WO1992019557A1 - Limescale remover - Google Patents

Limescale remover Download PDF

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Publication number
WO1992019557A1
WO1992019557A1 PCT/GB1992/000785 GB9200785W WO9219557A1 WO 1992019557 A1 WO1992019557 A1 WO 1992019557A1 GB 9200785 W GB9200785 W GB 9200785W WO 9219557 A1 WO9219557 A1 WO 9219557A1
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WO
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Prior art keywords
composition
acid
quaternary ammonium
cationic surfactant
ammonium salt
Prior art date
Application number
PCT/GB1992/000785
Other languages
French (fr)
Inventor
Inderhir Tranter
Philip Ian Tideswell
Catherine Eva Donnelly
Original Assignee
Cussons (International) Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cussons (International) Limited filed Critical Cussons (International) Limited
Publication of WO1992019557A1 publication Critical patent/WO1992019557A1/en
Priority to DK126493A priority Critical patent/DK126493A/en
Priority to GB9323711A priority patent/GB2273925B/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
    • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
    • C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
    • C02F5/12—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing nitrogen
    • C02F5/125—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing nitrogen combined with inorganic substances
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
    • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
    • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
    • C02F5/083—Mineral agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
    • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
    • C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
    • C02F5/12—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/025—Cleaning or pickling metallic material with solutions or molten salts with acid solutions acidic pickling pastes

Definitions

  • This invention relates to a composition for removing deposits of scale and the like.
  • Water hardness is a condition which results when rainwater percolates through rock formations such as limestone or chalk and dissolves inorganic salts, particularly calcium carbonate. Water which contains more than about 100 parts per million of calcium
  • limescale When hard water evaporates the dissolved calcium carbonate is deposited on the adjacent surface in the form of tiny crystals. This is known as limescale. With time these limescale deposits can build up into quite a large size. Limescale is strongly bonded to the surfaces on which it is deposited and is difficult to remove. Well known examples of limescale deposits are the
  • Limescale deposits can also occur when hard water is heated an example of this being the well known furring of kettles. Deposits can also be formed in washing machines and dishwashing machines.
  • Limescale removers have been developed in order to deal with these problems. These are generally based on acid which will react with the deposited scale to form a salt which is more readily soluble in water than calcium carbonate and which can thus be washed away.
  • limescale remover There are two main types of limescale remover.
  • One type includes a strong acid (e.g. hydrochloric acid, sulphamic acid) so that the pH of the limescale remover composition is about 1.0 or less. As a result of this low pH such compositions have a thin, watery consistency since stable thickening systems have not been previously achievable.
  • this type of limescale remover is quite effective it is difficult if not impossible to maintain contact between the limescale remover
  • the other type of limescale remover includes a weak acid, (e.g. citric acid, acetic acid) resulting in a composition having a pH usually in the range of from 3 to 5. With such mild pH conditions such compositions can be easily thickened.
  • a weak acid e.g. citric acid, acetic acid
  • compositions may remain in contact with a non-horizontal surface to be treated for a longer time than the strong acid type of composition, they have a poor performance. Hence they must remain in contact with the surface being treated for a considerable time for example up to half an hour. Even quite viscous compositions cannot with certainty be expected to remain in contact for that length of time with non-horizontal surfaces, particularly vertical surfaces such as the sides of a bath or on a tap.
  • the present invention has been made in order to deal with this problem.
  • compositions for effectively removing deposits of scale and the like from horizontal and inclined surfaces comprising an acid, a cationic surfactant and a desolubiliser.
  • thickener providing increased viscosity for example up to 800 cps (Brookfield RV3/25°). Compositions having a viscosity of this order will tend to "cling" to vertical and non-horizontal surfaces thus giving the necessary contact time for effective scale removal.
  • the acid used in the composition may be one which is used in conventional limescale removers, such as mineral acids, e.g. sulphamic acids, hydrochloric acids, phosphoric acid and organic acids, e.g. acetic acid, hydroxyacetic, citric acid, lactic acid.
  • mineral acids e.g. sulphamic acids, hydrochloric acids, phosphoric acid and organic acids, e.g. acetic acid, hydroxyacetic, citric acid, lactic acid.
  • the preferred cationic surfactants are (higher alkyl) quaternary ammonium compounds (where higher alkyl means alkyl groups having from 8 to 30 carbons
  • Particularly preferred quaternary ammonium compounds are the following: -
  • R 2 is an acyclic aliphatic C 15 -C 22 hydrocarbon group.
  • R 3 is a C 1 -C 4 saturated alkyl or hydroxyalkyl group, R 4 is selected from R 2 and R 3 and A is an anion,
  • R 1 is an acyclic aliphatic C. t - _ C_ hydrocarbon group
  • R 2 is a divalent alkylene group having 1 to 3 carbon atoms
  • R 5 and R 8 are C 1 -C 4 saturated alkyl or hydroxyalkyl groups and A is an anion
  • n is equal to 1 to about 5, R 1 , R 2 , R 5 and A- are as defined above;
  • Component (i) examples include
  • dialkyldimethylammonium salts such as ditallowdimethylammonium chloride, ditallowdimethylammonium
  • component (ii) examples include
  • R 1 is an acyclic aliphatic C 15 -C 17 hydrocarbon group.
  • R 2 is an ethylene group, R is a methyl group, R 8 is a hydroxyalkyl group and A is a methylsulfate anion; these materials are available from Sherex Chemical Company under the trade names Varisoft (R) 222 and Varisoft (R) 110, respectively.
  • a particularly preferred cationic surfactant is a compound of Formula II wherein R 2 is as defined above, R 3 is methyl and R 4 is also methyl.
  • the quaternary ammonium salt (b) preferably
  • composition comprises from 1% to 20%, more preferably 2% to 20% by weight of the composition herein.
  • the weight ratio amine (a): quaternary ammonium salt (b) is in the range from 10:1 to 1:10, preferably from 3:1 to 1:3.
  • di (higher alkyl) imidazolinium compounds are preferred for use in the invention, in particular the 1-(lower alkyl)-1-(higher alkyl)amidoethyl-2-(higher alkyl) imidazolinium compounds, where "lower alkyl” means alkyl having from 1 to 4 carbon atoms, and “higher alkyl” means alkyl having from 11 to 22 carbon atoms.
  • the preferred desolubilisers are for example sodium xylene sulphonate and sodium cumene sulphonate.
  • desolubiliser used are chosen having regard to the desired viscosity of the composition. However, amounts in the range 50.0 to 1.0% and 0.0 to 50% (by volume) respectively are preferred.
  • composition of the invention may include the usual additives such as perfume, colourant and the like.
  • a limescale remover composition was formulated as follows:-
  • the composition had a viscosity of 200 cps
  • surfactant and sodium xylene sulphonate and including 3.0% of emulsifier.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Detergent Compositions (AREA)

