Document B5x0qEEJq3zOvBLzdZjwgDJBk

United States Patent Office 3,300,927 Patented Jan.'31, 1967 1 Polyvinylfluoride, having the structural formula: 3,300.927 LAMINATED SHEET MATERIAL Phillip Stephen Dcfloli, Marlins* ille, NJ., assignor to Toe Ruberoid Company, a corporation of New Jersey Filed Jan. 21,1963,'Ser.No. 252,890 14 Claims. (Cl. 52--309) U U--TCi --C'H-- and in the form of a plastic film of uniform thickness, is the polyvinylfluoride used in the laminant of this inven* This invention relates to a laminated sheet material * lion. Ii is extremely inert and unrc.'iCtivc, and withstands for covering and protecting a variery of surfaces, and extremes of temperature and humidity. Moicover, it is more particularly relates to a polyvinylfluoride laminant 10 not significantly degraded by ultraviolet radiation. Being with excellent weathering characteristics for use in the flexible and readily available in pigmented form, il is roofing and siding trades. suitable for use with roofs having unusual contour or form, It is an object of this invention to provide a material for example, parabolic roofs which cannot readily be for covering and protecting the exposed surfaces of a covered with conventional asphaltic maicriah. It is also variety of structures, ll is a further object to provide 15 suitable for roofs where a particular color is desired, with a flexible roofing or siding material which can be used out the disadvantages of having to paint the same. It is on surfaces having irregular or unusual contours. The not practical to use polyvinylfluoride film alone, however. material of this invention, polyvinylfluoride plastic film The thickness of the film, usually I to 4 mils, presents laminated to a non-flammable, elastomeric-impregnated handling and working problems. U'-cd alone, it cannot be asbestos felt backing, has excellent weathering charac 20 handled with available roofing tools according to estab teristics and will not erode, crack or craze upon long ex lished techniques. In addition, adhesives available for posure to visible or ultraviolet radiation or climatic ex on site application to roofs and the like, are inadequate tremes of temperature or humidity. It has excellent di for producing a satisfactory bond between Ihe inert film mensional stability and substantially permanently remains and the surface to which it is applied. strong and flexible under all climatic conditions. In addi 25 Referring to FIG. 1 the laminant 10 of this invention tion, the pigmented covering material of this invention comprises polyvinylfluoride plastic film 11 secured 10 ao provides a decorative and colorful material having durable asbestos backing 12 by means of a thermosetting elasto color and one which is substantially stain-resistant. meric adhesive 13. The bond between film and fell is It is another object of this invention to provide a rigid permanent. The felt backing 12, which is impregnated structural material having an ouier covering of poly 30 with an elastomer, preferably neoprene, is also flexible. vinylfluoride plastic film, for use in the building trades, The combination of film and fett hacking obviates the which incorporates the advantages of the laminated sheet material described in the preceding paragraph. It is a further object of this invention lo provide a handling difficulties referred to above and enables the laminant 10 to he applied to surfaces with the usual asphaltic type adhesives. Moreover, the laminant has roof having a roof deck covered with a laminanl ma 35 increased resistance to mechanical damage, punctures and terial which is less than one-sixth the weight of a con lears, to which the unsupported pol^in^ifluoride film ventional built-up roof covering, and which possesses would otherwise be particularly susceptible. the desirable characteristics of being non-flammable and Bitumen-impregnnled felts arc unsatisfactory as a back of not degrading with age or upon exposure to climatic ing material for polyvinylfluoride. They can cause some extremes of weather. In its pigmented form, the laminant 4 staining of the plastic film, but more importantly, they are maicria) retains its color and does not require periodic or become inflexible, usually embrittle on aging and are painting. Moreover, the mechanical strength and flexi bility of ibe laminant accomodates itself lo the expansion inflammable. Elastomeric-impregnated felt, on the other hand, remains substantially permanently