Reflective dry strip transfer
US 3172942 A
Abstract available in
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Description (OCR text may contain errors)
March 9, 1965 H. A. BERG 3,172,942
REFLECTIVE DRY STRIP TRANSFER Filed NOV. 2, 1959 United States Patent C 3,172,942 K Y AREFLliLCiIVE DRY ST TRANSFER Harold A. Berg, St. Paul, Minn., assignor to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware Filed Nov. 2, 1959, Ser. No. 850,155 9 Claims. (Cl. 88-82) This invention relates to a reflex-reflecting transfer film provided with a dry-strippable carrier on its reflex-reflecting face. The invention further provides a novel method for manufacturing reflex-reflecting articles.
The articles of this invention are particularly adapted for use in providing reflex-reflecting markers and indicia upon flexible substrates such as various articles of apparel, draperies, etc. Jackets, coats, headgear, raincoats, overshoes, and similar articles of ready-made apparel may conveniently be marked with reflex-reflecting indicia according to the invention.
leretofore, insofar as is known, no one has successfully provided a reflex-reflecting transfer film from which a required protective carrier over the reflex-reflecting face may be stripped while in dry condition, leaving behind on an article of apparel a firmly adhered, weatherresistant, and heat-resistant flexible reflex-reflecting marker or indicia immediately effective as a reflex-reflecting device, free of contamination over its lenticular reflexreecting surface. The very nature of a lenticular reflexreflecting structure means that the surface from which complete release of carrier material must be obtained is an irregular surface with projections extending into the release material of the protective carrier thereover. Mechanical locking of the release surface of a carrier to the lenticular surface of a reflex-reflecting structure has been a problem in the past; and solvent washing of contamination from the lenticular surface has appeared to be a necessary expedient. Thus, even though lenticular fedex-reflective structures have been known for many years, none prior to my invention was known to be available in the form of a flexible transfer film structure having a dry-strippable protective carrier on the face of the lenticular-surfaced structure.
This invention further provides a transfer film structure as described, which may be securely applied to fabric articles by simply pressing a hot iron over the carrier of the structure', followed by stripping the drystrippable carrier from the reflex-reflecting transfer film. Reflex-reflecting transfer films of the invention applied in this marmer to washable articles of childrens apparel have withstood repeated laundering using conventional household detergents, and repeated re-ironing and wearing (i.e., abrasion, temporary dirt contamination, etc.) over a period of about six months without loss of their brilliant reflex-reflecting properties and without loss of adhesion to underlying fabric. Portions of fabric covered with a reflex-reflective marker hereof have been noted to drape and wrinkle essentially as the fabric in other portions of a marked article of apparel.
Reex-reflecting fabrics are now, of course, well known, as taught in Palmquist et al. U.S. Patent No. 2,567,233. As distinguished from the Palmquist et al. teaching, however, the reflex-reflecting transfer lm of the instant invention lis provided with a dry-strippable carrier; and the transfer film structure of the instant invention is useful to provide reflex-reflecting markers and indicia on ready-made existing articles of apparel. This may be done by using a hot iron in application, or, if desired, by using organic solvents to activate the adhesive of the reflex-reflecting transfer film of my composite structure. Solvent activation is particularly useful in applying the transfer film of the invention to plastic raincoats and ice similar articles of apparel, as well as overshoes and the like. Where mass application of the transfer film to an article of apparel or garment is envisaged, dielectric sealing of the transfer film structure to an underlying substrate may conveniently be employed.
The portion of the composite article of this invention which is transferred and permanently ailixed to an article of apparel by methods as aforedescribed is extremely thin and flimsy. It is so flimsy that one cannot conveniently handle it alone with the lingers. In essential respects, this flimsy reflex-reflecting transfer film includes a layer of small glass beads partially embedded and permanently bonded in a flexible and stretchable rubber-base binder layer with reflective means underlying the glass beads of the structure, and with an adhesive layer on the rear face of the structure. The structure is very easily stretched, yet the glass beads of the structure are permanently bonded therein and do not pop out during flexure or stretching (e.g., wrinkling of fabric) in practical use of the film. The general optical principles of reflexreilection, as applicable to this structure, are well described in U.S. patent to Gebhard et al., No. 2,326,634; and for the purpose of this disclosure, the Gebhard et al. patent teaching is here incorporated by reference. In the re-ironable structures of the invention, a heat-barrier film or primer is interposed between the rubber-base binder layer for the beads and the adhesive coating on the rear face of the transfer film. In its entirety, the transfer film is flexible, stretchable and essentially not handlerable as a discrete entity.
