AQUEOUS COMPOSITION FOR CLEANING OR REMOVING COATINGS

Abstract

An aqueous composition for cleaning surfaces, for removing coatings from surfaces, or for plasticising or softening coatings or other surface-adhered materials prior to stripping or mechanical removal thereof from the surface, comprises a trialkyi or triaryl phosphate, a dibasic or tribasic carboxylic acid ester, and greater than 80% by weight of water. The composition is useful in removing grease, waxes, oil, resins, tar, ink, magic marker ink, paint (including spray-paint), varnish, lacquer, stains (including wood staining compositions applied to a wooden surface), dirt, mould or foodstuffs from surfaces.

Claims

1. An aqueous composition comprising: (a) the following components (i) and (ii): (i) at least one compound of formula (I) ##STR00006## wherein R, R.sup.1 and R.sup.2, which may be the same or different, represent optionally substituted lower alkyl, optionally substituted phenyl or optionally substituted lower alkyl-phenyl groups; and (ii) at least one ester selected from optionally substituted lower alkyl diesters of dibasic C.sub.2-20 carboxylic acids and optionally substituted lower alkyl triesters of tribasic C.sub.4-20 carboxylic acids; (b) optionally, at least one surfactant; (c) water; (d) optionally, a rheology control agent to cause the composition to be in the form of a gel; and (e) optionally, one or more anti-foaming agent cooperating with the surfactant(s) to reduce foaming; characterised in that: component (c) (water) is present in an amount of greater than 80% and less than about 99.0% by weight of the aqueous composition; the composition is a stable emulsion; and preferably, the composition formed by components (a), (c) and if present (b) is optically transparent; with the proviso that, when component (a(i)) is or includes tributoxyethyl phosphate and component (a(ii)) is or includes simultaneously dibutyl phthalate, then component (c) (water) is present in an amount of greater than 85.0% by weight of the aqueous composition.

2. (canceled)

3. A method for cleaning a surface, or a method for removing a coating from a surface, or a method for plasticising or softening a coating or other surface-adhered material prior to stripping or mechanical removal thereof from a surface, comprising applying to the surface or coating an aqueous composition comprising: (a) the following components (i) and (ii): (i) at least one compound of formula (I) ##STR00007## wherein R, R.sup.1 and R.sup.2, which may be the same or different, represent optionally substituted lower alkyl, optionally substituted phenyl or optionally substituted lower alkyl-phenyl groups; and (ii) at least one ester selected from optionally substituted lower alkyl diesters of dibasic C.sub.2-20 carboxylic acids and optionally substituted lower alkyl triesters of tribasic C.sub.4-20 carboxylic acids; (b) optionally, at least one surfactant; (c) water; (d) optionally, a rheology control agent to cause the composition to be in the form of a gel; and (e) optionally, one or more anti-foaming agent cooperating with the surfactant(s) to reduce foaming; characterised in that: component (c) (water) is present in an amount of greater than 80% and less than about 99.0% by weight of the aqueous composition; the composition is a stable emulsion; and preferably, the composition formed by components (a), (c) and if present (b) is optically transparent.

4. A process for making an aqueous composition according to claim 1, comprising mixing components (a), (b), (c) and optionally (d) and optionally (e) to form a stable emulsion.

5. A aqueous composition consisting essentially of: (a) the following components (i) and (ii): (i) at least one compound of formula (I) ##STR00008## wherein R, R.sup.1 and R.sup.2, which may be the same or different, represent optionally substituted lower alkyl, optionally substituted phenyl or optionally substituted lower alkyl-phenyl groups; and (ii) at least one ester selected from optionally substituted lower alkyl diesters of dibasic C.sub.2-20 carboxylic acids and optionally substituted lower alkyl triesters of tribasic C.sub.4-20 carboxylic acids; (b) optionally, at least one surfactant; (c) water; (d) optionally, one or more rheology control agent to cause the composition to be in the form of a gel; and (e) optionally, one or more anti-foaming agent cooperating with the surfactant(s) to reduce foaming; characterised in that: component (c) (water) is present in an amount of greater than 80% and less than about 99.0% by weight of the aqueous composition; the composition is a stable emulsion; and preferably, the composition foamed by components (a), (c) and if present (b) is optically transparent.

6. The aqueous composition of claim 5, said composition consisting only of: (a) said components (i) and (ii) ##STR00009## (b) optionally, said at least one surfactant; (c) said water; (d) optionally, said rheology control agent to cause the composition to be in the form of a gel; and (e) optionally, said one or more anti-foaming agent cooperating with the surfactant(s) to reduce foaming.