flexible on ex or contraction of the underlying Toof deck. posure to climatic extremes of temperature and humidity. These and other objects implicit in this specification are 4 Proper selection of the elastomer will yield a non-flam- accomplished, in general, by the advantageous use of a mable laminant. In this regard, polychloroprene (Du laminant comprising a polyvinylfluoride plastic film ad Pont neoprene) is the preferred elastomeric binder for hesively secured lo an asbestos felt backing which has been impregnated with an elastomeric binder, such as ihe laminant of this invention. Since polyvinylfluoride plastic film is also non-flammable, the resultant laminant polychloroprene, neoprene and polyvinylacetale, poly- (with the nonflammable polychloroprene-impregnated chloroprene and acrylonitrile or polychloroprene and backing) will possess this desirable characteristic. Other other elastomeric additives which yield a non-flammable non-flammable elastomers, including mixtures of poly product. The polyvinylfluoride film is pigmented, yield, ine a decorative, colored laminant material. The pigment, ed film is substantially opaque to incident ultraviolet and chloroprene and polyvinylacetale or polychloroprene and other non-flammable additives may also be used to impregnate the asbestos felt. Non-flammable mixtures of visible radiation and protects the elastomer-impregnated backing and under-sinicture from possible photochemical degradation. The laminant may be used alone as a polychloroprene and acrylonitrile or other elastomeric binders are also suiiable.__In any case, Ihejmpregnated product should mm->hly fhy which te'rm'is meant"* roofing or siding material or it may be combined with either nnmfnmhimiKU nr sMr-exiin?mshing) providing suitable rigid slabs of insulating material for use generally 00 material having an advantage over inflammable prior art as a covering materia] for buildings. products such a* binimen-saturmeo tens. " In the accompanying drawings. FIGURE I is a cross- Asbestos felt is the preferred material for u*< in the sectional view of Ihe laminated material of this inven tion; FIGURE 2 is a plan view of a section of a roofing material embodiment of this invention; FIGURE 3 is a plan view of a roof with portions of the roofing material broken away to show the disposition laminant product of this invention. Organic fells or papers have been found to lack dimensional stability and flame resistance. They also embrittle and degrade with age. Glass fibers are difficult to bond lo polyvinylfluoride and lack desirable elongation characteristics. Aluminum foil does not provide optimum handling characteristics of the laminated material of this invention; and 70 and is susceptible to mechanical damage. EhMomeric- FIGURE 4 is a cross-sectional view of a rigid structural impregnaied asbestos felt is preferred over ordinary- un" material of this invention. saturated asbestos paper, which is not suitable as a back- MICH0915 ,3 300,027 1ng for use in this invention, since unimprggnaled asbes celerate the rate at which the photochemical decompo tos docs not have the tensile strength, the tear resistance sition of the polychloroprene takes place, leading to early and the general toughness of the iinptegnaled form. In failure of the adhesive binding of the film to the felt. In addition, the unimpregnaied felt is adversely affected by the presence of asphalt oils, the short wave lengths of moisture, having poor vet strength when vetted. The visible light are particular destructive of the pclvchforo- porosity of unsaturated asbestos fell is such that the as bestos fibers would absorb excessive quantities of elas tomeric adhesive during the step of laminating polyvinyl- prene. Accordingly, the film ?K'uld be sufficiently opaque to ultraviolet and visible light, and particularly to visible light of the shorter wave lengths, to substantially com fluoride film to the backing. pletely obscure the passage of such light to the underlying Thus, the preferred backing of the invention herein 10 polychloroprene-impregnaled felt. is polychloroprene-impregnaled asbestos fell. It is non A 2-mil white film, pigmented with titanium dioxide flammable, retains its flexibility for long periods of time (15% by weight) will transmit about 10% of near-ultra and is resistant to heat aging. It is also suitable for use violet incident radiation. If the concentration of the pig with conventional mopping asphalts or cold-applied ce ment is raised to 25% by weight, 8.4% is transmitted. ments. Polychloroprene-impregnated asbestos fell, more 15 The addition of Vi% carbon black to the latier film pig over, is not subject to microbiological degradation and is mentation reduces light transnvssion to 4.5% of the inci therefore superior to organic-fiber backings. The impreg dent radiations. With the addilion of sufficient carbon nated asbestos felt contains from about 13% to about black to make the film gray, it will transmit less than 25% by weight of polychloroprene. 