` To impart handleable properties to the transfer film, a carrier is removably secured over the projecting optical elements of the reflex-reflecting structure. The carrier includes a carrier base which is dimensionally stable and a coating on the carrier base of a plastic material having low adhesion to glass beads and to the rubberbased binder layer in which the glass beads are partially embedded. In the article as supplied to the user, the plastic coating on the carrier base surrounds the projecting optical elements (i.e., the glass beads of the transfer film structure), and holds the transfer lrn in position against wrinkling or sagging and the like. In the absence of the carrier, the flimsy transfer film would wrinkle and be extremely difficult to spread out in a manner as required in afxing it to a substrate. In practical use, it has been impossible to aflix the flimsy refiex-reflecting transfer structure to a substrate without the aid of the required carrier. It will also be recognized that the carrier imparts a desired dimensional stability to the sheet article of the invention so that variously shaped reflexreflecting markers may be cut from the composite sheet material and applied to articles of apparel. For example, silhouettes of aircraft, Indian heads, Girl Scout insignia, letters, etc., may be cut from the sheet material and applied to underlying fabric.
In further describing the invention hereof, reference will be made to a drawing, made a part of this disclosure, illustrating schematically a preferred embodiment of the invention. In the drawing:
FIGURE l is a cross-sectional View of an article of the invention as supplied to a user;
FIGURE 2 is a cross-sectional View of the transfer film portion of my structure affixed to an underlying surface of cloth; and l FIGURE 3 is a cross-sectional view of a further o alternative embodiment of an article of the invention, identical to the article in FIGURE 1 except that the beads 14 in FIGURE 3 are provided with hemispherical reflective caps 21 instead of the pigment reflective means as shown in FIGURE 1.
In FIGURE 1 the laminated structure of the invention is illustrated in cross-section as it comes olf an assembly 3 line in production'. The structure is inverted, with the dry-strippable carrier being lowermost in the figure. The carrier 10 comprises a dimensionally stable carrier base 11 or sheet material with a plastic coating 12 adhcred thereto. This carrier is removable as a unit from the remainder of the structure. The transfer film portion 13 of the structure in FIGURE 1l includes the transparent beads 14 (with associated reflective pigment means 15 in the bead-binder layer 16), the bead-binder layer 16 itself, the heat-barrier film 17, and adhesive layer 13. As marketed, a temporary removable liner 19 is applied over the adhesive layer 18 of the structure so as to protect it from contamination prior to application to a substrate.
It is important that the temporary removable liner 19 protecting the adhesive 18 exhibit less adhesion to the adhesive 18 than the dry-strippable carrier 10 exhibits to the face of the reflex-reliecting transfer film 13, so that removal of the temponary liner 19 for the adhesive 1S is easily accomplished without disruption' of the temporary release bond between the face of the reflex-redecting film 13 and the plastic coating 12 of the carirer 1t). A suitable low-adhesion surface for the protective liner 19 next to the adhesive layer 1S is provided by embossing the surface of a low-adhesion removable liner 19 prior to applying it to the adhesive layer 18. This serves to reduce the 2 areas of contact between the removable liner 19 and the adhesive layer 18, and in addition, provides a surprising additional advantage. After cutting the structure of FIG- URE 1 into a shape or insignia as desired for application to a substrate, those portions of the removable embossed liner 19 which remain away from the adhesive layer 18 by virtue of the embossed character of the liner 19 permit one to conveniently use a finger nail or the like to pluck away the temporary removable liner 19 over the adhesive 18.