7. The method according to claim 3, wherein at least one of grease, waxes, oil, resins, tar, ink, magic marker ink, paint (including spray-paint), varnish, lacquer, stains (including wood staining compositions applied to a wooden surface), dirt, mould or foodstuffs is removed from surfaces.

8. The composition according to claim 1, wherein the composition is optically transparent and exists as a stable emulsion which does not have a cloudy appearance.

9. The composition according to claim 1, wherein a surfactant is present in the composition.

10. The composition according to claim 1, wherein a rheology control agent is present in the composition.

11. The composition according to claim 10, wherein the composition containing the rheology control agent is optically transparent.

12. The composition according to claim 1, wherein an anti-foaming agent is present in the composition.

13. The composition according to claim 1, wherein the component (a(i)) is or comprises triethyl phosphate.

14. The composition according to claim 1, wherein the component (a(ii)) is or comprises one or more of dimethyl adipate, dimethyl succinate and dimethyl glutarate.

15. The composition according to claim 1, wherein the component (b) is present and is or comprises a non-ionic water-soluble block copolymer of more than one alkylene oxide.

16. The composition according to claim 1, wherein the component (d) is present and is or comprises a synthetic hectorite clay.

17. The composition according to claim 1, wherein the component (e) is present and is or comprises a C.sub.1-10 alkyl alcohol, for example hexan-1-ol.

18. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0180] The accompanying drawings show the following results:

[0181] FIG. 1 shows the results of the experiment described in Example 1.

[0182] FIG. 2 shows the results of the experiment described in Example 2.

[0183] FIG. 3 shows the results of the experiment described in Example 4.

[0184] FIG. 4 shows the results of the Experiment described in Example 5.

EXAMPLES

Formulations

[0185] The following aqueous compositions were prepared (proportions are % by weight).

TABLE-US-00001 A (com- parison) B C D E F Triethyl- 10 5 2.5 1.25 4.86 7.50 phosphate (a(i)) Dibasic Ester* 10 5 2.5 1.25 4.86 7.50 (a(ii)) Synperonic 1.46 0.73 0.36 0.18 0.71 1.09 F127 (b) Water 78.43 89.21 94.61 97.31 86.79 80.83 (c) Laponite 2.72 3.00 RD (d) Hexan-1-ol 0.11 0.06 0.03 0.01 0.06 0.08 (e) Total 100.00 100.00 100.00 100.00 100.00 100.00 *A mixture consisting of 10-25% by weight dimethyl adipate, 15-25% by weight dimethyl succinate and 55-65% dimethyl glutarate.

[0186] Composition A, a comparison composition similar to Example 1 of EP-B-0869997 but omitting the Germaben biocide, was prepared by mixing the components until a stable microemulsion was formed. Composition B was prepared by adding an equal weight of water to the weight of composition A. Composition C was prepared by adding an equal weight of water to the weight of composition B. Composition D was prepared by adding an equal weight of water to the weight of composition C. Composition E was prepared by adding 2.8% by weight of Laponite to the composition B.

[0187] Composition A was found to be slightly biphasic (the emulsion was inclined to separate into oil and water phases and the Synperonic F127 surfactant had a tendency to settle out of the mixture). Unexpectedly, when composition B was prepared by 1:1 (w/w) dilution of composition A with water, the composition became clear and transparent and would not separate on standing into component parts. From this it is apparent that at above 80% by weight of water the composition takes on a substantially enhanced stability and a clear transparent product is produced.

[0188] Compositions A to E were compared to a marketed aqueous alkali cleaning product, Krud Kutter, available from Krud Kutter UK, Histon, Cambridge CB24 9NU, United Kingdom (www.krudkutter.co.uk), which has the following formulation (available from http://krudkutter.com/imaqes/msds/kk-oriqinal%20krud %20kutter.pdf retrieved on 19 Jun. 2014; or from http://www.homedepot.com/catalog/pdfImaqes/aa/aae0fe79-7b1e-4cdf-90b5-60d9ffbd3594.pdf retrieved on 5 Jun. 2015): [0189] 90 to 97% water; [0190] 1 to 3% trisodium salt; [0191] 1 to 3% ethoxylated alcohol; and [0192] 1 to 3% sodium metasilicate.

[0193] The compositions B, C, D, E and F were stable monophasic, clear, transparent, compositions with very good action to clean surfaces, or to remove a coating from a surface, or to plasticise or soften a coating or other surface-adhered material prior to stripping or mechanically removing it from the surface, as shown by the following test examples.

