Re-Orientable Spray Foam Gun Nozzles

Abstract

The invention pertains to a plastic spray gun nozzle having an orientable spray pattern achieved by rotational movement of the repositionable plastic nozzle.

Claims

1. In combination, a plastic spray gun nozzle with a spray gun, wherein: the plastic spray gun nozzle comprises a tapered elongated cylindrical nozzle bore extending along a longitudinal axis, said cylindrical nozzle bore having an expanded cylindrical nozzle entrance collar at an ingress end and an opposed egress exit end having a pair of divergent opposed lips at the egress exit end; said nozzle entrance collar comprising an interior and an exterior; and the nozzle entrance collar in at least partial rotational mating engagement with an exterior of a front portion of a housing of the spray gun, the at least partial rotational mating engagement selected from the group consisting of (a) at least one depressed channel extending at least partially around the exterior circumference of the front portion of the housing of the spray gun and at least one raised projection extending at least partially around the interior circumference of the nozzle entrance collar; and (b) at least one depressed channel extending at least partially around the interior circumference of the nozzle entrance collar and at least one raised projection extending at least partially around the exterior circumference of the front portion of the housing of the spray gun; and wherein said plastic spray nozzle dispenses a pressurized polyurethane foam or a polyurethane froth in an oriented spray pattern.

2. The combination of claim 1 wherein a rotational position of the nozzle is continuously adjustable while mated with the front portion of the housing of the spray gun.

3. The combination of claim 1 wherein a rotational position of the nozzle is continuously adjustable within a restricted range defined by the at least one depressed channel while mated with the front portion of the housing of the spray gun.

4. The combination of claim 3 wherein the restricted range is limited to less than 180.

5. The combination of claim 1 wherein the at least one raised projection is a ridge.

6. The combination of claim 1 wherein the at least one raised projection is a knob.

7. The combination of claim 1 wherein the entrance collar exterior comprises at least one pair of longitudinally extending raised ridges along at least a portion of an exterior surface of the entrance collar.

8. The combination of claim 1 further comprising at least one thermochromic material disposed within or affixed thereupon said plastic spray gun nozzle.

9. The combination of claim 7 wherein said thermochromic material changing color by measuring the temperature of either the flow of pressurized chemicals or flow of synthesized froth foam or both egressing through said plastic nozzle to illustrate to the end-user of the spray gun if the pressurized chemicals and propellant used to prepare the polyurethane foam or the polyurethane froth are at a minimum temperature for proper chemical cure of the A and B chemicals, the propellant comprising a fluorocarbon and an inert gas in which the propellant enters into the nozzle as a liquid component under the pressure of between approximately 130-250 psi and changes to a gaseous state component during travel through the nozzle and egress therefrom into the environment with turbulent flow between the liquid components, gaseous components and synthesized froth foam.

10. The combination of claim 7 wherein said thermochromic material is affixed upon said plastic nozzle by a label containing said thermochromic material.

11. A plastic spray gun nozzle comprising: a tapered elongated cylindrical nozzle bore extending along a longitudinal axis, said cylindrical nozzle bore having an expanded cylindrical nozzle entrance collar at an ingress end and an opposed egress exit end; said nozzle entrance collar comprising an interior and an exterior; and the nozzle entrance collar in mating engagement with a front portion of a housing of a spray gun; a tip comprising a pair of divergent opposed lips at a first end and a connecting collar at a second end, the connecting collar in at least partial rotational mating engagement with the egress exit end of the nozzle, the at least partial rotational mating engagement selected from the group consisting of (a) at least one depressed channel extending at least partially around the exterior circumference of the egress exit end of the nozzle and at least one raised projection extending at least partially around the interior circumference of the tip connecting collar; (b) at least one depressed channel extending at least partially around the interior circumference of the tip connecting collar and at least one raised projection extending at least partially around the exterior circumference of the egress exit end of the nozzle; (c) at least one depressed channel extending at least partially around the interior circumference of the egress exit end of the nozzle and at least one raised projection extending at least partially around the exterior circumference of the tip connecting collar, the connecting collar further comprising a pair of notches; and (d) at least one depressed channel extending at least partially around the exterior circumference of the tip connecting collar and at least one raised projection extending at least partially around the interior circumference of the egress exit end of the nozzle, the connecting collar further comprising a pair of notches; and wherein said plastic spray nozzle dispenses a pressurized polyurethane foam or a polyurethane froth in an oriented spray pattern.