0.2% of incident radiation. (These figures alt apply to Other elastomeric compounds may be used to impreg 20 transmission through the film of radiation of 5461 A.) nate the asbestos. As indicated above, however, it is Accordingly, the presence of at least a small amount of preferred that the final product be non-flammable. By carbon black in the film pigments is desirable to prevent way of an example, a blend of one part by weight of degradation of the adhesive bond of the film to a poly- polyvinylacetate with three parts by weight of polychloro cbloroprene-impregnated felt in consequence of exposure prene is also suitable. As in the case of polychloroprene 25 to sunlight. alone, this blend is added to the asbestos felt in an Another means that may be adopted to protect the amount sufficient to provide a backing having from about bond of the film to a polychloroprene-impregnsted felt is 15% to about 25% by weight of the blend. The quan to pigment the adhesive which binds the film to the felt, tity of polyvinylacetale in the blend may be increased to thereby to reduce its light-transmission characteristics. about 35%. Other suitable elastomeric mixtures in 30 Transmission of light through the adhesive may be sub clude: a copolymer consisting of 82% by weight of poly- stantially nullified by the incorporation therein of carbon cbloroprene and 18% by weight of acrylonitrile; or a black. Thus, a 2-mil film, containing 25% by weight of blend of one part by weight of polychloroprene to one TiOj and with 1% by weight of carbon black in the ad . part by weight of acrylonitrile. Again, the quantity of hesive will transmit only about 3.3% of incident radiation . these mixtures added to the asbestos should preferably 35 of 5461 A., which is in the range of destructive wave be sufficient to produce a final product containing about lengths. With 8% to 10% carbon in the adhesive, trans 15% to about 25% by weight of elastomer. mission of light through it is substantially precluded. Polyvinjlflnoride plastic film is clear and transparent The effect of light transmission on bond strength is to ultraviolet and visible radiation. As an increasing illustrated in the following table. In the table, results are amount of pigment is added to the film, the latter be 40 given of tests on bind strength of film to felt after accel comes increasingly opaque to both ultraviolet radiation erated radiation exposure of laminants of various films and to light in the visible wave length range. Pigment bonded to polychloroprene-impregnaled asbestos felt with may be added to the polyvioylfiuoride in a quantity up to 0.3 mil of clear adhesive (except for the laminates speci about 25% by weight, depending upon the color effect and opacity desired. It is not recommended that an 45 fied on the last line, in which case the adhesive was pig mented) the laminates in all cases were adhered to a sup amount of pigment greater than 25% by weight be added, porting panel by an asphalt. TABLE 1.--EFFECTS OF RADIATION ON BOND STRENOTH (All bonds measured at 90* and given In grarasflneh) Laminate Percent transmission at 5,461 A. Initial Bood Accelerated Radiation Exposure Hours 150 350 500 i.oao 2-mil whit* <197, TiOi)....................................... white TOi>............................................ 2-miI while (with 4% carbon In adhesive)............ 10 1* 4.7 a is as 600 1.100 83) 8*0 980 490 l, 080 180 8BO 1. 