Patent Publication Number: US-2021171804-A1

Title: Low combustibility adhesive composition with layered construction

Description:
FIELD OF INVENTION 
     The present disclosure relates to a film article having a layered adhesive construction, where at least one adhesive layer includes a fire-retardant additive. 
     BACKGROUND 
     Many countries have low combustibility or low flammability requirements for film products applied to surfaces such as the interior or exterior of a building, such as a hotel, school, hospital or restaurant; or to a vehicle, such as a train, tractor trailer or personal vehicle or aircraft. Such requirements can help to increase safety for individuals in that area by decreasing likelihood of an explosion or fire spreading in the event of a spark or ignition. 
     At the same time, many customers also have adhesive tack and peel requirements when purchasing film to ensure that the film will weather well, remain adhered to the desired surface for the desired length of time, and can be removed when desired. 
     It can be challenging to create a product that meets both low combustibility and low flammability requirements and adhesion requirements simultaneously. 
     SUMMARY 
     The present invention provides a way to decrease combustibility or flammability of a film construction while maintaining good adhesive tack and peel. The present disclosure provides a solution for constructing a film that is sufficiently thin so that it meets fire growth rate (FIGRA) requirements, and total heat release (THR) requirements instituted by different jurisdictions or customers. In some jurisdictions, FIGRA and THR can be very difficult to meet while maintaining acceptable adhesion properties. Even though the film is thin, the layered adhesive construction of the present disclosure allows for the film to also meet adhesion requirements. 
     In one instance, the present disclosure includes a low-combustibility film construction. The film construction includes a film layer; a first adhesive layer with a fire-retardant additive of at least 41% by weight; and a second adhesive layer. The total thickness of the adhesive layers is in the range of 18.5 to 44.5 microns; and wherein the total thickness of the fire retardant adhesive layer is 32% to 85% of the total adhesive thickness. 
     In another instance, the present disclosure includes a low-combustibility film construction. The film construction includes a film layer; a first adhesive layer with a fire-retardant additive of at least 41% by weight; and a second adhesive layer. The total thickness of the fire retardant adhesive layer is 32% to 85% of the total adhesive thickness, and the film has a peel adhesion greater than or equal to 20 N under the 180 Peel Adhesion Test. 
     In another instance, the present disclosure includes a low-combustibility film construction. The film construction includes a film layer; a first adhesive layer with a fire-retardant additive of at least 41% by weight; and a second adhesive layer. The total thickness of the adhesive layers is in the range of 18.5 to 44.5 microns; and the film has a total heat release less than or equal to 8 MJ/m 2  under the flammability test and wherein the film construction has a Fire Growth Rate (FIGRA) of less than or equal to 8 KW/(m 2 *s). 
     In some instances, the film layer comprises at least one of: polyvinylchloride (PVC), polyester, polyethylene terephthalate, low density polyethylene, ethylene methacrylate copolymer, polypropylene, polyimide, polyurethane, polyinylidene fluoride, polymethyl methacrylate, acrylic, silicone, and polyolefin films. 
     In some instances, the film is a graphic film and an ink layer is deposited on the film layer. 
     In some instances, the film layer has a thickness of 200 microns or less. 
     In some instances, the film layer has a thickness in the range of 125-145 microns. 
     In some instances, the first adhesive layer is adjacent to the film layer. 
     In some instances, the film construction further comprises a third adhesive layer, wherein the third adhesive layer does not have a fire retardant additive, and wherein the third adhesive layer is disposed between the film layer and the first adhesive layer. 
     In some instances, the first adhesive layer comprises at least one of: acrylic adhesive, natural rubber, synthetic rubber, silicone, polyester, polyolefin, rosin, and epoxy adhesive resins, not limited to these general pressure sensitive adhesive resins. 
     In some instances, the second adhesive layer comprises acrylic adhesive. 
     In some instances, the film construction has a peel adhesion greater than or equal to 20 N under the 180 Peel Adhesion Test. 
     In some instances, the film construction has a total heat release less than or equal to 8 MJ/m 2  under the flammability test. 
     In some instances, the film construction has a Fire Growth Rate (FIGRA) of less than or equal to 8 KW/(m 2 *s). 
     In some instances, the fire retardant additive comprises at least one of: tris(tribromoneopentyl) phosphate (TTBP), antimony trioxide (ATO) flame retardant, ammonium polyphosphate (APP) flame retardant, alumina trihydrate (ATH) flame retardant, and antimony trioxide (SbO 2 ) flame retardant. 
     In some instances, the film construction further comprises a third adhesive layer, wherein the third adhesive layer does not have a fire retardant additive, and wherein the third adhesive layer is disposed between the film layer and the first adhesive layer. 
     In some instances, the first adhesive layer comprises at least one of: acrylic adhesive, natural rubber, synthetic rubber, silicone, polyester, polyolefin, rosin, and epoxy adhesive resins, not limited to these general pressure sensitive adhesive resins. 
     In some instances the fire retardant additive comprises at least one of: tris(tribromoneopentyl) phosphate (TTBP), antimony trioxide (ATO) flame retardant, ammonium polyphosphate (APP) flame retardant, alumina trihydrate (ATH) flame retardant, and antimony trioxide (SbO 2 ) flame retardant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood when considered with the following detailed description in connection with the accompanying drawings, in which: 
         FIG. 1  shows a film construction with two layers of adhesive. 
         FIG. 2  shows a film construction with three layers of adhesive. 
         FIG. 3  shows a film construction with a liner. 
     