12. The plastic spray gun nozzle of claim 11 wherein a rotational position of the tip is continuously adjustable while mated with the egress exit end of the nozzle.

13. The plastic spray gun nozzle of claim 11 wherein a rotational position of the tip is continuously adjustable within a restricted range defined by the at least one depressed channel while mated with the egress exit end of the nozzle.

14. The combination of claim 13 wherein the restricted range is limited to less than 180.

15. The combination of claim 11 wherein the at least one raised projection is a ridge.

16. The combination of claim 11 wherein the at least one raised projection is a knob.

17. The plastic spray gun nozzle of claim 11 wherein the entrance collar exterior comprises at least one pair of longitudinally extending raised ridges along at least a portion of an exterior surface of the entrance collar.

18. The plastic spray gun nozzle of claim 11 further comprising at least one thermochromic material disposed within or affixed thereupon said plastic spray gun nozzle.

19. The plastic spray gun nozzle of claim 17 wherein said thermochromic material changing color by measuring the temperature of either the flow of pressurized chemicals or flow of synthesized froth foam or both egressing through said plastic nozzle to illustrate to the end-user of the spray gun if the pressurized chemicals and propellant used to prepare the polyurethane foam or the polyurethane froth are at a minimum temperature for proper chemical cure of the A and B chemicals, the propellant comprising a fluorocarbon and an inert gas in which the propellant enters into the nozzle as a liquid component under the pressure of between approximately 130-250 psi and changes to a gaseous state component during travel through the nozzle and egress therefrom into the environment with turbulent flow between the liquid components, gaseous components and synthesized froth foam.

20. The plastic spray gun nozzle of claim 17 wherein said thermochromic material is affixed upon said plastic nozzle by a label containing said thermochromic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawing which form a part hereof, and wherein:

[0031] FIG. 1 is a perspective view of the nozzle of the present invention mated with a dispensing gun;

[0032] FIG. 2 is a side view of the tip of the nozzle, displaying the divergent lips;

[0033] FIG. 3 is a perspective view of the nozzle of the present invention with a spray gun having a depressed channel extending substantially around the circumference of the front portion of the housing of the spray gun;

[0034] FIG. 4 is a perspective view displaying the interior of the entrance collar of one embodiment of the nozzle of the present invention;

[0035] FIG. 5 is a perspective view of the nozzle of the present invention with a spray gun having raised protrusions on the front portion of the housing of the spray gun;

[0036] FIG. 6 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention;

[0037] FIG. 7 is a perspective view displaying a spray gun, a nozzle, and two embodiments of a reorientable tip;

[0038] FIG. 8 is a perspective view of the nozzle of the present invention with a spray gun having depressed channels extending around a portion of the circumference of the front portion of the housing of the spray gun;

[0039] FIG. 9 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention;

[0040] FIG. 10 is a perspective view displaying a spray gun, a nozzle, and two embodiments of a reorientable tip;

[0041] FIG. 11 is a perspective view displaying a spray gun, a nozzle, and another embodiment of a reorientable tip; and

[0042] FIG. 12 is a perspective view displaying a color-changing label affixed to the exterior of the nozzle.

DETAILED DESCRIPTION OF THE INVENTION

[0043] The best mode for carrying out the invention will now be described for the purposes of illustrating the best mode known to the applicant at the time of the filing of this patent application. The examples and figures are illustrative only and not meant to limit the invention, which is measured by the scope and spirit of the claims.

[0044] For consistency in terminology, when describing the plastic spray gun nozzle 20 or the spray gun 50, longitudinal will refer to the direction of the dispensing gun along the long axis of dispensing passage; transverse will refer to the direction perpendicular to a longitudinal axis. Protrusion can refer to at least a raised ridge, knob, or thread.

[0045] The invention relates to, as shown in the perspective view in FIG. 1, a plastic spray gun nozzle 20 which can be used in dispensing a pressurized polyurethane foam or a polyurethane froth. As displayed by mated assembly 100, nozzle 20 removeably mates with an exterior of front portion 62 of a housing of spray gun body 50. As illustrated, spray gun 50 has a pair of upwardly canting hose openings 52a, 52b in communication with removable nozzle 20. Safety lock 60 is pivotally positioned within dispensing trigger 58 which is positioned before rearward-sloping curvilinear handle 56. Safety lock 60 is accessed and controlled typically via index finger control by the user. In one aspect of the invention, snap-on nozzle 20 is a temperature sensitive nozzle in which the nozzle changes color upon sensing the temperature of the dispensed chemicals, thereby permitting the user to visually see if the chemicals are being dispensed at the proper temperature, which at least in part, governs the applied A/B ratio. The dispensing gun is further provided with high/low or on/off output control lever 54 for further control by an operator. When used for high/low flow control, different diametered channels are bored into a transverse shaft of control lever 54.