In FIGURE 2, the transfer film portion 13 of the structure hereof is shown aliixed to a cloth backing v20. It will be noted that the adhesive portion 18 of the transfer film structure 13 is pressed into the weave of the cloth' 20, leaving very llittle of the transfer film structure 13 projecting or extending above theV surface of the cloth 2li itself. The flexible heat-barrier film 17 and beadbinder layer 16 both tend to conform to the minute ir-l regularities of the weave of the cloth 2G; yet the transparent beads 14 of the struct-ure remain firmly bonded in the bead-binder layer 16 and the composite structure is in proper position for brilliant reex-reection, The schematic relationship illustrated in FIGURE 2 is `representat'ive of that obtained by ironing the transfer film 13 of the invention on a woven cloth substrate 20. It will be appreciated that the adhesive layer 18 of the transfer film 13 will not penetrate, to any significant extent, a exible plastic substrate such as a plastic raincoat; but secure adhesion is nevertheless obtained to such articles of apparel, without any pronounced projection of the transfer lrn from the surface of the apparel.
Referring again to FIGURE l, the method of making the composite structural article of the invention will be described. A suitable dimensionally-stable carrier base 11 (which is non-thermoplastic under the conditions of forming my article and use thereof) is coated with a layer of plastic material 12 which exhibits low adhesion to glass beads 14 and low adhesion to the particular bead-binder material 16 employed in formulating the transfer film 13. In addition, the plastic coating 12, in the preferred method of manufacture, and one which has been found to give superior end-article results, should be thermoplastic and exhibit a melting point some where in the range of about 150 F. to about 350 F., preferably 225 F. to 300 F., as will be evident as this description proceeds. The coated carrier 10 is entrained around a hot drum with its dirnensionally-stable carrier base 11 next to the hot drum, the drum being heated to a temperature suiiicient to cause the thermoplastic coating 12 on the carrier to become tacky.
Simultaneously, the heat-tackified coating 12 on the carrier base 11 is dipped in contact with a mass of small glass beads 14 in a trough beneath the hot drum (i.e., the drumis recessed into a mass ofbeads in a trough therebeneath).v The tackiness of the plastic coating 12 on the carrier base 11 causes a monolayer of the glass beads 1- to be' picked up by the coating 12. its monolayer of beads 14 is heated, while lying essentially flat, preferably with its dimensionally-stable carrier base 11 lowermost, to a temperature sufhcient to= cause the plastic coating 12 on the carrier base 11 tof soften and allow the beads 14 to sink or be drawn-into it.- The extent to which the beads 14 sink into the plastic coating 12 is surprisingly easily controlled, and may furt-her be controlled by the time and temperature of heating. The latter, of course, will depend upon the specific: melting characteristics of the plastic coating 12 ern-- ployed on the carrier base 11. It is important that thev beads 14 be allowed to sink at least about 15% (pref-4 'erably at least 30%) of their diameter into the plasticy 1 the beads 14-tol sink sufficiently therein, even to the extent that they may become tangentially in contact with the surface of the underlying dimensionally-stable carrier base 11, Another reason for using rather thin coatings 12 of plastic is that the articles hereof adapted to be afxed to apparel by using an ironing tool should exhibit good heat transfer through the strippable carrier 10, which feature is more easily attained when thinner coatings 12 are employed.
While4 I have used the term sink in the foregoing description, I wishgto make it clear that it is also possible* to accomplish suitable partial embedding of the beads in the plastic coating 12 by heating the structure formed at this point while it is in inverted condition. Apparently, capillary forces on heating the plastic coating 12 are responsible for drawing the beads partially into"V the coating even when the beads 14 are lowermost while heating the structure. As a further alternative, if desired, the glass beads 14 may be partially embedded to the extent aforedescribed by employing a combination of heat and pressure.
The glass beads 14 employed in forming the structure may vary in diameter, but beads larger than about 5 mils tend to leave a rough-textured, grainy-type of reflex-reflecting surface on the reiiex-reflecting transfer film portion 13 of the article. In fact, glass beads larger than microns generally are undesired `and those up to about 75 microns in diameter are preferred. While beads of the smallest possible diameter (e.g., about 5 microns) may be useful in forming the structure, it has generally been found that those above 25 microns in diameter are the most convenient to employ in the manufacture of the article.
In lenticular-surfaced reflex-reflecting structures as described, it is preferable to employ glass beads 14 having a refractive index (11D) of about 1.9, but suitableresults are gained using beads of a refractive index as low as 1.7 or up to 2.0. For maximum brilliance of reflex-reflection, however, beads having an effective refractive index of about 1.9 are employed.
