WO1996033953A1

WO1996033953A1 - Stain corrosion and scale inhibitors

Info

Publication number: WO1996033953A1
Application number: PCT/EP1996/001727
Authority: WO
Inventors: Keith Philip Davis; Euen Thomas Graham Gunn; Ajit Kumar; William John Nicholson
Original assignee: Albright & Wilson Uk Limited
Priority date: 1995-04-26
Filing date: 1996-04-25
Publication date: 1996-10-31
Also published as: AU5761496A

Abstract

Reaction products of carboxylating agents such as epoxysuccinic acid with amines comprising a plurality of nitrogen atoms such as polyethylene polyamines provide corrosion inhibitors with particular effectiveness in treatment of soft water and stain removers, and in particular polymeric stain removers for use in detergents.

Description

STAIN CORROSION AND SCALE INHIBITORS

This invention relates to corrosion and scale inhibitors for use in the treatment of aqueous systems, and to polymeric stain removers capable of removing, or reducing the intensity of, bleachable stains on fabrics, which do not depend upon available oxygen or on phosphonate groups.

A large number of compounds are known which inhibit corrosion of metals by water systems under various conditions and with varying degrees of effectiveness. They are frequently added to water used in evaporative or other cooling systems and central heating systems, as well as to process water, boiler water, water for hydrostatic testing of pipelines and water injected into or produced in oil wells to reduce corrosion of metal parts. The most cost effective of these compounds can be used in concentrations typically in the range 1 to 1000 ppm.

Many corrosion inhibitors are dependent on the presence of calcium and are only effective in relatively hard water, while others are being challenged on environmental grounds. There is. therefore, a need for a cost effective way of reducing corrosion in soft water systems, especially at around neutral pH, which does not rely on environmentally unacceptable metals such as zinc or chromium, and in particular for a non-phosphorus based inhibitor for application in areas where the use of phosphorus compounds is restricted. A particular problem arises with base exchange water, that is hard water which has been softened by removing the calcium with an ion exchange resin.

The prevention or inhibition of corrosion of aluminium and its alloys also presents a problem. Existing corrosion inhibitors are either environmentally suspect or lack sufficient stability or consistency over a full range of pH encountered in practice. There is a need for an effective phosphorus-free corrosion inhibitor for aluminium in open or closed industrial water cooling systems, vehicle cooling systems, central heating and air conditioning installations, aluminium cleaning, aircraft deicers. aircraft toilet disinfectants, coil coating and other surface treatments.

A further problem in water treatment is inhibition of barium sulphate scale. This is encountered most commonly in oil wells, where the formation water contains high concentrations of barium and other alkaline earth metals. When sea water is injected into the formation to assist oil recovery, the resulting scale can block the pipe, and may even necessitate drilling a new well. Existing scale inhibitors are inadequate to prevent costly problems at some severely affected locations. Such treatments are referred to as "squeeze treatments".

Laundry detergents contain surfactants to remove fatty or other hydrophobic soil, usually builders to increase the cost effectiveness of the surfactant and usually fillers or diluents. The surfactant could be present in amounts up to 90%, e.g. from 2 to 60% by weight but is usually within the range 10 to 40% by weight. The builder, to be fully effective is required in amounts comparable to or greater than the surfactant, ideally about double the weight of surfactant. The filler can be an inert solid such as sodium sulphate or a liquid medium such as water and is required to obtain a material having suitable physical properties to permit easy handling. The filler usually constitutes up to 70% of the weight of the detergents.

In addition to the foregoing major ingredients laundry detergents require stain removers, usually in amounts of from 0.5 to 20% in order to be effective. They also usually contain various ancillary ingredients which are typically present in proportions less than 5% by weight each and less than 10% total.

The most important of these other ingredients for cleaning effectiveness are soil suspenders and optical brighteners. Stains may be classified as "enzymatic" and "bleachable". The former comprise the proteinaceous stains such as blood and egg and can be treated with enzymes such as protease while the latter comprise stains which are oxidisable by strong bleaches such as perborate. Bleachable stains include tea, coffee, fruit juice and wine.

Traditionally bleachable stains have been treated by including sodium perborate in the detergent formulation. However there are a number of circumstances which can render the use of perborate and similar oxidising bleaches impossible or undesirable. For instance the oxidising bleaches cannot be included in most liquid detergents because they are chemically unstable in the presence of water, and they are too aggressive to be included in detergents designed for washing delicate and/or brightly coloured fabrics. There are also environmental objections to the use of borates. Finally oxidising bleaches tend to inactivate any enzymes present and so inhibit the removal of enzymatic stains.

An alternative to the use of oxidising bleach is the use of phosphonates such as the methylene phosphonates of various amines. These are generally used instead of bleach in liquid detergents and often as an adjunct to bleach in powders. The method of action of phosphonates on bleachable stains has not hitherto been determined.