Abstract

Known compositions for removing limescasle do not remain in contact with the scale on non-horizontal surfaces for a sufficient time to be effective. The invention provides a limescale remover composition comprising an acid, a desolubiliser and a cationic surfactant. The cationic surfactant increases the viscosity so that the composition does not readily run off non-horizontal surfaces.

Description

LIMESCALE REMOVER
This invention relates to a composition for removing deposits of scale and the like.
Water hardness is a condition which results when rainwater percolates through rock formations such as limestone or chalk and dissolves inorganic salts, particularly calcium carbonate. Water which contains more than about 100 parts per million of calcium
carbonate is usually considered as hard. When hard water evaporates the dissolved calcium carbonate is deposited on the adjacent surface in the form of tiny crystals. This is known as limescale. With time these limescale deposits can build up into quite a large size. Limescale is strongly bonded to the surfaces on which it is deposited and is difficult to remove. Well known examples of limescale deposits are the
encrustations around the nozzles of taps, shower heads and around plugholes, the staining of the surfaces of baths, basins and sinks below the taps and the general dulling of the surfaces of such vessels that receive hard water. Limescale deposits can also occur when hard water is heated an example of this being the well known furring of kettles. Deposits can also be formed in washing machines and dishwashing machines.
Limescale removers have been developed in order to deal with these problems. These are generally based on acid which will react with the deposited scale to form a salt which is more readily soluble in water than calcium carbonate and which can thus be washed away. There are two main types of limescale remover. One type includes a strong acid (e.g. hydrochloric acid, sulphamic acid) so that the pH of the limescale remover composition is about 1.0 or less. As a result of this low pH such compositions have a thin, watery consistency since stable thickening systems have not been previously achievable. Although this type of limescale remover is quite effective it is difficult if not impossible to maintain contact between the limescale remover
composition and limescale when the surface being treated is inclined to the horizontal. The other type of limescale remover includes a weak acid, (e.g. citric acid, acetic acid) resulting in a composition having a pH usually in the range of from 3 to 5. With such mild pH conditions such compositions can be easily thickened.
While these compositions may remain in contact with a non-horizontal surface to be treated for a longer time than the strong acid type of composition, they have a poor performance. Hence they must remain in contact with the surface being treated for a considerable time for example up to half an hour. Even quite viscous compositions cannot with certainty be expected to remain in contact for that length of time with non-horizontal surfaces, particularly vertical surfaces such as the sides of a bath or on a tap. The present invention has been made in order to deal with this problem.
According to the invention there is provided a composition for effectively removing deposits of scale and the like from horizontal and inclined surfaces, said composition comprising an acid, a cationic surfactant and a desolubiliser.
It has been discovered that the combination of cationic surfactant and desolubiliser acts as a
thickener providing increased viscosity for example up to 800 cps (Brookfield RV3/25°). Compositions having a viscosity of this order will tend to "cling" to vertical and non-horizontal surfaces thus giving the necessary contact time for effective scale removal.
