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. A plastic spray gun nozzle which comprises: a tapered elongated cylindrical bore extending along a longitudinal axis, said cylindrical bore having an expanded cylindrical 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 entrance collar comprising an interior and an exterior, the entrance collar interior having at least two pairs of recessed and opposed channels in the expanded cylindrical entrance collar which extend longitudinally from a periphery of the interior of the entrance collar and transition to a transverse portion extending transverse to the longitudinal axis of the cylindrical bore in the expanded cylindrical entrance collar; the interior of the entrance collar removeably mating with an exterior of a front portion of a housing of the spray gun; and said plastic spray nozzle dispensing a pressurized polyurethane foam or a polyurethane froth.

2. The plastic spray gun nozzle of claim 1 wherein the transverse portions of the at least two pairs of recessed channels terminate with a detent.

3. The plastic spray gun nozzle of claim 1 wherein the plastic spray gun nozzle can mate with the housing of the spray gun in a first rotational position or a second rotational position.

4. The plastic spray gun nozzle of claim 3 wherein the pair of divergent opposed lips directs a vertical spray pattern in the first rotational position and a horizontal spray pattern in the second rotational position.

5. The plastic spray gun nozzle of claim 3 wherein the second rotational position is 90 from the first rotational position.

6. The plastic spray gun nozzle 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.

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

8. The plastic spray gun nozzle 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.

9. The plastic spray gun nozzle of claim 7 wherein said at least one thermochromic material is a liquid crystal or a leuco dye.

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

11. The plastic spray gun nozzle of claim 7 wherein said at least one thermochromic material is at least two thermochromic materials disposed within or thereupon said nozzle, each of said at least two thermochromic materials effecting a color change at a different temperature.

12. A plastic spray gun nozzle which comprises: a tapered elongated cylindrical bore extending along a longitudinal axis, said cylindrical bore having an expanded cylindrical 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 entrance collar comprising an interior and an exterior, the entrance collar interior having a pair of recessed and opposed channels in the expanded cylindrical entrance collar which extend longitudinally from a periphery of the interior of the entrance collar and transition to a transverse portion extending transverse to the longitudinal axis of the cylindrical bore in the expanded cylindrical entrance collar wherein the transverse portion comprises a first detent corresponding with a first rotational position of the spray gun nozzle and a second detent corresponding with a second rotational position of the spray gun nozzle, wherein the plastic spray gun nozzle is adjustable from the first rotational position to the second rotational position by continued rotational movement in the same direction as the first detent while mated with the exterior of the front portion of the housing of the spray gun; the interior of the entrance collar removeably mating with an exterior of a front portion of a housing of the spray gun; and said plastic spray nozzle dispensing a pressurized polyurethane foam or a polyurethane froth.

13. The plastic spray gun nozzle of claim 12 wherein the pair of divergent opposed lips directs a vertical spray pattern in the first rotational position and a horizontal spray pattern in the second rotational position.

14. The plastic spray gun nozzle of claim 12 wherein the second rotational position is 90 from the first rotational position.

15. The plastic spray gun nozzle of claim 12 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.

16. The plastic spray gun nozzle of claim 12 further comprising at least one thermochromic material disposed within or affixed thereupon said plastic spray gun nozzle.

17. The plastic spray gun nozzle of claim 16 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.

18. The plastic spray gun nozzle of claim 16 wherein said thermochromic material is affixed upon said plastic nozzle by a label containing said thermochromic material.

19. The plastic spray gun nozzle of claim 16 wherein said at least one thermochromic material is a liquid crystal or a leuco dye.

20. The plastic spray gun nozzle of claim 16 wherein said at least one thermochromic material is at least two thermochromic materials disposed within or thereupon said nozzle, each of said at least two thermochromic materials effecting a color change at a different temperature.

21. A plastic spray gun nozzle which comprises: a tapered elongated cylindrical bore extending along a longitudinal axis, said cylindrical bore having an expanded cylindrical 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 entrance collar comprising an interior and an exterior, the entrance collar interior having a pair of recessed and opposed T channels in the expanded cylindrical entrance collar which extend longitudinally from a periphery of the interior of the entrance collar and transition to a transverse portion extending transverse to the longitudinal axis of the cylindrical bore in the expanded cylindrical entrance collar in a first direction and in a second direction opposite the first direction wherein the transverse portion terminates with a first detent in the first direction and a second detent in the second direction; the interior of the entrance collar removeably mating with an exterior of a front portion of a housing of the spray gun; and said plastic spray nozzle dispensing a pressurized polyurethane foam or a polyurethane froth.

