Adhesive indicator for roof membranes

Abstract

To provide a thermal color change indicator and its use for visually determining whether adjacent surfaces of overlapping edges of adjacent roof membrane segments have been sufficiently heated to a pre-selected temperature threshold in order to achieve a desired weld between adjacent surfaces and, accordingly, to seal the joint of the roof membrane. [Solution] Referring mainly to Figures 1A and 1B, these figures illustrate a method of using a specific embodiment of the thermal color change indicator (1) of the present invention to visually determine whether the roof membrane joint (2) formed by the overlapping edges of the upper and lower roof membrane segments (3) and (4), i.e., the edge portion of the upper roof membrane segment (5) and the edge portion of the lower roof membrane segment (6), has been sufficiently heated to a pre-selected temperature threshold (7) in order to weld the adjacent surfaces of the edge portions (5) and (6), and accordingly to seal the roof membrane joint (2).

Description

Technical Field

[0001] This PCT patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 971,544, filed Feb. 7, 2020, which is incorporated herein by reference.

Background Art

[0002] I. Background Thermoplastic roofing membranes are excellent products for roof protection in the construction industry. These roofing membranes are typically manufactured as elongated sheets having a width of about 5 feet or greater, and such sheets can be provided in rolls. Subsequently, the roofing membranes can be spread over the roof in segments, and the edge portions of adjacent roofing membrane segments can be overlapped to form a roofing membrane seam. The overlapping edge portions can be welded together in proximity to the roofing membrane seam to form a seal. As a result, the roofing membrane segments can function as one monolithic layer of an impermeable material against the infiltration of water and moisture.

[0003] For continuous and fixed sealing, the overlapping edge portions of adjacent roofing membrane segments can be welded by heating the adjacent surfaces of the overlapping edge portions and then pressing the heated surfaces together to fuse the material of the roofing membrane segments to obtain the required seal. The seal and, accordingly, the overall roof integrity may depend on the application of suitable and sufficient heat to achieve melting of the adjacent surfaces of the overlapping edge portions to create a continuous seal between the roofing membrane segments.

[0004] One method to ensure a tight seal between membranes may involve the intentional over-application of heat. While this can achieve a sufficient seal, the process can be relatively slow, as applying more heat may take longer than applying a moderate, lower amount. Furthermore, excessive heat application can damage the roof membrane, potentially shortening its lifespan. Moreover, such methods can be energy inefficient.

[0005] Another measure to ensure airtightness could include manually lifting the edges of the upper roof membrane segments, either visually or mechanically, and either spot-welding or continuous-base welding, to determine if the lower roof membrane segments were properly welded down to the lower segments and to verify the seal. Of course, spot checks may miss uninspected, unsealed areas, and inspecting all roof membrane joints can be time-consuming and therefore costly.

[0006] Therefore, means of providing a positive indication that adequate heat exposure, and thus proper sealing of the roof membrane seams, can be easily observed, would be highly desirable. [Overview of the project] [Means for solving the problem]

[0007] II. Disclosure of the Invention A broad object of a particular embodiment of the present invention may be to provide a thermochromic indicator for visually determining whether a roofing membrane has been sufficiently heated to a pre-selected temperature threshold in order to seal the seams of the roofing membrane, the thermochromic indicator comprising a contained reversible color change system having a dye, a developer, and a solvent, wherein the developer variably interacts with the dye according to the temperature of the color change system. Before use, the color change system can be activated to form a visibly colored dye-developer complex. During use, exposure to a pre-selected temperature threshold allows the dye-developer complex to dissociate, resulting in a visible color change. Furthermore, a decrease in temperature from the temperature threshold can maintain the visible color change, thereby effectively recording exposure to the temperature threshold.

[0008] Another broad object of a particular embodiment of the present invention may be to provide a method for using a thermochromic indicator bonded to a roofing membrane to visually determine whether adjacent surfaces of overlapping edge portions of adjacent roofing membrane segments have been sufficiently heated to a pre-selected temperature threshold in order to achieve a desired weld between adjacent surfaces and, accordingly, to seal the roofing membrane joint.

[0009] Inevitably, further objects of the present invention are disclosed throughout the specification, drawings, photographs, and other areas of the claims. III. Brief Description of the Drawings [Brief explanation of the drawing]

[0010] [Figure 1A] Figure 1A shows a specific embodiment of the heat-change indicator of the present invention bonded to an upper roof membrane segment, where the edge portion of the upper roof membrane segment is shown overlapping with the edge portion of the lower roof membrane segment. In this figure, the edges are not yet welded.

[0011] [Figure 1B]Figure 1B is a diagram of the thermochromic indicator shown in Figure 1A, but in this case, the adjacent surfaces of the overlapping edges are sufficiently heated to a pre-selected temperature threshold and welded accordingly.

[0012] [Figure 2A] Figure 2A shows a specific embodiment of the thermal color change indicator of the present invention bonded to a roofing membrane, in which the thermal color change indicator has not yet been exposed to a pre-selected temperature threshold.

[0013] [Figure 2B] Figure 2B shows the same temperature indicator as in Figure 2A, but here the temperature indicator is exposed to a pre-selected temperature threshold. As a result, the thermal color change indicator undergoes a visible color change.

[0014] [Figure 2C] Figure 2C shows the temperature indicator shown in Figure 2B after the temperature has decreased from the temperature threshold to the ambient temperature. The thermal color-changing indicator retains its color change due to the color memory properties of the color-changing system.

[0015] [Figure 3A] Figure 3A is an enlarged and exaggerated view of a portion of the thermal color change indicator shown in Figure 2A, illustrating the components of the enclosed reversible color change system.

[0016] [Figure 3B] Figure 3B is an enlarged and exaggerated view of a portion of the thermal color change indicator shown in Figure 2B, illustrating the components of the enclosed reversible color change system.

[0017] [Figure 3C] Figure 3C is an enlarged and exaggerated view of a portion of the thermal color change indicator shown in Figure 2C, illustrating the components of the enclosed reversible color change system.

[0018] [Figure 4A]Figure 4A is an enlarged, exaggerated view of a particular embodiment of the thermochromic display of the present invention configured as an ink containing an encapsulated reversible discoloration system, where the discoloration system has not yet been exposed to a preselected activation temperature.

[0019] [Figure 4B] Figure 4B is a view of the ink shown in Figure 4A, where the discoloration system has been exposed to the activation temperature. As a result, the discoloration system has undergone a visible color change.

[0020] [Figure 4C] Figure 4C is a view of the ink shown in Figure 4B printed on a roof membrane.

[0021] [Figure 5] Figure 5 is a diagram of the hysteresis characteristics of a particular embodiment of the reversible discoloration system of the present invention having color memory characteristics.

[0022] [Figure 6] Figure 6 is a photograph of a particular embodiment of the thermochromic display of the present invention configured as an ink containing an encapsulated reversible discoloration system, where the ink has been printed on a roof membrane via a slot-die coater.

[0023] [Figure 7] Figure 7 is a photograph of the roof membrane shown in Figure 6 on which the thermochromic display of the present invention has been printed, where the roof membrane has been wound into a roll.

[0024] [Figure 8] Figure 8 is a photograph of the roof membrane shown in Figures 6 and 7 on which the thermochromic display of the present invention has been printed, where the roof membrane has been exposed to a preselected temperature threshold via a heat gun from left to right. Accordingly, the irreversible thermochromic display has undergone a visible color change from blue to colorless.

