set as that high lamp and 600 × 600dpi resolution ratio run printer.Ink level is set to 100% or 300% ink is laid.Use the printing figure comprising the point arranged with rhomboid parallelogram Case, the most each point is centrally located at the apex of parallelogram, as shown schematically in Figure 6.Point Radius be 400 to 600mm, the distance between the center of the point that level is adjacent is " S " Distance between (spacing), and the center of the most adjacent point is " S "/2." S " is 1418 To 2127mm.The width of printed patterns is calculated by deducting 2R from distance values.Based on The relative quantity of printing zone and non-printing zone calculates area coverage (% area).For preparing warp The details of the pattern of the adhesive phase 1-5 of printing is shown in table 1 below.

Table 1: the ink level of adhesive phase 1-5 through printing, spacing " S ", some radius, width Degree, spacing/width and area coverage。

Retroreflecting optical construction (example 1-5) is prepared: utilize pressure to be set to 40psi by following manner (276kPa) hand pressure layer of rolls clutch will be laminated to retroreflective layer through the adhesive phase 1-5 of printing, wherein barrier The Cube corner microstructures of material retroreflective layer.

0.2,1.0 and 2.0 degree of view angles ,-4 degree incidence angles and 0 degree orientation get off to measure according to Retroeflection rate (the R of the sample of preparation described in example 1-5_A).Measure the retroeflection of retroreflective layer (" initially ") Rate (that is, before the adhesive phase through printing is laminated to Cube corner microstructures) and retroreflection optical structure Make the retroeflection rate of (that is, laminated after the adhesive of printing) (" after laminated "), and show In table 2 below.

Table 2: the Retroreflecting optical construction (after laminated) of preparation in retroreflective layer (initially) and example 1-5 Retroeflection rate (R _A )。

The quantity of barrier material and/or the size being printed onto on PSA film is depended in the formation in optically-active region. High area coverage (a large amount of and/or large-area barrier material e.g., being printed onto on PSA film) causes producing The optically-active region of raw higher percent, thus improves retroeflection rate.

Example 6:

Preparing PSA composition described in example 1-5, except for the difference that monomer ratio is 90/10 IOA/AA and do not use TiO₂.It is 0.8 grain/in by PSA composition with thickness²(7.95mg/cm²) Film pour into a mould.

By barrier material to be printed onto on PSA film the bonding prepared through printing with grid grid pattern Oxidant layer 6, wherein each grid is 500 × 500 μm.Spacing is (between the center of each adjacent square Distance) it is 700 μm.Distance (width) between each grid is 200 μm.Spacing relative width Ratio be 3.5.Ink level is 300%.Area coverage (% area) is based on sample and printing The area of pattern carries out calculating, and corresponding to 51%.

As described in example 1-5, prepare by the adhesive phase 6 through printing is laminated to retroreflective layer Retroreflecting optical construction (example 6).

Get off to measure retroeflection rate in 0.2 degree of view angle ,-4 degree incidence angles and 0 and 90 degree of orientation, And it is shown in table 3 below.

Table 3: Comparative examples A and the example 6 retroeflection rate under 0 and 90 degree of orientation。

Example 7:

Barrier material is printed onto by the UV ink-jet printer and the yellow inkjet ink that utilize example 1-5 On the separation layer of silicones coating.Ink level used is 100%.Use described in example 1-5 Dot pattern, and described dot pattern is illustrated schematically in Fig. 6.Utilize the print being specified in table 4 below Map brushing case prepares the separation layer 7 of printing.

Table 4: through the distance " S " of adhesive phase 7, some radius and the area coverage of printing。

	S(μm)	Radius (μm)	% area
				Separation layer 7 through printing	1418	400	50

Prepared by the PSA film separation layer 7 of printing being laminated to by preparing described in example 1-5 Adhesive phase 7 through printing.Retroeflection is prepared by the adhesive phase 7 through printing is laminated to retroreflective layer Optical configuration (example 7).

Get off to measure retroeflection in 0.2,1 and 2 degree of view angle ,-4 degree incidence angles and 0 degree of orientation Rate, and be shown in table 5 below.