440 140 480 440 1.550 80 ?40 350 1,150 1.550 however, as this will adversely affect the durability of The presence of carbon in the adhesive maintains bond the film. strength at a high level for long periods of lime. The Opacity of the covering film is considerably important. increase in bond strength upon aging shown io one in- It has been found that if there is any substantial pene 55 stance in Table 1 is due to post-curing. Translated into tration of visible or ultraviolet light through the film, terms of service life of a roof deck covered with the lami- the bond of the film to the pohchloroprcne-impregnated nant material of this invention, a laminant having a 2 mil felt deteriorates slowly, and ultimately will fail. Careful while film (25% TiOj) has a projected exterior life of at studies have shown that visible radiation in the near-ultra least 20 years. A laminant employing a 2 mil white film violet portion of the spectrum causes a slow degradation TO with carbon black in the adhesive has a projected exterior of the polychloroprene, with the result that the adhesive life in excess of 30 years, which is considerably greater bonj to the felt fails over a period of time. When an than that of the usual roofing materials heretofore avail asphaltic cement is used to adhere (he felt to a roof deck able. or wall surface, asphalt oils which tend to migrate through It should be noted that the covering film may be varied the felt to the interface of felt and adhesive greatly ac- 75 in thicknesses. The minimum acceptable thickness is MICH09158 r\ i i l i i i o I I ,3 300,927 iboul 1 roil. Four mils thickness is approximately ;he it may be laminated, in turn, to a suitable, rigid insulating upper limit, taking factors of economy and film manu substance for use as a covering material wbeic rigidity facturing specifications into consideration. Should the is a desired characteristic, as in sidings for buildings. laminant be applied 1o area subject to heavy traffic, a 4 In the production of flexible roofing material 14 the mil layer of polyvinylfluoride film would be preferable. 6 film and felt are preferably trimmed and cut in predeter Curing-type elastomeric adhesives are suitable for mined widths. The final product thus obtained is shown laminating polyvinylfluoride securely to the saturated as in FIG. 2. Film II is applied to the felt 12 in a bestos fell backing. An acrylonitrile adhesive with phe manner such that, in the final pie'duci, the lorgiiudi- nolic tackifiers and an isocyanate curing agent is perhaps nal edge of the film 15 defines a selvedge IS of a uniform most suitable and may be regarded as yielding optimum |n width. Selvedge IS permits overlapping of successive results. In general, any elastomeric adhesive may be used lengths of roofing material as described bclw. li also al which retains its flexibility and will nol undergo resinifi- lows for the bonding of asbestos felt on asbestos fell, and calion upon long exposure to light or climatic extremes. not felt on polyvinylfluoride. Hence, a wide variety of Polysulfide adhesives, although expensive and difficult to adhesives, including bitumen cements may be used, handle, are also suitable. ix Roofing material of a standard width may also be pro Elastomeric saturated asbestos 12 is manufactured ac duced without providing a film-free selvedge IS, should cording to established techniques with the components this be desired. and in the quantities stated above. The following exam Referring now to FIG. 3, application of the roofing ples are included for purposes of illustration, it being un material shown in FIG. 2 will be described. FIG. 3 de- derstood that other ingredients are also useful to provide 20 picts a standard wood roof deck 17 which is mopped with Ihe laminant material of this invention. roofing asphalt 18 (12 lbs./100 sq. fL). It should be understood that the roofing material of this invention may Example I be applied to a variety of roof decks, including decks of Polychloroprene was slurried in a paper maker's beater wood, concrete and insulation. It may also be applied at about 60-70' F., along with a dispersing agent, an 25 by a variety of means, including either hot asphalt or cold anti-oxidant, zinc oxide and alum, the latter having been cement applications. Conventional coaled, sanded and added to precipitate ihe polychloroprene. The poly- asphalt-saturated base sheet 19-22 is applied to deck 17 chloroprene was added in the form of a 209c solids latex which has been asphalt mopped. The base sheet is ap (Du Pont Neoprene Latex #735.) Additions of alum plied in successive lengths 19, 20, 21 and 22, with one were made at the beater head box to control foant and in length (21 for example) overlapping the preceding sub to maintain an acid pH. Polychloroprene latex was added jacent length (20) by about 4 inches. The base sheet in sufficient quantity to provide a finished product con is nailed according to