MXPA00004973A - Spray can nozzle for spraying viscous substances - Google Patents

Abstract

The present invention relates to a very high solid content contact adhesive (VHS) which has a higher solid content than previously thought attainable in the prior art without increasing the viscosity beyond operable levels. Additionally, the present invention provides a VHS application device comprising a specific nozzle configuration which allows substantially more uniform application of the VHS than was previously attainable.

Description

SYSTEM OF SUPPLY OF AERQjSOfc WITH CONTENT ig VERY HIGH ELEMENTS 1. Technical Field The present invention relates to aerosols with very high solids contents, and, more particularly, to aerosol adhesives with very high solids contents and aerosol adhesive application apparatuses and aerosol adhesive application devices. 2. BACKGROUND OF THE INVENTION In general, aerosol spray cans for a variety of aerosol products include a substance to be sprayed, an optional filler fluid, and a propellant. Typically, the propellant is a combination that pressurizes the can and assists in the atomization of the substance to be sprayed. In the past, chlorofluorocarbons (CFCs) were widely used as propellants but, due to environmental issues, these propellants are now banned by international agreement. The optional "charger" can also, in some cases, represent environmental or health hazards. For example, in the case of paints and adhesives, a solvent is included in the composition that is sprayed. The solvent, often a "volatile organic compound" (VOC), is lately vaporized, when the paint or adhesive "dries", to leave the sprayed composition aside. The vaporization of these solvents in the environment has now increased in both health and environmental issues: do they adversely represent a risk that affects human health? In response, the industry has sought ways to reduce the amounts of organic solvents present in adhesives and other aerosol sprayers that may pose a risk.

A reduction in the solvent would also produce other benefits: such as • ^ ¡_w_? proportion of the solvent present in the aerosol adhesive decreases, more of the same adhesive composition is present in the aerosol. This results in a reduction in wear to provide the shape of the package for the mixture of adhesives (for example, empty spray cans). Thus, for example, adhesive / solvent mixtures applied in aerosol cans containing 20-25% by weight composed of adhesive, also known as very high solids content (HSV) adhesives, have become increasingly desirable in the field of contact adhesives for the use of small proportions of organic solvents, and their potential for reducing hazards to health and the environment. Our co-pending US Patent Application No. 09 / 126,383, entitled "Very High Solid Adhesives" filed on July 30, 1998, which is incorporated herein by reference, discloses a composition for a VHS adhesive and a method for making the VHS adhesive. In a preferred embodiment, the adhesive is included in a resin / rubber / solvent mixture. Resins typically used include polyterpene resins, phenolic resins, modified terpene phenolic resins, aliphatic petroleum hydrocarbon resins, and the like. The rubbers used in adhesive blends generally use a combination of synthetic polychloroprene rubbers. A wide range of solvents can be used depending on the composition of the adhesive with which it is compatible to form a solution. Thus, the solvents used may include, among others, various chlorinated solvents, ketones, aliphatics, aromatics, alcohols, and esters, and even inorganic solvents such as water. However, it has been found that in practice the use of VHS adhesives can be somewhat difficult. For example, in general, as the solid content of the adhesive increases, the viscosity of the adhesive / solvent mixture increases. When they are used & i * '; Standard sprinklers and buttons on ípi? §f fe | of aerosol spray, the increased viscosity causes the spray pattern to be uneven. For example, if a Faceplate, valve, and button (such as a Variable Valve Model # V8-10-118, with a collar 906 and button model # 166-197-1620-white, both provided by Newman-Green of Addison, Illinois) are used to spray a VHS adhesive / solvent mixture that has Sf l ft weight of adhesive, such as neoprene, the dew tends to be uneven. That is, the spray pattern will have concentrations that vary across the application area. It is believed that this generally occurs because the button contains a substantially circular shaped exit port that the mixing stream of VHS adhesive passes in such a way that it is limited or not "fanned" from the spray; the current comes out in a substantially straight line. Additionally, if some external fanning could occur, the fanning is not controlled and the concentration of the sprayed fluid is not uniform and tends to vary throughout the area of application. Several spray buttons are designed to try to overcome the non-uniformity of the spray problem. U.S. Patent No. 4,401, 272, filed for Merton et al, on August 30, 1983, and U.S. Patent No. 4,401, 271, filed for Hansen, on August 30, 1983, each discloses sprinklers that connect the cotones of spray can spray. These sprinklers do not appear to resolve this issue. For example, the '272 patent discloses that the sprayer is only capable of spraying mixtures with levels of solids content greater than 11.1%, well below typical levels of VHS. When such sprinklers are used, the spray tends to be more concentrated at the top and bottom of the spray area and less concentrated near the center of the spray area. The '271 patent provides another attempt at a solution for the issue of spray non-uniformity.