    
    
     The embodiments shown and described herein may be utilized and structural changes may be made without departing from the scope of the invention. The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. 
     DETAILED DESCRIPTION 
       FIG. 1  shows a film construction  100  with two layers of adhesive  104 ,  106  applied to substrate  108 . Film  102  may be any suitable film, such as a film comprising polyvinylchloride (PVC), polyester, polyethylene terephthalate, low density polyethylene, ethylene methacrylate copolymer, polypropylene, polyimide, polyurethane, polyinylidene fluoride, polymethyl methacrylate, acrylic, silicone, and polyolefin films or any combination thereof. Film  102  may be calendared or case and may be made of any of the materials discussed herein, including in the examples. The thickness of film  102  may vary. For example, it may range from, for example, about 20 um to 300 um. Film thickness  102  may be about 20 um, 30 um, 40 um, 50 um, 60 um, 70 um, 80 um, 90 um, 100 um, 125 um, 150 um, 175 um, 200 um, 225 um, 250 um 275 um and 300 um, or any range between any of the preceding values. The maximum thickness of a particular film will depend on a variety of factors, including the relative combustibility of the polymer in the film. 
     Film  102  may be a graphic film. It may have colors, patterns, textures or images printed on it with a variety of inks and methods. In some instances, film  102  may be transparent or translucent. Film  102  may have a range of opacities and a variety of colors. In some instances, film  102  may be a functional film which provides functions including abrasion resistance, easy cleaning or surface protection from damage. 
     Adhesive layer  104  is disposed between and adjacent to each of film layer  102  and adhesive layer  106 . In some instances, a primer may be added between film layer  102  and adhesive layer  104  to increase adhesion between the two layers. Film layer  102  and adhesive layer  104  are considered adjacent when a primer layer is used to bond film layer  102  and adhesive layer  104 . Adhesive layer  104  includes an adhesive and a fire-retardant additive  105 . Some examples of adhesives that may be used in adhesive layer are: acrylic adhesive, natural rubber, synthetic rubber, silicone, polyester, polyolefin, rosin, and epoxy adhesive resins, not limited to these general pressure sensitive adhesive resins and combinations thereof. Adhesive layer  104  may be the same adhesive as adhesive layer  102 , or may be a different adhesive. Factors that contribute to a choice adhesive type include a desire to for an adhesive to adhere well to a film layer, or the adhesive layers to adhere well to each other. Some examples of suitable fire-retardants include: tris(tribromoneopentyl) phosphate (TTBP), antimony trioxide (ATO) flame retardant, ammonium polyphosphate (APP) flame retardant, alumina trihydrate (ATH) flame retardant, and antimony trioxide (SbO 2 ) flame retardant. Fire retardant additive  105  may be added in an amount of, for example 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80% by weight. The total thickness of adhesive layer  104  may be about 8 um, 10 um, 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um or any range between any of these thicknesses. The total thickness of adhesive layer  106  may be about 3 um, 5 um, 6 um, 8 um, 10 um, 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um or any range between any of these thicknesses. The combined thickness of adhesive layer  104  and  106  may be in the range of 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um, 80 um, 85 um, 90 um, 95 um, 100 um, 110 um, 120 um, 130 um, 140 um or 150 um or any range between any of these thicknesses. 
     Adhesive layer  106  does not include any substantial amount of fire retardant. Adhesive layer  106  may include acrylic adhesive, natural rubber, synthetic rubber, silicone, polyester, polyolefin, rosin, and epoxy adhesive resins, not limited to these general pressure sensitive adhesive resins and combinations thereof. Fire retardant additives can have the effect of decreasing adhesion. However, they can be highly important to meeting flammability requirements. By including a layer of adhesive with fire retardant additives, adhesive layer  104 , and a layer of adhesive without fire retardant additives, layer  106 , the present disclosure can meet flammability standards and retain the required adhesion performance, including both peel and tack. 