established techniques. taining 20% polychloroprene solids. Lamination of the Roofing material 14, having a selvedge 16, as shown in polyvinylfluoride plastic film 11 10 the polychloroprene FIG. 2, is applied in a manner similar 10 base sheet 19; saturated felt backing 12 vvas accomplished with a nitrile- 35 viz, by mopping and applying overlapping lengths of phenolic adhesive (Du Pont Modified Synthetic Rubber roofing material 14. Thus, the area to be occupied by a Adhesive type 4684, containing 10% DuPont Curing length 23 of roofing material 14 is mopped with roofing Agent RC 805), to which 4% by weight of aqueous car asphalt 24 (20 lbs./100 sq. ft.) and a length 23 is laid. bon black had been added. The laminating adhesive w-as An area adjacent the length 23 is also mopped with adjusted 10 a viscosity of 16 to 18 (Zahn cup No. 3) with 40 asphalt. The selvedge 16 of length 23 is also mopped methyl ethyl ketone, and the coating rot! employed for the to within one inch of the longitudinal edge 15 of the poly- lamination operation was adjusted to apply Ihe equivalent vinylfluoride film 11. A next length 25 of roofing male- ol 0.5 mil of dry adhesive solids. The adhesive was ap- rial 14 is then laid with an edge 26 thereof completely plied directly to a polyvinylfluoride film of 2 mils thick- covering the selvedge 16 of the first length 23 and super ness, ihe film then being passed through a drying tower 45 adjacent the same. Successive lengths are applied in the to remove a portion of the methyl ethyl ketone. The same fashion, care being taken that the selvedge 16 of film 11 was laminated to the smooth side of the poly- each length is mopped only to a maximum of one inch chloroprene-impregnated felt backing 12 by a conven away from the longitudinal edge 15. This will insure tional nip roll laminating operation. The nip roll was that asphalt 24 does not ooze out onto the exposed sur- maintained at 200* F. and 120 p.s.i. Machine speed was 50 face of the material 14. The end result of overlapping about 150 feel per minute. (At speeds below 150 feet successive lengths of roofing material 14 is shown in per minute, the temperature should be reduced 10 150* FIGURE 3 as lengths 27 and 28. The operation may be F.) The laminated product 10 was then subjected to completed by sealing the seams between overlapping additional heat and to a high velocity air stream to re lengths (i.e., end laps 29 and side laps 30) with a pres- move the remainder of the laminating solvent from the 55 sure-sensitive tape, preferably a similarly pigmented poly- finished prodJ uct vinylfluoride plastic film. The seams may also be closed Example 2 wilh a silicone caulking compound or suitable polysulfide A slurry of asbestos was made in a beater under the rubber cements. conditions and with the ingredients described in Example A roof to which a preferred pigmented while film 1, except that in place of polychloroprene. a mixture of (10 roofing material 14 has been applied has a reflectivity up polychloroprene and polyvinylacelale in Ihe weight ratio of 3:1 was charged to the beater. The amount intro wards of 75% and is completely waterproof and vaporproof. duced was sufficient to produce a product having 18% Variations of Ihe above methods may be employed in by weigh! of the elastomeric mixture. Lamination was order to adopt the product of this invention to various carried out in the manner described in Example 1. A G5 environments or to use the product with other mopping 2% by weight addition of carbon black was made 10 ihe materials, such as a cold method cement. For example, adhesive prior 10 lamination and Ihe coating roll was ad a pre-cast concrete roof deck may be coaled wilh the justed to apply the equivalent of 0.35 mi! dry adhesive solids. The resulting product was non-flammable, flex ible and otherwise suiled 10 the variety of uses to which Ihe laminant of this invention may be puL 70 roofing material 14, by simply priming wilh a suitable concrete primer and (hen applying the roofing malerial 14 directly thereto with conventional roofing bitumens. Should it be desirable, a roofing material without the selvedge may also be employed. In this case, lengths 0/ The laminant material produced in either of-the ways material 14 are not overlapped and Ihe longitudinal edges described above, or in other ways may be further proc- of Ihe successive lengths of material merely abut each essed for use as a flexible roofing or siding