Mode for Carrying Out the Invention

[0025] IV. Modes for Carrying Out the Invention Referring primarily to Figures 1A and 1B, these figures illustrate a method of using a specific embodiment of the thermal color change indicator (1) of the present invention to visually determine whether a roof membrane joint (2), formed by the overlapping edges of the upper and lower roof membrane segments (3) and (4), i.e., the edge portion of the upper roof membrane segment (5) and the edge portion of the lower roof membrane segment (6), has been sufficiently heated to a pre-selected temperature threshold (7) in order to weld the adjacent surfaces of the edge portions (5) and (6), and accordingly to seal the roof membrane joint (2).

[0026] In a particular embodiment, the thermochromic indicator (1) can be bonded to the upper surface (8) of a roofing film and may contain a contained reversible color change system (9) comprising a dye (10), a developer (11), and a solvent (12), where the developer (11) variably interacts with the dye (10) according to the temperature of the color change system (9). For example, before use of the present invention, the reversible color change system (9) can be activated to form a visibly colored dye-developer complex (13). During use, exposure to a pre-selected temperature threshold (7) can cause the dye-developer complex (13) to dissociate, resulting in a visibly perceptible color change.

[0027] Therefore, the method of use may include, for example, visually observing a heat-sensitive indicator (1) bonded to the upper surface (8) of the roof membrane to detect whether a visible color change has occurred. By visually detecting the visible color change caused by the dissociation of the dye (10) and developer (11), it can be indicated that the adjacent surfaces of the overlapping edges (5) (6) of the upper and lower roof membrane segments (3) (4) have been exposed to a pre-selected temperature threshold (7), and accordingly, that the roof membrane joints (2) have been sufficiently welded in close proximity. Conversely, visual detection of the absence of a visible color change means that no visible color change occurred, and it may indicate that the adjacent surfaces of the overlapping edges (5) (6) of the upper and lower roof membrane segments (3) (4) have not been exposed to a pre-selected temperature threshold (7), and accordingly, that the roof membrane joints (2) have not been sufficiently welded in close proximity.

[0028] definition As used herein, the term “indicator” means a composition or device that indicates, means, points to, informs, or shows that a predetermined event has occurred.

[0029] As used herein, the term “contained” means that the dye (10), developer (11), and solvent (12) are continuously held within a range of physical proximity that allows for interaction between the components. Furthermore, by being contained, the reversible color change system (9) is isolated from the external environment, which could damage or destroy the color change system (9).

[0030] As used herein, the term “pre-selected” means predetermined or determined.

[0031] As used herein, the term "threshold" means a point that must be reached or exceeded in order for a particular phenomenon to occur or manifest.

[0032] As used herein, the term “dye” means a chemical compound capable of changing color, such as a color former that reacts with the color developer (11) of the present invention to form a dye-color developer complex (13) exhibiting optical properties distinguishable by the human eye.

[0033] As used herein, the term "chromogen" means a chemical compound capable of reacting with the dye (10) of the present invention to form a dye-chromogen complex (13) that exhibits optical properties distinguishable by the human eye. The term "chromogen" may also be synonymous with "color developer," both of which refer to chemical compounds that promote the color change of the dye (10).

[0034] As used herein, the term “solvent” may, though not necessarily, be synonymous with “phase change material,” and thus, a phase change material is defined herein simply as a material that changes one phase to another.

[0035] As used herein, the term “detect” and its forms mean to discover or confirm the existence of something.

[0036] As used herein, the term "welding" means, for example, to fuse together, join together, bond together, or melt together through heat.

[0037] As used herein, the term “color” means any color other than white, and accordingly any color other than white.

[0038] Dyes and chromogens The color-changing system (9) contained in the present invention may be a reversible color-changing system, meaning that the temperature-modulated visible color change may be reversible, as opposed to an irreversible or permanent color change.

[0039] With respect to a particular embodiment, the dye (10) of the reversible color change system (9) of the present invention may include a leuco dye (10) that can reversibly change between two forms, one of which is typically colorless (or substantially colorless).

[0040] For the purposes of this application, the use of a leuco dye (10) may be advantageous, as opposed to a dye that changes from one color to another. This is because, once changed to a colorless state upon exposure to a pre-selected temperature threshold (7), the leuco dye (10) and, accordingly, the thermochromic indicator (1) can be effectively invisible on a sealed roofing film (14), which may be preferable (for functional and / or aesthetic purposes) to a sealed roofing film (14) having multiple colored strips thereon.

[0041] For illustrative purposes only, as a few non-limiting examples, leuco dyes (10) include: crystalline violet lactone (CAS No.: 1552-42-7); pigment blue 63 (CAS No.: 16521-38-3); 2'-(dibenzylamino)-6'-(diethylamino)fluorane (CAS No.: 34372-72-0); 7-(4-(diethylamino)-2-ethoxyphenyl)-7-(1-ethyl-2-methyl-1H-indole-3-yl)fl[3,4-b]pyridine-5(7H)-one (CAS No.: 69898-40-4); 6'-(diethylamino)-1',3'-dimethylfluorane (CAS No.: 21934-68-9); 3,3-bis(1-butyl-2-methyl-1H-indole-3-yl)phthalide (CAS No.: 50292-91-6); combinations of these may also be acceptable.

[0042] In certain embodiments, the leuco dye (10) may be an electron-donating compound (or a proton-withdrawing compound). Furthermore, the developer (11) may include an electron-withdrawing compound (or a proton-donating compound), such as an acid, particularly a weak acid. Through interaction (specifically, an electron transfer reaction) between the electron-donating leuco dye (10) and the electron-withdrawing developer (11), the leuco dye (10) reversibly changes color, for example, from colorless to a visible color.

[0043] For illustrative purposes only, as a few non-limiting examples, the color developer (11) may be 3,5-di-tert-butylcatechol (CAS No.: 1020-31-1); 4,4'-(1,3-dimethylbutylidene)diphenol (CAS No.: 6807-17-6); 2,2'-biphenol (CAS No.: 1806-29-7), etc.

[0044] Without being constrained by any particular operating theory, it is believed that within this reversible color change system (9), depending on the temperature of the color change system (9), the developer (11) can reversibly interact with the leuco dye (10) via an electron transfer reaction, thereby opening the lactone ring of the leuco dye (10), stabilizing the ring-open structure, and forming a visibly colored supramolecular dye-developer complex (13). When the ring is opened, the lactone ring is cationic, and therefore broadens its π-electron conjugation, enabling absorption in the visible spectrum and resulting in a visibly colored dye-developer complex (13). Thus, the stability of the dye-developer complex (13) is at least partially determined by the affinity of the developer (11) for the leuco dye (10).

[0045] solvent The reversible color change system (9) of the present invention further comprises a solvent (12) that performs or controls the reversible interaction between a leuco dye (10) and a color developer (11).

[0046] With respect to a particular embodiment, the solvent (12) that may be useful in the reversible color change system (9) of the present invention may be (i) a solvent (12) in which both the leuco dye (10) and the developer (11) are soluble, and (ii) a solvent (12) that can be contained together with the leuco dye (10) and the developer (11) in, for example, a capsule (or microcapsule) (15) for providing the corresponding encapsulated reversible color change system (9). When contained in a capsule (15), the solvent (12) can facilitate the interaction between the leuco dye (10) and the developer (11).

[0047] With respect to a particular embodiment, the solvent (12) may be a hydrocarbon.

[0048] With respect to a particular embodiment, the solvent (12) may be a ketone.

[0049] With respect to a particular embodiment, the ketone may have the following formula I: [ka]

[0050] With respect to a particular embodiment, the ketone may have formula I (wherein R' and R'' may be the same or different, and R' and R'' may be (i) a linear, branched, or cyclic alkyl group, (ii) a linear, branched, or cyclic alkenyl group, (iii) a linear, branched, or cyclic alkynyl group, (iv) an aryl group, or (v) a heteroaryl group, so that any of the groups may be unsubstituted or substituted).