Unfortunately phosphonates cannot be used in some countries due to legislation banning phosphorus compounds from detergents. Elsewhere some consumers prefer phosphorus-free products. There is therefore a need for a non-phosphorus containing stain remover for bleachable stains which is comparable in effectiveness to phosphonates and which does not suffer the disadvantages of oxidising bleach.

Various novel compounds, have been proposed in an attempt to meet the above requirements but have not been developed commercially. An important obstacle to their development has been the high cost of obtaining regulatory approval for the use of novel compounds, which sometimes precludes investment in products whose applicability may be restricted to specialised applications, or untested market niches. It is much easier and less costly to obtain approval for the use of new polymers.

The prior art includes numerous references to the use in detergents of various phosphonomethylene amines (e.g. GB 2 259 519). DE-A-2241134 describes the use of certain reaction products of epoxysuccinic acid with amines as builders, based on their ability to chelate calcium. However the chelating power was not sufficient to encourage commercial development. WO 94/20599 describes the use of certain carboxy amines as stain removers in detergents. The products described are single novel compounds which would require expensive testing to secure regulatory approval.

It is known to prepare amido amines of the formula RCOHNCH₂CH₂NHCH₂CH₂OH (where R is a C₈.₂o alkyl or alkenyl Group) e.g. by hydrolysing the corresponding imidazoline

R—

It is further known to react the amido amine so obtained with sodium chloracetate in the presence of a base to manufacture a surfactant of the formula

R CONHCaCH₂-N-CH₂CH,OH

CH₂ COONa which is referred to as "amphoacetate". Amphoacetate is widely used in cosmetics and toiletries because of its mildness. Unfortunately the sodium chloride which is formed as an unavoidable by-product of the above method of manufacture is often undesirable in the end formulation and this has seriously limited to the potential application of the surfactant.

Attempts to prepare salt-free carboxylated amido amines have included the reaction of ethyl acrylate with imidazoline followed by hydrolysis to form the carboxyethyl homologue of amphoacetate. However this has not provided a commercially acceptable alternative.

We have now discovered that compounds containing at least one N-CH-CH-COOH group, and their salts, wherein the number of [-CHCHCOOH] substituents exceeds the number of free amine hydrogen atoms, are extremely effective corrosion inhibitors, for ferrous metals, in the soft water systems which have hitherto presented a particular problem, and are also effective for inhibiting corrosion of aluminium and for inhibiting barium scale formation.

The discovery is suφrising. Carboxy methyl amines such as ethylene diamine tetracetic acid and amino triacetic acid are notoriously corrosive towards metals.

Among the preferred corrosion inhibitors of our invention we include certain novel amine hydroxy succinates and hydroxy propionates which can be prepared by reacting epoxysuccinic or epoxyacrylic acids or their salts with amines.

Certain amine hydroxy succinates were described, more that 20 years ago, in DE OS2241134, which noted their ability to sequester calcium and suggested their use as detergent builders. However their calcium chelating power was not sufficient, in comparison to established builders, to justify their commercial development for this purpose, and the compounds did not find an industrial application. More recently US5130052 described the use of certain amine hydroxy succinates as corrosion inhibitors. The compounds used, however, have a number of free amine hydrogen atoms and are not very effective in soft or neutral pH water systems. Even in hard water, as exemplified in the above patent, the results quoted in the patent are so poor as to discourage those skilled in the art from investigating the compounds further. In each case the performance is substantially worse than that available using current commercial products. In contrast this invention provides corrosion inhibition which is substantially greater than can be obtained from any existing commercial product at comparable levels.

We have discovered that the corrosion inhibitors of the present invention, unlike conventional corrosion inhibitors, are not dependant on the presence of calcium to exert effective protection although they are tolerant of high levels of calcium. They are especially effective when the level of strong acid anions such as chloride and sulphate is relatively low, e.g. less than 150 ppm, especially less than 100 ppm. Soft water typically contains low levels of such anions. Conversely hard water usually contains relatively high levels of chloride and/or other strong acid anions.

We have further discovered certain novel polymers which are effective as stain removers, are environmentally acceptable, and which, because of their polymeric character, can meet regulatory requirements at substantially lower cost than the prior art products.

As used herein "polymer" means a substance consisting of molecules characterised by the sequence of one or more types of monomer units .and comprising a simple weight majority of molecules containing at least 3 monomer units which are covalently bound to at least 1 other monomer unit or other reactant and consists of less than a simple weight majority of molecules of the same molecular weight. Such molecules are distributed over a range of molecular weights wherein differences in the molecular weight are primarily attributable to differences in the number of monomer units. In the context of this definition a "monomer unit" means the reacted form of a monomer in a polymer. We have also discovered that when alkyl amido amines are reacted with epoxy succinic or epoxyacrylic acid or their salts, a novel surfactant is formed which is free from inorganic salt and exhibits the characteristic mildness of amphoacetate and which in addition is capable of sequestering calcium ion and decolourising oxidisable stains. It may thus be used as a self-building surfactant and a non-aggressive substitute for bleach. It also inhibits the corrosion of ferrous metals by water.