The acid used in the composition may be one which is used in conventional limescale removers, such as mineral acids, e.g. sulphamic acids, hydrochloric acids, phosphoric acid and organic acids, e.g. acetic acid, hydroxyacetic, citric acid, lactic acid.
The preferred cationic surfactants are (higher alkyl) quaternary ammonium compounds (where higher alkyl means alkyl groups having from 8 to 30 carbons
preferably from 11 to 22 carbons). Particularly preferred quaternary ammonium compounds are the following: -
(i) acyclic quaternary ammonium salts having the formula:-
Figure imgf000006_0001
or
Figure imgf000006_0002
wherein R2 is an acyclic aliphatic C15-C22 hydrocarbon group. R3 is a C1-C4 saturated alkyl or hydroxyalkyl group, R4 is selected from R2 and R3 and A is an anion,
(ii) diamido quaternary ammonium salts having the formula:-
Figure imgf000006_0003
wherein R1 is an acyclic aliphatic C. t-_C_ hydrocarbon group, R2 is a divalent alkylene group having 1 to 3 carbon atoms, R5 and R8 are C1-C4 saturated alkyl or hydroxyalkyl groups and A is an anion,
(iii) diamido alkoxylated quaternary ammonium salts having the formula:-
Figure imgf000007_0001
wherein n is equal to 1 to about 5, R1, R2, R5 and A- are as defined above;
(iv) quaternary imidazolinium compounds.
Examples of Component (i) include
dialkyldimethylammonium salts such as ditallowdimethylammonium chloride, ditallowdimethylammonium
methylsulfate, di(hydrogenated tallow) dimethylammonium chloride, distearyldimethylammonium chloride,
dibehendyldimethylammonium chloride.
Examples of component (ii) include
methylbis(tallowamidoethyl) (2-hydroxyethyl) ammonium methylsulfate and methylbis(hydrogenated
tallowamidoethyl) (2-hydroxyethyl) ammonium
methylsulfate and methylbis(hydrogenated
tallowamidoethyl) (2-hydroxyethyl) ammonium
methylsulfate wherein R1 is an acyclic aliphatic C15-C17 hydrocarbon group. R2 is an ethylene group, R is a methyl group, R8 is a hydroxyalkyl group and A is a methylsulfate anion; these materials are available from Sherex Chemical Company under the trade names Varisoft (R) 222 and Varisoft (R) 110, respectively. A particularly preferred cationic surfactant is a compound of Formula II wherein R2 is as defined above, R3 is methyl and R4 is also methyl.
Examples of (iv) include
1-methyl-1-tallowamido-ethyl-2-tallowimidazolinium methylsulfate and 1-methyl-1(hydrogenated
tallowamidoethyl)-methylsulfate.
The quaternary ammonium salt (b) preferably
comprises from 1% to 20%, more preferably 2% to 20% by weight of the composition herein.
The weight ratio amine (a): quaternary ammonium salt (b) is in the range from 10:1 to 1:10, preferably from 3:1 to 1:3.
The di (higher alkyl) imidazolinium compounds are preferred for use in the invention, in particular the 1-(lower alkyl)-1-(higher alkyl)amidoethyl-2-(higher alkyl) imidazolinium compounds, where "lower alkyl" means alkyl having from 1 to 4 carbon atoms, and "higher alkyl" means alkyl having from 11 to 22 carbon atoms.
The preferred desolubilisers are for example sodium xylene sulphonate and sodium cumene sulphonate.
The amounts of cationic surfactant and
desolubiliser used are chosen having regard to the desired viscosity of the composition. However, amounts in the range 50.0 to 1.0% and 0.0 to 50% (by volume) respectively are preferred.
The composition of the invention may include the usual additives such as perfume, colourant and the like.
The following Example further illustrates the invention:-
EXAMPLE
A limescale remover composition was formulated as follows:-
% by volume
Sulphamic acid 12.5
Cationic surfactant 6.0
("Arquad" 18-50)
Sodium xylene sulphonate 4.0
(SXS-40)
Perfume 0.5
Ink Blue R 0.002
Water to 100.00
The composition had a viscosity of 200 cps
(Brookfield, RV 3 @ 25°C) compared to the viscosity of 10 cps of a known composition having the same
formulation as above, but without the cationic
surfactant and sodium xylene sulphonate and including 3.0% of emulsifier.