As explained, there is a need for a mixture A. adhesive / VHS solvent with exploitable emollient contents higher than those hitherto known and a device for substantially uniformly applying such mixture.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a contact adhesive with very high solids content (HSV) having a higher solids content than previously achievable in the prior art without increasing the viscosity beyond the operable levels. Additionally, the present invention provides a VHS application device that allows a substantially more uniform application than previously achievable.

BRIEF DESCRIPTION OF THE DRAWINGS Additional aspects of the present invention will become apparent upon reviewing the non-limiting embodiments described in the specifications and claims taken in conjunction with the accompanying figures, wherein numerous similar designations designate like elements, and: Figure 1 is a side view of a can of VHS adhesive spray; Figure 2 is a top view of a VHS adhesive spray can; Figure 3 is a cross-sectional side view of an exemplary embodiment of a sprayer and a button of the present invention; Figure 4 is a side view of an exemplary embodiment of a sprayer of the present invention; Figure 5 is a top view of the present invention; Figure 6 is a cross-sectional side view of a beveled insertion end of the sprayer of the present invention; Figure 7 is a cross-sectional view of the outlet end of the sprinkler; and Figure 8 is a front view of the outlet end of the sprinkler.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY MODALITIES The following descriptions are of preferred embodiments, and are not intended to limit the scope, applicability, or configuration of the invention in any way. In addition, the following description provides a convenient illustration for implementing a preferred embodiment of the invention. Various changes can be made in the function and arrangement of the elements described in the preferred embodiments without departing from the spirit and scope of the invention as disclosed in the appended claims. Furthermore, while the following detailed description is generally described with respect to certain mixtures of HSV adhesives, the invention is also applicable to other mixtures of higher viscosity which are propelled or applied by an aerosol spray can. Likewise, the sprinklers of the invention are not limited to those specifically described herein, but encompass those that are equivalent to those described. In the specifications and claims, the term VHS refers to "very high solids content". While the following description relates mainly to VHS adhesives, it is clear that the principles discussed and devices described are also applicable to other VHS substances that are provided and propelled by aerosol cans, for example, paints, lacquers, polish waxes, waxes and similar.

The term "very high solids content" in the context of a mixture of adhesives / solvents is the mixture. As the solids content increases, generally so? it makes the viscosity of the mixture, but the "shear stress" method of our previous application, described below, minimizes the increase in viscosity by increasing the content of the adhesive. In this context, the "very high solids content" refers to a mixed slurry mixture having a viscosity that is in the range of at least about 50 cps, preferably from about 200 to about 400, and up to about 600 cps. Thus, the VHS, although referred to the adhesive concentration in an adhesive / solvent solution, can also be appreciated in the context of viscosity. For specific adhesives, like neoprene, a commonly used adhesive for decorative adhesive laminates for substrates, an adhesive / VHS solvent mixture contains at least about 28% by weight of neoprene, preferably from about 28 to about 30% by weight of neoprene, and more preferably from about 29 to about 31% by weight of neoprene based on the weight of the neoprene and solvent mixture. With respect to the VHS adhesive / solvent mixtures, the adhesives include neoprene, styrene butyrylene (SBR), styrene isoprene styrene (SIS), nitrile, and the like. Solvents can be selected from those compositions compatible with the adhesives and include, among others, various chlorinated solvents, ketones, aliphatics, aromatics, alcohols, esters, water, and the like. By itself the VHS adhesive can be selected from any of those that are commercially useful. VHS adhesives useful in decorative lamination techniques can be formed using any of many useful processes, including for example the shear mixing process disclosed in the art.