[0046] In one embodiment, nozzle 20 is molded from an ABS (Acrylonitrile-Butadiene-Styrene) plastic. However, the nozzle may be constructed of any rigid material using sound engineering judgment. Nozzle 20 comprises a tapered elongated cylindrical bore extending along a longitudinal axis, the cylindrical bore having an expanded cylindrical entrance collar 22 at an ingress end and an opposed egress exit end having a pair of divergent opposed lips 26. Entrance collar 22 exterior can optionally include at least one pair of longitudinally extending raised ridges 24 along at least a portion of an exterior surface of the entrance collar. Raised ridges 24 create a gripping surface, making it easier for a user to twist nozzle 20. In one embodiment illustrated in FIG. 1, raised ridges 24 extend longitudinally onto the tapered section of the nozzle 20. Nozzle 20 is designed to removeably mate with front portion 62 of the housing of spray gun 50 in different rotational positions. This re-orienting feature allows the operator of a foam dispensing gun to modify the angle of the foam's spray pattern without needing to change the angle at which the user holds the spray gun. Rather than holding the gun at awkward angles to achieve a specific spray pattern, a user of spray gun 50 can simply twist the gun's nozzle 20 while mated with front portion 62 of the housing of spray gun 50 and continue to spray holding the gun in the same orientation, yet achieve a different spray pattern.

[0047] The tip of the nozzle 20 has a pair of flared or divergent lips 26 that meet to create a triangular notch near the base of the tip. The notch at the base of the tip of the nozzle 20 in a most preferred embodiment is triangular in shape to create the desired spray pattern. The lips 26 diverge at an angle between the divergent lips 26, shown in FIG. 2, preferably 2-55, inclusive, and more preferably an angle of 5-25, inclusive. A gap exists between the end of the lips 26 of the nozzle 20 where the spray foam exits the nozzle 20.

[0048] As better illustrated in FIG. 3, the exterior of front portion 62 of the housing of spray gun 50 has at least one depressed channel 64 extending substantially around the circumference of front portion 62 of the housing of spray gun 50. In certain embodiments, depressed channel 64 extends completely around (360 around) the circumference of front portion 62. In other embodiments, depressed channel 64 extends less than completely around the circumference of front portion 62. As depicted in FIG. 4, the interior of the nozzle's 20 entrance collar 22 has at least one protrusion 28. The at least one protrusion 28 can be matingly engaged with depressed channel 64 on the exterior of front portion 62 of the housing of spray gun 50 so that nozzle 20 is secured to front portion 62 of the housing of spray gun 50. Once secured to front portion 62, nozzle 20 can be rotated freely by a user. This free rotation of nozzle 20 allows for continuous adjustment of the rotational position of nozzle 20. The benefit of this ability is that continuous adjustment of the rotational position of nozzle 20 allows the user to implement different angles of the foam spray pattern created by divergent lips 26. The spray pattern can be adjusted to a vertical spray pattern, a horizontal spray pattern, or a spray pattern having any angle therebetween. While at least one protrusion 28 is illustrated, it is recognized that a series of protrusions may be employed. It is further recognized that a mating ring and depressed channel 64 may be employed to connect nozzle 20 to spray gun 50.

[0049] It should be appreciated that the mating structure locations can be interchanged. For example, FIGS. 5 & 6 depict another embodiment in which the exterior of front portion 62 has at least one protrusion 66. Nozzle's 20 entrance collar interior has at least one depressed channel 30 extending substantially around the circumference of expanded cylindrical entrance collar 22 interior. In certain embodiments, depressed channel 30 extends completely around (360 around) the circumference of expanded cylindrical entrance collar 22 interior. In other embodiments, depressed channel 30 extends slightly less than completely around the circumference of expanded cylindrical entrance collar 22 interior. The at least one protrusion 66 on the exterior of the front portion 62 can be matingly engaged with the depressed channel 30 of the interior of the expanded cylindrical entrance collar 22 so that nozzle 20 is secured to front portion 62 of the housing of spray gun 50. Once secured to front portion 62, nozzle 20 can be rotated freely by a user. This free rotation of nozzle 20 allows for continuous adjustment of the rotational position of nozzle 20 similar to the above embodiment.

