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Publication numberUS3899621 A
Publication typeGrant
Publication dateAug 12, 1975
Filing dateOct 10, 1972
Priority dateFeb 8, 1971
Publication numberUS 3899621 A, US 3899621A, US-A-3899621, US3899621 A, US3899621A
InventorsMichael E Willdorf
Original AssigneeMaterial Distributors Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Security film for shatter-proofing windows
US 3899621 A
Abstract
A security film for shatter-proofing windows comprises a polyurethane stratum interposed between a pair of polyester strata, each of which is self supporting, the film being bonded to the inner face of the window by a pressure sensitive adhesive.
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Description  (OCR text may contain errors)

United States Patent Willdorf ]*Aug. 12, 1975 [54] SECURITY FILMFORSHATTER-PROOFING 3,290,203 12/1966 Antonson et a1. 161/167 3,445,423 5/1969 Sunshine et a1 161/190 3,657,057 4/1972 Shorr et a1. 161/408 Inventor: Michael Willdorf, Maiden, Mass- 3,671,370 6/1972 Litteli 161/190 1731 Assigiieei Maiiiiai iiisiiiiiiiiiiis Ciiiwaiiiiii, 33311112 1111335 EZZTKJIIIIIIIII: '13:"1517142 wobumi Mass- 3,718,535 2/1973 Armstrong et a1... 161/190 1 Notice: The p i of the term f i 3,775,226 11/1973 Wmdorf 161/4 patent subsequent to Nov. 27, 1990, has been disclaimed. Primary Exam1ner-George F. Lesmes Filed! 1972 Assistant Examiner-Wi11iam R. Dixon, Jr. [21] AppL Nos. 295,816 gttgrney, Agent, or FirmMorse, Altman, Oates &

e 0 Related US. Application Data [63] Continuation-impart of Ser. No. 113,426, Feb. 8,

1971, Pat. NO. 3,775,226.

[57] ABSTRACT [52] US. Cl. 428/216; 350/1; 428/40;

/3 4; 428/ /458 A security film for shatter-proofing windows com- [51] Int. Cl- B4417 1/100 prises a polyurethane stratum interposed between a Field Of Search pair of polyester strata, each of which is self support- 161/165 ing, the film being bonded to the inner face of the window by a pressure sensitive adhesive. [56] References Cited UNITED STATES PATENTS 7 Claims, 5 Drawing Figures 2,955,961 10/1960 Koller 161/190 6 O P O LYES TER 62 VAPOR DEPOSITED ALUMINUM COAT 64 POLYURETHANE 66 POLYESTER POLYURETHANE POLYESTER PRESSU RE SENSITIVE ADHES 1 VE RELEASE STRATU 1V1 PATENIEII I 3,899,621

SHEET 1 POLYESTER POLYURETHANE POLYESTER I0 v PRESSURE SENSITIVE ADHESIVE AQUEOUS DETERGENT APPLICATOR SECURITY FILM DEACTIVATED PRESSURE SENSITIVE ADHESIVE AQUEOUS DETERGENT WINDOW SECURITY FILM I REACTIVATED PRESSURE SENSITIVE ADHESIVE WINDOW IMPACT OR 2 EXPLOSION SIiEET 2 POLYESTER VAPOR DEPOSITED ALUMINUM COAT gig/ L POLYURETHANE POLYESTER 42 PRESSURE SENSITVE ADHESIVE RELEASE STRATUM FIG 3 POLYESTER POLYURETHANE /POLYESTER POLYURETHANE [\POLYESTER PRESSURE SENSITIVE ADHESIVE RELEASE STRATUM 6O POLYESTER VAPOR DEPOSITED ALUMINUM /COAT 64 1 POLYURETHANE 66 POLYESTER 68 POLYURETHANE 7O POLYESTER 72 Sa i S \PRESSURE SENSITIVE ADHESIVE T4 RELEASE STRATUM 1 SECURITY FILM FOR SHATTER-PROOFING WINDOWS RELATED APPLICATION The presentapplication is a continuation-in-part of application Ser. No. 113,426, filed Feb. 8, 1971, now US. Pat. No. 3,775,226, issued Nov. 27, 1973.