     As shown in  FIG. 1 , film construction  100  is applied to substrate  108 . Substrate  108  is shown as a horizontal substrate in  FIG. 1 ; however, substrate  108  may be horizontal, vertical, at any angle, or curved. Substrate  108  may be, for example, an interior or exterior wall or structure of a building. Substrate  108  may be a vehicle, such as a tractor-trailer or a train or aircraft. In some instances a primer may be used to increase adhesion between the film construction  100  and substrate  108 . 
       FIG. 2  shows a film construction  200  with three layers of adhesive. In  FIG. 2 , film layer  202  may be made of the same materials as film layer  102  in  FIG. 1 . Adhesive layer  203  is adjacent to film layer  202  and also adjacent to adhesive layer  204 . Adhesive layer  206  is adjacent to the opposite side of adhesive layer  204 , and contacts a substrate  208  to which film construction  200  may be applied. In this instance, adhesive layer  204  may be made of the same materials as adhesive layer  104  of  FIG. 1 . Adhesive layers  203  and  206  may be made of the same materials as adhesive layer  106 . Fire retardant additive  205  may be of the same materials as fire retardant additive  105 . The thickness of adhesive layer  204  may range from 8 um, 10 um, 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um or any range between any of these thicknesses. Adhesive layer  203  may range in thickness between 3 um, 5 um, 6 um, 8 um, 10 um, 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, and 75 um or any range between any of these thicknesses. Adhesive layer  206  may range in thickness 3 um, 5 um, 6 um, 8 um, 10 um, 12 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, and 75 um or any range between any of these thicknesses. The total thickness of all three of adhesive layers may range from 14 um, 17 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um, 80 um, 85 um, 90 um, 95 um, 100 um, 110 um, 120 um, 130 um, 140 um or 150 um, 175 um, 200 um, 225 um or any range between any of these thicknesses. 
       FIG. 3  shows a film construction  300  with a liner  307 . The film construction with film layer  302 , adhesive layer  304  and adhesive layer  306  is very similar to the film construction in  FIG. 1 , except that  FIG. 3  shows a liner adjacent to adhesive liner  307 . The film construction  300  is typically sold attached to a liner to allow a customer to remove the liner before applying the film construction  300  to a substrate. Line  307  may have a release coating. In some instances, liner  307  may have structures so as to create posts in adhesive layer  306  to allow increased slidability of the film construction for easy placement during application of the film construction  300  to a substrate. Liner  307  may also have ridges which form channels in adhesive layer  306  to allow for easy release of air bubbles that may otherwise become trapped during installation. 
     EXAMPLES 
     Film article examples were prepared with layered pressure sensitive adhesives that provide good low combustibility while also maintaining good adhesion to a substrate. 
     These examples are merely for illustrative purposes only and are not meant to be limiting on the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, unless noted otherwise. The following abbreviations are used herein: mm=millimeters; um=micrometers; mm/min=millimeters per minute; N/in=Newton per inch; g=gram; kg=kilogram; kgf=kilogram force; phr=parts per hundred; MJ/m 2 =megajoules per meters squared; kW/m 2 =kilowatt per meter squared. 
     Abbreviations for Materials 
       
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 FILM 1 
                 Calendared polyvinyl chloride film with 19.5% plasticizer, 
               
               
                   
                 12.7% organic stabilizer, 1.3% organic pigment, 135 um thick, 
               
               
                   
                 from Tatsuta Chemical Co., Ltd., Japan. The film surface was 
               
               
                   
                 corona treated prior to use. 
               