[0050] FIG. 7 depicts further embodiments of the present invention. In these embodiments, nozzle 20 can have any of the same structures as previously described. Nozzle 20 can mate with front portion 62 of spray gun 50 in any manner previously described or in any other manner using sound engineering judgment. Tip 32 is removeably mated with an egress exit end 68 of nozzle 20. Tip 32 has a pair of divergent opposed lips 26 at a first end and a connecting collar 34 at a second end. In a first embodiment 110, egress exit end 68 of nozzle 20 has a first raised ridge 70 or a depressed channel 72, wherein the first raised ridge 70 or depressed channel 72 extends substantially around a circumference of an exterior of the egress exit end 68. Connecting collar 34 of tip 32 has a second raised ridge 38 or a depressed channel 36 extending substantially around the circumference of the interior of connecting collar 34. First raised ridge 70 or depressed channel 72 is matingly engaged with the second raised ridge 38 or depressed channel 36 so that the tip is secured to egress end 68 of the cylindrical bore. It should be appreciated that the raised ridges (70, 38) and depressed channels (72, 36) can extend around the entire circumference of its respective surface or around a smaller portion of its respective surface in a manner that creates restricted rotation of the tip 32.

[0051] In a second embodiment 120, the egress exit end 68 of nozzle 20 has a first raised ridge 70 or a depressed channel 72, wherein the first raised ridge 70 or depressed channel 72 extends substantially around a circumference of an interior of the egress exit end 68. Connecting collar 34 of tip 32 has a pair of notches 40 and a second raised ridge 38 or a depressed channel 36 extending substantially around the circumference of the exterior of connecting collar 34. First raised ridge 70 or depressed channel 72 is matingly engaged with the second raised ridge 38 or depressed channel 36 so that the tip is secured to egress end 68 of the cylindrical bore. Notches 40 allow connecting collar 34 to be slightly compressed, allowing connecting collar 34 to fit into the interior of egress exit end 68.

[0052] Looking now to FIG. 8, embodiments of the present invention can have at least one depressed channel 74 in front portion 62 of spray gun 50, the channel 74 extends only partially around circumference of the exterior of front portion 62. For example, in certain embodiments, depressed channel 74 extends along less than 180 of the circumference of the exterior of front portion 62. In other embodiments, depressed channel 74 extends along 90 of the circumference of the exterior of front portion 62. This feature creates a restricted rotation of nozzle 20. Rotational position of nozzle 20 in this embodiment is continuously adjustable by twisting within the restricted range of rotation defined by depressed channels 74. The termination of depressed channels 74 on either end acts as a detent. The corresponding expanded cylindrical entrance collar 22 interior has protrusions 28 as shown in FIG. 4. It should be appreciated that the mating connections can be interchanged. For example, the front portion 62 can have the protrusions 66 as shown in FIG. 5 while the interior of expanded cylindrical entrance collar 22 can have depressed channels 42 extending along a portion of the circumference of the interior of expanded cylindrical entrance collar 22 as shown in FIG. 9.

[0053] FIG. 10 shows additional embodiments of the present invention. These embodiments have a similar tip 32 as described in reference FIG. 7. In one embodiment, connecting collar 34 of tip 32 has a pair of depressed channels 44 that each extend along a portion of the interior circumference of connecting collar 34. For example, each depressed channel 44 of the pair may extend about less than 180 along the inner circumference of the connecting collar 34. In another example, each depressed channel 44 of the pair may extend about 90 along the inner circumference of the connecting collar 34. These depressed channels 44 matingly engage with a pair of raised protrusions 76 located on the exterior of egress exit end 68 of nozzle 20 so that tip 32 is secured to egress end 68 of the cylindrical bore. Alternatively, egress exit end 68 of nozzle 20 can have the pair of depressed channels 78 extending along a portion of the exterior perimeter of the egress exit end 68 of the nozzle 20 while the interior of the connecting collar 34 has the raised protrusions 46 that matingly engage with the pair of depressed channels 78 so that the tip 32 is secured to the egress end 68 of the cylindrical bore. In these embodiments, the pair of channels 78 create restricted rotation of the tip 32. The rotational position of tip 32 is continuously adjustable by twisting within the restricted rotational range defined by depressed channels 78. The termination of depressed channels 78 on either end acts as a detent.