[0051] With respect to a particular embodiment, the solvent (12) may be an ester.

[0052] With respect to a particular embodiment, the ester may have the following formula II: [ka]

[0053] With respect to a particular embodiment, the ester may have formula II (wherein R' and R'' may be the same or different, and R' and R'' may be (i) a linear, branched, or cyclic alkyl group, (ii) a linear, branched, or cyclic alkenyl group, (iii) a linear, branched, or cyclic alkynyl group, (iv) an aryl group, or (v) a heteroaryl group, so that any of the groups may be unsubstituted or substituted).

[0054] With respect to a particular embodiment, the ester may be (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dipentanoate (CAS No.: 144482-79-1).

[0055] In particular embodiments, the ester may be (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dibutyrate (CAS No.: 144482-78-0).

[0056] With respect to a particular embodiment, the solvent (12) may be an alcohol.

[0057] In particular embodiments, the alcohol may be an aliphatic alcohol, an aromatic alcohol, or a combination thereof.

[0058] With respect to a particular embodiment, the solvent (12) may be a single compound.

[0059] With regard to other specific embodiments, solvent (12) may be a mixture of two or more compounds. With regard to other specific embodiments, solvent (12) may be a mixture of two or more of the exemplary solvents (12) described above.

[0060] Without being constrained by any particular operating theory, in the reversible color change system (9) of the present invention, depending on the temperature of the color change system (9), the developer (11) can interact with the solvent (12) to form a solvent-developer complex, and thus this interaction is considered to be determined at least in part by the affinity of the developer (11) for the solvent (12).

[0061] Next, the visible color change may be linked to competition between the leuco dye (10) and the solvent (12) for complexation with the developer (11), and thus it can be assumed that the developer (11) forms a complex with a molecule that has a greater affinity for it.

[0062] Once a complex is formed, it is important to understand that sufficient energy is input into the system to destabilize it, and that this keeps the complex stable until its components dissociate.

[0063] Referring mainly to Figures 2A, 3A, 4A, and 4B, with respect to the thermochromic indicator (1) of the present invention, before use, the reversible color change system (9) can be "activated" for use by being exposed to a pre-selected activation temperature (16) such that the color developer (11) has a higher affinity for the leuco dye (10) than for the solvent (12), thereby resulting in the formation of a visibly colored dye-color developer complex (13).

[0064] Referring primarily to Figures 2B, 2C, 3B, and 3C, upon exposure to a pre-selected temperature threshold (7) during use, the developer (11) can have a greater affinity for the solvent (12) than for the leuco dye (10). Thus, the developer (11) can dissociate from the leuco dye (10) and subsequently form a solvent-developer complex. When a complex is formed with the solvent (12), the developer (11) can be excluded from interaction with the leuco dye (10). Accordingly, the lactone ring of the leuco dye can be cyclized, and the leuco dye (10) can become colorless.

[0065] Color memory As described above, the reversible color change system (9) of the present invention may be susceptible to the effects of temperature-modulated color changes. Furthermore, the reversible color change system (9) of the present invention may have color memory properties, so that after the dissociation of the visibly colored dye developer complex (13) upon exposure to a pre-selected temperature threshold (7), the dye (10) and developer (11) may remain dissociated even when the temperature is reduced from the temperature threshold (7) to, for example, a temperature lower than or below the temperature threshold (e.g., ambient temperature). Thus, a visible color change, for example, a color change from colored to colorless, may be retained at temperatures lower than or below the temperature threshold (7). Accordingly, the thermal color change indicator (1) can effectively record exposure to a pre-selected temperature threshold (7), which may be in contrast to conventional thermometers that can only show the current temperature and cannot show temperatures to which the thermometer was exposed prior to the exposure to the current temperature.

[0066] The reversible color change system (9) of the present invention may include a color temperature (which may have the same meaning as a pre-selected activation temperature (16)) at which the color change system (9) changes from a colorless state to a visually colored state (17). The reversible color change system (9) of the present invention may also include a decolorization temperature (which may have the same meaning as a pre-selected temperature threshold (7)) at which the color change system (9) changes from a visually colored state (17) to a colorless state.

[0067] Significantly, the coloring and decolorization temperatures of the reversible color change system (9) of the present invention may be different, meaning that the coloring temperature may differ from the decolorization temperature. For example, the coloring temperature may be less than the decolorization temperature.

[0068] As a result, the color memory characteristics of the reversible color change system (9) of the present invention promote the retention of a colorless state by decreasing the temperature from the decolorization temperature to a temperature lower than or below the decolorization temperature, and thus allow for recording of exposure to the decolorization temperature. Furthermore, the color memory characteristics of the reversible color change system (9) of the present invention promote the retention of a visually colored state (17) by increasing the temperature from the coloring temperature to a temperature higher than or above the coloring temperature.

[0069] With respect to a particular embodiment, the coloring temperature may differ from the decolorization temperature by at least about 50°C, meaning that the coloring temperature may be at least about 50°C lower than the decolorization temperature.

[0070] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 55°C, meaning that the coloring temperature may be at least about 55°C lower than the decolorization temperature.

[0071] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 60°C, meaning that the coloring temperature may be at least about 60°C lower than the decolorization temperature.

[0072] With respect to a particular embodiment, the coloring temperature may differ from the decolorization temperature by at least about 65°C, meaning that the coloring temperature may be at least about 65°C lower than the decolorization temperature.

[0073] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 70°C, meaning that the coloring temperature may be at least about 70°C lower than the decolorization temperature.

[0074] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 75°C, meaning that the coloring temperature may be at least about 75°C lower than the decolorization temperature.

[0075] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 80°C, meaning that the coloring temperature may be at least about 80°C lower than the decolorization temperature.

[0076] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 85°C, meaning that the coloring temperature may be at least about 85°C lower than the decolorization temperature.

[0077] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 90°C, meaning that the coloring temperature may be at least about 90°C lower than the decolorization temperature.

[0078] With respect to certain embodiments, the coloring temperature may differ from the decolorization temperature by at least about 95°C, meaning that the coloring temperature may be at least about 95°C lower than the decolorization temperature.

[0079] With respect to a particular embodiment, the coloring temperature may differ from the decolorization temperature by at least about 100°C, meaning that the coloring temperature may be at least about 100°C lower than the decolorization temperature.

[0080] With respect to a particular embodiment, the decolorization temperature may be related to the melting point of the reversible color change system (9), while the coloring temperature may be related to the freezing point of the reversible color change system (9). Accordingly, the reversible color change system (9) of the present invention may include (i) a melting point at which the reversible color change system (9) changes from a visibly colored state (17) to a colorless state, and (ii) a freezing point at which the reversible color change system (9) changes from a colorless state to a visibly colored state (17).

[0081] The hysteresis features of a particular embodiment of the reversible color-changing system (9) of the present invention having color memory properties can be illustrated by illustrating the temperature dependence of the color density. Referring mainly to Figure 5, the y-axis represents the color density and the x-axis represents the temperature. The color density of the reversible color-changing system (9) changes with temperature along the curve in the direction indicated by the arrow. Point A shows the color density at the maximum temperature T1 for achieving a fully colored state (where T1 is the complete coloring temperature). Point B shows the color density at the maximum temperature T2 for maintaining a fully colored state (where T2 is the decolorization start temperature). Point C shows the color density at the minimum temperature T3 for achieving a completely decolorized or colorless state (where T3 is the complete decolorization temperature). Point D shows the color density at the minimum temperature T4 for maintaining a completely decolorized or colorless state (where T4 is the coloring start temperature).