22. The plastic spray gun nozzle of claim 21 wherein the first detent corresponds with a first rotational position of the spray gun nozzle and the second detent corresponds with a second rotational position of the spray gun nozzle.

23. The plastic spray gun nozzle of claim 22 wherein the plastic spray gun nozzle is adjustable from the first rotational position to the second rotational position by rotating the nozzle while mated with the exterior of the front portion of the housing of the spray gun.

24. The plastic spray gun nozzle of claim 22 wherein the pair of divergent opposed lips directs a vertical spray pattern in the first rotational position and a horizontal spray pattern in the second rotational position.

25. The plastic spray gun nozzle of claim 22 wherein the second rotational position is 90 from the first rotational position.

26. The plastic spray gun nozzle of claim 21 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.

27. The plastic spray gun nozzle of claim 21 further comprising at least one thermochromic material disposed within or affixed thereupon said plastic spray gun nozzle.

28. The plastic spray gun nozzle of claim 27 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.

29. The plastic spray gun nozzle of claim 27 wherein said thermochromic material is affixed upon said plastic nozzle by a label containing said thermochromic material.

30. The plastic spray gun nozzle of claim 27 wherein said at least one thermochromic material is a liquid crystal or a leuco dye.

31. The plastic spray gun nozzle of claim 27 wherein said at least one thermochromic material is at least two thermochromic materials disposed within or thereupon said nozzle, each of said at least two thermochromic materials effecting a color change at a different temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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:

[0032] FIG. 1 is a perspective view of the nozzle of the present invention mated with a dispensing gun;

[0033] FIG. 1b is a side view of the tip of the nozzle, displaying the divergent lips;

[0034] FIG. 2 is a perspective view of the nozzle of the present invention detached from a dispensing gun and oriented in two different rotational positions;

[0035] FIG. 3 is a perspective view displaying the interior of the entrance collar of one embodiment of the nozzle of the present invention;

[0036] FIG. 4 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention;

[0037] FIG. 5 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention;

[0038] FIG. 6 is a perspective view of the nozzle of another embodiment of the present invention detached from a dispensing gun and oriented in two different rotational positions;

[0039] FIG. 7 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention;

[0040] FIG. 8 is a perspective view of the nozzle of another embodiment of the present invention detached from a dispensing gun and oriented in two different rotational positions;

[0041] FIG. 9 is a perspective view of the nozzle of another embodiment of the present invention detached from a dispensing gun and oriented in two different rotational positions;

[0042] FIG. 10 is a perspective view displaying the interior of the entrance collar of another embodiment of the nozzle of the present invention; and

[0043] FIG. 11 is a perspective view displaying a color-changing label affixed to the exterior of the nozzle.

DETAILED DESCRIPTION OF THE INVENTION

[0044] 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.

[0045] For consistency in terminology, when describing the plastic spray gun nozzle 20, 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.

[0046] The invention relates to, as shown in perspective views in FIGS. 1 & 2, a plastic spray gun nozzle 20 which can be used in dispensing a pressurized polyurethane foam or a polyurethane froth. As displayed by the mated assembly 100, the 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 passages 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, twist and click nozzle 20 is a temperature sensitive nozzle in which the nozzle changes color depending upon 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 NB 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.

[0047] 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 FIGS. 1 & 2, 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 at least two 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 remove the gun's nozzle 20 and re-orient nozzle 20 onto 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.

[0048] 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 ensure the wide spray pattern that contributes to the high application rates of the nozzle 20. The lips 26 diverge at an angle a between divergent lips 26, shown in FIG. 1b, preferably of 2-55, and more preferably an angle of 5-25. A gap exists between the end of the lips 26 of the nozzle 20 where the spray foam exits the nozzle 20.