Table 5: the retroeflection rate of Comparative examples A and example 7。

Example 8:

Barrier material is produced: (can by cross-linking for white UV screen painting ink by following manner Public purchased from the 3M of Paul, MN (St.Paul, MN) with trade name " 9808Series " Department) screen painting is to (use derives from the A.W.T. world in Chicago, IL city (Chicago, IL) The Accu-Print printer of trading company (A.W.T.World Trade, Inc.)) silicones coating every On absciss layer.By 380 eye mesh screens, utilize the some printed patterns of example 1-5 to produce barrier material. Utilize the printed patterns of example 1-5 to prepare the separation layer 8 of printing.

After screen painting, utilize by the U.S. in Ma Rui mountain city, New Jersey (Murray Hill, NJ) purple Prepared by connecting company (American Ultraviolet Company), be set to 226mJ/cm²And with The UV curing station that 50fpm (15.24m/min) runs is to solidify barrier material.

The adhesive phase 8 through printing is prepared by the separation layer 8 through printing is laminated to PSA film. Retroreflecting optical construction 8 is prepared by the adhesive phase 8 through printing is laminated to retroreflective layer.

Example 9:

Substantially according to being incorporated by reference institute in United States Patent (USP) No.6,254,675 (Mikami) herein State, use roller platen to prepare structured layer.Laser Processing roller platen has following shape to provide Pattern, described in be shaped as having the butt rectangular pyramid of exposed surface and be arranged on the exposure table of the first pyramid The second rectangular pyramid on face, such as United States Patent (USP) No.6, shown in Fig. 4 a of 254,675.This structure has The spacing of 200 μm, the height of 15 μm and the width of 25 μm, as substantially in United States Patent (USP) No. Described in the example 6 of 6,254,675.The paper release liner of polyethylene coated (is had and is positioned at polyethylene On silicone coatings) (such as, be available from Rexam or Inncoat those) at the rubber that is heated Carry out between roller and roller platen imprinting to produce the microstructured liner with ridge.Rubber rollers is heated to The temperature of 110 DEG C, and added before in release liner roll gap between entrance rubber rollers and roller platen The surface temperature of heat to 110 DEG C.Release liner is passed to after walking around approximately half of roller platen can be cold But on the cold containers of liner.

Coating composition includes the vinyl solution containing 10% solid, wherein that vinyl is (permissible Trade name " UCAR VYHH " is purchased from the Dow Chemical Company in available city (Midland, MI) (Dow Company)) it is dissolved in MEK (MEK).Coating composition is applied on structured layer with Form the separation layer 9 of coating.Linear velocity is 5fpm (1.52m/min), and flow rate pump is 5ml/min, and And in the baking oven being set to 170 (77 DEG C), it is dried coating.

By coated separation layer 9 being laminated to according to the PSA film system of preparation described in example 6 The standby adhesive phase 9 through printing.Prepare back by the adhesive phase 9 through printing is laminated to retroreflective layer Penetrate optical configuration (example 9).

Get off measurement in 0.2,1 and 2 degree of view angle ,-4 degree incidence angles and 0 and 90 degree of orientation Retroeflection rate.Retroeflection rate is recorded with the mean value of the retroeflection rate of 0 and 90 degree of orientation in table 6 below.

Table 6: the average retroeflection rate of example 9。

Example 10-13:

Use the example 10-13 for preparing described below: use and be generally described in being incorporated by reference this Laser etching system in United States Patent (USP) No.6,285,001 (Fleming) of literary composition to apply for polymer film Predetermined pattern.Laser etching system includes the KrF quasi-molecule launching the light beam with 248nm optical wavelength Laser instrument, utilize pattern mask prepared by standard semiconductor lithographic mask technology, will be through covering The pattern image of the light of mould projects suprabasil imaging len.Substrate includes that be attached to layers of copper 5 is close The polyimide layer that ear is thick.Gained knot substrate being exposed in patterned radiation and polyimide layer Structure has hexagon channel patterns as shown in Figure 4.Each hexagon be 0.731mm width and 0.832mm length.The width (that is, the distance between each adjacent wall of adjacent hexagons) of groove is 0.212mm (between width d), and a hexagonal center and the center of adjacent hexagons away from From for 0.943mm (space D), as shown in Figure 4 A.