[0082] Referring again primarily to Figure 5, both a completely colored state and a completely decolorized or colorless state can exist between T2 and T4, but the retained state depends on the previously achieved state. For example, if a completely colored state was previously achieved by exposure to T1, the completely colored state will be retained until exposure to a temperature equal to or greater than T2. ​​Alternatively, if a completely decolorized or colorless state was previously achieved by exposure to T3, the completely decolorized or colorless state will be retained until exposure to a temperature equal to or lower than T4.

[0083] With respect to a particular embodiment, the colored state or the decolorized or colorless state can be maintained by exposure to temperatures between approximately 50°C and approximately 100°C from the temperature at which the colored state or decolorized or colorless state was achieved. In other words, the length of segment EF shown in Figure 5 represents the width of the temperature range that indicates the degree of hysteresis or hysteresis range or hysteresis window ΔH, which may be in the range between approximately 50°C and approximately 100°C.

[0084] As one illustrative example relating to the thermochromic indicator (1) of the present invention, exposure to a pre-selected activation temperature (16) causes a visible color change in the reversible color change system (9), which may become fully colored at T1. Subsequently, the visibly colored dye-developer complex (13) remains stable until temperature T2 is reached, so the fully colored state can be maintained as the temperature rises. Exposure to a pre-selected temperature threshold (7) causes a visible color change in the reversible color change system (9) at T3, which may become completely decolorized or colorless. Subsequently, the completely decolorized or colorless state can be maintained as the temperature falls, since the dye (10) remains dissociated from the developer (11) until temperature T4 is reached.

[0085] With respect to a particular embodiment, T1 may be a temperature lower than approximately 0°C, although it is not necessarily required. For example, T1 may be a temperature between approximately -5°C and approximately -25°C, although it is not necessarily required.

[0086] T2 may be a temperature related to the thermal welding of the roof membrane segments (3)(4) and may depend on the heat transfer characteristics of the specific roof membrane material to be welded.

[0087] With respect to a particular embodiment, T2 may be a temperature higher than approximately 50°C, although it is not necessarily required. For example, T2 may be a temperature between approximately 50°C and approximately 90°C, although it is not necessarily required.

[0088] With respect to a particular embodiment, the roofing membrane (14), for example, comprising polyvinyl chloride (PVC) or thermoplastic polyolefin (TPO), may have a welding temperature of about 135°C to about 150°C. Accordingly, the reversible color change system (9) may be formulated to have a T1 of about -10°C and (i) a T2 of about 67°C to about 70°C (e.g., applicable to hot or warm weather) or (ii) a T2 of about 40°C to about 45°C (e.g., applicable to cold or cool weather).

[0089] Microcapsules As described above, the reversible color change system (9) of the present invention is contained, meaning that the dye (10), developer (11), and solvent (12) are continuously held within a range of physical proximity that allows for interaction between the components. Furthermore, by being contained, the reversible color change system (9) is isolated from external environments that could damage or destroy the color change system (9).

[0090] Referring primarily to Figures 3A to 4B, in a particular embodiment, the reversible color change system (9) can be encapsulated within a capsule (or microcapsule) (15) to provide the corresponding encapsulated color change system (9), which, depending on the embodiment, may have a diameter in the range of about 500 nanometers to about 50 microns. In a particular embodiment, the capsule (15) of the present invention may have an average diameter in the range of about 1 micron to about 3 microns.

[0091] The capsule walls forming the capsules (15) around the reversible color change system (9) are made of many and a wide variety of polymers, such as melamine formaldehyde resin (CAS No.: 9003-08-01); CYMEL (registered trademark) 385; polyurethane resin (CAS No.: 9009-54-5); It can be formed from one of the following materials: acrylic resin, etc.

[0092] It should be noted that the capsule walls do not need to rupture or burst to produce a visible color change. This can be a significant difference from conventional temperature-sensitive capsules, which require the rupture or bursting of these walls to produce a visible color change. For example, conventional temperature-sensitive capsules may contain a color former and a chromogen, with at least one of these physically enclosed separately from the others to prevent interaction between the color former and the chromogen. Subsequently, the capsule walls must rupture or burst to bring the color former and chromogen within a range of physical proximity that allows interaction between the components, thereby forming a visibly colored dye-developer complex. For example, the rupture or bursting of the capsule releases the color former from the capsule, which comes into contact with the chromogen and reacts to form a visibly colored product.

[0093] With respect to the use of the present invention, the preceding description means that it is not required or necessary for the capsule wall containing the reversible color change system (9) of the present invention to rupture or burst in order to activate the thermochromic indicator (1) of the present invention for use. Thus, a visibly colored dye developer complex (13) may be formed and contained within a capsule (15).

[0094] Similarly, the preceding description means that, upon exposure to a pre-selected temperature threshold (7), it is not required or necessary for the capsule wall containing the reversible color change system (9) of the present invention to rupture or burst in order for the thermochromic indicator (1) of the present invention to produce a visible color change resulting from the dissociation of a visibly colored dye-developer complex (13). Accordingly, the dissociated dye (10) and developer (11) can be contained within the capsule (15) and prevented from interacting with each other to form the dye-developer complex (13).

[0095] With respect to certain embodiments, it may be necessary that the capsule wall does not rupture or burst in order to produce a visible color change. In other words, a visible color change can only occur if the capsule wall remains intact and thus functions to contain the reversible color change system (9).

[0096] The properties of the capsule wall, such as its composition, rigidity, flexibility, wall thickness, and size (corresponding to the diameter of the capsule or microcapsule), can be selected to result in an enclosed, reversible color change system (9) that visibly changes color at a pre-selected temperature threshold (7), which can be selected according to specific circumstances, including a particular roofing membrane (14) to be welded.

[0097] In particular embodiments, the thermal color change indicator (1) may include a plurality of clusters of enclosed reversible color change systems (9), each cluster having a characteristic pre-selected temperature threshold (7) at which it reacts to produce a visible color change.

[0098] coating With respect to a particular embodiment of the thermal color change indicator (1), the encapsulated reversible color change system (9) may be incorporated into a coating. Referring mainly to Figures 4A-4C and 6-8, as one illustrative example, the encapsulated reversible color change system (9) may be incorporated into an ink (18).

[0099] With respect to a particular embodiment, the ink (18) may include or be selected from the group consisting of: flexographic inks, gravure inks, offset inks, and screen inks. Depending on the application, the ink (18) may be water-based, solvent-based, UV-curable, wet, dry, or a combination thereof.

[0100] With respect to a particular embodiment, the ink (18) can be specially formulated to be applied to a substrate by printing, for example, printing onto a substrate configured as a roofing film (14).

[0101] The weight percentage of the capsule (15) of the present invention containing a reversible color change system (9) in a particular embodiment of an ink (18) that may be useful for printing on a roofing membrane (14) may be in the range of about 5 to 50%.

[0102] The weight percentage of the capsule (15) of the present invention containing a reversible color change system (9) in a particular embodiment of the ink (18) which may be useful for printing on a roofing membrane (14) may be in the range of about 15 to 20%.

[0103] In certain embodiments, following printing on the roofing film (14), the ink (18) can be cured relatively quickly or immediately by, for example, UV curing or solvent evaporation and / or drying. Thus, the roofing film (14) on which the thermochromic indicator (1) is printed can be packaged relatively quickly or immediately, for example, as a wound roll.

[0104] Welded membrane indicator for roofs As described above, the thermal color change indicator (1) of the present invention can be used by welding adjacent surfaces of the upper roof membrane segment edge portion (5) and the lower roof membrane segment edge portion (6), and accordingly, by using a method for visually determining whether the roof membrane joint (2) formed by the overlapping edges of the upper and lower roof membrane segments (3) and (4), i.e., the edges (5) and (6), has been sufficiently heated to a pre-selected temperature threshold (7) in order to seal the roof membrane joint (2).