BACKGROUND AND SUMMARY The present invention relates to a security film for shatter-proofing windows against impact or explosion, and, more particularly, to security film for application to one face of a window as a shield to prevent fragmentation of glass notwithstanding its splintering or cracking when damaged. Prior security films, when adhered to window faces, have tended to rip in the event of impact or explosion to the accompanyment of flying glass, which is the primary danger that safety film is intended to prevent.

The object of the present invention is to provide, as

i a security film for shatterproofing ordinary window panes, a laminated assemblage in which at least one polyurethane stratum is interposed between at least a pair of polyester strata, each of the latter of which are self supporting, and one of the latter of which is provided with a pressure sensitive surface. It has been found that such an assemblage, when adhered to the inner or outer face of an ordinary window pane, is characterized by an unusual ability to absorb energy without rupture, possibly because of the microstructure of the polyester which is devoid of surface discontinuities, the tenacity with which polyurethane can be bonded to polyester and the energy redistribution of which the entire assemblage is capable when incrementally under stress.

Another object of the present invention is to provide a process for applying such an assemblage to the inside or outside of an ordinary window pane, by wetting the pressure sensitive adhesive with an aqueous detergent, which permits the assemblage to be slipped into optically clear contact with the window pane face and which then evaporates through the assemblage, which fortuitously is moisture permeable, and via its edges to permit activation of the pressure sensitive adhesive.

Other objects of the present invention are to provide, in an assemblage of the present invention: a vapor deposited aluminum coat on at least one of the polyester strata for reduction of infrared transmission; and/or an ultra-violet absorbing pigment for reduction of ultraviolet transmission.

Further objects of the present invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the products and processess of the present invention, together with their components, steps and interrelationships, which are referred to in the present disclosure, the scope of which will be indicated in the appended claims.

BRIEF DESCRIPTION OF DRAWINGS For a fuller understanding of the nature and objects of the present invention, reference is made to the following detailed description, taken in connection with the accompanying drawing wherein:

FIG. 1 is a flow diagram illustrating a security film, in exaggerated cross section, undergoing a process of the present invention;

FIG. 2 illustrates a window incorporating the present invention;

FIG. 3 is an alternative product, in exaggerated cross section, analogous to the product of FIG. 1;

FIG. 4 is another alternative product embodying the present invention; and

FIG. 5 is a further alternative product embodying the present invention.

DETAILED DESCRIPTION Generally, the security film of FIG. 1, which is flexible, comprises, in laminated sequence, a moisture permeable polyester stratum 12, an elastomeric polyurethane bonding stratum l4, a moisture permeable polyester stratum 16 and a pressure sensitive adhesive straturn 18. All of these strata are optically clear and transparent. Typically polyester strata 12 and 16 are of the type sold by Dupont under the trademark Mylar or by I.C.I. under the trademark Melinex. Typically polyurethane bonding stratum 14 is formed as an elastomer by casting a mixture of an isocyanate containing compo- -nent and a hydroxyl containing component on one of the faces of polyester strata 12, 16, then superposing another of the faces thereon and compressing the two strata during heat curing. Typically pressure sensitive adhesive 18 is composed of a mixture of synthetic and natural rubbers, e.g. neoprene and latex, a tackifier such as terpene, and an organic solvent such as toluene or methyl ethyl ketone. This pressure sensitive adhesive is optically clear and transparent.

Preferably, polymeric strata l2 and 14 each range in thickness from 0.5 to 5 mils, elastomeric bonding stratum l4 ranges in thickness from 0.2 to 0.4 mils and pressure sensitive adhesive 18 ranges in thickness from 0.5 to 1.5 mils.