U.S. Patent No. 5,733,961 for Purvis II, et al., Filed March 31, made using a Micro _Br® processor (made by Microfluidics International Corp. of Newton, Massachusetts) using an electric powered, dual piston or piston, pump hydraulic intensifier that pressurizes the fluid product. The neoprene and the solvent are mixed in the process and the Microfluidizer® properly moves a stream of the mixture at extremely high pressures and velocities. These effects dramatically reduce the size of the particles in the mixture, thereby reducing the viscosity of the mixture and facilitating additional neoprene to be introduced into the mixture. In accordance, the percentage of the weight of the solvent mixture Neoprene 10 can be increased in ranges of solids contents even higher than previously thought without unduly increasing the viscosity of the mixture. The invention also provides a delivery system for the adhesive / VHS solvent mixture. The delivery system requires an aerosol can, and includes the use of a propeller. With reference to Figures 1 and 2, according to a preferred embodiment of the present invention, the spray device 10 is capable of substantially uniformly applying a layer of the adhesive / VHS solvent mixture to a substrate. In the present embodiment, the spray device 10 is an aerosol spray can composed of a can 12, a valve 14 at an upper end of the can 12, a Button 16 mounted on valve 14 to open the valve, and a sprinkler 18 arranged on the button, as explained below. The can 12 is generally any suitable aerosol spray can capable of containing the VHS, the solvent and propellant mixture. The valve 14 can appropriately be any aerosol spray can valve, although, according to the present preferred embodiment, the valve 14 can be selected from Variable Valve Model # C8-10-118 and equivalent valves, with a 906 or equivalent collar both provided by Newman-Green of Addison, Illinois. The valve the button 16 and the present preferred embodiment, the valve 14 preferably contains markers designating "low", "medium" and "high" ranges of fluid that aid in the determination of the flow range through the valve 14. The button 16 is any suitable conventional aerosol spray can button, and, in accordance with the present exemplary embodiment, can be selected from the Model # 166-197-1620-white button, also provided by Newman-Green, and its equivalents. With respect to Figures 3-5, the illustrated embodiment of the sprinkler 18 of the invention is configured as an elongated body member formed of any material resistant to any corrosion or other effects that deteriorate the adhesive / solvent mixture VHS and that by itself does not contaminate the fluid to be sprayed, for example, inert plastic, metals and the like In accordance with the present preferred embodiment of the present invention, the sprayer 18 is adapted to to be used with the button 16. For example, in accordance with one aspect of the present exemplary embodiment, the substantially cylindrical or tapered shape of the sprinkler 18 has an insertion end 22 and an adhesive spray exit end. In the present embodiment, the sprinkler 18 has a diameter of approximately 0.120 in. (3.05 mm). The insertion end 22 is of an appropriate size to be placed on a button outlet bridge 20 for fluid communication between the holder and the continuous perforation 26 of the sprinkler 18 when the valve 14 is opened. According to the illustrated embodiment, the sprinkler 18 can also be detached or permanently pressed into the button outlet 20 of the button 16. However, alternatively, the insertion end 22 can be placed to the button exit holder 20 by other means, including helical threads, adhesives and the like. Also, the sprinkler 18 can be integrally formed on the button 16 to produce a one-piece button with the sprinkler 18. Quietly, with the momentary reference to Figure 6, the insertion end 22 can optionally include a bevel 24 formed by an angle a for facilitating the mounting of the insertion end 22 the output holder 20 of the button 16. For example, in the present exemplary embodiment, the slot 24 is approximately 0.0125 in. (0.32 mm) deep and the angle a is approximately 45 °. According to another aspect of the present invention, and with respect to Figure 7, the sprayer 18 is appropriately configured with an axial continuous perforation or cannula 26 extending longitudinally throughout. The continuous