CLEANING COMPOSITIONS

Abstract

The present invention relates to cleaning compositions, in particular to cleaning compositions for use in heating, ventilation and air-conditioning (HVAC) installations. We describe an acidic cleaning composition concentrate comprising: at least one acid having a pKa.sub.1 of 4 or less, wherein the at least one acid is at least one organic acid and/or non-oxidising mineral acid; a rheology modifier; and a polar protic solvent. In some examples, compositions may also include at least one of one or more weak nitrogenous bases, one or more carboxylate salts and one or more one surfactants;

Claims

1. An acidic cleaning composition, comprising: i) at least one acid having a pKa.sub.1 of 4 or less, wherein the at least one acid is at least one organic acid and/or non-oxidising mineral acid; ii) a rheology modifier; and iii) a polar protic solvent.

2. The composition as claimed in claim 1, wherein the acid is selected from the group consisting essentially of hydrochloric acid, phosphoric acid, methanoic acid, hydrofluoric acid, lactic acid, oxalic acid, malic acid, sulfamic acid, tartaric acid, gluconic acid and citric acid, or one or more salts thereof, or is at least one acidic salt, optionally urea hydrochloride.

3. The composition as claimed in claim 1, wherein the acid is present in an amount of 35 to 75 wt.% based on the total weight of the cleaning composition concentrate.

4. The composition as claimed in claim 1, wherein the composition has an acid molarity based on the total amount of the at least one acid of 5 M to 20 M at 25° C.

5. The composition as claimed in claim 1, wherein the rheology modifier is present in an amount of 2 to 20 wt.% based on the total weight of the cleaning composition concentrate.

6. The composition as claimed in claim 1, wherein the rheology modifier is either one of a polyurethane and polyacrylate copolymer.

7. The composition as claimed claim 1, wherein the composition has a Brookfield viscosity in the range of 1,000 mPa.s to 9,999 mPa.s.

8. The composition as claimed in claim 1, further comprising a buffer.

9. The composition as claimed in claim 1, wherein the polar protic solvent is water.

10. The composition as claimed in claim 1, wherein the polar protic solvent includes a glycol ether and an organic co-solvent.

11. The composition as claimed in claim 1, further comprising a nitrogenous base and/or a carboxylate salt.

12. The composition as claimed in claim 11, wherein the at least one salt includes the-trisodium salt of citric acid.

13. The composition as claimed in claim 11, wherein the nitrogenous base is at least one base selected from the group of urea, triethanolamine, diethanolamine, pyridine, ammonia and aniline.

14. A composition as claimed in claim 13, wherein the nitrogenous base is present in an amount of 2 to 10 wt.% based on the total weight of the cleaning composition concentrate.

15. The composition as claimed in claim 1, further comprising at least one surfactant.

16. The composition as claimed in claim 15, wherein the surfactant is at least one amphoteric, anionic and cationic surfactant.

17. The composition as claimed in claim 15, wherein the surfactant is present in an amount of 5 wt.% or less based on the total weight of the cleaning composition concentrate.

18. The composition as claimed in claim 15, wherein the surfactant is selected from the groups consisting essentially of sodium salts of C.sub.10-C.sub.13 alkyl derivatives of benzenesulfonic acid, Amphoterge K 2N [68411-57-4] and salt-free, coco-substituted imidazoline surfactants.

19. The composition as claimed in claim 15, wherein the surfactant is either one of a biocidally-active surfactant and didecyldimethylammonium chloride.

Description

EXAMPLE 1 - ACID ICE MACHINE CLEANER CONCENTRATE

[0031] 50 wt% aqueous solution Citric acid (25 g) was added to a 75 wt% aqueous solution of phosphoric acid (63 g) with stirring. Di(propylene glycol) methyl ether (2 g) was added with stirring until an even mixture was obtained.

[0032] Rheosolve T450 (10 g) was added, with stirring until a homogeneous mixture was obtained. The concentrate had a pH of 1 to 2 with a Brookfield viscosity (at 100 rpm, 25° C.) of about 3000 mPa.s.

[0033] Dilution with water at a rate of up to 32:1 (parts by volume) gave a highly effective cleaner for ice-making machines. The cleaner is safe for the nickel and stainless-steel surfaces typically found in ice machines, and performed well at dissolving limescale, water spots and grease.