[0105] The roof membrane (14) can be formed from a wide variety of thermoplastic and / or thermosetting materials that can be heat-welded. Illustrative examples of thermoplastic materials include PVC, thermoplastic olefin (TPO), polyethylene, polypropylene, chlorinated polyethylene (CPE), chlorosulfonated polyethylene (CSPE), or polyisobutylene (PIB). Illustrative examples of thermosetting materials include ethylene propylene diene monomer (EPDM), butyl rubber, or neoprene.

[0106] In a particular embodiment, the roof membrane (14) may be a single-ply roof membrane.

[0107] As a non-limiting example, the roofing membrane (14) may be Sikaplan single-ply PVC roofing membrane, available from Sika Corporation, 100 Dan Road, Canton, MA 02021.

[0108] As a second example of a non-limiting example, the roofing membrane (14) may be Sarnafil single-ply PVC roofing membrane, available from Sika Corporation, 100 Dan Road, Canton, MA 02021.

[0109] As a non-limiting example, a third example is that the roofing membrane (14) may be SURE-FLEX® PVC roofing membrane, available from Carlisle SynTec Systems, Carlisle, PA 17013.

[0110] The thermal color change indicator (1) of the present invention can be bonded, directly bonded, connected, directly connected, or integrated with the roof membrane (14) adjacent to and substantially parallel to its longitudinal edge. With respect to a particular embodiment, the thermal color change indicator (1) can be incorporated into a strip to obtain a thermal color change indicator strip (19) (solid, dashed, dotted, etc.) positioned close to the edge.

[0111] In a particular embodiment, the heat-sensitive indicator strip (19) can be positioned at a relatively short distance inward from the edge of the roof membrane (14) so ​​that the strip can be positioned generally laterally centered across the roof membrane seam region created by the overlapping edge portions (5)(6).

[0112] Referring primarily to Figures 1A and 1B, the upper and lower roof membrane segments (3)(4) are illustrated to be superimposed on a roofing substrate (20) (e.g., metal, agglomerate, gypsum board, wood board, wood panel, particleboard, etc.). Typically, though not always, the roofing substrate (20) can accommodate layers of insulation and / or other materials (not shown).

[0113] For installation, the lower roof membrane segment (4) can be rolled up to a predetermined position so that it overlaps with the roof substrate (20). Subsequently, the lower roof membrane segment (4) can be attached to the roof substrate (20) by means of adhesion or mechanical attachment, for example. Then, the upper roof membrane segment (3) can be rolled up to a predetermined position so that the edge portion (5) of the upper roof membrane segment, which includes such a heat-sensitive indicator strip (19), overlaps with the edge portion (6) of the lower roof membrane segment, thereby exposing the heat-sensitive indicator strip (19) upwards and making it visible in close proximity to the roof membrane seam (2).

[0114] It should be noted that the entire length of the roof membrane (14) may include a thermochromic indicator strip (19) along one of its edges, and the roof membrane segments (3)(4) may be positioned on the roof substrate (20) such that the thermochromic indicator strip (19) is positioned close to the roof membrane joint (2) on the upper surface (21) of the upper roof membrane segment (3), and the thermochromic indicator strip (19) is exposed upward and visible.

[0115] The adjacent surfaces of the overlapping edges (5) and (6) are heated (specifically, the upper surface (22) of the lower roof membrane segment and the lower surface (23) of the upper roof membrane segment), and the heat can pass through the upper roof membrane segment (3) to the heat-sensitive indicator (1) located on its upper surface (21), causing a visible color change.

[0116] Since heat is supplied to the lower surface (23) of the upper roof membrane segment and the thermal color change indicator (1) is bonded to the upper surface (21) on the opposite side, it should be recognized that a certain amount of experimentation may be necessary to determine an appropriate and accurate color shift temperature for a given composition and thickness of the roof membrane (14) in order to demonstrate reliable welding. Therefore, not only the characteristics of the roof membrane material that are relevant to achieving reliable welding, but also the thickness of the roof membrane (14) and its heat transfer characteristics determine how much heat is transferred to its upper surface (21) via the upper roof membrane segment (3), and thus how high the temperature of the upper surface (21) rises, and accordingly, the temperature at which the thermal color change indicator (1) should visibly change color.

[0117] More specifically, the thermal welding of the upper and lower roof membrane segments (3)(4) can be achieved via a hot air welder that can be inserted between adjacent surfaces of the overlapping edge portions (5)(6). This hot air welder can deliver heat in a controlled manner to the upper surface (22) of the lower roof membrane segment and the lower surface (23) of the upper roof membrane segment, thereby sufficiently heating and softening these surfaces so that when the hot air welder is removed (i.e., slid further forward longitudinally along the roof membrane joint (2)) and pressure is applied by an accompanying roller or pressure plate, the adjacent surfaces of the overlapping edge portions (5)(6) are welded together.

[0118] Naturally, if sufficient heat is applied to the adjacent surfaces of the overlapping edge portions (5)(6) to seal the roof membrane joint (2), it should be recognized that a sufficient amount of heat to achieve a visible color change will pass from the upper roof membrane segment (3) to the thermal color change indicator (1) on its upper surface (21).

[0119] How to apply As described above, the heat-change indicator (1) of the present invention can be bonded, directly bonded, connected, directly connected, or integrated with the roof membrane (14) adjacent to and substantially parallel to the longitudinal edge.

[0120] With regard to a particular embodiment, the heat-changeable indicator (1) of the present invention can be printed on a roof film (14).

[0121] In a particular embodiment, the encapsulated reversible color change system (9) of the present invention can be incorporated into an ink (18), which is then printed onto a roofing film (14).

[0122] In a particular embodiment, a sealed reversible color change system (9) can be incorporated into the ink (18) and this ink is printed onto the roofing film (14) during manufacturing. For example, a slot die coating machine can be used, which can dispense the ink (18) (using pre-formed shims) from a narrow slot using air pressure (e.g., 20-100 psi) from a pressurized reservoir. Depending on the print head, the ink (18) can be dispensed as one or more continuous lines or may have any desired printable pattern. Relatively quickly or immediately after printing, the ink (18) can be cured, for example, via a UV lamp. Relatively quickly or immediately after curing, the roofing film (14) can be wound up and rolled for storage, transport, and / or use. [Examples]

[0123] (Example 1) The subject matter of this disclosure is described herein with reference to the following embodiments. Note that these embodiments are provided for illustrative purposes only, and the subject matter is not limited to these embodiments but rather encompasses all variations that are apparent as a result of the teachings provided herein.

[0124] To test whether a particular embodiment of the thermal color change indicator (1) of the present invention described herein can be used to visually determine whether a sufficient amount of heat has been applied thereto, a sealed, reversible color change system (9) was developed and incorporated into an ink (18).

[0125] In particular, the thermochromic indicator (1) contains approximately 5-20% w / w of 7-[4-(diethylamino)-2-ethoxyphenyl]-7-(1-ethyl-2-methylindole-3-yl)flo[3,4-b]pyridine-5-one (CAS No.: 69898-40-4) as a dye, approximately 10-30% w / w of 4-[2-(4-hydroxyphenyl)-4-methylpentan-2-yl]phenol (CAS No.: 6807-17-6) as a developer, and approximately 30-60% w / w of (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dipentanoate (CAS The microencapsulated reversible color change system (9) having the color memory properties described above, comprising approximately 10-30% w / w of CYMEL® 385 as the capsule wall resin, and the microencapsulated reversible color change system (9) being prepared as taught in U.S. Patent No. 8,883,049, U.S. Patent No. 9,175,175, and U.S. Patent No. 9,695,320, respectively, which are incorporated herein by reference. The microcapsules (15) had an average diameter between approximately 1 micron and approximately 3 microns.