[0054] FIG. 11 depicts another embodiment of the present invention. In this embodiment, connecting collar 34 of tip 32 has a pair of depressed channels 48 that each extend along a portion of the exterior circumference of connecting collar 34. For example, each depressed channel 48 of the pair may extend less than 180 along the outer circumference of the connecting collar 34. In another example, each depressed channel 48 of the pair may extend about 90 along the outer circumference of the connecting collar 34. These depressed channels 48 matingly engage with a pair of raised protrusions 80 located on the interior of egress exit end 68 of nozzle 20 so that tip 32 is secured to egress end 68 of the cylindrical bore. In this embodiment, the pair of channels 48 create restricted rotation of the tip 32. The rotational position of tip 32 is continuously adjustable by twisting within the restricted rotational range defined by depressed channels 48. The termination of depressed channels 48 on either end acts as a detent.

[0055] In one additional aspect of the invention, the ability to determine the chemical temperature as the foam or froth enters and/or exits nozzle 20 is effected by having a thermochromic material contained within the plastic used to mold disposable nozzle 20. Turning to FIG. 12, still another approach involves affixing a label 82 either permanently using a permanent adhesive or non-permanently, using a pressure-sensitive adhesive (the label 82 optionally having thermochromic text or thermochromic graphic material printed thereupon) which changes in one instance from colored (below the recommended use temperature, illustrated by the text Cold in FIG. 12), to colorless or a different color when the chemicals have transferred a sufficient amount of heat to the nozzle or label 82. While a label is only illustrated in one figure, it is recognized that a label may be affixed to any nozzle illustrated in any of the figures.

[0056] Thermochromism is typically implemented via one of two common approaches: liquid crystals and leuco dyes. Liquid crystals are used in precision applications, as their responses can be engineered to accurate temperatures, but their color range is limited by their principle of operation. Leuco dyes allow wider range of colors to be used, but their response temperatures are more difficult to set with accuracy.

[0057] Some liquid crystals are capable of displaying different colors at different temperatures. This change is dependent on selective reflection of certain wavelengths by the crystalline structure of the material, as it changes between the low-temperature crystalline phase, through anisotropic chiral or twisted nematic phase, to the high-temperature isotropic liquid phase. Only the nematic mesophase has thermochromic properties. This restricts the effective temperature range of the material.

[0058] The twisted nematic phase has the molecules oriented in layers with regularly changing orientation, which gives them periodic spacing. The light passing through the crystal undergoes Bragg diffraction on these layers, and the wavelength with the greatest constructive interference is reflected back, which is perceived as a spectral color. A change in the crystal temperature can result in a change of spacing between the layers and therefore in the reflected wavelength. The color of the thermochromic liquid crystal can therefore continuously range from non-reflective (black) through the spectral colors to black again, depending on the temperature. Typically, the high temperature state will reflect blue-violet, while the low-temperature state will reflect red-orange. Since blue is a shorter wavelength than red, this indicates that the distance of layer spacing is reduced by heating through the liquid-crystal state.

[0059] Some such materials are cholesteryl nonanoate or cyanobiphenyls. Liquid crystals used in dyes and inks often come microencapsulated, in the form of suspension. Liquid crystals are used in applications where the color change has to be accurately defined.

[0060] Thermochromic dyes are based on mixtures of leuco dyes with suitable other chemicals, displaying a color change (usually between the colorless leuco form and the colored form) in dependence on temperature. The dyes are rarely applied on materials directly; they are usually in the form of microcapsules with the mixture sealed inside. An illustrative example would include microcapsules with crystal violet lactone, weak acid, and a dissociable salt dissolved in dodecanol; when the solvent is solid, the dye exists in its lactone leuco form, while when the solvent melts, the salt dissociates, the pH inside the microcapsule lowers, the dye becomes protonated, its lactone ring opens, and its absorption spectrum shifts drastically, therefore it becomes deeply violet. In this case the apparent thermochromism is in fact halochromism.

[0061] The dyes most commonly used are spirolactones, fluorans, spiropyrans, and fulgides. The weak acids include bisphenol A, parabens, 1,2,3-triazole derivates, and 4-hydroxycoumarin and act as proton donors, changing the dye molecule between its leuco form and its protonated colored form; stronger acids would make the change irreversible.