As shown in FIG. 1, following stripping of a silicone release stratum 20 from pressure sensitive adhesive stratum 18, a clear aqueous detergent 22 is applied to pressure sensitive stratum 18 in order to deactivate the pressure sensitive adhesive during application of the film shown at 10, to a window 24. During such superposition, the aqueous detergent coat serves as a lubricant to permit smoothing of the film and elimination of air pockets between the film and the window. Following application of the film to the window, the aqueous detergent diffuses through the edges of the interface between the film and the window and through the film itself. In order to facilitate such evaporation, preferably all of the strata of the film are selected for their vapor permeability, the pressure sensitive adhesive in particular being vapor permeable but insoluable with respect to water. In other words, the detergent is polar and the pressure sensitive adhesive is non-polar.

The alternative embodiment of FIG. 3 comprises, in laminated sequence, a moisture permeable polyester stratum 32, an elastomeric polyurethane bonding stratum 34, a moisture permeable polyester stratum 36, a pressure sensitive adhesive stratum 38, and a release stratum 40, all analogous to their counterparts in the embodiment of FIG. 1. In addition, this alternative embodiment comprises a vapor deposited aluminium coat 40 that is characterized by a visible light transmission of 5% to and a thickness of no more than 300 angstrom units. In a modification of the embodiment of FIG. 2, one or both of the polyester strata contains an ultraviolet absorbent, for example, a dispersed substituted benzophenone of the type sold by Antara Chemicals under the trademark Uvinul.

Alternative heavier duty security films embodying the present invention are shown in FIGS. 3 and 4. The security film of FIG. 3 comprises in laminated sequence a polyester stratum 46, a polyurethane stratum 48, a polyester stratum 50, a polyurethane stratum 52, a polyester stratum 54, a pressure sensitive adhesive stratum 56 and a release stratum 58. The security film of FIG. 4 comprises all of the strata of FIG. 3, designated 60, 64, 66, 68, 70, 72, and 74, and additionally an interposed vapor deposited aluminum coat 62. In FIGS. 4 and 5, the polyester strata, polyurethane strata, vapor deposited strata, pressure sensitive strata and release strata are analogous to their counterparts in FIGS. 1 and 3.

In operation of each of the security films of FIGS. 1, 3 and 4, the security film is applied at 76 to the inside or outside face of a window pane 78. When in position, the security film of FIGS. 1 or 4 is capable of preventing fragmentation of window 78 when it is cracked or otherwise damaged by an external impact or explosion at a position 80. When in position, the security film of FIG. 2 or 5, in addition to serving the function of that of FIG. 1 or 4, serves as a solar control window for reduction of transmission of infrared, visible and ultraviolet radiation.

The present invention accordingly comprises a security film for application to an ordinary window pane in order to render it splinter proof. Since certain changes may be made in the foregoing disclosure without departing from the scope of the invention herein involved, it is intended that all matter shown in the accompanying drawing or described in the foregoing specification be interpreted in an illustrative and not in a limiting sense.

What is claimed is:

1. An assemblage consisting of only one sheet of window glass and a security film, said security film comprising an assemblage of strata including at least one first polyester support stratum, at least one second polyester support stratum, at least one elastomeric bonding stratum, and only one pressure sensitive adhesive stratum, said one first polyester support stratum and said one second polyester stratum each being com.- posed of polyethylene terephthalate and ranging from 0.5 to 5 mils in thickness, said one elastomeric bonding stratum being composed of polyurethane and being interposed between said one first polyester support stra- .tum and said one second polyester support stratum and in direct contact with the inner faces of said one first polyester support stratum and said one second polyester support stratum, said polyurethane bonding stratum ranging in thickness from 0.2 to 0.4 mil, said pressure sensitive stratum being coated on one of the outer faces of said assemblage and being adhered to said only one face of only one sheet of window glass, said pressure sensitive stratum being composed of a composition including a rubber and a tackifier and ranging in thickness from 0.5 to 1.5 mil, all of the strata of said assemblage being optically clear and moisture permeable, and a light transmitting aluminum coat that is vapor deposited on one inner face of said one first polyester stratum and said one second polyester stratum, said vapor deposited aluminum coat being characterized by a visible light transmission ranging from 5 to and a thickness of no more than 300 angstrom units, at least one of said one firstpolyester stratum and said one second polyester stratum containing an ultraviolet absorbing dye.