material; or 75 other. The seams are then scaled with polyvinylfluoride MICH09159 3,800,027 78 plastic tape, silicone caulking compound or polysulfide polyvinylfluoride plastic film having a uniform thickness rubber cement. Referring to FIG. 4, a product for use in covering and of at least about one mil, and an asbestos fell backing impregnated with from abom 15% to about 25% by protecting structures may be made by securing the bmi- weight of pcilvrhioroprene. said film Secured to said Danl 10 of this invention to a rigid slab of insulating ma 5 asbestos fell barkingby means of a thermosetting elas terial 31 with a suitable adhesive 32, such as asphalt or tomeric adhesive. the like. The laminant comprises a layer of poly-vinyl- 9. A roof in accordance with claim 8,wherein the width fluoride plastic film 11 adhesively secured (by means of of said polyviny lfluoride plastic film is less than the width adhesive 13) to elastomer-impregnated asbestos 12. The of said backing such that a film-free edge of uniform felt backing 12 is secured to the insulating material, pro 20 width is defined by the longitudinal edge of said film, ducing a structural material wherein the polyvinylfluoride said roofing material being disposed on said reef deck film 11 is the exposed surface. The rigid slab 31 may be in overlapping fashion such that a supc-adjaccnt length manufactured from a variety of conventional insulating of said roofing material covers the said film-fre: edge of materials which have been found to be useful In the build a subjacent length of said roofing materia!, and wherein ing trades, such as wood, including shredded wood, wood IS the seams between said length of roofing materials are shavings, excelsior, or paper, newspaper, vermiculile, scaled with pressure-sensitive adhesive tape, said tape gravel, stones, cement or cement with light aggregates. comprising polyvinylfluoride plastic film. I claim : 10. A roof comprising a roof deck and successive 1. A material for covering and protecting the exposed lengths oT flexible roofing material having a uniform surfaces ftr structures comprising a substantially opaque 20 width, said material covering said roof deck, said roofing polyvinylfluoride plastic film of low light transmissability material being weather and fire resistant and uniformly having a uniform thickness of at least about one mil and secured to said roof deck with an asphaltic adhesive, said an asbestos fglt hacking impregnated with polvchloro- roofing material comprising a pigmented substantially nrene. said polyvinylfluoride plastic film having uniform opaque polyvinylfluoride plastic film having a uniform ly incorporated therein up to 25% by weight of an opacify 25 thickness of at least about one mil, and an asbestos felt ing pigment, said film adhesively secured to said backing backing impregnated with from ahout 15^ to nbnnt '*5% by means of an ebstomeric adhesive of low light trans- bv weight of nnKrhtnrnnrene s-iiri film secured to said missability containing up to 10% by weight of opacifying asbestos fell backing by means of a thermosetiing elas pigment. tomeric adhesive containing up to 10% by weight of car- 2. A weather and fire resistant roofing material com 30 bon black. prising a polyvinylfluoride plastic film adhesively lami 11. A roof comprising a roof deck and successive nated to an asbestos felt backing hv means of a thermo- lengths of flexible roofing material having a uniform selting elastomeric adhesive, asN-stnr -felt w-i-Vinr. im width, said material covering said roof deck, said roofing pregnated with nnn.ftiTi.nfliae elastnmerir hinder and matcriat being weather and fire resistant and uniformly said plastic film being substantially opaque to protect the 35 secured to said roof deck with an asphaltic adhesive, said adhesive bond thereof to the backing from photochemical roofing material comprising a pigmented substantially degradation. opaque polyvinylfluoride plastic film having a uniform 3. A flexible roofing material comprising an asbestos thickness of at least one mil, andan asbestos felt backing felt backing impregnated with from about 15% to about impregnated with from about iT* > m swim nsCk hy 25% ot ixmcnlo-oarcnc and a polyvinylfluoride plastic 40 weight of polvchlcroprene^ said film secured to said film having a uniform thickness of at least about one mil asbestos felt backing by means of a ihermo-ctling, elas secured to said asbestos felt backing by means