AU2012201608B2

AU2012201608B2 - Anti-Graffiti Paint Formulations and Removal

Info

Publication number: AU2012201608B2
Application number: AU2012201608A
Authority: AU
Inventors: Gavin Fisher; Barry Kenman; Barry Roper
Original assignee: ONEBIOSCI Pty Ltd
Current assignee: ONEBIOSCI Pty Ltd
Priority date: 2008-04-28
Filing date: 2012-03-19
Publication date: 2013-12-12
Anticipated expiration: 2028-04-28
Also published as: AU2012201608A1; AU2008201835A1

Abstract

A composition for the removal of paint, ink or other surface coatings, the composition 5 comprising an enzyme and a biodiesel vehicle.

Description

ANTI-GRAFFITI PAINT FORMULATIONS FIELD OF THE INVENTION The present invention relates to compositions for the removal of paint, ink or other 5 surface coatings. In particular, the present invention relates to compositions containing enzymes that provide the compositions with properties that make them useful for the removal of paint, ink or other surface coatings, and more specifically for graffiti removal. 10 The present invention also relates to methods of using the compositions for the removal of paint, ink or other surface coatings, and more specifically for the removal of graffiti. BACKGROUND OF THE INVENTION 15 Graffiti is usually applied on public and other buildings by way of 'spray-can' aerosol paints. These paints are usually alkyd and/or paints or oil enamels which are designed to dry rapidly. Their legal use is most helpful in 'touch-up' and small job applications where a rapid drying gloss finish is required. In the 'hit and run' world of so-called graffiti art, they are the most popular paint used. 20 The estimated cost of graffiti removal throughout the world is variously estimated by municipal authorities to be in the hundreds of millions of dollars each year. In many countries the call for the removal from sale of oil enamel spray (aerosol) type paint cans is very strong. 25 In Australia to date, the movement to ban the sale of such paints has been overcome by a voluntary paint industry initiative; which also includes the insertion of the following warning label on the paint cans: "IMPORTANT: Deliberate misuse of this aerosol to damage private property is a crime.' 30 Some attempts have been made to produce anti-graffiti paint formulations. The applicant's Australian patent no. 2001281583, the entire contents of which are herein 2 incorporated by reference, disclosed one such anti-graffiti paint formulation. In this patent, the paint formulation contains enzymes. However, prior art paint formulations suffer from the drawback that the vehicle for the formulation generally comprises a solvent, such as mineral turpentine. While effective, solvents such as mineral 5 turpentine have a number of associated health and safety issues, not the least of which is the fact that these solvents are highly flammable. Thus, there would be an advantage if it were possible to provide an effective anti graffiti paint formulation with low flammability. 10 Biodiesel is a non-petroleum based fuel consisting of short chain esters. Biodiesel is typically made by the transesterification of vegetable oils (e.g. canola, soybean or sunflower oil), animal fats (e.g. tallow or lard), waste vegetable oil (e.g. from cooking processes) and a number of other sources. The transesterification process may be base 15 catalysed or acid catalysed. Alternatively, biodiesel may be manufactured by the enzyme esterification of free fatty acids. It has now surprisingly been found that using biodiesel as a carrier for an anti-graffiti paint formulation or a graffiti removal formulation significantly reduces the 20 flammability of the formulation, while at the same time maintaining the properties of the formulation that make it particularly useful as an anti-graffiti formulation or a graffiti removal formulation. It will be clearly understood that, if a prior art publication is referred to herein, this 25 reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. Throughout this specification, the term "comprising" and its grammatical equivalents shall be taken to have an inclusive meaning unless the context of use 30 indicates otherwise. OBJECT OF THE INVENTION 3 It is an object of the present invention to provide a composition for the removal of paint which may overcome at least some of the abovementioned disadvantages, or provide a useful or commercial choice. 5 In one aspect, the invention resides broadly in a graffiti removal composition comprising a lipase enzyme and a biodiesel vehicle; wherein the lipase enzyme is present of an amount of between 0.05% and 10% v/v of the composition; and wherein the biodiesel vehicle is present in an amount of between 50% and 98% v/v of the composition. 10 The enzyme may be present in the composition in any suitable quantity. In some embodiments of the invention, the enzyme is provided in the composition in an enzyme solution. The enzyme solution may contain from 0.1% to 50% active enzymes. The enzyme solution may be present in an amount of between 0.1% to 15 20%v/v of the composition, more preferably between 1% to 10%v/v of the composition, even more preferably between 5% and 10%v/v of the composition. The composition may contain between 0.01% and 2% v/v of the composition of active enzymes. Preferably, the composition contains between 0.05% and 1% v/v of 20 the composition of active enzymes. More preferably, the composition contains an amount of approximately 0.5% v/v of the composition of active enzymes. In some embodiments of the invention, at least a portion of the enzyme solution is an active enzyme. Preferably, the enzyme solution comprises up to 50% active enzymes, 25 more preferably up to 20% active enzymes. More preferably, the enzyme solution comprises between 1% and 10% active enzymes. Any suitable active enzyme may be used in the composition of the present invention. However, in a preferred embodiment of the invention, the active enzyme is a Lipase 30 enzyme, such as that classified by the Chemical Abstracts Service Registry as: Lipase, triocylglycose, CAS NO 9001-62-1. Another suitable enzyme preparation for inclusion in compositions according to the invention is classified by the International 3a Union of Biochemistry as EC 3.1.1.3. An example of such an enzyme is the lipase enzyme derived from Thermomyces lanuginosus produced by submerged 4 fermentation of a genetically modified Aspergillus oryae microorganism, ideally with an activity of 100 KJU/g. Such an enzyme in aqueous solution with a lipolytic activity of 100 KLU/g is determined relative to an analytical standard under the following conditions: Substrate, Tributyrin. Temperature 30 degrees centigrade and 5 pH 7.0. According to one preferred embodiment the active enzyme is a lipase enzyme derived from Rhizomucor miehei produced by submerged fermentation. The lipase enzyme can be derived from a variety of microorganisms. 