               
                 FILM 2 
                 Calendared polyvinyl chloride film with 19.5% plasticizer, 
               
               
                   
                 12.7% organic stabilizer, 1.3% organic pigment, 174 um thick, 
               
               
                   
                 from Bando Chemical Industries, Ltd., Japan 
               
               
                 FILM 3 
                 Low Density Polyethylene (LDPE) film, 80 microns thick, film 
               
               
                   
                 was extruded using a single screw extruder with resin 
               
               
                   
                 available from Equistar Chemicals, LP, Houston, TX, as  
               
               
                   
                 PETROTHENE NA217000 
               
               
                 FILM 4 
                 Ethylene and methyl acrylate copolymer (EMA) film, 75 
               
               
                   
                 microns thick, film was extruded using a single screw extruder 
               
               
                   
                 with resin available from DuPont Company, Wilmington, DE, 
               
               
                   
                 as ELVALOY1609 
               
               
                 FILM 5 
                 Polypropylene (PP) film, 33 microns thick, film was extruded 
               
               
                   
                 using a single screw extruder with resin available from Exxon 
               
               
                   
                 Mobil, as PP1013H1 
               
               
                 FILM 6 
                 Polyethylene terephthalate (PET) film, 25 microns thick, film 
               
               
                   
                 was available from DuPont Teijin Films U.S. Ltd, Chester, VA, 
               
               
                   
                 as MELINEX S 
               
               
                 FILM 7 
                 Polyimide (PI) film, 25 microns thick, film was extruded using 
               
               
                   
                 a single screw extruder with resin available from DuPont 
               
               
                   
                 Company, Wilmington, DE, as KAPTON E 
               
               
                 FILM 8 
                 Polyurethane (PU) film, 20 microns thick. Urethane resin 
               
               
                   
                 solution was a formulation of 14.3 weight percent crosslinker 
               
               
                   
                 added to 85.7 weight percent polyurethane resin. The 
               
               
                   
                 polyurethane resin was coated by hand onto LINER using a 
               
               
                   
                 notch bar coater, then dried at 65 degrees C. for 2 minutes, 
               
               
                   
                 followed by 120 degrees C. for 2 minutes: 
               
               
                   
                 Polyurethane base resin available from Tosoh 
               
               
                   
                 Corporation, Japan, as MCPV-12 
               
               
                   
                 Crosslinker available from Tosoh Corporation, 
               
               
                   
                 Japan, as CORONATE HX 
               
               
                 FILM 9 
                 Polyvinylidene fluoride (PVDF) film, 20 microns thick, 
               
               
                   
                 available from Denka Company Ltd., Japan, as DX-14S0220 
               
               
                 LINER 
                 Polyester release liner, silicone coated polyester release liner  
               
               
                   
                 for pressure sensitive adhesives available from Toray  
               
               
                   
                 Advanced Film Co., Ltd., Japan, as CERAPEEL WZ 
               
               
                 RESIN 
                 Acrylic pressure sensitive adhesive resin, available from 
               
               
                   
                 Nippon Synthetic Chemical Industry Co., Ltd., Japan, as AR- 
               
               
                   
                 2422 
               
               
                 CL 
                 Crosslinker, Polyisocyanate available from Tosoh Corp., Japan, 
               
               
                   
                 as L-55E 
               
               
                 FR1 
                 Tris(tribromoneopentyl) phosphate (TTBP) flame retardant, 
               
               
                   
                 available from ICL Industrial Products, Japan, as FR-370 
               
               
                 FR2 
                 Antimony trioxide (ATO) flame retardant, available from 
               
               
                   
                 Chemtura, Middlebury, CT., as TMS 
               
               
                 FR3 
                 Ammonium polyphosphate (APP) flame retardant, available 
               
               
                   
                 from Clariant International Ltd., Muttenz, Switzerland, as 
               
               
                   
                 EXOLIT AP423 
               
               
                 FR4 
                 Alumina trihydrate (ATH) flame retardant, available from 
               
               
                   
                 Huber Engineered Materials, Atlanta, GA., as MICRAL 1500 
               
               
                 FRS 
                 Antimony trioxide (SbO 2 ) flame retardant, available from 
               
               
                   
                 Yamanaka &amp; Co., Ltd., Japan, as MSA 
               
               
                 PRIMER 
                 Water based primer for walls, available from 3M Japan 
               
               
                   
                 Company, Sumitomo, Japan, as WP-246 
               
               
                   
               
            
           
         
       
     