[0062] Leuco dyes have less accurate temperature response than liquid crystals. They are suitable for general indicators of approximate temperature. They are usually used in combination with some other pigment, producing a color change between the color of the base pigment and the color of the pigment combined with the color of the non-leuco form of the leuco dye. Organic leuco dyes are available for temperature ranges between about 23 F. (5 C.) and about 140 F. (60 C.), in wide range of colors. The color change usually happens in about a 5.4 F. (3 C.) interval.

[0063] The size of the microcapsules typically ranges between 3-5 m (over 10 times larger than regular pigment particles), which requires some adjustments to printing and manufacturing processes.

[0064] Thermochromic paints use liquid crystals or leuco dye technology. After absorbing a certain amount of light or heat, the crystalline or molecular structure of the pigment reversibly changes in such a way that it absorbs and emits light at a different wavelength than at lower temperatures.

[0065] The thermochromic dyes contained either within or affixed upon either the disposable nozzle or hoses may be configured to change the color of the composition in various ways. For example, in one embodiment, once the composition reaches a selected temperature, the composition may change from a base color to a white color or a clear color. In another embodiment, a pigment or dye that does not change color based on temperature may be present for providing a base color. The thermochromic dyes, on the other hand, can be included in order to change the composition from the base color to at least one other color.

[0066] In one particular embodiment, the plurality of thermochromic dyes are configured to cause the cleansing composition to change color over a temperature range of at least about 3 C., such as at least about 5 C., once the composition is heated to a selected temperature. For example, multiple thermochromic dyes may be present within the cleansing composition so that the dyes change color as the composition gradually increases in temperature. For instance, in one embodiment, a first thermochromic dye may be present that changes color at a temperature of from about 23 C. to about 28 C. and a second thermochromic dye may be present that changes color at a temperature of from about 27 C. to about 32 C. If desired, a third thermochromic dye may also be present that changes color at a temperature of from about 31 C. to about 36 C. In this manner, the cleansing composition changes color at the selected temperature and then continues to change color in a stepwise manner as the temperature of the composition continues to increase. It should be understood that the above temperature ranges are for exemplary and illustrative purposes only.

[0067] Any thermochromic substance that undergoes a color change at the desired temperature may generally be employed in the present disclosure. For example, liquid crystals may be employed as a thermochromic substance in some embodiments. The wavelength of light (color) reflected by liquid crystals depends in part on the pitch of the helical structure of the liquid crystal molecules. Because the length of this pitch varies with temperature, the color of the liquid crystals is also a function of temperature. One particular type of liquid crystal that may be used in the present disclosure is a liquid crystal cholesterol derivative. Exemplary liquid crystal cholesterol derivatives may include alkanoic and aralkanoic acid esters of cholesterol, alkyl esters of cholesterol carbonate, cholesterol chloride, cholesterol bromide, cholesterol acetate, cholesterol oleate, cholesterol caprylate, cholesterol oleyl-carbonate, and so forth. Other suitable liquid crystal compositions are possible and contemplated within the scope of the invention.

[0068] In addition to liquid crystals, another suitable thermochromic substance that may be employed in the present disclosure is a composition that includes a proton accepting chromogen (Lewis base) and a solvent. The melting point of the solvent controls the temperature at which the chromogen will change color. More specifically, at a temperature below the melting point of the solvent, the chromogen generally possesses a first color (e.g., red). When the solvent is heated to its melting temperature, the chromogen may become protonated or deprotonated, thereby resulting in a shift of the absorption maxima. The nature of the color change depends on a variety of factors, including the type of proton-accepting chromogen utilized and the presence of any additional temperature-insensitive chromogens. Regardless, the color change is typically reversible.