[0049] As better illustrated in FIG. 2, in the nozzle's first rotational position 20a, the pair of divergent opposed lips 26 are angled vertically in order to dispense foam or froth in an essentially vertical spray pattern. In the nozzle's second rotational position 20b, the pair of divergent opposed lips 26 are angled 90 from the first rotational position 20a. In this second rotational position, the pair of divergent opposed lips 26 are angled horizontally in order to dispense foam or froth in an essentially horizontal spray pattern. Front portion 62 of the housing of spray gun 50 includes at least one pair of raised knobs or protrusions 64. Nozzle 20 mates with front portion 62 of the housing of spray gun 50 by inserting nozzle 20 onto front portion 62 so that knobs or protrusions 64 align with the corresponding channels on the interior surface of entrance collar 22. Once inserted, nozzle 20 can be twisted in order to lock in place onto front portion 62 of the housing of spray gun 50.

[0050] The interior of the entrance collar 22 of one embodiment is shown in FIG. 3. In this embodiment of nozzle 20, entrance collar interior 22 has at least two pairs of recessed and opposed channels 28 in the expanded cylindrical entrance collar 22. Channels 28 extend longitudinally from a periphery of the interior of the entrance collar 22 and transition to transverse portion 30 extending transverse to the longitudinal axis of the cylindrical bore in the expanded cylindrical entrance collar 22. Transverse portions 30 of the at least two pairs of recessed channels 28 preferably terminate with detent 32. To attach nozzle 20 in a first position, nozzle 20 is inserted onto front portion 62 of the housing of spray gun 50 so that knobs or protrusions 64 of the spray gun align with and enter into channels 28. When knobs 64 contact the end of the longitudinal portion of channels 28, nozzle 20 is twisted so that raised knobs 64 enter transverse portion 30 of channels 28. Nozzle 20 is twisted until knobs 64 contact and lock into place with detent 32. In this first rotational position, the pair of divergent opposed lips 26 create a linear opening at any angle depending on the construction of the nozzle 20. In various embodiments, in the first rotational position, the opposed lips 26 are angled vertically or horizontally.

[0051] To change the angle of the linear opening created by divergent opposed lips 26, nozzle 20 is twisted in the opposite direction of initial locking, removed from front portion 62 of the housing of the spray gun 50, and rotated in either direction so that any given knob 64 is aligned with channel 28 that is immediately adjacent to its previous channel 28. Nozzle 20 may then be reconnected. The linear opening created by divergent opposed lips 26 in this second rotational position is now different than that of the first rotational position. In the embodiment shown in FIG. 3, the angle of the linear opening created by divergent opposed lips 26 in the second rotational position is approximately 90 different from the angle when nozzle 20 is in its first rotational position. In certain embodiments, the mating connections can be inverted. As shown in FIGS. 6 and 7, channels 74 having the same general shape as channels 28 displayed on the embodiment in FIG. 3 are formed into the front portion 72 of spray gun 70. Nozzle 66 shown in FIG. 7 comprises raised knobs 68 formed into the interior of expanded collar 22. In a fashion similar to the other embodiments, nozzle 66 mates with front portion 72 in multiple positions, such as vertical position 66a and horizontal position 66b.

[0052] FIG. 4 shows the interior of the entrance collar 22 of another embodiment of the plastic spray gun nozzle. In this embodiment of nozzle 20, the entrance collar 22 interior has a single pair of recessed and opposed channels 34 in the expanded cylindrical entrance collar 22. Channels 34 extend longitudinally from a periphery of the interior of entrance collar 22 and transition to transverse portion 38 extending transverse to the longitudinal axis of the cylindrical bore in expanded cylindrical entrance collar 22. Transverse portions 38 of the pair of recessed channels 34 lead to first detent 36 and second detent 40. To attach nozzle 20 in a first position, nozzle 20 is inserted onto front portion 62 of the housing of spray gun 50 so that raised knobs 64 of the spray gun align with and enter into channels 34. When raised knobs 64 contact the end of the longitudinal portion of channels 34, nozzle 20 is rotated so that knobs 64 enter transverse portion 38 of channels 34. Nozzle 20 is rotated until raised knobs 64 contact and lock into place with first detent 36. While knobs 64 are secured within first detent 36, nozzle 20 is in its first rotational position. In this first rotational position, the pair of divergent opposed lips 26 create a linear opening at any angle depending on the construction of nozzle 20. In various embodiments, in the first rotational position, opposed lips 26 are angled vertically or horizontally.