perforation 26 is of a substantially uniform diameter along a greater portion of its length but has a flow restrictor 28 near its outlet end 30. The restrictor 28 results in a reduction in the cross-sectional area for the flow of fluids through the sprayer 18, causing a decrease in fluid pressure at the restriction 28. According to the present exemplary embodiment, the quotient of the cross-sectional area for the fluid flow of the continuous perforation 26 to the area of The cross-sectional fluid flow of the restrictor 28 is approximately 4.7 Beyond the restrictor 28 the spray nozzle assumes a substantially rectangular shaped outlet port and has at least one pair of opposite side walls that expand externally towards the end of the port. exit 30 as described below. According to various aspects of the present invention, the diameters (or the cross-sectional area for the flow of fluids) or the larger portion of the continuous perforation 26 and the restrictor 28 vary appropriately depending on factors such as the solid content of the HSV which passes through the sprinkler 18, the viscosity of the VHS, the attempted concentration of the sprayed adhesive, and the desired spray pattern. In the present exemplary embodiment, the largest portion of the continuous perforation 26 is approximately 0.040 in. (1.02 mm) and the short side 48 is preferably approximately 0.016 in. (0.41 mm). According to the present exemplary embodiment, as the viscosity of the VHS decreases, the cross-sectional area of the restrictor 28 desirably decreases. For example, if the viscosity of the VHS decreases to 50 cps. The cross-sectional area for the fluid flow of the restifier 28 may decrease by about 20% relative to the area based on the preferred dimensions described above. On the other hand, if the viscosity of the VHS increases to 400 cps, the cross-sectional area for the fluid flow of the restrictor 28 may be approximately 30% larger than the area based on the dimensions described above. According to another aspect of the present exemplary embodiment, to facilitate the flow of fluids and maintain a uniform flow pattern, the portion of the continuous perforation 26 gradually transits to the narrower narrowing of the restrictor 28. This is achieved by curving the terminal end of the major portion 26 uniformly inwardly in a radius of curvature 34 to form the walls of the substantially preferred rectangular outlet port. The radius is 0.0302 in. Wax. (0.77 mm) with a center 36 that is located 0.0503 in. (1.28 mm) from the outlet end 30, along a line of centers 38 of the continuous perforation 26. According to another aspect of the present exemplary embodiment, and with respect to Figure 8, an exit port 40 is Properly provided at the outlet end 30 of the sprinkler 18. The outlet port 40 is appropriately formed in a manner designed to facilitate the spraying of the aerosol spray by exiting therethrough in a fan-like manner. The preferred exit portAs it is described below, it is of a substantial and quantum-angular form, with vertical opposite sides longer than the horizontal sides. The outlet port 40 is suitably formed with an external widening of the restrictor 28 having at least one pair of opposite side walls forming the upper and lower walls 42, 44 of the rectangular shaped carrier 40 which facilitates the The external widening of the side walls 42, 44 at an angle ß which appropriately widens from the start points 42a, 44a in the restrictor 28 to the face of the spray or the nozzle to direct the spray. an adhesive / solvent mixture of a viscosity of about 200 cps, an angle β of about 20 ° to 75 ° is operable, and of about 45 ° is preferred, while the length of a wide side of spreading output 50 is about 0.0471 to 0.1125 in. (1.20 to 2.86 mm), and preferably approximately 0.0663 in. (1.68 mm) When the viscosity is higher or lower, the experimental ß-angle test will lead to the selection ion of an optimum widening angle. Thus, while the principles of the invention have been described in illustrative embodiments, many combinations and modifications of the structures described above, arrangements, proportions, elements, materials and components, used in the practice of the invention in addition to those not specifically described can be varied and particularly adapted for an environment and specific operating requirements without departing from those principles.