2. A security film for application to only one face of only one sheet of window glass, said security film comprising an assemblage of strata including at least one first polyester support stratum, at least one second polyester support stratum, at least one elastomeric bonding stratum, and only one pressure sensitive adhesive stratum, said one first polyester support stratum and said one second polyester stratum each being composed of polyethylene terephthalate and ranging from 0.5 to 5 mils in thickness, said one elastomeric bonding stratum being composed of polyurethane and being interposed between said one first polyester support stratum and said one second polyester support stratum and in direct contact with the inner faces of said one first polyester support stratum and said one second polyester support stratum, said polyurethane bonding stratum ranging in thickness from 0.2 to 0.4 mil, said pressure sensitive stratum being coated on one of the outer faces of said assemblage for adhesion to said only one face of only one sheet of window glass, said pressure sensitive stratum being composed of a composition including a rubber and a tackifier and ranging in thickness from 0.5 to 1.5 mil, all of the strata of said assemblage being optically clear and moisture permeable.

3. The security film of claim 2 wherein a light transmitting aluminum coat is vapor deposited on one inner face of said one first polyester stratum and said one second polyester stratum. I i

4. The security film of claim 3 wherein said vapor deposited aluminum coat is characterized by a visible light transmission ranging from 5 .to 60% and a thickness of not more than 300 angstrom units.

5. The security film of clairnj2 wherein at least one of said one first polyester stratum and said one second polyester stratum contains an ultraviolet absorbing dye.