EXAMPLE 2 - ICE MACHINE CLEANER CONCENTRATE

[0034] The composition of the ice machine cleaner concentrate of Example 6 was modified to the following proportions:

TABLE-US-00001 Citric acid (50% solution in water) 22 wt.% Phosphoric acid (75% solution in water) 63 wt.% Di(propylene glycol) methyl ether 2 wt.% Rheosolve T450 13 wt.%

to give a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

EXAMPLE 3 - HVAC CONDENSER CLEANER CONCENTRATE

[0035] Prilled Urea [CAS: 57-13-6] (5 g) was added to a mixture of 37% hydrochloric acid [7647-01-0] (18 g) and 75% phosphoric acid [7664-38-2] (60 g) with stirring and heating at 30° C. until the urea had fully dissolved. Di(propylene glycol) methyl ether [34590-94-8] (4 g), Amphoterge K 2N [68411-57-4], a salt-free, coco-substituted imidazoline amphoteric surfactant available from Lonza Group Ltd, (2 g) were added, without applying heating and with reduced stirring, to avoid excessive foaming. Rheosolve T450 (11 g), an acid-compatible, water soluble, non-ionic polyurethane rheology modifier, available from Coatex Arkema Group, was added to the mixture, with stirring to form a homogenous mixture.

[0036] The example provided a moderate to low foaming, dilutable cleaner concentrate having a pH of 1. Dilution with water at a rate of up to 32:1 (parts by volume) produced a highly effective cleaner for removing limescale, road film, rust and mild organic residues, from surfaces of a HVAC condenser, including for cleaning the coils of the unit.

EXAMPLE 4 - HVAC CONDENSER CLEANER CONCENTRATE

[0037] In a modification of Example 3, the composition was varied to provide a composition having the following formulation:

TABLE-US-00002 Urea 3 wt.% Hydrochloric acid (16%) 18 wt.% Phosphoric acid (75% solution in water) 58 wt.% Di(propylene glycol) methyl ether 2 wt.% Amphoterge K 2N 4 wt.% Rheosolve T450 15 wt.%

In this example, the phosphoric acid solution was added with the di(propylene glycol) methyl ether and Amphoterge K 2N, rather than being pre-mixed with the hydrochloric acid. This gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

EXAMPLE 5 - HVAC EVAPORATOR CLEANER AND DISINFECTANT CONCENTRATE

[0038] To a solution of 50 wt% citric acid (20 g) and 75 wt% aqueous solution of phosphoric acid (60 g), prilled Urea [CAS: 57-13-6] (6 g) a was added with stirring until a clear solution was formed. Acticide DDQ80 [7173-51-5], an 80% solution of di-n-decyldimethylammoniumchloride (3 g), available from Thor Group, was added, with stirring, whilst avoiding excessive foaming. Rheosolve T450 (11 g) was added with further stirring until a homogenous mixture was obtained having a pH of 2, with a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

[0039] The concentrate was diluted with water at a rate of 16:1 (parts by volume) to give a biocidal cleaning composition for removing organic residues and scale on HVAC evaporators.

EXAMPLE 6 - HVAC EVAPORATOR CLEANER AND DISINFECTANT CONCENTRATE

[0040] In a variation of Example 5, ethanolamine was included instead of urea, with the Acticide DDQ80 addition. The proportions of the components were adjusted as follows:

TABLE-US-00003 Citric acid (50% solution in water) 17 wt.% Ethanolamine 6 wt.% Phosphoric acid (75% solution in water) 64 wt.% Acticide DDQ80 2 wt.% Rheosolve T450 11 wt.%

EXAMPLE 7 — UNIVERSAL CLEANER CONCENTRATE

[0041] Trisodium sodium citrate (6 g) and citric acid (29.5 g) were mixed and a 75 wt% aqueous solution of phosphoric acid (50 g) was added, with stirring and heating at 30° C. until a clear solution was formed. Di (propylene glycol) methyl ether (2 g), Surco 30S (0.5 g) and ethanolamine (1 g) were added, with stirring at a reduced speed to avoid excessive foaming. Rheosolve T450 (11 g) was added with stirring until a homogenous mixture, having a pH of 3, was obtained, with a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

TABLE-US-00004 Citric acid (50% solution in water) 29.5 wt.% Trisodium Citrate 6 wt.% Phosphoric acid (75% solution in water) 50 wt.% Di (propylene glycol) methyl ether 2 wt.% Surco 30s 0.5 wt. % Ethanolamine 1 wt.% Rheosolve T450 11 wt.%

EXAMPLE 8 - DRAIN CLEANER CONCENTRATE

[0042] Hydrochloric acid (48.5 g, 16%) was added to urea (12.5 g) with stirring until dissolved. Citric acid [77-92-9] (26 g) was added with continued stirring, followed immediately by the addition of ethanolamine [141-43-5] (3 g). Stirring was continued until the solution was evenly mixed. Rheosolve T450 (10 g) was added to the mixture, with stirring to form a homogenous, having a pH of about 2.

TABLE-US-00005 Hydrochloric acid (16%) 48.5 wt.% Urea 12.5 wt.% Citric acid (50% solution in water) 26 wt.% Ethanolamine 3 wt.% Rheosolve T450 10 wt.%

The viscosity was observed to increase over two days before decreasing, forming a viscously stable composition after seven days to a Brookfield viscosity (at 100 rpm, 25° C.) of about 3400 mPa.s.