[0126] The microencapsulated reversible thermochromic system (9) was incorporated into a UV-curable flexographic ink (18), and the weight percentage of the microcapsules (15) in the ink (18) was approximately 15-20%.

[0127] Next, the ink (18) was printed onto the roofing film (14) (as shown in Figure 6), and then the film was heated to a pre-selected temperature threshold of 65°C using a heat-ray gun from left to right (as shown in Figure 8). In response to the heat, it can be observed that the thermochromic indicator (1) underwent a visible color change from blue to colorless.

[0128] As can be easily understood from the preceding description, the basic concepts of the present invention can be embodied in various ways. The present invention includes many and modified embodiments of thermal color change indicators and methods for manufacturing and using such thermal color change indicators.

[0129] Therefore, the specific embodiments or elements of the Invention disclosed herein or shown in the figures or tables attached to this application are not intended to be limiting, but rather to be illustrative of the many and varied embodiments collectively encompassed by the Invention, or equivalents encompassed with respect to any particular element thereof. In addition, a specific description of a single embodiment or element of the Invention cannot expressly describe all possible embodiments or elements. Many alternative forms are implicitly disclosed in the specification and figures.

[0130] It should be understood that each element of the apparatus or each step of the method may be described using the terms "apparatus" or "method." Such terms may be replaced if it is desired to make explicit the implicitly broad coverage over which the invention is authorized. As just one example, it should be understood that all steps of a method may be disclosed as an action, as a means for performing that action, or as an element causing that action. Similarly, each element of the apparatus may be disclosed as a physical element or as an action that facilitates a physical element. As just one example, the disclosure of a “combination” should be understood to include the disclosure of the act of “showing,” whether or not it is explicitly discussed, and conversely, if the act of “showing” is effectively disclosed, such disclosure should be understood to include the disclosure of a “display,” and even “means for showing.” Such alternative terms for each element or step are understood to be expressly included herein.

[0131] In addition, with respect to each term used, to the extent that its use in this application does not contradict such interpretation, each definition is included in a common dictionary such as the one contained in Random House Webster's Unabridged Dictionary, second edition, which is incorporated herein by reference. It should be understood that the definition is included in the description for each term.

[0132] All numerical values ​​in this specification, whether expressly indicated or not, are assumed to be modified with the term “approximately.” For the purposes of the present invention, a range can be expressed as “approximately” one particular value to “approximately” another particular value. Where such a range is expressed, an alternative embodiment includes from one particular value to another particular value. An enumeration of numerical ranges by endpoints includes all numerical values ​​that fall within that range. A numerical range of 1 to 5 includes, for example, the numerical values ​​1, 1.5, 2, 2.75, 3, 3.80, 4, 5, and so on. It should be further understood that each endpoint of a range is significant in relation to other endpoints or independently of other endpoints. Where values ​​are expressed as approximations by the use of “approximately” as set forth herein, it should be understood that particular values ​​form an alternative embodiment. The term “approximately” generally refers to a range of numerical values ​​that a person skilled in the art would consider equivalent to, or to have the same function or result, the enumerated numerical values. Similarly, “substantially” as set forth herein means primarily, but not entirely, the same form, style or degree, and particular elements have a range of configurations that a person skilled in the art would consider to have the same function or result. When a particular element is expressed as an approximation using the aforementioned "substantially," it should be understood that the particular element forms a different embodiment.

[0133] Furthermore, for the purposes of the present invention, the term “one (a)” or “one (an)” refers to one or more such entities, unless otherwise limited. Thus, the terms “one (a)” or “one (an),” “one or more,” and “at least one” can be used interchangeably herein.

[0134] Therefore, the applicant should be considered to claim at least the following: i) each of the thermochromic indicators disclosed and described herein; ii) related methods disclosed and described herein; iii) similar, equivalent, and further implicit variations of each of these devices and methods; iv) alternative embodiments that perform each of the functions shown, disclosed or described; v) alternative designs and methods that perform each of the functions implicitly shown to perform each of the functions disclosed and described herein; vi) each feature, component, and step shown as a distinct and independent invention; vii) applications enhanced by the various systems or components disclosed; viiii) resulting products produced by such systems or components; ix) methods and apparatus relating to any of the embodiments substantially described and accompanying herein; x) various combinations and permutations of each of the disclosed prior elements.

[0135] The background art section of this patent application provides, if any, a description of the field of focus to which the invention pertains. This section may also incorporate or include certain U.S. patents, patent applications, publications, or paraphrases of the subject matter of the claimed invention that are useful in relating information, issues, or concerns about the state of the art to which the invention relates. This is not intended to mean that any U.S. patent, patent application, publication, description, or other information cited or incorporated herein is to be accepted, received, or deemed to be prior art with respect to the invention.

[0136] The claims described herein, if any, are incorporated herein by reference as part of this description of the invention, and the applicant expressly has the right to use all or any part of such incorporated content of such claims as additional statements supporting any or all of the claims or any elements or components thereof, and, where necessary, to define matters for which such protection is sought by this application or any subsequent application or continuation, divisional application or continuation thereof, or to obtain any benefit, fee reduction in accordance with or in accordance with patent laws, rules or regulations of any country or treaty, the applicant expressly has the right to move any or all of such incorporated content of such claims or any elements or components from the specification to the claims (or vice versa), and such incorporated content by reference shall survive for the entire duration of the pendency of this application, including any subsequent continuation, divisional application or continuation thereof, or any reissue or extension thereof.