After partially embedding the beads 14 in the plastic 12,` the plastic 12 is allowed to come to room temperature. The beads 14 and then provided with a hemisphere reflectorizing coating 21 of silver, aluminum, or other lightreflecting metal by vapor deposition; or the required refleeting means for the glass beads 14 is provided by using a,
Then the carrier 10 with' bead-bond 16 cont-aining reflective pigment 15. For example, pigment iiakes of aluminum, copper, or other reliective metal material may be incorporated in the beadbond 16, or a reflective pigment 15 such as titanium dioxide may be used, if desired. Where reflective pigment 1S in the bead-bond 15 is employed, which is preferred, a rubber-based adhesive composition containing the reflective pigment 15 is used to form the bead-binder layer 16, which simultaneously results in providing the beads with associated reflective means. The reflective means may be noted to underlie the beads 14 as the reex-reilecting transfer lm 13 is positioned in practical use applications. The rubber-based binder 16 composition with reflective pigment 15 is generally applied over the protruding glass beads 14 of the plastic layer 12 using a diluent such as an organic solvent. Solvent is evaporated from the coating at mildly elevated temperatures; and the coating may be cured or partially cured at this point of manufacture.
Other layers of the structure are then built up, the heatbarrier film 17 being applied preferably from a suitable solvent solution followed by drying and curing, and the adhesive layer 18 likewise being suitably applied from a solvent solution thereof followed by drying, after which a temporary removable low adhesion liner 19 is applied over the exposed rear face of the adhesive 18.
As a specific illustration of forming a composite structure according to the invention, a calendered paper 11 of approximately 6 mils thickness was coated with a 1.2 mil thick layer of polyethylene 12 having a molecular weight of about 18,000. The polyethylene coated paper 10 was then passed around a hot cylinder heated to approximately 170 F., while simultaneously entraining the heat-tackied polyethylene surface 12 through a trough of glass beads 14 beneath the cylinder. The glass beads 14 were in a size range of about to 75 microns and had a refractive index of about 1.9. The calendered paper 11 with a monolayer of glass beads 14 picked up and sticking to the polyethylene coating 12 thereon was then passed through an oven and exposed to a temperature of about 270 F., with each portion of the polyethylene coating 12 being exposed to this temperature for about 2 minutes. This heating action caused the polyethylene to soften and draw the beads 14 into it. They were drawn into it in the range of about 40 to 50% of their diameter. Since a coating 12 of polyethylene about half the diameter of the beads 14 was employed on the calendered paper 11, it would be possible in following this specific illustration, to allow the glass beads to sink essentially through the polyethylene and tangentially contact the surface of the calendered paper 11 therebeneath. Surprisingly, however, the heating step as here described results in the beads 14 dropping or passing into the polyethylene coating 12 to approximately an equal extent, regardless of the size thereof.
Thereafter, the polyethylene coated web 10 was cooled and a bead-bond 16 containing reflective pigment 15 was applied over the projecting beads 14 on the carrier structure 10. The formula for the bead-bond 16 was as follows:
Parts by weight Rubbery butadiene acrylonitrile copolymer (Hycar 1001, about parts butadiene and 45 parts acrylonitrile) Dioctylphthalate plasticizer Ketone-soluble heat-reactive (heat-advancing, heathardenable) phenolaldehyde resin (50% solids in methyl isobutyl ketone) 15.6 Ethylene glycol monoethyl ether organic solvent (Cellosolve) 5.6 Methyl isobutyl ketone organic solvent 56.0
To the foregoing composition was added 11.5 parts of large non-leafing -aluminum akes 15 having a particle size smaller than 150 microns and larger than about 20 microns. Aluminum flakes or metal powders 15 smaller than 200 microns are generally required for the br-illiance of reflex-reiiection necessary in structures of the type here S described; and metal akes or reflective pigments 1S as small as 2 or 3 microns may be useful.