     Test Methods 
     Flammability Test 
     Equipment: Cone calorimeter per ISO5660-1. 
     Substrate: Incombustible plasterboard, 12.5 mm thickness from American Gypsum, Dallas, Tex. 
     Sample preparation: The plasterboard was coated with a primer for adhesion promotion using PRIMER at 10 g solids per square meter and allowed to dry at room temperature. The polyester release liner was peeled from the adhesive side of the film article, and the film article was adhered to the primed plasterboard using a flat plastic squeegee to remove air bubbles. 
     Flammability acceptance criteria: THR=Total heat release less than or equal to 8 MJ/m 2  as measured over a period of 20 minutes. FIGRA=Fire Growth Rate is less than or equal to 8 KW/(m 2 *s). FIGRA is the peak heat release rate (KW/(m 2 )) divided by the time to the peak(s). 
     180 Peel Adhesion Test 
     Equipment: Tensilon RTG series tensile tester from A&amp;D Co., Ltd., Japan. 
     Substrate: Bonderized steel plate from MSC Industrial Supply, Melville, N.Y. 
     Temperature: 20 degrees C., room temperature. 
     Aging time: Peel was done 48 hours after lamination of film to substrate. 
     Sample Preparation: A 25 mm×150 mm film article sample was laminated to a substrate with 1 kg weighted roller. The substrate was cleaned by wiping with Isopropyl alcohol before laminating. 
     Testing: After aging, the sample was peeled at a 180 degree angle from the substrate at a speed of 300 mm/min. Three samples were tested and averaged for each condition. Results are reported in N/in. 
     Peel adhesion acceptance criteria: greater than or equal to 20 N/in. 
     Loop Tack Adhesive Test 
     Equipment: Tensilon RTG series tensile tester from A&amp;D Co., Ltd., Japan. 
     Substrate: Vinyl film, FILM  2 . 
     Temperature: 5 degrees C. 
     Sample Preparation: A 25 mm wide×150 mm long film article sample was curved into a loop (where the ends did not overlap) with the adhesive on the outside of the loop. 
     Testing: The sample was contacted to the substrate at a speed of 1000 mm/min until 30 mm length of film was adhered to the substrate. Then the sample was immediately peeled from the substrate at a speed of 100 mm/min. Three samples were tested and averaged for each condition. Results are reported in N/in. 
     Loop tack acceptance criteria: greater than or equal to 15 N/in. 
     Probe Tack Adhesive Test 
     Equipment: TE-6002 Probe Tack Tester with Chamber from Tester Sangyo Co., Ltd., Japan 
     Chamber Temperature: 5 degrees C. 
     Sample Preparation: The exposed adhesive side of the film article was tested. 
     Testing: Cold temperature tackiness was measured following equipment operating manual instructions. Three samples were tested for each example and the results were averaged. Results are reported in kgf. 
     Probe tack acceptance criteria: greater than or equal to 2.5 kgf. 
     Example 1: 2-Layer Adhesive 
     Calendared PVC films were laminated with two layered adhesives, the combined adhesive layers totaling 38 um. The inner adhesive layers, the adhesive layer between the film and the outer adhesive layer, were formulated with different percentages of flame retardant fillers as described in Table 1. The outer adhesive layers contained no flame retardant fillers. Comparative Examples were made, one without flame retardant filler (CE1-1) and one with flame retardant filler throughout the entire adhesive (CE1-2). 
     Each adhesive layer was formulated from CL added at 2.17 phr to acrylic adhesive RESIN. Each adhesive layer was coated by hand onto LINER using a notch bar coater, then dried at 65 degrees C. for 2 minutes, followed by 95 degrees C. for 2 minutes. 
     Each adhesive layer was subsequently laminated between rubber nip rollers to FILM  1  for adhesion testing or FILM  2  for flammability testing, and each LINER was removed. Samples for Flammability Testing, 180 Degree Peel Adhesion Testing, and Loop Tack Testing were prepared as indicated in the Test Methods. Results are shown in Table 1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 2-Layer Adhesive Examples 
               
            
           
           
               
               
               
               
               
            
               
                 Example 1 
                 E1-1 
                 E1-2 
                 CE1-1 
                 CE1-2 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Inner 
                 Weight g 
                 RESIN 
                 16.7 
                 45.8 
                 97.9 
                 65.2 
               
               
                 adhesive 
                   
                 CL 
                 0.5 
                 1.4 
                 2.1 
                 2.0 
               
               
                 layer 
                   
                 FR1 
                 25.0 
                 25.0 
                 0 
                 25.0 
               
               
                   
                   
                 FR2 
                 7.8 
                 7.8 
                 0 
                 7.8 
               
               
                   