After cutting pattern, by following manner, substrate used isolation processing: first pass through Plasma deposition deposits silicon-containing film, is coated with fluoro-containing composition subsequently.Relatively low being configured to have 26 (model 3032, is available from the commercial Reactive Ion Etcher of current electrode and central authorities' air pump Plasmatherm) perform plasma-deposited in.Substrate is arranged on current electrode and passes through Following manner utilizes oxygen plasma to process: make oxygen in 500 standards cm³The flow velocity of/min Flow 30 seconds under plasma power with 1000 watts.Oxygen plasma process after, by under Mode of stating is to deposit siliceous diamond sample glass-film: make tetramethylsilane gas with 150 standards cm³/min Flow velocity and make oxygen with 500 standards cm³The flow rate of/min 10 seconds.At deposition diamonds sample glass After glass film, it is 500 standards cm by substrate at flow velocity³The oxygen plasma of/min exposes 60 seconds. Then (can be with trade name " EGC-1720 " purchased from Minnesota by fluoro-containing composition by following manner The 3M company of Sao Paulo City, state (St.Paul, MN)) it is applied to substrate: substrate is manually immersed molten Liquid is interior and makes it be dried.Then substrate is heated 15 minutes in the baking oven of 120 DEG C.

Comparative example B1 and B2:

Retroreflective layer is prepared described in Comparative examples A 1 and A2.

Example 10:

Out prepared sealant by co-extrusion, described sealant include the ethene of acid/acrylate modified- Vinylacetate (EVA) polymer (can be with trade name " Bynel 3101 " purchased from Michigan State Usa The Dow Corning Corporation (Dow Corning) of (Michigan, USA)) double-layer structural, wherein ground floor is Transparent and the second layer colours because adding TiO2 during extruding.By 80/20 with 20 weight % TiO₂Bynel 3101 globule of/EVA blend mixing sends into extruder and with 0.005cm (2mil) The tunica albuginea of thickness is poured on pet vector.By hyaline layer (that is, without TiO₂) with 0.002cm (1mil) film of thickness carries out pouring into a mould and at about 1J/cm²Energy under carry out sided corona treatment.

On sealant, structure is produced: (can be with trade name " PW-at hot press by following manner 220H " type is purchased from the IHI company in Houston, TX city (Houston, TX)) in will previously retouch The transparent Bynel side of the multilayer film stated is suppressed 3 minutes on patterning polyimides.The top of hot press The imprint temperature of portion and bottom is about 230 (110 DEG C), and embossing pressure is 10psi (69kPa).

Subsequently structuring sealant is laminated to retroreflective layer and makes hyaline membrane adjacent with Cube corner microstructures, It is consequently formed Retroreflecting optical construction.Using laminated temperature about 200, pressure is 30psi (207kPa) Hot press (derive from the model " N-of the HIX company in city of Pittsburgh, the Kansas State (Pittsburg, KS) 800 ") and persistently use 30 seconds.

Example 11:

Described in example 10, prepare sealant, be except for the difference that laminated to back at structuring sealant Utilize low-refraction to be coated with cloth material before penetrating layer to be coated.

The M-5 silica dispersion using the alkali of non-surface modification stable (can be with trade name " Cabo-SpersePG002 " is purchased from Bill Li Ka city, Massachusetts (Bellerica, MA) And polyvinyl alcohol (PVA) (can be with trade name " Poval 235 " purchased from the Kuraray of the U.S.) Cabot) Prepare low-refraction coating composition.This silica is characterised by it typically is about 80-120m²/g Low surface area.7.2% solid PVA water-soluble of 150g is added in 1000ml plastic beaker Liquid, the nonionic surfactant of 2.0g (can be purchased from trade name " Tergitol Min-Foam 1X " Dow Chemical (the Dow Chemical in available city (Midland, Michigan) ) and the concentration NH of 1ml Company)₄OH solution.It is pneumatic built on stilts that use runs under the low speed Laboratory mixing machine mixed solution at low shear.By silica dispersion (216g, 20 weight % The aqueous solution) add in solution, add 130g deionized water subsequently.Blend is made to mix about 15 points Clock.Then by comprising 1 part of PVA, the blend of 4 parts of silica (in terms of dry weight) is transferred to 1L In round-bottomed flask, it is placed in temperature and is about on the Rotary Evaporators of 40 DEG C and 600mmHg vacuum.Profit By deionized water, the final solids content of low-refraction coating composition is adjusted to 5%.