10 Enzyme types, other than lipase, with specific catalytic activity may also be useful. For instance, the active enzyme according to the invention can be of a non-lipolytic type and may be of any or a mixture of the following types, protease, amylase, cellulase, or hemicellulase. 15 The enzyme solution may also contain (but is not limited to) demineralized water, polyoxyethlene (20) oleyl ether, and liquid hydrocarbon solution/s. The biodiesel vehicle of the present invention may be produced from any suitable 20 source. Any suitable quantity of biodiesel may be used in the composition. However, in some embodiments of the invention, the biodiesel vehicle comprises between about 50% and 98% v/v of the composition. Preferably, the biodiesel vehicle comprises between 70% and 95% v/v of the composition. Still more preferably, the biodiesel vehicle comprises between 75% and 91% v/v of the composition. 25 In some embodiments of the invention, the composition may also comprise a surfactant. In these embodiments, the surfactant may comprise any suitable surfactant, such as an anionic surfactant, a nonionic surfactant, a cationic surfactant or a quaternary surfactant. 30 The surfactant may be present in any suitable quantity. However, it is preferred that the surfactant is present in an amount of up to 30% v/v of the composition. Preferably, 5 the surfactant is present in an amount of between 10% and 30% v/v of the composition. More preferably, the surfactant is present in an amount of between 15% and 25% v/v of the composition. 5 In other embodiments of the invention, the composition may further comprise one or more of the following additional components: an emulsifier, a wetting agent, a solubiliser, and a spreading agent. In a preferred embodiment of the invention, the composition comprises all of the additional components. The additional components may be of any suitable form. 10 In some embodiments of the invention, the additional components may be present in an amount of between 1% and 30% v/v of the composition. Preferably, the additional components are present in an amount of between 2% and 25% v/v of the composition. 15 In some embodiments, the additional component comprises an emulsifying agent. In embodiments of the invention in which the composition comprises two or more additional components, the additional components may be provided in the form of an additive that performs two or more of the functions of the additional components. In 20 one embodiment of the invention, the additive comprises a fatty alcohol ethoxylate (ethoxylated oleyl alcohol), which acts as a surfactant and an emulsifying agent. A suitable ethoxylated oleyl alcohol may be Volpo N10, manufactured by Croda International. An alternative ethoxylated oleyl alcohol may be Teric 17-AO, manufactured by Huntsman Corporation. 25 Preferably, the ethoxylated oleyl alcohol used in the present invention has a suitable alkyl chain length and extent of ethoxylation to provide the composition with good wetting and cleansing properties that result in an improved ability to break the ester bonds within the paint or ink to be removed. 30 in addition, it is preferred that the ethoxylated oleyl alcohol used in the composition is stable over a wide pH range. Preferably, the ethoxylated oleyl alcohol has a middle 6 range of solubility, meaning that it is not designed specifically for total solubility in water or oil. Any additional components added to the composition should be selected so that they 5 are compatible with the other components in the composition. In some embodiments of the invention, the composition may further comprise one or more of the following ingredients: one or more stabilizers, colouring agents or odours/fragrances. 10 In some embodiments of the present invention, the composition may further comprise a thickener. Any suitable thickener may be used, and a skilled addressee will understand the type of thickener which would be suitable for use with the present invention. The thickener may be any suitable commercial thickener, such as, but not 15 limited to, PVC or polyurethane. Preferably, however, the thickener is a cellulosic thickener. Cellulosic thickeners have the advantage of having a relatively low toxicity in comparison to other varieties of thickener. If present, it is preferred that the thickener is present in an amount of up to 10% v/v of the composition. Preferably, the thickener is present in an amount of between 0.1% and 5% v/v of the composition. 20 More preferably the thickener is present in an amount of about 1% of the composition. The thickener may be added to the composition directly or in a mixture with another suitable substance. 25 In some embodiments of the invention, a solvent may be added to the composition. Any suitable solvent may be used, such as, but not limited to, N-methyl-2 pyrrolidone, isophorone, glycol ester acetates, methylene chloride, butyl diglycol, acetone, butyl diglycol acetate, glycol ethers, ketones, ethyl ethoxy propionate, cresylic acid, 30 cyclohexanone, pentane diol esters, d'limonene, propylene glycol, monomethyl ether acetate, White Spirit, isoparaffin, ethylene glycol ethers, butyl acetate, amyl acetate, ethyl acetate, kerosene, ethyl lactate, butyl lactate, ethyl propionate, butyl propionate, 7 isoamyl alcohol and 2-ethyl hexyl deconoate. It will be understood, however, that other solvents may be used depending on legislative requirements, environmental concerns, occupational health and safety factors and the like. Thus, other solvents may be used as required. For instance, it has been found that solvents comprising one or more of dimethyl succinate, dimethyl adipate and dimethyl glutarate may provide a number of benefits over other solvents, including one or more of higher flash points, reduced toxicity, reduced volatile organic compound (VOC) content, reduced odour and low evaporation. In a preferred embodiment, the solvent may comprise a combination of all three of dimethyl succinate, dimethyl adipate and dimethyl glutarate. Any suitable proportions of these three substances may be present in the solvent, however, in a preferred embodiment, the solvent may comprise between 10% and 30% v/v