                   
                 Total g 
                 50.0 
                 80.0 
                 100.0 
                 100.0 
               
               
                   
                 Filling % 
                   
                 65.5%   
                 41.0%   
                 0 
                 32.8%  
               
               
                   
                 Thickness 
                   
                 19 
                 30 
                 38 
                 38 
               
               
                   
                 um 
               
               
                 Outer 
                 Weight g 
                 RESIN 
                 48.4 
                 19.4 
                 — 
                 — 
               
               
                 adhesive 
                   
                 CL 
                 1.5 
                 0.6 
                 — 
                 — 
               
               
                 layer 
                   
                 Total g 
                 50.0 
                 20.0 
                 — 
                 — 
               
               
                   
                 Filling % 
                   
                 0 
                 0 
               
               
                   
                 Thickness 
                   
                 19 
                 8 
                 — 
                 — 
               
               
                   
                 um 
               
            
           
           
               
               
               
               
               
            
               
                 Filled adhesive thickness percent 
                 50% 
                 79% 
                 0 
                 100% 
               
               
                 Total adhesive thickness um 
                 38 
                 38 
                 38 
                 38 
               
               
                 Loop tack N/in 
                 17.5 
                 17.1 
                 18.2 
                 10.6 fail 
               
               
                 180 Peel adhesion N/in 
                 29.7 
                 30.0 
                 30.0 
                 28.8 
               
               
                 Flammability THR MJ/m 2   
                 &lt;8 
                 &lt;8 
                 &gt;8 fail 
                 &lt;8 
               
               
                   
               
            
           
         
       
     
     Example E1-1 has 65.5% filled inner layer adhesive of 19 um with flame retardants and unfilled outer layer adhesive 19 um. E1-1 passed the Total Heat Release criterion, the 180 Peel Adhesion Test, and the Loop Tack Adhesive Test. 
     Example E1-2 has 41.0% filled inner layer adhesive of 30 um with flame retardants and unfilled outer layer adhesive of 8 um. E1-2 passed the Total Heat Release criterion, the 180 Peel Adhesion Test, and the Loop Tack Adhesive Test. 
     Example CE1-1 has a standard single layer of unfilled adhesive of 38 um. CE1-1 failed the Total Heat Release criterion. However, CE1-1 passed the 180 Peel Adhesion Test, and the Loop Tack Adhesive Test. 
     Example CE1-2 has a single layer 32.8% filled adhesive of 38 um with flame retardants. CE1-2 passed the Total Heat Release criterion and the 180 Peel Adhesion Test. However, CE1-2 failed the Loop Tack Adhesive Test. 
     Example 2: Various Flame Retardant Fillers 
     Calendared PVC film article samples with adhesive layers were prepared as described in Example 1 with the following changes. A variety of flame retardants were used, as well as thinner adhesive layers as described in Table 2. Flammability testing, 180 degree peel adhesion, and probe tack samples were prepared as indicated in the Test Methods. Results are shown in Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Various Flame Retardant Filler Examples 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Example 2 
                 E2-1 
                 E2-2 
                 E2-3 
                 E2-4 
                 E2-5 
                 E2-6 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Inner 
                 Filling % 
                 FR3 
                 50% 
                 0 
                 0 
                 0 
                 0 
                 50% 
               
               
                 adhesive 
                   
                 FR4 
                 0 
                 50% 
                 0 
                 0 
                 0 
                 0 
               
               
                 layer 
                   
                 FR1/FR5 
                 0 
                 0 
                 50% 
                 50% 
                 50% 
                 0 
               
               
                   
                   
                 at 50/50 
               
               
                   
                 Thickness 
                   
                 30 
                 30 
                 30 
                 19 
                 12 
                 19 
               
               
                   
                 um 
               
               
                 Outer 
                 Filling % 
                   
                 0 
                 0 
                 0 
                 0 
                 0 
                 0 
               
               
                 adhesive 
                 Thickness 
                   
                 8 
                 8 
                 8 
                 19 
                 26 
                 19 
               
               
                 layer 
                 um 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Filled adhesive thickness percent 
                 79% 
                 79% 
                 79% 
                 50% 
                 32% 
                 50% 
               
               
                 Total adhesive thickness um 
                 38 
                 38 
                 38 
                 38 
                 38 
                 38 
               
               
                 Probe tack kgf 
                 2.5 
                 2.6 
                 3.0 
                 3.1 
                 3.5 
                 4.1 
               