Utilize knife coater that low-refraction coating composition is applied to the structured side of sealant.If Put scraper to provide zero-base body in the coating, i.e. remove the silica of excess from sealant.By close Sealing was placed 10 minutes before being laminated to Cube corner microstructures in the baking oven of 50 DEG C.

Get off to measure retroeflection rate in 0.2 degree of view angle ,-4 degree incidence angles and 0 and 90 degree of orientation. Retroeflection rate is recorded with the mean value of the retroeflection rate of 0 and 90 degree of orientation in table 7 below.

Table 7: the average retroeflection rate of comparative example B1 and example 10-11。

	Retroeflection rate (cd/lux.m2)
		View angle/incidence angle (°)	0.2/-4
Comparative example B1	434
		Example 10	388
Example 11	381

Example 12:

PSA film is prepared described in example 6.As described in example 10, by sub-against polyamides Amine layer compacting binder film obtains structured adhesive film.

Retroreflecting optical construction is prepared, wherein structure by structured adhesive film is laminated to retroreflective layer Change adhesive contact Cube corner microstructures.At room temperature utilize hand roller laminated to carry out.

Example 13:

Structured adhesive film is prepared, except for the difference that by the low folding of example 11 described in example 12 The rate coating composition of penetrating is applied in structured adhesive.By at room temperature utilize hand roller will through be coated with The structured adhesive film of cloth is laminated to retroreflective layer to prepare Retroreflecting optical construction, wherein said film viscous Mixture side contacts Cube corner microstructures.

Get off to measure retroeflection rate in 0.2 degree of view angle ,-4 degree incidence angles and 0 and 90 degree of orientation. Retroeflection rate is recorded with the mean value of the retroeflection rate of 0 and 90 degree of orientation in table 8 below.

Table 8: comparative example B2, the average retroeflection rate of example 12-13。

	Retroeflection rate (cd/lux.m2)
		View angle/incidence angle (°)	0.2/-4
Comparative example B2	212
		Example 12	120
Example 13	64

Comparative example C:

Acquisition can be with trade name " Diamond Grade 3910 " purchased from Paul, MN (St. Paul, MN) the sealing prism retroreflection sheet material of 3M company.

Comparative Example D:

Acquisition can be with trade name " License Plate Sheeting Series 4770 " purchased from 3M company Pearl retroeflection sheet material.

Comparative Example E

Obtain according to the sealant of preparation described in example 10.

Comparative Example F, G and H and example 14-19:

Use Comparative Example F, G and H and the example 14-19 of preparing described below: according to " returning Penetrate the preparation of layer " described in prepare retroreflective layer, except for the difference that cube corner structures has spacing or major trough Spacing is three groups of grooves intersected of 101.6 microns (0.004 inches).The groove intersected forms angle 58, the solid angle bottom triangle of 58,64 degree, so that the height of solid angle element is 49.6 microns (0.00195 inch).Major trough spacing is defined as at two the 58 degree of base angles forming bottom triangle Separation between groove.

According to preparing Comparative Example F and G described in " preparation of retroreflective layer ", except for the difference that use State cube corner structures.

Comparative example is prepared by the retroreflective layer of Comparative Example F and G being laminated to the sealant of example 10 H。

Preparing polyimide layer (mould 1-6), except for the difference that pattern form is shown in Fig. 8 and Fig. 9 Rhombus, wherein angle 1 (A1) and angle 2 (A2) are respectively 20 degree and 153 degree.The size characteristic of mould 1-6 It is shown in table 9 below.The sealing retroeflection sheet material of com-parison and analysis example C, measures spacing and the line of seal pattern Bar width, and record in table 9 below.

Table 9: mould 1-6 and the size characteristic of comparative example C。

As substantially in United States Patent (USP) No.4,478,769 (Pricone) and No.5,156,863 (Pricone) Described, come from polyimide layer (master mold) by nickel electroforming polyimide layer in bathing at nickel sulfamic acid Manufacture first generation negative norm tool.Forming extra many generations is just copying and is bearing copy so that these moulds with Master mold has substantially the same geometry.