The adhesive composition was formed in a manner generally well known in the art, including milling the rubbery copolymer and plasticizer preparatory to dissolving the mass in the solvent mixture of Cellosolve and methyl isobutyl ketone. The dissolved or finely dispersed rubber and plasticizer were then mixed with the phenolaldehyde resin solution and the aluminum akes 15 dispersed in the composition. The composition was then knife-coated over the glass beads 14 projecting from the polyethylene coating 12 so as to leave a dry film thickness of reflective pigmentized binder 0f about l mil (i.e., about 5 to 7 grains per 24 square inches). This bead-bond coat 16 was then dried by evaporating the solvent therefrom using mildly elevated temperatures and gradually elevating the temperature to F. Heating to about 150 F. fails to effect any substantial cure of the bead-bond coat 16 at this point in manufacture; but a slight cure may be noted on extended heating, and is not objectionable. In fact, if desired, curing of the bead-bond 16 may be accomplished by using elevated temperatures at this point.
1t will be noted, as illustrated in the drawing made a part hereof, that the bead-bond coat 16 formed in a manner as here illustrated, tends to present an irregular or contoured exposed surface after drying of solvent, the surface being more or less rippling and contouring about the beads 14 of the structure. Where very small glass beads 14 are employed and/ or where a relatively thicker bead-bond layer 16 is used, this contouring effect may go unnoticed.
Over the bead-bond 16 then is applied, in the preferred structures of the invention, a heat-barrier coating 17 or a coating which sometimes has been considered a primeradhesive type of coating. A suitable formula for such a coating in the structure here described has the following formula:
Rubbery butadiene acrylonitrile copolymer as in This barrier composition was blended using techniques well known in the art, e.g., the rubbery copolymer was banded with plasticizer on a rubber mill to render it easily dispersible in the methyl isobutyl ketone, and the phenol-aldehyde resin powder was blended therein by stirring.
The liuid barrier coating composition was then knifecoated at a thickness sufficient to give a dry film of about 0.4 mil over the bead-binder layer, after which solvent Was evaporated by gradually raising the temperature of the structure to about 150 F. Then curing of the heatbarrier coating 17 and the bead-bond layer 16 was accomplished by further elevating the temperature to about 270 F. for 10 to l5 minutes. Suitable curing may be accomplished by longer or shorter times of heating; but the foregoing heat-curing step is considered suicient and has proven adequate to provide a stretchable and retractable rubbery structure of solvent-resistant heat-stable character permitting washing, or ordinary dry-cleaning, and re-ironing in practical use on fabrics.
A 3-mil dry film thickness of a heat and solvent-activatable adhesive film 18 was then coated over the barrier coating 17. The adhesive composition consisted of about 25 parts of a thermoplastic copolymer composed of 85% vinyl chloride and 15% vinyl acetate, about 16.7 parts of dioctylphthalate plasticizer, and about .5 part of aluminum powder pigment such as employed in the heat-binder layer. This composition was dispersed or dissolved in a mixture of about 38 parts of methyl ethyl ketone and 19.8
parts of toulene. The solvated mixture was then knifecoated over the heat-barrier film 17 and solvent evaporated from the coating at mildly elevated temperatures, eg., 150 F.
Over the exposed dry adhesive coating 1d was then applied a protective temporary low-adhesion liner 19 consisting of a 4 mil thick sheet of embossed polyethylene film.
The resulting structure was easily handled and cut to provide emblems and insignia of desired size. The protective temporary liner 19 on the adhesive f8 could be easily removed, and the remaining structure then placed on an article of apparel such as a cloth coat. Application of a hot household iron (temperature set for cotton) over the carrier surface with mild ordinary ironing pressures for 2G to 30 seconds effectively secures the article in place on underlying fabric. Thereafter, removal of the carrier 11 and its plastic coating 12 is accomplished by peeling as soon as the pressed area has been allowed to cool slightly, eg., cool to a temperature of about 109 F.