of a thermo tomeric adhesive, said roofing material disposed on said setting ebstomeric adhesive, said film having uniformly roof deck in a manner such that a longitudinal edge of incorporated therein up to 25% by weight of pigments one of said lengths of roofing material abuts the longi- comprising carbon black and being substantially opaque. tudinal edge of another of said lengths adjacent to it, the 4. The roofing material of claim 3 wherein the elas seam defined by said abutting longitudinal edges being tomeric adhesive contains up to 10% by weight of carbon sealed by pressure-sensitive adhesive tape, said tape com black. prising polyvinylfluoride plastic film. 5. The roofing material of claim 3 wherein the asbestos 12. A structure for covering surfaces comprising a rigid ft!Lfe9sJcingisi[npregnated with from about 15% toabout 50 slab of an insulating material selected from the group 25% bv weigh! of nolvchloronrene. " consisting of wood, shredded wood, wood shavings, ex 6". A weather and fire resistant flexible roofing mate celsior, paper, vermiculite, gravel, cement and cement rial comprising an asbestos felt backing impregnated with with light aggregates incorporated therein, said slab from about 15% to about 25% bv weight of a mixture covered with a weather and fire resistant sheet material 55 comprising an asbestos felt backing adhesively secured to one part.bv_wxighl of. acrylonitrile and a pigmented to said slab, said asbestos felt backing impregnated with substantially opaque, polyvinylfluoride plastic film hav from about 15% to about 25% py werent ol polvchloro- ing a uniform thickness of at least about One mil secured prene, and a pigmented suoslantiallv opaque polyvinyl- to said asbestos fell backing by means of a thermosetting fluoride plastic film having a uniform thickness of at least elastomeric adhesive. 50 one mil, said film secured to said backing with a thermo 7. A weather and fire resistant flexible roofing mate setting elastomeric adhesive containing up to 10% by rial comprising an asbestos felt backing impregnated with weight of carbon black. from about 15% to about 25% by weight of a mixture <onTa7Bihg polychloroprcnt and polyvinylacetate in the weight ratio of about 3 to 1. and a pigmented substan tially opaque polyvinylfluoride plastic film having a uni form .thickness of at least about one mil secured to said asbestos felt backing by means of a thermosetting elas tomeric adhesive. 8. A rogX.comprising a roof deck and flexible roofing 13. A weather and fire resistant material for covering and protecting the exposed surfaces of structures com-. 15 prising a laminate ot polyvinylfluoride plastic film secured by an elastomeric adhesive to an asbestos felt backing imprcc.mted with a non-flammable elastomeric binder, said plastic film being substantially opaque to protect the ad hesive bond thereof to the backing from photochemical f0 degradation. 14. A structure for covering surfaces comprising a rigid materia! covering said roof deck, said roofing material slab of*insulating malcrial covered with a wcathcr~and being weather and fire resistant and uniformly secured fire resistant sheet material comprising an nvhrsmv felt to said roof deck with an asphaltic adhesive, said roofing backing impregnated with a non-flammable elastomeric material comprising a pigmented substantially opaque 1 15 binder and a pigmented polyvtnyllluoride plastic film sc- , ' ' I MICH09160 ,3 300,027 9 10 cured to said bad ins by a thermosetting elastomeric ad FOREIGN PATENTS hesive, said plastic film being substantially opaque to pro tect the adhesive bond thereof to the' bacVing from photo chemical degradation. 579,626 7/1959 Canada. OTHER REFERENCES References Cited by (be Examiner 6 American Roofer and Building Improvement Contrac tor, TH2431.A1.A5., October 1961, page 14. UNITED STATES PATENTS Modern Plastics, TP9S6.AI.M6, October 1959, pages 1,044,788 2,164,790 2.376.854 6/1936 Harshbeiger et al..............52--419 89-91, 200. 7/1939 Smith.......................... 52--409 X Modern Plastics, TP9S6.A1M6, September 1961, page 5/1945 Saunders................... 161--205 X 10 45. 2,874,652 3.056.214 2/1959 Wilson............................... 52--419 10/1962 Almy et al............... 161--205 X FRANK L. ABBOTT, Primary Examiner, 3.133.854 5/1964 Simms ............................. 161--189 A. C. PERHAM, Assistant Examiner. 3,228,823 1/1966 Usala et al.................... 161--186 MICH09161