               
                 180 Peel adhesion N/in 
                 37 
                 29 
                 33 
                 35 
                 39 
                 36 
               
               
                 Flammability THR MJ/m 2   
                 7 
                 8 
                 8 
                 7 
                 8 
                 8 
               
               
                 FIGRA seconds 
                 4.6 
                 6.9 
                 5.2 
                 4.3 
                 5.8 
                 7.6 
               
               
                   
               
            
           
         
       
     
     Examples E2-1 through E2-6 have a 50% filled inner layer adhesive of 12-30 um with a variety of different flame retardants and an unfilled outer layer adhesive of 8-26 um. Each of E2-1 through E2-6 passed both the THR and FIGRA criterion in the Flammability Test, the 180 Peel Adhesive Test and the Loop Tack Adhesive Test. 
     Example 3: 3-Layer Adhesive 
     Calendared PVC film article samples with adhesive layers were prepared as described in Example 1. As shown in Table 3, Example 3 had three layers of adhesive with a highly 65% filled middle layer adhesive of 25 microns, an additional unfilled inner layer adhesive of 6.5 um, and unfilled outer layer adhesive of 6.5 um. The unfilled and filled adhesive layers have thickness to add up to a total thickness for the three layer adhesive of 38 um. Flammability testing, 180 degree peel adhesion, and probe tack samples were prepared as indicated in the Test Methods. Results are shown in Table 3. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 3-Layer Adhesive Example 
               
            
           
           
               
               
               
            
               
                   
                 Examples 3 
                 E3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Inner 
                 Filling % 
                   
                 0 
               
               
                   
                 adhesive 
                 Thickness 
                   
                 6.5 
               
               
                   
                 layer 
                 um 
                   
                   
               
               
                   
                 Middle 
                 Filling % 
                 FR1/FR5 
                 65% 
               
               
                   
                 adhesive 
                   
                 at 50/50 
                   
               
               
                   
                 layer 
                 Thickness 
                   
                 25 
               
               
                   
                   
                 um 
                   
                   
               
               
                   
                 Outer 
                 Filling % 
                   
                 0 
               
               
                   
                 adhesive 
                 Thickness 
                   
                 6.5 
               
               
                   
                 layer 
                 um 
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 Filled adhesive thickness percent of 
                 66% 
               
               
                   
                 total adhesive thickness 
                   
               
               
                   
                 Total adhesive thickness um 
                 38 
               
               
                   
                 Probe tack kgf 
                 2.5 
               
               
                   
                 180 Peel adhesion N/in 
                 29 
               
               
                   
                 Flammability THR MJ/m 2   
                 7 
               
               
                   
                 FIGRA KW/(m 2 *s) 
                 4.9 
               
               
                   
                   
               
            
           
         
       
     
     Example E3 with three layers of adhesive passed the THR and FIGRA criteria of the Flammability Test, the 180 Peel Adhesive Test and the Loop Tack Adhesive Test. 
     Example 4: Various Adhesive Layer Thickness 
     Calendared PVC film article samples with adhesive layers were prepared as described in Example 1 with the following changes. A range of adhesive layer thickness were used, described in Table 4. Comparative Examples (CE4-1, 2) were made, as indicated in Table 4. Flammability testing and 180 degree peel adhesion samples were prepared as indicated in the Test Methods. Results are shown in Table 4. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Various Adhesive Layer Thickness Examples 
               
            
           
           
               
               
               
               
               
               
            
               
                 Example 4 
                 E4-1 
                 E4-2 
                 E4-3 
                 CE4-1 
                 CE4-2 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Inner 
                 Filling % 
                   
                 — 
                 0 
                 — 
                 — 
                 — 
               
               
                 adhesive 
                 Thickness 
                   
                 — 
                 6.5 
                 — 
                 — 
                 — 
               
               
                 layer 
                 um 
               
               
                 Middle 
                 Filling % 
                 FR 3 
                 50% 
                 50% 
                 50% 
                 50% 
                 50% 
               
               
                 adhesive 
                 Thickness 
                   
                 12 
                 30 
                 30 
                 6.5 
                 8 
               
               
                 layer 
                 um 
               
               
                 Outer 
                 Filling % 
                   
                 0 
                 0 
                 0 
                 0 
                 0 
               
               
                 adhesive 
                 Thickness 
                   
                 6.5 
                 8 
                 6.5 
                 38 
                 2 
               