It will be appreciated that the specific materials employed in forming the compositions of the various layers of the afore-illustrated structures may be varied without departing from the essential character of the invention. For example, the rubber-base of the bead-binder layer 16 and the heat-barrier film 17 may be natural or synthetic rubber other than the specific butadiene-acrylonitrile copolymer illustrated. Likewise, a suitable hea"- activatable adhesive or solvent-activatable adhesive (with or Without pigment, extenders, etc.) for the structure may be formed using conventional thermoplastic adhesive materials other' than plasticized polyvinyl chloride or the like. If desired, other thermoplastics may be employed as part of the dry-strippable carrier 1li; and the low adhesion temporary liner 19 for the adhesive 1.3 may also vary in its specific composition. The critical relationship between the carrier 1t), the transfer film 13, and any removable protective liner t9 for the adhesive layer 18 is as aforenoted. it is essential that the removable liner 19 for the adhesive 1S exhibit less adhesion to the adhesive 18 than the carrier 10 exhibits to the lenticular exposed surface of the reflex-refiecting transfer film structure 13. On the other hand, the carrier base 11 and its plastic coating 12 must be completely removable by dry-stripping from the flimsy, essentially non-handleable, lenticular-surfaced, reflex-refleeting transfer film structure 13. A major contribution to the art has been made in providing such a lenticularsurfaced, reiieX-reecting structure 13 which has a drystrippable carrier 1d obviating the problem of leaving behind foreign matter obscuring the proper optical function of the projecting glass beads 14 of the transfer film 13.
If desired, colored transparent glass beads 14 may be employed in the structure. Combinations of colored binders 1d (or variously colored strata of a binder layer), and variously colored beads 14 may be employed to give attractive design effects, including effects which give different visual appearance under refleX-reecting conditions as compared to normal day-viewing. j
That which is claimed is:
l. A sheet article comprising (1) a thin, flimsy, drapeable, stretchable and flexible transfer film structure including a layer of projecting transparent glass beads of refractive index between 1.7 and 2.0 partially embedded and permanently bonded in a iiexible and stretchable binder layer, said glass beads having reflective means optically underlying the same, said reflective means being Within said transfer film structure and being such that light transmitted through said glass beads from the projecting front face thereof to said refiective means is reficcted back through said glass beads by said refiective means, and an adhesive coating on the rear face of said structure opposite said projecting glass beads, (2) a dimensionally-stable dry-strippable temporary carrier structure over the projecting glass beads of said transfer film structure, said carrier structure having a low-adhesion plastic coating into which the projecting portions of the glass beads of said transfer film structure are embedded, the carrier structure being such as to impart dimensional stability to the composite consi-sting of said carrier structure and said transfer film structure, and said carrier structure being easily removed by hand as a complete unit in dry condition from the bead-containing surface of said transfer film structure after afiixing said flimsy transfer film structure onto a substrate, and (3) a removable protective low-adhesion temporary liner over the adhesive coating on the rear face of said transfer film structure, said temporary liner being characterized by exhibiting less adhesion to said adhesive coating than said dry-strippable carrier exhibits to the bead-containing surface of said transfer film structure.
2. A flexible sheet article comprising (1) a flimsy, drapeable, stretchable and iiexible transfer film structure including a layer of projecting transparent glass beads of diameter up to microns and refractive index between 1.7 and 2.() partially embedded and permanently bonded in a flexible and stretchable binder layer, said glass beads having reflective means optically underlying the same, said refiective means being Within said transfer film structure and being such that light transmitted thnough said glass beads from the projecting front face thereof to said refiective means is reflected back through said glass beads by said refiective means, and an adhesive coating which is heat and solvent activatable on 'hc rear face of said structure opposite said projecting glass heads, and (2) a dimensionally-stable dry-strippable temporary carrier over the projecting glass beads of said transfer film, said carrier having a low-adhesion plastic layer into which the projecting portions of the glass beads of said transfer film are embedded, the dimensionally-stable carr-ier being such as to impart dimensional stability to the composite consisting of -said carrier and transfer' film structure, and said carrier being easily removed by hand as a complete unit in dry condition from the bead-containing surface of said transfer film structure after affixing said fiirnsy transfer lm structure onto a substrate.
3. The transfer film article of claim 2 in which the fiexible and stretchable binder layer of the transfer film structure is a substantially-cured rubber-based layer.