Example 1Cleaning/Stripping a Wax Coating and Remove the Stain from a Stained Wood Panel

[0194] Compositions A and B, and the comparative product Krud Kutter were used to clean a wax coating and remove the stain from a stained wood panel. The results immediately after application and 5 minutes after application were observed and are shown in FIG. 1.

[0195] The dark brown horizontal band across the middle of FIG. 1 shows the colour of the untreated original wax coated stained wood.

[0196] It was found that compositions A and B worked better than the comparative product, Krud Kutter at removing the wax coating and the stain to leave good quality bare wood. The wood revealed by A and B is a lighter colour than the wood revealed by Krud Kutter, and all three are a lighter colour than the untreated original wax coated wood (central horizontal band). The stain was not removed by Krud Kutter.

[0197] Surprisingly, composition B demonstrated better results that composition A. This is shown by the lighter colour of the portion of wood revealed by the treatment with composition B, compared to that revealed by composition A. In addition, the surface texture of the portion of wood revealed by composition B was superior to the surface texture of the portion of wood revealed by composition A.

[0198] This result is surprising because it would not be expected that increasing the water content of the A composition, namely diluting it, would lead to a better cleaning or coating-removal action coupled with stain removal.

[0199] Similar amounts of a standard oil-based white paint were then applied to the six areas of the same wood panel resulting from the above experiment (i.e. the two areas cleaned by Krud Kutter, the two areas cleaned by composition A and the two areas cleaned by composition B). Once dry, masking tape was applied to the top half (as seen in FIG. 1) of each of the six areas of white paint, left for a standard length of time and then removed in a similar manner in each case, in order to test the adhesion strength of the paint to the cleaned bare wood surface.

[0200] The results are shown in FIG. 1. It was found that less damage to the paint was caused (i.e. the paint adhered more strongly to the bare wood) when compositions A and B had been used, in comparison to where the comparative product, Krud Kutter had been used. The paint adhered more strongly to the area of bare wood that had been cleaned by composition B, according to the present invention, than to the area of bare wood that had been cleaned by the comparison composition A. The paint adhered less strongly to the area of bare wood that had been cleaned by Krud Kutter than to either of the areas of bare wood that had been cleaned by composition A or B. The dark patches in the painted areas at the end of the above test (FIG. 1) are the underlying wood showing through, and provide the visual evidence for the above conclusions.

[0201] The results of this paint adhesion test correlate with the observable colour of the stripped and de-stained wood and the quality of the surface of the bare wood, shown in FIG. 1 and described above.

Example 2Cleaning/Stripping a Wooden Box

[0202] Composition B was used to clean a wooden 50 year old box having old varnish and grease on the wood surface. The composition was applied to a cloth and gently rubbed onto the box surface without being left to stand. The result is shown in FIG. 2, the cleaned/stripped portion being indicated by the arrow.

[0203] Composition B was able to clean/strip the surface of the box, removing all old varnish and grease down to bare wood, in less than one minute.

Example 3Cleaning/Stripping a Range of Substrates

[0204] Compositions A, B, C and D were applied to a range of surfaces, including wood, uPVC and slate. The cleaning and paint removal action was monitored under comparable conditions. Compositions B, C and D all worked to clean or strip the surfaces, although more rubbing was required with composition D. The use of a higher temperature would be expected to reduce the need for more rubbing. Composition A also worked, but not so well as B and C.

[0205] From this experiment it is shown that the improved efficacy of the composition of the present invention above 80% by weight of water is maintained to at least 97% by weight of water.

Example 4Removal of Old Paint

[0206] Composition E was applied to a small section of old (c. 100 years old) Victorian painted wood which is used as a test piece for paint removal experiments. A section having three layers of old paint was selected. After 20 minutes of standing the composition and paint were removed by lifting with a blade instrument. It was found that this composition can remove the three coats of old paint in 20 minutes down to bare wood.

[0207] The result is shown in FIG. 3. The treated section showing the bare wood is in the centre of the photograph.

Example 5Removal of Old Paint

[0208] Composition F was applied to a small section of old painted wood having five coats of paint. After 1 and 2 hours of standing the composition and paint were removed by lifting with a blade instrument. It was found that this composition can remove the five coats of old paint in 1 hour down to bare wood, although the result is more complete after 2 hours.

[0209] The result after 2 hours is shown in FIG. 4. The treated section showing the bare wood is in the centre of the photograph.

[0210] The foregoing broadly describes certain embodiments of the present invention without limitation. Variations and modifications as will be readily apparent to those skilled in the art are intended to be within the scope of the present invention as defined in and by the appended claims.