6. The security film of claim 3 wherein there are two polyester strata and one bonding stratum.

7. The security film of claim 2 where there are more than two polyester strata and more than one bonding Stratum. I

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2955961 *Jan 24, 1958Oct 11, 1960Du PontProcess of coating polyethylene terephthalate substrate with a polyurethane and resultant article
US3290203 *Feb 8, 1965Dec 6, 1966Minnesota Mining & MfgTransparent and reflecting articles
US3445423 *Jun 30, 1966May 20, 1969Du PontPolyurethane composition for glass coating and laminating stabilized by resorcinol monobenzoate
US3657057 *Jun 17, 1969Apr 18, 1972Ppg Industries IncLaminated windows
US3671370 *Jun 15, 1970Jun 20, 1972Ppg Industries IncIntegral transparent safety glass armor unit
US3681179 *Jul 20, 1970Aug 1, 1972Minnesota Mining & MfgMoisture-resistant solar control film
US3703426 *Nov 18, 1970Nov 21, 1972Goodyear Tire & RubberMethod of making polyester laminates
US3718535 *Mar 26, 1970Feb 27, 1973Sierracin CorpPreformed self-supporting, flexible and coherent electrically heatable laminar structure and method of manufacture thereof
US3775226 *Feb 8, 1971Nov 27, 1973Material Distributors CorpSolar control film
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4075386 *Jul 21, 1975Feb 21, 1978Material Distributors CorporationPolyesters, polyurethanes, pressure sensitive adhesives, detergents
US4257536 *Oct 15, 1979Mar 24, 1981American Can CompanyComprising layers of acrylic acid-ethylene copolymer, a thermoplastic resin, a metal foil, and a polyester
US4678690 *Jan 10, 1986Jul 7, 1987Rexham CorporationFor automobiles; strippable polyester film
US5304224 *Oct 1, 1992Apr 19, 1994Minnesota Mining And Manufacturing CompanyStiff mono- or copolyester; ductile; sebacic acid comonomer
US5355636 *Oct 1, 1992Oct 18, 1994Minnesota Mining And Manufacturing CompanyMultilayer polymeric film
US5427842 *May 27, 1994Jun 27, 1995Minnesota Mining And Manufacturing CompanySecurity control laminates for windows; tear resistant, stiff polyester oriented in at least one direction and a ductile polymeric material
US5604019 *Apr 20, 1995Feb 18, 1997Minnesota Mining And Manufacturing CompanyHaving more than five layers, wherein at least two are stiff polyester or copolyester, at least two other are ductile polymer oriented in at least one direction
US5773112 *Jan 2, 1997Jun 30, 1998Lintec CorporationMultilayer; transparent film, metallic layer and adhesive
US5956175 *Jul 31, 1998Sep 21, 1999Msc Specialty Films IncA laminated transparent glass comprising a thin, optically transparent metal layer, an optically transparent layer of near infrared energy absorbing material and a transparent layer of protective coatings; heat insulation
US6040061 *Oct 1, 1992Mar 21, 20003M Innovative Properties CompanyFor sign faces and backings for coated abrasive articles
US6444076Jun 16, 1998Sep 3, 2002Corning IncorporatedOptical devices and their method of assembly
US7883777 *Jul 31, 2006Feb 8, 2011Garware Polyester Ltd.multi layered polyester film( polyethylene terephthalate) laminates with sandwiched adhesive layer ( polyurethanes) containing dispersed mixed metal oxides ( e.g. CuO-Cr2O3-MnO2) as solar-energy-screen particles to exhibit desired transmittance in the visible region; and lanthanide hexaborides ( LaB6)
US8658273 *Sep 10, 2001Feb 25, 2014Arjowiggins SecuritySecurity sheet comprising a transparent or translucent layer
US8765263 *Apr 26, 2006Jul 1, 20143M Innovative Properties CompanyMultilayer polyurethane protective films
DE19526912C3 *Jul 24, 1995Oct 11, 2001Haverkamp Sst SicherheitstechnVerfahren zur Verbesserung der Einbruchsicherheit von Glasfenstern und -türen mit Hilfe einer transparenten Schichtfolie
DE202008006624U1 *May 15, 2008Sep 24, 2009K.M.B. Klebetechnik GmbhKantenschutzband zum Schutz von Rändern von Mehrfach-Glasscheiben
EP0022636A1 *Jul 1, 1980Jan 21, 1981Minnesota Mining And Manufacturing CompanyComposite sheets
WO2001068360A1 *Mar 15, 2001Sep 20, 2001Cpfilms IncFlame retardant optical films
WO2005000577A2 *Mar 4, 2004Jan 6, 2005Andrea CruzPet as edge seal for multilaminated glazings
WO2005070666A1 *Aug 28, 2004Aug 4, 2005K M B Klebetechnik GmbhFire-resistant glass provided with an edge protection
Classifications
U.S. Classification428/216, 428/40.9, 428/336, 428/423.7, 428/425.6, 428/354, 428/458, 428/40.4, 428/41.3
International ClassificationC09J7/02, B44F1/06
Cooperative ClassificationB32B2367/00, C09J2400/163, C09J2475/006, C09J7/0296, C09J2201/606, C09J2201/162, B32B17/10018, C09J2467/006, B44F1/06
European ClassificationB44F1/06, C09J7/02K9F, B32B17/10C2
Legal Events
DateCodeEventDescription
Sep 30, 1982AS02Assignment of assignor's interest
Owner name: VAN LEER PLASTICS B.V., 64 INDUSTRIAL PARKWAY, WOB
Owner name: VAN LEER U.S.A.
Effective date: 19820929
Sep 30, 1982ASAssignment
Owner name: VAN LEER PLASTICS B.V., 64 INDUSTRIAL PARKWAY, WOB
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VAN LEER U.S.A.;REEL/FRAME:004063/0228
Effective date: 19820929
Owner name: VAN LEER PLASTICS, VALVAC FILMS DIVISION, KEYES FI
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VAN LEER PLASTICS, B.V.,;REEL/FRAME:004063/0226