of dimethyl succinate, between 5% and 30% dimethyl adipate, and between 50% and 75% dimethyl glutarate. More preferably, the solvent comprises between 15% and 25% v/v of dimethyl succinate, between 10% and 25% dimethyl adipate, and between 55% and 65% dimethyl glutarate. One suitable solvent may be manufactured by Dow Chemical Company Pty Ltd under the trade mark Estasol. The purpose of the solvent may be to break down the ink or paint the composition is being used to remove without causing damage to the underlying structure. Preferably, the solvent is present in an amount of less than 25% v/v of the composition. It is envisaged that the "safer" solvents (i.e. solvents having higher flash points, reduced toxicity, reduced volatile organic compound (VOC) content, reduced odour and/or low evaporation etc) may either entirely replace more traditional "unsafe" solvents, or may be used in conjunction with the "unsafe solvents" to reduce the amount of "unsafe" solvent used in the composition. In another aspect, the invention resides broadly in a graffiti removal composition comprising a lipase enzyme and one or more fatty acid methyl esters; wherein the lipase enzyme is present of an amount of between 0.05% and 10% v/v of the composition; and wherein the fatty acid methyl esters are present in an amount of between 50% and 98% v/v of the composition. Any suitable fatty acid methyl esters may be used in the composition. However, in a preferred embodiment of the invention, the fatty acid methyl esters are produced by 8 the transesterification of vegetable oils or animal fats. Alternatively, the fatty acid methyl esters may be produced by the esterification of free fatty acids, and, in particular, the enzyme esterification of free fatty acids. 5 The composition of the present invention may be provided as a clear composition or may be tinted to allow a user to see where the composition has been applied to a surface structure. In a further aspect, the invention resides broadly in a method for the removal of paint, 10 ink or other surface coatings applied to a surface comprising applying to the paint or ink a composition as described above. When the composition is applied to a paint deposit or ink, the active enzyme hydrolyses the ester bonds in the 1, 3 position of the tryglyceride molecules present in 15 the paint binder and weakens the paint film so that cleaning and removal can be effected. The composition may be applied using a brush (such as a soft-bristled paintbrush), cloth, towel (for instance, paper towel), scrub pad (such as a non-scratch scrub pad) or roller, or it may be applied by spraying. 20 Cleaning and removal may be performed using any suitable technique. For instance, the deposit or surface coating may be removed by wiping with cloths, towels, paper or any other suitable material. Alternatively, the deposit or surface coating may be washed off using water or any other suitable fluid. In one embodiment of the invention a vacuum type water cleaner, similar to those used in carpet cleaning, may 25 be used for one-step removal of the paint film weakened by the application of the composition. This apparatus produces in-situ warm to hot water and with either a brush or brushes action vacuums the paint debris into a contained vessel and minimizes clean up time. 30 It is envisaged that the composition of the present invention may be applied to a surface coating or deposit placed on any suitable surface structure. For instance, suitable surface structures may include painted brick or block, rendered cement 9 surfaces, tiled surfaces, stainless steel surfaces, timber and general high traffic area surfaces which can be at risk of graffiti damage. The composition of the present invention has the significant advantage over prior art 5 compositions of being substantially non-flammable and non-toxic. This makes the composition of the present invention more attractive for use in a wide variety of applications due to the reduced health and safety hazards to those using the composition as well as to the public in general. Moreover, the composition allows for the removal of graffiti without unduly affecting the underlying service to which the 10 graffiti has been applied. A skilled addressee will understand that, while the present invention has been discussed with particular reference to its ability to remove paint and ink, the composition of the present invention may be suitable for use in the removal of surface 15 coatings (such as graffiti) that have been applied using other substances, such as crayon, marker pen, glue or the like. DETAILED DESCRIPTION OF THE INVENTION The nature of the present invention may be more clearly understood from the 20 following preferred but non-limiting examples. Example I A composition according to an embodiment of the present invention was prepared using the following ingredients in sufficient quantities to produce 1000ml of 25 composition: - Volpo N 10 manufactured by Croda International (Ethoxylated oleyl alcohol) - Lipolase 1 OOL, Type EX (1-10% active enzyme) manufactured by Novozymes - Biodiesel (Methyl fatty acid esters) 30 The composition was manufactured according to the following procedure: 1. The Volpo N10 was heated to beyond its melting point; 10 2. 200ml of liquid Volpo NI was added to a beaker and heated slowly under low heat whilst stirring until the liquid became clear; 3. 50ml of Lipolase solution was added to the heated Volpo N10 whilst stirring; 4. The solution was removed from the heat and allowed to cool to below 40'C; 5 5. 750ml of biodiesel was added to the stirred solution. The above procedure produced a composition having the following make-up: Volpo N10 20% v/v 10 Enzyme Solution 5% v/v Biodiesel Balance If desired, a thickener could be added to the composition in an amount of approximately 1% v/v of the composition. 15 The composition produced by the method of Example I is a non-flammable, fully biodegradable and environmentally friendly product that may be used to remove solvent based paints and inks from acrylic painted surfaces without significant damage to the surface paint. 20 Example 2 A composition according to an embodiment of the present invention was prepared using the following ingredients in sufficient quantities to produce 1000ml of composition: 25 - The composition produced in Example I - N-methyl-2 pyrrolidone The composition was manufactured according to the following procedure: 30 1. 760ml of the composition produced by the method of Example 1 was added to 240ml of N-methyl-2 pyrrolidone.