Claims (9)

REIVi ^ tp ^ p EN

1. A very high solids content contact adhesive, comprising: a mixture of an adhesive and a solvent, the mixture comprises at least about 28% by weight of adhesive and a viscosity of said mixture which is in the range of about 50. at 600 cps.

2. A very high solids content contact adhesive according to claim 1, characterized in that said adhesive comprises neoprene.

3. A contact adhesive of very high solids content according to claim 1, characterized in that said solvent is selected from the group consisting of ketones, aliphatic hydrocarbons, aromatics, alcohols, esters, chlorinated solvents, and water.

4. A very high solids content contact adhesive according to claim 1, characterized in that said mixture comprises a weight percentage of a rubber adhesive in a range of about 29% to about 31%.

5. A very high solids content contact adhesive according to claim 1, characterized in that said viscosity of said mixture is from about 50 to about 400 cps.

6. A contact adhesive with very high solids content according to claim 1, characterized in that said viscosity of said mixture is approximately 200 cps. very high of said mixture is 8. A contact adhesive of very high solids content according to claim 2, characterized in that said viscosity of said mixture is approximately 200 cps. 9. A very high solids content contact adhesive according to claim 2, characterized in that said mixture comprises from about 29% to about. 34% weighing the neoprene. 10. A very high solids content contact adhesive according to claim 1, characterized in that said adhesive comprises a resin selected from the group consisting of polyetherpene, phenolic, phenolic modified terpene resins, and aliphatic petroleum hydrocarbon resins. 11. A very high solids content contact adhesive according to claim 1, characterized in that the adhesive is selected from the group consisting of neoprene, styrene, styrene butadiene, styrene isoprene styrene, and nitrile. 12. A contact adhesive spray of very high solids content adapted for use with an aerosol spray can, the sprinkler, comprising: an elongated body; an axial continuous perforation extending along said elongated body; a flow restrictor approximated to an outlet end of said elongated body, and an outlet port at the outlet end of the elongate body, the substantially rectangular exit port in form comprising at least one pair of walls of outward broadening from the flow restrictor to the outlet end of the sprinkler. 13. A very high solids content contact adhesive sprayer according to claim 12, comprising an insertion end of a size to fit in an exit port of a button of an aerosol can. 14. A spray of contact adhesive application of very high solids content according to claim 12, characterized in that at least said pair of walls comprise an upper and a lower wall. 15. A very high solids content contact adhesive application sprayer according to claim 12, characterized in that at least said pair of spreading walls out at an angle in the range of about 20 ° to approximately 75 °. 16. A very high solids content contact adhesive sprayer according to claim 12, characterized in that at least said pair of spreading walls outwardly at approximately 45 °. 1

7. A very high solids content contact adhesive sprayer according to claim 12, characterized in that a quotient of a cross-sectional area of said perforation continuous to a transcersal-sectional area of said restrictor is approximately 4.7. 1

8. An aerosol spray device, comprising: a spray can; a valve placed in the can; a button placed on the valve to control the opening and closing of the valve, the button that has a Jalera holder a fluid communication with an inside of the can when the valve is open; and a sprinkler, positioned in the exit port of the button, said sprinkler including a continuous perforation a substantially rectangular exit port, the holder having at least a pair of opposite side walls from the fluid restrictor to an exit end of the spray nozzle. 1

9. An aerosol spray device according to claim 18, characterized in that a quotient of the cross-sectional area of said perforation continues to a cross-sectional area of said stringers of about 4.7. The present invention relates to a contact adhesive with very high solids content (HSV) having a more solid content than previously achieved in the prior art thinking without increasing the viscosity beyond the operable levels. Additionally, the present invention provides a VHS application device that substantially allows a more uniform application of the VHS than previously achieved.