From one aspect our invention provides a method of inhibiting corrosion of ferrous metals, by aqueous systems containing less than 150 mg chloride per litre which comprises adding to said systems a corrosion inhibiting amount of a carboxy amine corrosion inhibitor of the formula: R₂ NCHRCHRCOOH wherein each R is hydrogen, hydroxyl, amino or an organic group, provided that the total number of N linked [CHRCHRCOOH] groups equals or, preferably, exceeds the total number of amine hydrogen atoms; or a salt thereof.

According to a further embodiment the invention provides a method of inhibiting the corrosion of aluminium and its alloys in aqueous systems which comprises adding to said systems a corrosion inhibiting amount of a carboxy amine corrosion inhibitor of the formula R₂NCHRCHRCOOM as hereinbefore defined.

According to a further embodiment our invention provides a composition for cleaning and disinfecting aluminium surfaces comprising a bacterocidally or bacterostatically effective amount of a disinfectant which tends to promote corrosion of aluminium and an amount of a corrosion inhibitor as aforesaid sufficient to inhibit said corrosion.

According to a further embodiment our invention provides a deicing composition comprising a corrosion inhibitor as aforesaid. According to a further embodiment our invention provides a method of inhibiting scale formation in or around drill pipes in the presence of formation water containing barium salts, which comprises injecting a corrosion inhibitor as aforesaid into the formation.

The corrosion inhibitor is typically a compound of the above formula in which at least two R groups are organic groups.

We have found that novel products of the formula H[NXCH₂CH₂]_n NHX, where each X is a CHCOOM CHOH COOM group and n is from 3 to 10, and mixtures of said products are especially effective as corrosion inhibitors, and the invention according to another embodiment therefore provides such novel products. Particularly preferred are compounds of the above formula wherein n is 3 to 6 and mixtures of two or more of such compounds, e.g. a mixture of compounds having n=3, 4 and 5.

The invention according to a second aspect provides a novel polymer composition for reducing the intensity of bleachable stains, which polymer has the formula

R [NCH₂CH₂]„ NRR¹ I

R¹

wherein :

(i) each R is hydrogen, methyl, ethyl, hydroxyethyl, hydroxy propyl,

poly oxy ethylene, carboxyethyl or carboxymethyl; (ii) each R is a mono or di-carboxy substituted ethyl group, optionally also substituted with a hydroxyl group e.g. a CHCOOM CHOHCOOM group, or hydrogen, provided that more than 50% and preferably all, of the R¹ groups are said substituted ethyl groups;

(iii) n has an average value between 2 and 10;

(iv) M is hydrogen or an alkali metal, alkaline earth metal or ammonium, or a base such that said polymer is water soluble;

(v) at least 50% by weight of said polymer consists of molecules having n equal to or greater than 3; and

(vi) molecules having the same value of n do not constitute 50% or more of the total weight of said polymer.

According to a second embodiment the invention provides a laundry detergent composition comprising a surfactant, a builder and said novel polymer.

The invention further provides a method of treating bleachable stains which comprises applying said novel polymer or said laundry detergent thereto.

According to a preferred embodiment the invention provides a polymer of the formula HRN[CH₂CH₂NR]_n H wherein each R is a -CHCOOMCHOHCOOM group, M is as hereinbefore defined, and the polymer consists essentially of: 10 to 45% by weight, based on the total weight of the polymer, of molecules with n=3; 10 to 45% by weight, based on the total weight of the polymer, of molecules having n=4; 10 to 45% by weight, based on the total weight of the polymer, of molecules having n=5: and optionally up to 30% by weight total, based on the total weight of the polymer, of molecules having n from 6 to 8.

According to another preferred embodiment the invention also provides a composition comprising 2 to 60% by weight surfactant, 10 to 70% by weight builder, up to 70% by weight of a filler or diluent and 0.1 to 5% of said polymer.

The invention further provides a liquid detergent comprising surfactant, water, said polymer, and optionally a builder.