As substantially described in example 10, come by suppressing the sealant of example 10 on mould 1-6 Preparation structuring sealant 14-19.

Retroreflecting optical construction (example is prepared by structuring sealant 14-19 is laminated to retroreflective layer 14-19)。

0.2,0.5,1,2,3 and 4 degree of view angles ,-4 degree incidence angles and 0 and 90 degree It is orientated and measures retroeflection rate (R_A).With retroeflection rate average of 0 and 90 degree of orientation in table 10 below Value records retroeflection rate.

Table 10: comparative example C, D, F and G and the average retroeflection rate of example 14-19

Retroeflection rate (R_A) generally measure at discontinuous view angle, and surveyed adjacent view angle at two Between annular region in average.The %RT increment of given view angle, is by this is average R_AIt is multiplied by annular region area, measures divided by incident cosine of an angle.Mark retroeflection rate %RT be between The summation of the %RT increment of all view angles between 0 and the view angle (α max) paid close attention to.Given view angle Mark retroeflection rate slope (%RT slope) be that %RT increment is divided by the difference between adjacent view angle. Calculate %RT slope and record in table 11 below.

Table 11: the %RT slope of comparative example C, D, F and G and example 14-19。

Calculate %RT and record in table 12 below.

Table 12: comparative example C, D, F and G and the %RT of example 14-19。

(Virginia thunder can be derived from trade name " ColorFlex " at color measurements spectrophotometer The Hunterlab in Si Dun city (Reston, VA)) on measure CAP-Y.All samples all utilizes and is positioned at this Sample white background below measures.CAP-Y and % coverage rate (that is, the % area of retroeflection) Between there is linear relationship because increase % coverage rate cause reduce CAP-Y.Reduce exposure The quantity (that is, reducing % coverage rate) of Cube corner microstructures causes the white increase of this structure.Licence plate The typical CAP-Y value of sheet material is equal to 50 or bigger.Comparative example C, E, F and H and example The CAP-Y value of 14-19 is shown in table 13 below.

Table 13. comparative example C, E, F and H and the CAP-Y value of example 14-19

	CAP-Y	% coverage rate
			Example 14	70.93	31
Example 15	68.7	37
			Example 16	64.97	37
Example 17	62.63	45
			Example 18	59.49	59
Example 19	57.09	64
			Comparative example C	53.97	75
Comparative Example E	90.59	0
			Comparative Example F	41.15	100
Comparative Example H	85.94	0

As shown in table 10,12 and 13, the quantity reducing the Cube corner microstructures exposed is (e.g., logical Cross structured film printing or be laminated to Cube corner microstructures) cause return light amount reduce, as 2, seen in mark retroeflection rate %RT at 3 and 4 degree of view angles.

The another way of the size characterizing sample is the ratio using sealing unit spacing relative to line thickness Rate (D/d).Space D is the distance between the minimum repeated characteristic in pattern.It alternatively referred to as seals list Elemental size or feature unit size.Width d is the width sealing leg.Spacing/width ratio (D/d) for CAP-Y and 2, the impact of %RT slope at 3 and 4 degree are shown in table 10,11 and 13.

Microsealing Retroreflecting optical construction is used especially for examining distance in close up provides brilliant white with uniform Outward appearance shows the retroreflection characteristics with excellence simultaneously.Little or another important side of microsealing element method Face is the geometry (e.g., unit size (D), leg width (d)) when sealing unit and returns the total of light When amount reduces, light distribution remains geostationary.Seal Retroreflecting optical construction and demonstrate total light return The decline of rate, but light distributional pattern remains identical.

It will be understood by those within the art that, the shape of sealing unit is not limited to examples detailed above The diamond shape of middle offer.The shape of sealing unit can include (such as) circle, oval, triangle Shape, square and parallelogram.Actually can use meet the characteristic size that is illustrated above, % covers Lid rate or spacing/width factor or their any combination of any shape.Sealing unit can be also There is the shape of letter or image, such as, as inversion " M " or " 3M " of security feature.

(spacing, line thickness, angle is included for defining any geometric parameter of sealing unit shape Degree, orthostatic) can be random with the moire effect between minimizing sealing unit and retroeflection sheet material.Also Geometry can be optimized with the defect in hiding sheet material and engage or sealing wire.