S1I The above procedure produced a composition having the following make-up: Volpo NIO 15.2% v/v Enzyme Solution 3.8% v/v 5 N-methyl pyrrolidone 24% v/v Biodiesel Balance If desired, a thickener could be added to the composition in an amount of approximately 1% v/v of the composition. 10 The composition produced by the method of Example 2 is a non-flammable, fully biodegradable and environmentally friendly product that may be used to remove solvent based paints and inks from unpainted surfaces without significant damage to the surface. 15 Example 3 A composition according to an embodiment of the present invention was prepared using the following ingredients in sufficient quantities to produce 1000ml of composition: 20 - Volpo N 10 manufactured by Croda International (Ethoxylated oleyl alcohol) - Lipolase I 00L, Type EX (1-10% active enzyme) manufactured by Novozymes - Biodiesel (Methyl fatty acid esters) The composition was manufactured according to the following procedure: 25 1. The Volpo N 10 was heated to beyond its melting point; 2. 45ml of liquid Volpo N 10 was added to a beaker and heated slowly under low heat whilst stirring until the liquid became clear; 3. 1Oml of Lipolase solution was added to the heated Volpo N10 whilst stirring; 30 4. The solution was removed from the heat and allowed to cool to below 40'C; 5. 945ml of biodiesel was added to the stirred solution.