4. A flexible sheet article comprising (1) a iiimsy, drapeable, stretchable and flexible transfer film` structure including a layer of projecting transparent glass beads of diameter up to 75 microns and refractive index between 1.7 and 2.0 partially embedded and permanently bonded in a flexible and stretchable substantially-cured rubber-based binder layer, said glass beads having refiective means optically underlying the same, said reflective means being Within said transfer film structure and being such that light transmitted through said glass beads from the projecting front face thereof to said reflective means is reflected back through said glass beads by said refiective means, and an adhesive coating which is heat and solvent activatable on the rear face of said structure opposite said projecting glass beads, (2) a dimensionally-stable dry-strippable temporary carrier structure over the projecting glass beads of said transfer film structure, said carrier structure having a low-adhesion plastic layer into which the projecting portions of the glass beads of said transfer film structure are embedded, the carrier structure being such as to impart dimensional stability to the composite consisting of said carrier structure and said transfer film structure, and said carrier structure being easily removed by hand as a complete unit in dry condition from the bead-containing surface of said transfer film structure after afiixing said iiimsy transfer film structure onto a substrate, and (3) a removable protective low-adhesion temporary liner over the adhesive coating on the rear face of said transfer film structure, said temporary liner being characterized by exhibiting less adhesion to said adhesive coating than the said dry-strippable carrier exhibits to the bead-containing surface of said transfer lilrn structure.
5. The transfer film article of claim 4 in which the underlying reflective means comprises hemispherical rellective coatings of metal on the partially embedded portions of the glass beads.
6. The transfer iilm article of claim 4 in which the underlying reflective means comprises reflective pigment in the binder layer for the glass beads.
7. The transfer film article of claim 4 in which the removable protective low-adhesion temporary liner is embossed in such manner that its surface next to the adhesive coating on the rear face of the transfer film structure is in discontinuous contact With said adhesive coating.
8. A flexible sheet article comprising a thin, flimsy, drapeable, flexible and stretchable transfer film structure and a dimensionally-stable dry-strippable temporary earrier structure, (1) said transfer film structure including a layer of projecting transparent glass beads `of refractive index between 1.7 and 2.0 partially embedded and permanently bonded in a flexible and stretchable substantially-cured rubber-based binder layer, said glass beads having reflective means optically underlying the same, said reflective means being within said transfer film structure and being such that light transmitted ythrough said glass beads from the projecting front face thereof to said retlective means is reflected back through said glass beads by said reflective means, and an adhesive coating on the rear face of said binder layer of said transfer film structure, and (2) said dry-strippable carrier structure having a low adhesion plastic coating into which the projecting portions of the glass beads of said transfer' film structure are temporarily embedded such that dimensional stability is imparted to the composite consisting of said carrier structure and said transfer film structure, said drystrippable carrier structure being easily removed by hand as a complete unit in dry condition from the bead-containing surfaee of said transfer lilm structure after adhesively alfixing said iilmsy transfer lilm structure onto a substrate.
9. A sheet article comprising (1) a thin, flimsy, drapeable, stretchable, flexible and re-ironable transfer film structure including a layer of projecting transparent glass beads of refractive index between 1.7 and 2.0 partially embedded and permanently bonded in a flexible and stretchable binder layer, said glass beads having reflective means optioally underlying the same, said reflective means being within said transfer film structure and being such that light transmitted through said glass beads from the projecting front face thereof to said reflective means is reflected back through said glass beads by said reective means, lan adhesive coating on the rear face of said transfer film structure opposite said projecting glass beads, and an intermediate substantially-cured rubberbase lexible and stretchable heat-barrier film between said bead-binder layer and said adhesive coating, and (2) a dimensionally-stable dry-strippable temporary carrier structure over the projecting glass bead surface of said transfer film structure, said carrier structure having a low adhesion plastic coating into which the projecting portions of the glass beads of said transfer lilrn structure are embedded, the relationship between said ter porary carrier structure and said transfer film structure being such that dimensional stability for handling is imparted to the composite consisting of said carrier structure and transfer film structure, said carrier structure being easily removed by hand as a complete unit in dry condition from the bead-containing surface of said transfer film structure after adhesively afllxing said ilimsy transfer film structure on a substrate.
References Cited in the lle of this patent UNlTED STATES PATENTS 2,383,884 Palmquist Aug. 28, 1945 2,430,534 Rodli Nov. 11, 1947 2,432,928 Palmquist Deo. 16, 1947 2,555,715 Tatum June 5, 1951 2,607,130 Pearson Aug. 19, 1952 2,646,364 Perth July 21, 1953 2,647,849 Douglas et al Aug. 4, 1953 2,969,057 Simmons Ian. 24, 1961 3,043,196 Palmquist et al. July 10, 1962