Claims

1. A composition for effectively removing deposits of scale and the like from horizontal and inclined
surfaces, said composition comprising an acid, a
cationic surfactant and a desolubiliser.
2. A composition as claimed in Claim 1, wherein the
acid is a mineral acid such as sulphamic acid, phosphoric acid hydrochloric acid or an organic acid such as acetic
acid, hydroxy acetic acid and citric acid.
3. A composition as claimed in Claim 1 or Claim 2,
wherein the cationic surfactant is a quaternary ammonium compound.
4. A composition as claimed in Claim 3, wherein the
cationic surfactant is a (higher alkyl) quaternary
ammonium compound where higher alkyl is an alkyl group having from 8 to 30 carbon atoms.
5. A composition as claimed in Claim 4, wherein the
quaternary ammonium salt is an acyclic quaternary
ammonium salt having the formula
Figure imgf000012_0001
or
Figure imgf000012_0002
wherein R2 is an acyclic aliphatic C 15-C2 2 hydrocarbon group. R3 is a C1-C4 saturated alkyl or hydroxyalkyl group, R4 is selected from R2 and R3, and A is an anion, a diamido quaternary ammonium salt having the formula:
Figure imgf000012_0003
wherein R1 is an acyclic aliphatic C 15-C21 hydrocarbon group. R2 is a divalent alkylene group having 1 to 3 carbon atoms, R5 and R8 are C1-C4 saturated alkyl or hydroxyalkyl groups and is an anion a diamido alkoxylated quaternary ammonium salt having the formula:
Figure imgf000013_0001
wherein n is equal to 1 to about 5, and R1, R2, R5 and
A- are as defined above; or a quaternary imidazolinium compound.
6. A composition as claimed in Claim 5 wherein the quaternary ammonium salt is a compound of Formula II and wherein R3 and R4 are methyl groups.
7. A composition as claimed in any preceding claim, wherein the desolubiliser is sodium xylene sulphonate or sodium cumene sulphonate.
8. A composition as claimed in any preceding claim wherein the cationic surfactant and the desolubiliser are present in the proportions of from 15.0 to 1.0% and 1.0 to 15.0% by volume respectively.
PCT/GB1992/000785 1991-05-09 1992-04-29 Limescale remover WO1992019557A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DK126493A DK126493A (en) 1991-05-09 1993-11-08 LIME REMOVER
GB9323711A GB2273925B (en) 1991-05-09 1993-11-09 Limescale remover

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9110066.9 1991-05-09
GB919110066A GB9110066D0 (en) 1991-05-09 1991-05-09 Limescale remover
ATPCT/GB91/01372 1991-08-12

Publications (1)

Publication Number Publication Date
WO1992019557A1 true WO1992019557A1 (en) 1992-11-12

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Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/GB1991/001372 WO1992019549A1 (en) 1991-05-09 1991-08-12 Limescale remover
PCT/GB1992/000785 WO1992019557A1 (en) 1991-05-09 1992-04-29 Limescale remover

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Application Number Title Priority Date Filing Date
PCT/GB1991/001372 WO1992019549A1 (en) 1991-05-09 1991-08-12 Limescale remover

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DK (1) DK126493A (en)
GB (1) GB9110066D0 (en)
WO (2) WO1992019549A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5639722A (en) * 1993-01-13 1997-06-17 The Clorox Company Acidic aqueous cleaning compositions

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9515203D0 (en) * 1995-07-25 1995-09-20 Procter & Gamble Detergent compositions
GB9805714D0 (en) 1998-03-17 1998-05-13 Kvaerner Construction Limited Liquid effluent treatment process and plant

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4435303A (en) * 1983-01-03 1984-03-06 Khodabandeh Abadi Descaling composition
EP0157552A2 (en) * 1984-03-26 1985-10-09 Calgon Corporation Carboxylic/sulfonic/quaternary ammonium polymers for use as scale and corrosion inhibitors

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4435303A (en) * 1983-01-03 1984-03-06 Khodabandeh Abadi Descaling composition
EP0157552A2 (en) * 1984-03-26 1985-10-09 Calgon Corporation Carboxylic/sulfonic/quaternary ammonium polymers for use as scale and corrosion inhibitors

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5639722A (en) * 1993-01-13 1997-06-17 The Clorox Company Acidic aqueous cleaning compositions

Also Published As

Publication number Publication date
AU8421991A (en) 1992-12-21
GB9110066D0 (en) 1991-07-03
DK126493A (en) 1993-11-09
WO1992019549A1 (en) 1992-11-12
DK126493D0 (en) 1993-11-08

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