[0137] Furthermore, the claims described herein are intended to further describe only a limited number of preferred embodiments of the Invention, if any, and should not be taken as the broadest possible embodiments of the Invention or a complete list of embodiments of the Invention. The applicant does not waive any right to develop further claims based on the description described above as part of any continuation, divisional, or partial continuation or similar application. In one embodiment, for example, the following items are provided. (Item 1) A temperature indicator for visually determining whether a roof membrane has been sufficiently heated to a pre-selected temperature threshold in order to seal the seams of the roof membrane, dye, Chromogen, and solvent It contains a reversible color change system that includes The color developer interacts with the dye in a variable manner according to the temperature of the color change system. A temperature indicator in which exposure to the aforementioned temperature threshold causes the dye and the color developer to dissociate, resulting in a visible color change. (Item 2) The temperature indicator according to item 1, wherein the color-changing system records the exposure to the temperature threshold. (Item 3) The temperature indicator according to item 2, wherein the color-changing system includes color memory properties. (Item 4) The temperature indicator according to item 3, wherein the color memory characteristics promote the retention of the visible color change as the temperature decreases from the temperature threshold. (Item 5) The temperature indicator according to item 1, wherein exposure to a pre-selected activation temperature causes the dye and the developer to interact to form a visibly colored dye-developer complex. (Item 6) The temperature indicator according to item 5, wherein the visible color change includes a change from a visually colored state to a substantially colorless state. (Item 7) The temperature indicator according to item 6, wherein the colorless state effectively makes the temperature indicator on the roof membrane invisible. (Item 8) The temperature indicator according to item 6, wherein the aforementioned dye contains a leuco dye. (Item 9) The temperature indicator according to item 8, wherein the leuco dye reversibly changes between two forms, one of which is substantially colorless. (Item 10) The temperature indicator according to item 8, wherein the solvent contains hydrocarbons. (Item 11) The temperature indicator according to item 8, wherein the solvent contains a ketone. (Item 12) The temperature indicator according to item 8, wherein the solvent contains an ester. (Item 13) The temperature indicator according to item 12, wherein the ester comprises (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dipentanoate. (Item 14) The temperature indicator according to item 12, wherein the ester comprises (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dibutylate. (Item 15) The temperature indicator according to item 8, wherein the solvent contains an alcohol. (Item 16) The temperature indicator according to item 8, wherein the solvent comprises a single compound. (Item 17) The temperature indicator according to item 8, wherein the solvent comprises a mixture of two or more compounds. (Item 18) The aforementioned color change system The coloring temperature at which the color-changing system changes from the colorless state to the visibly colored state, Decolorization temperature at which the color change system changes from the visibly colored state to the colorless state A temperature indicator as described in item 6, including the one mentioned above. (Item 19) A temperature indicator according to item 18, wherein the coloring temperature is different from the decolorization temperature. (Item 20) The temperature indicator according to item 19, wherein the coloring temperature is lower than the decolorization temperature. (Item 21) The temperature indicator according to item 20, wherein the coloring temperature is at least about 50°C lower than the decolorization temperature. (Item 22) The temperature indicator according to item 20, wherein the coloring temperature is at least about 55°C lower than the decolorization temperature. (Item 23) The temperature indicator according to item 20, wherein the coloring temperature is at least about 60°C lower than the decolorization temperature. (Item 24) The temperature indicator according to item 20, wherein the coloring temperature is at least about 65°C lower than the decolorization temperature. (Item 25) The temperature indicator according to item 20, wherein the coloring temperature is at least about 70°C lower than the decolorization temperature. (Item 26) The temperature indicator according to item 20, wherein the coloring temperature is at least about 75°C lower than the decolorization temperature. (Item 27) The temperature indicator according to item 20, wherein the coloring temperature is at least about 80°C lower than the decolorization temperature. (Item 28) The temperature indicator according to item 20, wherein the coloring temperature is at least about 85°C lower than the decolorization temperature. (Item 29) The temperature indicator according to item 20, wherein the coloring temperature is at least about 90°C lower than the decolorization temperature. (Item 30) The temperature indicator according to item 20, wherein the coloring temperature is at least about 95°C lower than the decolorization temperature. (Item 31) The temperature indicator according to item 20, wherein the coloring temperature is at least about 100°C lower than the decolorization temperature. (Item 32) The temperature indicator according to item 20, wherein the complete coloring temperature of the color-changing system is lower than approximately 0°C. (Item 33) The temperature indicator according to item 32, wherein the complete coloring temperature of the color-changing system is between approximately -5°C and approximately -25°C. (Item 34) The temperature indicator according to item 20, wherein the decolorization start temperature of the discoloration system is related to the heat welding of the roof membrane joint. (Item 35) The temperature indicator according to item 34, wherein the decolorization initiation temperature of the color change system is a temperature higher than approximately 50°C. (Item 36) The temperature indicator according to item 35, wherein the decolorization start temperature of the discoloration system is between approximately 50°C and approximately 90°C. (Item 37) The temperature indicator according to item 4, wherein the dye, the color developer, and the solvent are continuously held within a range of physical proximity that allows interaction between the components. (Item 38) The temperature indicator according to item 37, wherein the dye, the color developer, and the solvent are enclosed in a capsule to provide an enclosed reversible color change system. (Item 39) The temperature indicator according to item 38, wherein the dye, the color developer, and the solvent are encapsulated in microcapsules. (Item 40) The temperature indicator according to item 38, wherein the capsule has an average diameter between approximately 1 micron and approximately 3 microns. (Item 41) The temperature indicator according to item 38, wherein the capsule includes a capsule wall. (Item 42) The temperature indicator according to item 41, wherein the capsule wall does not need to rupture in order to produce the visible color change. (Item 43) The temperature indicator according to item 41, wherein the capsule wall does not rupture in order to produce the visible color change. (Item 44) The temperature indicator according to item 41, wherein the visible color change may occur only if the capsule wall remains intact. (Item 45) A temperature indicator as described in item 38, further comprising multiple clusters of enclosed reversible color-changing systems. (Item 46) The temperature indicator according to item 38, wherein the enclosed reversible color change system is incorporated into the coating. (Item 47) The temperature indicator described in item 38, wherein the enclosed reversible color change system is incorporated into the ink. (Item 48) The temperature indicator according to item 47, wherein the ink is selected from the group consisting of flexographic ink, gravure ink, offset ink, and screen ink. (Item 49) The temperature indicator according to item 47, wherein the ink is formulated to be applied to the roof film by printing. (Item 50) The roofing membrane further comprises the aforementioned, The temperature indicator according to item 6, wherein the color-changing system is bonded to the roof membrane. (Item 51) The temperature indicator according to item 50, wherein the roof membrane comprises one or more thermoplastic and / or thermosetting materials. (Item 52) The temperature indicator according to item 50, wherein the color-changing system is incorporated into a strip bonded to the roof membrane adjacent to the longitudinal edge. (Item 53) The temperature indicator according to item 52, wherein the strip is adjacent to and substantially parallel to the longitudinal edge. (Item 54) A roofing membrane, The roof membrane segment includes a temperature indicator for visually determining whether it has been sufficiently heated to a pre-selected temperature threshold in order to seal the roof membrane joint, and the temperature indicator is dye, Chromogen, and solvent It contains a reversible color change system that includes The color developer interacts with the dye in a variable manner according to the temperature of the color change system. A roofing film in which exposure to the aforementioned temperature threshold causes the dye and the color developer to dissociate, resulting in a visible color change. (Item 55) The roofing film according to item 54, wherein the color change system records the exposure to the temperature threshold. (Item 56) The roofing film according to item 55, wherein the color-changing system includes color memory properties. (Item 57) The roof film according to item 56, wherein the color memory characteristics promote the retention of the visible color change as the temperature decreases from the temperature threshold. (Item 58) The roofing film according to item 54, wherein exposure to a pre-selected activation temperature causes the dye and the developer to interact to form a visibly colored dye-developer complex. (Item 59) The roofing film according to item 58, wherein the visible color change includes a change from a visually colored state to a substantially colorless state. (Item 60) The roofing membrane according to item 59, wherein the colorless state effectively makes the temperature indicator on the roofing membrane invisible. (Item 61) The roofing film according to item 59, wherein the aforementioned dye contains a leuco dye. (Item 62) The roofing film according to item 61, wherein the leuco dye reversibly changes between two forms, one of which is substantially colorless. (Item 63) The roofing film according to item 61, wherein the solvent comprises a hydrocarbon. (Item 64) The roofing film according to item 61, wherein the solvent contains a ketone. (Item 65) The roofing film according to item 61, wherein the solvent comprises an ester. (Item 66) The roofing film according to item 65, wherein the ester comprises (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dipentanoate. (Item 67) The roofing film according to item 65, wherein the ester comprises (1,4-phenylenebis(oxy))bis(ethane-2,1-diyl)dibutylate. (Item 68) The roofing film according to item 61, wherein the solvent comprises an alcohol. (Item 69) The roofing film according to item 61, wherein the solvent comprises a single compound. (Item 70) The roofing film according to item 61, wherein the solvent comprises a mixture of two or more compounds. (Item 71) The aforementioned color change system The coloring temperature at which the color-changing system changes from the colorless state to the visibly colored state, Decolorization temperature at which the color change system changes from the visibly colored state to the colorless state Roofing membranes as described in item 59, including those listed. (Item 72) The roofing film according to item 71, wherein the coloring temperature is different from the decolorization temperature. (Item 73) The roofing film according to item 72, wherein the coloring temperature is lower than the decolorization temperature. (Item 74) The roofing film according to item 73, wherein the coloring temperature is at least about 50°C lower than the decolorization temperature. (Item 75) The roofing film according to item 73, wherein the coloring temperature is at least about 55°C lower than the decolorization temperature. (Item 76) The roofing film according to item 73, wherein the coloring temperature is at least about 60°C lower than the decolorization temperature. (Item 77) The roofing film according to item 73, wherein the coloring temperature is at least about 65°C lower than the decolorization temperature. (Item 78) The roofing film according to item 73, wherein the coloring temperature is at least about 70°C lower than the decolorization temperature. (Item 79) The roofing film according to item 73, wherein the coloring temperature is at least about 75°C lower than the decolorization temperature. (Item 80) The roofing film according to item 73, wherein the coloring temperature is at least about 80°C lower than the decolorization temperature. (Item 81) The roofing film according to item 73, wherein the coloring temperature is at least about 85°C lower than the decolorization temperature. (Item 82) The roofing film according to item 73, wherein the coloring temperature is at least about 90°C lower than the decolorization temperature. (Item 83) The roofing film according to item 73, wherein the coloring temperature is at least about 95°C lower than the decolorization temperature. (Item 84) The roofing film according to item 73, wherein the coloring temperature is at least about 100°C lower than the decolorization temperature. (Item 85) The roofing film according to item 73, wherein the complete coloring temperature of the color change system is lower than approximately 0°C. (Item 86) The roofing film according to item 85, wherein the complete coloring temperature of the color-changing system is between approximately -5°C and approximately -25°C. (Item 87) The roofing membrane according to item 73, wherein the decolorization initiation temperature of the discoloration system is related to the heat welding of the roofing membrane seams. (Item 88) The roofing film according to item 87, wherein the decolorization initiation temperature of the discoloration system is a temperature higher than approximately 50°C. (Item 89) The roofing film according to item 88, wherein the decolorization initiation temperature of the discoloration system is between approximately 50°C and approximately 90°C. (Item 90) The roofing film according to item 57, wherein the dye, the developer, and the solvent are continuously held within a range of physical proximity that allows for interaction between the components. (Item 91) The roofing film according to item 90, wherein the dye, the color developer, and the solvent are encapsulated within a capsule to provide an enclosed, reversible color change system. (Item 92) The roofing film according to item 91, wherein the dye, the color developer, and the solvent are encapsulated in microcapsules. (Item 93) The roofing membrane according to item 91, wherein the capsules have an average diameter between approximately 1 micron and approximately 3 microns. (Item 94) The roofing membrane according to item 91, wherein the capsule includes a capsule wall. (Item 95) The roofing membrane according to item 94, wherein the capsule wall does not need to rupture in order to produce the visible color change. (Item 96) The roofing membrane according to item 94, wherein the capsule wall does not rupture in order to produce the visible color change. (Item 97) The roofing film according to item 94, wherein the visible color change may occur only if the capsule wall remains intact. (Item 98) A roofing membrane according to item 91, further comprising multiple clusters of encapsulated reversible color change systems. (Item 99) The roofing film according to item 91, wherein the enclosed reversible color change system is incorporated into the coating. (Item 100) The roofing film described in item 91, wherein the enclosed reversible color change system is incorporated into the ink. (Item 101) The roofing film according to item 100, wherein the ink is selected from the group consisting of flexographic ink, gravure ink, offset ink, and screen ink. (Item 102) The roofing film according to item 100, wherein the ink is formulated to be applied to the roofing film by printing. (Item 103) The roofing membrane further comprises the aforementioned, The roofing membrane according to item 59, wherein the color-changing system is bonded to the roofing membrane. (Item 104) The roofing membrane according to item 103, wherein the roofing membrane comprises one or more thermoplastic and / or thermosetting materials. (Item 105) The roofing membrane according to item 103, wherein the color change system is incorporated into a strip bonded to the roofing membrane near the longitudinal edge. (Item 106) The roofing membrane according to item 105, wherein the strip is adjacent to and substantially parallel to the longitudinal edge. (Item 107) A method for manufacturing a temperature indicator for visually determining whether a roof membrane has been sufficiently heated to a pre-selected temperature threshold in order to seal the joints of the roof membrane, dye, Chromogen, and solvent, The step includes including a reversible color change system containing, The color developer interacts with the dye in a variable manner according to the temperature of the color change system. A method comprising causing the dye and the color developer to dissociate upon exposure to the aforementioned temperature threshold, thereby resulting in a visible color change. (Item 108) The method according to item 107, further comprising the step of encapsulating the color-changing system to provide the contained color-changing system. (Item 109) The method according to item 108, further comprising the step of microencapsulating the color change system. (Item 110) The method according to item 109, further comprising the step of incorporating the contained color-changing system into a coating. (Item 111) The method according to item 110, further comprising the step of incorporating the contained color-changing system into the ink. (Item 112) The method according to item 111, further comprising the step of activating the color change system to form a visibly colored dye developer complex. (Item 113) The method according to item 112, comprising the step of exposing the color change system to a pre-selected activation temperature at which the activation occurs, so that the dye and the developer associate to form the visibly colored dye-developer complex. (Item 114) The method according to item 112, further comprising the step of printing the ink onto the roof film. (Item 115) The method according to item 114, further comprising the step of printing the ink onto the roofing film to form strips close to the longitudinal edges. (Item 116) The method according to item 115, wherein the strip is adjacent to and substantially parallel to the longitudinal edge. (Item 117) The method according to item 114, further comprising the step of curing the ink. (Item 118) The method according to item 117, further comprising the step of winding up the roofing membrane into a roll. (Item 119) A method for visually determining whether a roofing membrane has been sufficiently heated to a pre-selected temperature threshold in order to seal the seams of the roofing membrane, dye, Chromogen, and solvent A reversible color change system containing The step includes visually observing a temperature indicator that includes the following: The color developer interacts with the dye in a variable manner according to the temperature of the color change system. Upon exposure to the aforementioned temperature threshold, the dye and the color developer dissociate, resulting in a visible color change. method. (Item 120) The method according to item 119, wherein visual detection of the color change indicates that the roof membrane has been sufficiently heated to the pre-selected temperature threshold in order to seal the seams of the roof membrane. (Item 121) The method according to item 120, wherein the visual detection of the absence of the aforementioned color change indicates that the roof membrane has not been sufficiently heated to the pre-selected temperature threshold in order to seal the seams of the roof membrane. (Item 122) The method according to item 121, wherein the color change system records the exposure to the temperature threshold. (Item 123) The method according to item 122, wherein the color change system includes color memory properties. (Item 124) The method according to item 123, wherein the color memory characteristics promote the retention of the color change as the temperature decreases from the temperature threshold. (Item 125) A step of spreading the roofing membrane on the roof, The steps of overlapping the edges of adjacent roof membrane segments to form a roof membrane joint, and The step of welding the overlapping edge portions to form a sealed section. The method described in item 124, further including the method described in item 124. (Item 126) The process further includes the step of overlapping the lower roof membrane segment edge with the upper roof member segment edge, The upper roof member segment edge portion includes the temperature indicator, The method according to item 125, wherein the temperature indicator is exposed upward so as to be visible in close proximity to the roof membrane seam. (Item 127) The method according to item 125, further comprising the step of welding the overlapping edge portions and fusing the materials of the roof membrane segments to form the sealed portion. (Item 128) The method according to item 127, further comprising the step of inserting a hot air welding machine between adjacent surfaces of the overlapping edge portions. (Item 129) The method according to item 128, further comprising the step of applying pressure to the adjacent surfaces of the overlapping edge portions. (Item 130) The method according to item 129, further comprising the step of generating the continuous sealed portion between the roof membrane segments.

Claims

[Claim 1] The invention described herein.

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