               
                 layer 
                 um 
               
            
           
           
               
               
               
               
               
               
            
               
                 Filled adhesive thickness percent 
                 65% 
                 67% 
                 82% 
                 15% 
                 80% 
               
               
                 Total adhesive thickness um 
                 18.5 
                 44.5 
                 36.5 
                 44.5 
                 10 
               
               
                 180 Peel adhesion N/in 
                 &gt;20 
                 29-39 
                 29-39 
                 &gt;20 
                 &lt;20 fail 
               
               
                 Flammability THR MJ/m 2   
                 &lt;8 
                 &lt;8 
                 &lt;8 
                 &gt;8 fail 
                 &lt;8 
               
               
                   
               
            
           
         
       
     
     Examples E4-1, E4-2, and E4-3 have 50% a filled inner layer adhesive from 12 to 30 um with flame retardant and unfilled outer layer adhesive from 6.5 to 8 um, giving a total adhesive thickness range from 18.5 to 44.5 um. Each of E4-1, E4-2 and E403 passed the THR Criterion of the Flammability Test and the 180 Peel Adhesive Test. 
     Example CE4-1 has 50% filled inner layer adhesive of 6.5 um with flame retardant and unfilled outer layer adhesive of 38 um. CE4-1 failed the THR Criterion of the Flammability Test, but passed the 180 Peel Adhesive Test. 
     Example CE4-2 has 50% filled inner layer adhesive of 8 um with flame retardant and unfilled outer layer adhesive of 2 um. CE4-2 failed the 180 Peel Adhesion Test but passed the THR Criterion of the Flammability Test. 
     Example 5: Various Film Material Layers 
     Film article samples with adhesive layers were prepared as described in Example 1 with the following changes. A variety of film materials were used, described in Table 5. Flammability testing samples were prepared as indicated in the Test Methods. Results are shown in Table 5. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Various Film Materials Layers Examples 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Example 5 
                 E5-1 
                 E5-2 
                 E5-3 
                 E5-4 
                 E5-5 
                 E5-6 
                 E5-7 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Film layer 
                 Film 
                   
                 FILM 3 
                 FILM 4 
                 FILM 5 
                 FILM 6 
                 FILM 7 
                 FILM 8 
                 FILM 9 
               
               
                   
                 Thickness 
                   
                 80 
                 75 
                 33 
                 25 
                 25 
                 20 
                 20 
               
               
                   
                 um 
               
               
                 Inner 
                 Filling % 
                   
                 0 
                 0 
                 0 
                 0 
                 0 
                 — 
                 — 
               
               
                 adhesive 
                 Thickness 
                   
                 3 
                 3 
                 3 
                 3 
                 3 
                 — 
                 — 
               
               
                 layer 
                 um 
               
               
                 Middle 
                 Filling % 
                 FR3 
                 50% 
                 50% 
                 50% 
                 50% 
                 50% 
                 50% 
                 50% 
               
               
                 adhesive 
                 Thickness 
                   
                 34 
                 34 
                 34 
                 34 
                 34 
                 30 
                 30 
               
               
                 layer 
                 um 
               
               
                 Outer 
                 Filling % 
                   
                 0 
                 0 
                 0 
                 0 
                 0 
                 0 
                 0 
               
               
                 adhesive 
                 Thickness 
                   
                 3 
                 3 
                 3 
                 3 
                 3 
                 8 
                 8 
               
               
                 layer 
                 um 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Filled adhesive thickness percent 
                 85% 
                 85% 
                 85% 
                 85% 
                 85% 
                 79% 
                 79% 
               
               
                 Total adhesive thickness um 
                 40 
                 40 
                 40 
                 40 
                 40 
                 38 
                 38 
               
               
                 Flammability THR MJ/m 2   
                 7.8 
                 7.4 
                 6.6 
                 5.7 
                 0.9 
                 5.8 
                 6.7 
               
               
                 FIGRA KW/(m 2 *s) 
                 5.3 
                 7.2 
                 6.7 
                 5.0 
                 0.03 
                 0 
                 0 
               
               
                   
               
            
           
         
       
     
     Examples E5-1 through E5-7 have seven different typical film materials and 50% filled inner layer adhesive of 30-34 um with flame retardants and unfilled outer layer adhesive of 3-8 um. Each of E5-1 through E5-7 passed the FIGRA and THR Criterion of the Flammability Test.