12 The above procedure produced a composition having the following make-up: Volpo N10 4.5% v/v Enzyme Solution 1% v/v 5 Biodiesel Balance If desired, a thickener could be added to the composition in an amount of approximately 1% v/v of the composition. 10 The composition produced by the method of Example 3 is an ultra safe, non flammable, fully biodegradable, non-hazardous and environmentally friendly product that may be used to remove solvent based paints and inks from acrylic painted surfaces without significant damage to the surface paint. 15 Example 4 A composition according to an embodiment of the present invention was prepared using the following ingredients in sufficient quantities to produce 1000ml of composition: - Estasol manufactured by Dow Chemical Company Pty Ltd (A mixture of dimethyl 20 succinate, dimethyl adipate and dimethyl glutarate) - N-methyl-2 pyrrolidone - Solution of Biodiesel (Methyl fatty acid esters) and Lipolase 1OOL, Type EX (1-10% active enzyme) manufactured by Novozymes - Fragrance 25 The composition was manufactured according to the following procedure: 1. The Estasol, N-methyl-2 pyrrolidone and biodiesel were mixed at 40'C for at least one hour; and 30 2. The fragrance (apple scent) was added to the mixture and mixed for a further 5 minutes.

13 The above procedure produced a composition having the following make-up: Estasol 30.0% v/v Biodiesel/Enzyme Solution 66.5% v/v 5 N-methyl-2 pyrrolidone 2.9% v/v Fragrance 0.6% v/v Those skilled in the art will appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It will be 10 understood that the present invention encompasses all such variations and modifications that fall within its spirit and scope.

Claims

1. A graffiti removal composition comprising a lipase enzyme and a biodiesel vehicle; wherein the lipase enzyme is present of an amount of between 0.05% and 5 10% v/v of the composition; and wherein the biodiesel vehicle is present in an amount of between 50% and 98% v/v of the composition.

2. A composition according to claim 1 wherein the lipase enzyme is present in the composition in an enzyme solution. 10

3. A composition according to claim 2 wherein the enzyme solution comprises up to 50% active lipase enzymes.

4. A composition according to any one of the preceding claims wherein the composition further includes one or more additional components selected from the list including a surfactant, an emulsifier, a wetting agent, a 15 solubiliser and a spreading agent.

5. A composition according to claim 4 wherein a single additive is adapted to perform the function of two or more of the additional components.

6. A composition according to claim 4 or claim 5 wherein a single additive is adapted to perform the function of all of the additional components. 20

7. A composition according to claim 5 or claim 6 wherein the single additive is an ethoxylated oleyl alcohol.

8. A composition according to any one of claims 5 to 7 wherein the additional components are present in an amount of between 1% and 30% v/v of the composition. 25

9. A graffiti removal composition comprising a composition as claimed in any one of the preceding claims and a thickener.

10. A composition according to claim 9 wherein the thickener is present in an amount of up to 10% v/v of the composition.

11. A composition according to any one of the preceding claims wherein the 30 composition further comprises a solvent.

12. A composition according to claim 11 wherein the solvent is present in an amount of less than 25% v/v of the composition. 15

13. A composition according to claim 11 or claim 12 wherein the solvent includes a mixture of dimethyl succinate, dimethyl adipate and dimethyl glutarate.

14. A composition according to claim 11 or 12 wherein the solvent comprises N methyl-2 pyrrolidone. 5

15. A graffiti removal composition comprising a lipase enzyme and one or more fatty acid methyl esters; wherein the lipase enzyme is present of an amount of between 0.05% and 10% v/v of the composition; and wherein the fatty acid methyl esters are present in an amount of between 10 50% and 98% v/v of the composition.

16. A composition according to claim 15 wherein the one or more fatty acid methyl esters are produced by the transesterification of vegetable oils or animal fats or the enzyme esterification of free fatty acids.

17. A composition according to any one of the preceding claims wherein the 15 composition is a non-aqueous composition.

18. A method for the removal of paint, ink or other surface coatings applied to a surface comprising applying to the paint, ink or other surface coating a composition as claimed in any one of claims I to 17.