[0053] To change the angle of the linear opening created by divergent opposed lips 26, nozzle 20 is pressed inward towards spray gun 50 and rotated further, in the same direction as locking it in place with first detent 36. With this twisting motion, raised knobs 50 exit the locked position within first detent 36. Nozzle 20 is further rotated until raised knobs 64 contact and lock into place with second detent 40. While raised knobs 64 are secured within second detent 40, nozzle 20 is in its second rotational position. The linear opening created by divergent opposed lips 26 in this second rotational position is now different than that of the first rotational position. In this manner, the rotational position of nozzle 20 in this embodiment may be changed while nozzle 20 remains mated with front portion 62 of the housing of the spray gun. In the embodiment shown in FIG. 4, the angle of the linear opening created by divergent opposed lips 26 in the second rotational position is approximately 90 different from the angle when nozzle 20 is in its first rotational position. In certain embodiments, the mating connections can be inverted. As shown in FIG. 8, channels 76 having the same general shape as channels 34 displayed on the embodiment in FIG. 4 are formed into the front portion 72 of spray gun 50. Nozzle 66 shown in FIG. 10 comprises knobs 68 formed into the interior of expanded collar 22. In a fashion similar to the other embodiments, nozzle 66 can mate with front portion 72 in multiple positions, such as vertical position 66a and horizontal position 66b by rotational movement.

[0054] FIG. 5 shows the interior of the entrance collar 22 of still another embodiment of the plastic spray gun nozzle. In this embodiment of nozzle 20, the entrance collar 22 interior has a single pair of recessed and opposed T channels 42 in the expanded cylindrical entrance collar 22. T channels 42 extend longitudinally from a periphery of the interior of the entrance collar 22 and transition to transverse portion 44 extending transverse to the longitudinal axis of the cylindrical bore in the expanded cylindrical entrance collar 22 in a first direction and in a second direction opposite the first direction. Transverse portion 44 terminates with first detent 46 in the first direction and second detent 48 in the second direction. To attach nozzle 20 in a first position, nozzle 20 is inserted onto front portion 62 of the housing of spray gun 50 so that knobs 64 of the spray gun align with and enter into T channels 42. When knobs 64 contact the end of the longitudinal portion of T channels 42, nozzle 20 is rotated in a first direction so that knobs 64 enter transverse portion 44 of T channels 42. The first direction may be either a clockwise rotation or a counterclockwise rotation. Nozzle 20 is rotated until knobs 64 contact and lock into place with first detent 46. While knobs 50 are secured within first detent 46, nozzle 20 is in its first rotational position. In this first rotational position, the pair of divergent opposed lips 26 create a linear opening at any angle depending on the construction of nozzle 20. In various embodiments, in the first rotational position, opposed lips 26 are angled vertically or horizontally.

[0055] To change the angle of the linear opening created by divergent opposed lips 26, nozzle 20 is pressed inward towards spray gun 50 and rotated in a second direction, opposite of the first direction. With this rotating motion, knobs 50 exit the locked position within first detent 46. Nozzle 20 is rotated until knobs 64 contact and lock into place with second detent 40. While knobs 64 are secured within second detent 48, nozzle 20 is in its second rotational position. The linear opening created by divergent opposed lips 26 in this second rotational position is now different than that of the first rotational position. In this manner, the rotational position of nozzle 20 in this embodiment may be changed while nozzle 20 remains mated with front portion 62 of the housing of the spray gun. In the embodiment shown in FIG. 5, the angle of the linear opening created by divergent opposed lips 26 in the second rotational position is approximately 90 different from the angle when nozzle 20 is in its first rotational position. Referring to FIG. 5, it should be appreciated that depending on specific construction of nozzle 20, reference to the first rotational position 46 and second rotational position 48 can be interchanged. In certain embodiments, the connections can be inverted. As shown in FIG. 9, T channels 78 having the same general shape as channels 42 displayed on the embodiment in FIG. 5 are formed into the front portion 72 of spray gun 50. Nozzle 66 shown in FIG. 10 comprises knobs 68 formed into expanded collar 22. In a fashion similar to the other embodiments, nozzle 66 can mate with front portion 72 in multiple positions, such as vertical position 66a and horizontal position 66b.

[0056] 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. 11, still another approach involves affixing a label 80 either permanently using a permanent adhesive or non-permanently, using a pressure-sensitive adhesive (the label 80 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. 11), to colorless or a different color when the chemicals have transferred a sufficient amount of heat to the nozzle or label 80. 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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-aminofluorane, 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-am inophenyl)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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.