[0069] Although not required, the proton-accepting chromogen is typically an organic dye, such as a leuco dye. In solution, the protonated form of the leuco dye predominates at acidic pH levels (e.g., pH of about 4 or less). When the solution is made more alkaline through deprotonation, however, a color change occurs. Of course, the position of this equilibrium may be shifted with temperature when other components are present. Suitable and non-limiting examples of leuco dyes for use in the present disclosure may include, for instance, phthalides; phthalanes; substituted phthalides or phthalanes, such as triphenylmethane phthalides, triphenylmethanes, or diphenylmethanes; acyl-leucomethylene blue compounds; fluoranes; indolylphthalides, spiropyranes; cumarins; and so forth. Exemplary fluoranes include, for instance, 3,3-dimethoxyfluorane, 3,6-dimethoxyfluorane, 3,6-di-butoxyfluorane, 3-chloro-6-phenylamino-flourane, 3-diethylamino-6-dimethylfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, and 3-diethyl-7,8-benzofluorane, 3,3-bis-(p-dimethyl-aminophenyl)-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylamino-fluorane, 3-diethylamino-7-phenyl-am inofluorane, and 2-anilino-3-methyl-6-diethylamino-fluorane. Likewise, exemplary phthalides include 3,3,3-tris(p-dimethylamino-phenyl)phthalide, 3,3-bis(p-dimethyl-aminophenyl)phthalide, 3,3-bis(p-diethylamino-phenyl)-6-dimethylamino-phthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, and 3-(4-diethylamino-2-methyl)phenyl-3-(1,2-dimethylindol-3-yl)phthalide.

[0070] Although any solvent for the thermochromic dye may generally be employed in the present disclosure, it is typically desired that the solvent have a low volatility. For example, the solvent may have a boiling point of about 150 C. or higher, and in some embodiments, from about 170 C. to 280 C. Likewise, the melting temperature of the solvent is also typically from about 25 C. to about 40 C., and in some embodiments, from about 30 C. to about 37 C. Examples of suitable solvents may include saturated or unsaturated alcohols containing about 6 to 30 carbon atoms, such as octyl alcohol, dodecyl alcohol, lauryl alcohol, cetyl alcohol, myristyl alcohol, stearyl alcohol, behenyl alcohol, geraniol, etc.; esters of saturated or unsaturated alcohols containing about 6 to 30 carbon atoms, such as butyl stearate, methyl stearate, lauryl laurate, lauryl stearate, stearyl laurate, methyl myristate, decyl myristate, lauryl myristate, butyl stearate, lauryl palmitate, decyl palmitate, palmitic acid glyceride, etc.; azomethines, such as benzylideneaniline, benzylidenelaurylamide, o-methoxybenzylidene laurylamine, benzylidene p-toluidine, p-cumylbenzylidene, etc.; amides, such as acetamide, stearamide, etc.; and so forth.

[0071] The thermochromic composition may also include a proton-donating agent (also referred to as a color developer) to facilitate the reversibility of the color change. Such proton-donating agents may include, for instance, phenols, azoles, organic acids, esters of organic acids, and salts of organic acids. Exemplary phenols may include phenylphenol, bisphenol A, cresol, resorcinol, chlorolucinol, b-naphthol, 1,5-dihydroxynaphthalene, pyrocatechol, pyrogallol, trimer of p-chlorophenol-formaldehyde condensate, etc. Exemplary azoles may include benzotriaoles, such as 5-chlorobenzotriazole, 4-laurylaminosulfobenzotriazole, 5-butylbenzotriazole, dibenzotriazole, 2-oxybenzotriazole, 5-ethoxycarbonylbenzotriazole, etc.; imidazoles, such as oxybenzimidazole, etc.; tetrazoles; and so forth. Exemplary organic acids may include aromatic carboxylic acids, such as salicylic acid, methylenebissalicylic acid, resorcylic acid, gallic acid, benzoic acid, p-oxybenzoic acid, pyromellitic acid, b-naphthoic acid, tannic acid, toluic acid, trimellitic acid, phthalic acid, terephthalic acid, anthranilic acid, etc.; aliphatic carboxylic acids, such as stearic acid, 1,2-hydroxystearic acid, tartaric acid, citric acid, oxalic acid, lauric acid, etc.; and so forth. Exemplary esters may include alkyl esters of aromatic carboxylic acids in which the alkyl moiety has 1 to 6 carbon atoms, such as butyl gallate, ethyl p-hydroxybenzoate, methyl salicylate, etc.

[0072] The amount of the proton-accepting chromogen employed may generally vary, but is typically from about 2 wt. % to about 20 wt. %, and in some embodiments, from about 5 to about 15 wt. % of the thermochromic substance. Likewise, the proton-donating agent may constitute from about 5 to about 40 wt. %, and in some embodiments, from about 10 wt. % to about 30 wt. % of the thermochromic substance. In addition, the solvent may constitute from about 50 wt. % to about 95 wt. %, and in some embodiments, from about 65 wt. % to about 85 wt. % of the thermochromic composition.