It addition, when being laminated to sealant, the size of solid angle or spacing P can be because being formed during sealing Edge effect and affect brightness.Two parameters can be used to help to understand solid angle dimensional effect: real Unit line thickness (d) on border and effective unit line thickness (deff).Actual line thickness d is for producing The physical width of the material of sealing unit leg.Effectively line thickness deff is the optical width sealing leg, And depend on size and the geometry being laminated in the prismatic film of sealant solid angle used.When When sealant is laminated to retroreflective layer, the sealing leg section of the only a part covering Cube corner microstructures makes Whole solid angle blackening.This extra blackening region makes effective width be wider than developed width.This Effect is strongly dependent on the size of solid angle, and this effect is more serious for big solid angle.

The statement of all number ranges in end value is intended to include to be included into all numerals in the range of this (that is, the scope of 1 to 10 includes such as 1,1.5,3.33 and 10).

All bibliography mentioned above are all incorporated by reference.

Those skilled in the art is it will be appreciated that can be on the premise of without departing from its general principles The details of above-described embodiment and embodiment is made multiple change.Additionally, without departing from the present invention's On the premise of spirit and scope, those skilled in the art will be by various amendments and change to the present invention Obviously.Therefore, the scope of present patent application should only be determined by the claims that follow.

Claims (17)

1. a retroreflective articles, including:

Retroreflective layer, described retroreflective layer includes multiple solid angle element, the plurality of solid angle unit Part is collectively forming the patterned surface contrary with first type surface；

Pressure sensitive adhesive layer, described pressure sensitive adhesive layer includes titanium dioxide and has first Region and second area, wherein said second area contacts the described structuring of described retroreflective layer Surface；

Barrier layer, it is arranged on the described first area of described pressure sensitive adhesive layer；

Low-index layer, it is positioned at the described knot of described pressure sensitive adhesive layer and described retroreflective layer Between structure surface.

Retroreflective articles the most according to claim 1, wherein said low-index layer include air or At least one in low-index material.

Retroreflective articles the most according to claim 1, wherein said first area includes resin, oil At least one in ink, dyestuff, particle, globule, inorganic material and polymer.

Retroreflective articles the most according to claim 1, wherein said first area and described secondth district Territory has different polymer morphologies.

Retroreflective articles the most according to claim 1, wherein said first area and described secondth district Territory has different flow behaviors.

Retroreflective articles the most according to claim 1, wherein said first area and described secondth district Territory has different viscoelastic properties.

Retroreflective articles the most according to claim 1, wherein said first area and described secondth district Territory has different adhesion characteristics.

Retroreflective articles the most according to claim 1, its multiple secondth districts also including forming pattern Territory.

Retroreflective articles the most according to claim 8, wherein said pattern is irregular pattern, rule The then one in pattern, word and image.

Retroreflective articles the most according to claim 1, wherein said barrier layer has enough structures Integrality flows in described low-index layer to be essentially prevented from described pressure sensitive adhesive layer.

11. retroreflective articles according to claim 1, wherein CAP-Y is more than 50.

12. retroreflective articles according to claim 1, wherein the incidence for-4 degree incidence angles is visible Light, described patterned surface shows the total light return with not less than about 5%.

13. retroreflective articles according to claim 1, wherein the view angle and-4 for 0.2 degree is spent Incidence angle, described patterned surface shows the retroeflection system with not less than about 40cd/ (lux m2) Number RA.

14. 1 kinds of methods forming retroreflective articles, including:

The retroreflective layer including the patterned surface contrary with first type surface is provided；

Multiple barrier layers are applied to pressure sensitive adhesive layer and include the of described barrier layer to be formed One region and do not include the second area of described barrier layer；

The described second area of described pressure sensitive adhesive layer is applied to described in described retroreflective layer Patterned surface, the described first area of wherein said pressure sensitive adhesive layer does not contact described returning Penetrate the described patterned surface of layer.

15. methods according to claim 14, the second first type surface of wherein said pressure sensitive adhesive layer Adjacent with liner.

16. methods according to claim 14, also include:

Described pressure sensitive adhesive layer is laminated to the described patterned surface of described retroreflective layer.

17. methods according to claim 14, wherein said pressure sensitive adhesive layer also includes titanium dioxide Titanium.