[0043] The example provided a concentrate which, when diluted with water at a rate of up to 16:1 (parts by volume) gave a drain cleaner composition having excellent properties for dissolving slime, grime, limescale, fats and grease in drains.

EXAMPLE 9 - DRAIN CLEANER CONCENTRATE

[0044] In a variation of Example 8, sulphamic acid was included instead of citric acid addition. The proportions of the components were adjusted as follows:

TABLE-US-00006 Hydrochloric acid (16%) 48.5 wt.% Urea 12.5 wt.% Sulphamic acid 26 wt.% Ethanolamine 3 wt.% Rheosolve T450 10 wt.%

[0045] Further example compositions were prepared using Rewoteric AM TEG, a tallow betaine gelling agent in place of Rheosolve T450, following the same procedures as set out above. A source of chloride ions was added, as hydrochloric acid or sodium chloride, to increase cross-linking.

EXAMPLE 10 - ICE MACHINE CLEANER CONCENTRATE

[0046] TABLE-US-00007 Citric acid (50% solution in water) 27 wt.% Phosphoric acid (75% solution in water) 63 wt.% Di(propylene glycol) methyl ether 2 wt.% Sodium Chloride 3 wt.% Rewoteric AM TEG 5 wt.%

[0047] This mixture gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 3900 mPa.s.

EXAMPLE 11 - HVAC CONDENSER CLEANER CONCENTRATE

[0048] TABLE-US-00008 Urea 8 wt.% Hydrochloric acid (16%) 18 wt.% Phosphoric acid (75% solution in water) 58 wt.% Di(propylene glycol) methyl ether 2 wt.% Amphoterge K 2N 4 wt.% Rewoteric AM TEG 10 wt.%

[0049] This mixture gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

EXAMPLE 12 - HVAC EVAPORATOR CLEANER AND DISINFECTANT CONCENTRATE

[0050] TABLE-US-00009 Citric acid (50% solution in water) 12 wt.% Ethanolamine 6 wt.% Phosphoric acid (75% solution in water) 64 wt.% Acticide DDQ80 2 wt.% Sodium Chloride 5 wt.% Rewoteric AM TEG 11 wt.%

[0051] This mixture gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 3800 mPa.s.

EXAMPLE 13 - UNIVERSAL CLEANER CONCENTRATE

[0052] TABLE-US-00010 Citric acid (50% solution in water) 29.5 wt.% Trisodium Citrate 6 wt.% Phosphoric acid (75% solution in water) 45 wt.% Di (propylene glycol) methyl ether 2 wt.% Surco 30s 0.5 wt. % Ethanolamine 1 wt.% Sodium Chloride 5 wt.% Rewoteric AM TEG 11 wt.%

[0053] This mixture gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 3800 mPa.s.

EXAMPLE 14 - DRAIN CLEANER CONCENTRATE._

[0054] TABLE-US-00011 Hydrochloric acid (16%) 48.5 wt.% Urea 12.5 wt.% Citric acid (50% solution in water) 26 wt.% Ethanolamine 3 wt.% Rewoteric AM TEG 10 wt.%

[0055] This mixture gave a concentrate having a Brookfield viscosity (at 100 rpm, 25° C.) of about 4000 mPa.s.

Summary

[0056] The above compositions were all determined to exhibit excellent dilutability, and excellent cleaning properties for the indicated function. The composition of claim 1 provides an excellent base composition which can be modified to suit specific purposes. By way of example, the base composition can be used without modification for, for example, an ice machine cleaner. A condenser cleaner advantageously additionally includes at least one surfactant and a general purpose cleaning composition such as that of Example 7, advantageously includes a carboxylate salt.

[0057] The present invention provides stabilised, dilutable acidic cleaning compositions in a concentrated, aqueous gel form. As with powdered formulations, dilutable gel detergents are easier to transport in bulk than existing compositions, require less packaging material, and occupy less space on the store shelf. They additionally offer the excellent chemical dexterity of dilute liquid detergents, compared with powdered detergent concentrate compositions. When diluted, the range of products of the present invention are able to clean via four main conventional routes: a) neutralisation of acidic or alkaline soils, b) emulsification of oil and grease, c) suspension of removed soiling, and d) prevention of its redeposition.

[0058] Although indicated above as having specific purposes within the HVAC industry, it will be appreciated that each inventive composition is equally suitable for other purposes, both within the HVAC industry and elsewhere.

[0059] We have found that the inventive concentrates, following dilution, retain a sufficient gelatinousness to coat metallic surfaces, making the compositions ideal for cleaning difficultly positioned surfaces, such as those of vertically-installed condensers.