[0073] Regardless of the particular thermochromic substance employed, it may be microencapsulated to enhance the stability of the substance during processing. For example, the thermochromic substance may be mixed with a thermosetting resin according to any conventional method, such as interfacial polymerization, in-situ polymerization, etc. The thermosetting resin may include, for example, polyester resins, polyurethane resins, melamine resins, epoxy resins, diallyl phthalate resins, vinylester resins, and so forth. The resulting mixture may then be granulated and optionally coated with a hydrophilic macromolecular compound, such as alginic acid and salts thereof, carrageenan, pectin, gelatin and the like, semisynthetic macromolecular compounds such as methylcellulose, cationized starch, carboxymethylcellulose, carboxymethylated starch, vinyl polymers (e.g., polyvinyl alcohol), polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, maleic acid copolymers, and so forth. The resulting thermochromic microcapsules typically have a size of from about 1 to about 50 micrometers, and in some embodiments, from about 3 to about 15 micrometers. Various other microencapsulation techniques may also be used.

[0074] Thermochromic dyes are commercially available from various sources. In one embodiment, for instance, thermochromic dyes marketed by Chromadic creations, Hamilton, Ontario and sold under the trade name SpectraBurst Thermochromic Polypropylene.

[0075] The thermochromic dyes can be present in the composition in an amount sufficient to have a visual effect on the color of the composition. The amount or concentration of the dyes can also be increased or decreased depending upon the desired intensity of any color. In general, the thermochromic dyes may be present in the composition in an amount from about 0.01% by weight to about 9% by weight, such as from about 0.1% by weight to about 3% by weight. For instance, in one particular embodiment, the thermochromic dyes may be present in an amount from about 0.3% to about 1.5% by weight.

[0076] As described above, thermochromic dyes typically change from a specific color to clear at a certain temperature, e.g., dark blue below 60 F. to transparent or translucent above 60 F. If desired, other pigments or dyes can be added to the composition in order to provide a background color that remains constant independent of the temperature of the composition. By adding other pigments or dyes in combination with the thermochromic dyes to the composition, the thermochromic dyes can provide a color change at certain temperatures rather than just a loss of color should the thermochromic dye become clear. For instance, a non-thermochromic pigment, such as a yellow pigment, may be used in conjunction with a plurality of thermochromic dyes, such as a red dye and a blue dye. When all combined together, the cleansing composition may have a dark color. As the composition is increased in temperature, the red thermochromic dye may turn clear changing the color to a green shade (a combination of yellow and blue). As the temperature further increases, the blue thermochromic dye turns clear causing the composition to turn yellow.

[0077] It should be understood, that all different sorts of thermochromic dyes and non-thermochromic pigments and dyes may be combined in order to produce a composition having a desired base color and one that undergoes desired color changes. The color changes, for instance, can be somewhat dramatic and fanciful. For instance, in one embodiment, the composition may change from green to yellow to red.

[0078] In an alternative embodiment, however, the composition can contain different thermochromic dyes all having the same color. As the temperature of the composition is increased, however, the shade or intensity of the color can change. For instance, the composition can change from a vibrant blue to a light blue to a clear color.

[0079] In addition to the above, it should be understood that many alterations and permutations are possible. Any of a variety of colors and shades can be mixed in order to undergo color changes as a function of temperature.

[0080] It should be noted that it is surprising that the color-changing effect is capable of being visualized in the first instance, in that the sequence is that an aerosol (gas and liquid droplet mixture) of A and B reactants are formed upon entry from the hoses from the A and B cylinders which upon contact begins the frothing process in the synthesis of a foam having the consistency of shaving cream. As is known in the industry, the final crosslinking process which gives the foam some rigidity, is effected after egress from the nozzle tip and upon exposure to moisture in the air as well as coming from typically the B cylinder as a reactant.

[0081] The heat transfer characteristics of an aerosol froth foam are not good. The froth would be in contact with the walls of the nozzle for a period of approximately 85-100 milliseconds at a typical flow rate of 50 g/sec. in that most two-component spray systems use 130-250 psi pressure in the hoses which results in the above nozzle residence time. The very short contact time coupled with the large amount of void space, which is inherent in the definition of a froth foam makes it quite surprising that any type of indication of temperature is possible in the nozzle of a spray foam gun. It is counter-intuitive to believe that any indication of temperature is possible under these conditions. This is all the more remarkable in that foam is used as insulation, and for that very reason, its heat-transfer characteristics are not good.

[0082] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.