Our invention according to a third aspect provides a novel surfactant of the general formula :-

OX

Wherein R is a C_g to ₂₅ alkyl or alkenyl group; R' is CO, CONHCH₂CH₂, CONCH₂CH₂CH₂ or (OCH₂CH₂)_a ; R² is (CH₂CH₂O)_b(CH,CH,N)_c R³ ; ^{' M}

7

R³

R³ is [CHACHOHCOOX] or a C, to ₄ alkyl or C₂ to ₄ hydroxy alkyl group; A is H or COOX;X is hydrogen or an alkali metal, alkaline earth metal, ammonium or C, to ₆ alkylammonium or alkanol ammonium; n is 0 or 1 ; a is 1 to 50; b and c are each 0 to 50; na +b + c < 50 and, where b and c are both greater than O, the respective monomer units to which they are subscribed may be distributed either at random or in any order within the R² chain. The corrosion inhibitor according to said first aspect of the invention may for example be an amino propionate, amino succinate, amino-2-hydroxy propionate or amino hydroxy succinate of the formula

RNR¹ or RNR¹ or RNR¹

I I I CH₂CH₂COOX CHCOOX CH,

I I ^' CH,COOX HOCHCOOX

RNR¹

I or CHCOOX respectively

I

HOCHCOOX

where R and R¹ are each organic groups and X is hydrogen or a salt forming cation, preferably forming a water soluble salt, such as an alkali metal, alkaline earth metal, ammonium or a C_1-4 mono, di or tri alkyl or alkanol ammonium group.

R in each of the above formulae may for example be: hydrogen; or a C_1-25 alkyl or C₂.₂₅ alkenyl group; or a hydroxy substituted C₂.₂₅ alkyl or alkenyl group; or an R²CONHR³ group, wherein R² may be a C_1-25 alkyl or C₂.₂₅ alkenyl group or a hydroxy substituted C₂.₂₅ alkyl or alkenyl group and R³ is a C₂.₃ alkylene group; or a -CH₂CH₂COOX, -CHCOOXCH₂COOX, -CH₂CHOHCOOX or -CH.COOX OH.CH.COOX group; or an R⁴[NR⁴R³]_X group, where each R⁴ group is independently selected from hydrogen, C,.₂₅ alkyl, C_2-25 alkenyl and hydroxy substituted C_2-25 alkyl or alkenyl groups R³ has the same significance as before and x is 1 to 100; or an XOOCCH₂ group.

Preferably R contains from 1 to 25 preferably 2 to 20 carbon atoms total excluding any polymeric groups, which preferably contain an average of less than 20 monomer units. R¹ may for example be any of the aforesaid R groups, but may additionally be an [R³O]_nH group where n is 1 to 100 or a [NR⁵R³]_a [NR⁴R ]_b R⁶ group wherein R⁵ is -CH₂CH,COOX. -CHCOOX CH₂COOX, -CH₂CHOHCOOX or CHCOOX CH.OH.COOX group, R³ and R⁴ have the same significance as before, R⁶ is any of the aforesaid R groups or an [R³O]_nH group, a and n are each 1 to 100 b is 0 to 100 and, where b is greater than 0 the comonomers may be either randomly distributed or arranged in any order. R- preferably has from 1 to 25 carbon atoms total, excluding any polymeric groups, which preferably contain less than 50 monomer units, more preferably less than 20 monomer units.

Although the invention according to said first aspect works if the number of hydroxsuccinyl or other carboxy substituents exceeds the number of amine hydrogens, generally speaking we prefer higher proportions of the substituent. For example ethylene diamine bis (hydroxy succinic acid) and its salts, diethylene triamine tris (hydroxy succinic acid) and its salts and triethylene tetramine tetrakis (hydroxy succinic acid) and its salts are suitable.

Preferred corrosion inhibitors for use according to our invention are epoxysuccinated or epoxyacrylated amines of the formula, R⁵ (NR⁵CH₂CH₂)_a N(R⁵)₂ where a is 3, 4,5 or 6, eg, pentaethylene hexamine hexakis (hydroxy succinic acid) and its salts. A particularly preferred product is obtained by reacting epoxy succinic acid with a mixture comprising two or more amines of the afores-aid formula, either as a blend or as a mixed fraction, obtained by distillation over relatively broad temperature range. Useful mixtures of compounds may also be obtained by reacting an epoxysuccinate with the relatively high molecular weight mixed homologues remaining after a reaction mixture used to prepare ethylene diamine has been distilled to separate out lower homologues.

Other preferred products for use according to the invention include epoxysuccinated, succinated or carboxyethylated derivatives of alkyl amido amines such as RCONH (CH₂CH₂NH)_a CH₂CH₂A where R is preferably an alkyl or alkenyl group having 8 to 20 carbon atoms, A may be OH or NH₂ and a may be 1 to 30. Particularly preferred are the epoxysuccinated and the carboxythylated derivatives of the above compound wherein a is and A is OH. which may be obtained by hydrolysis of the hydroxyethyl imidazoline

CH₂

N Λ CH₂

II I

R ■C-N-CH₂CH₂OH.

The hydroxy succinated derivatives have been found to have value as a mild halogen free amphoteric surfactant and constitute a further aspect of the invention.

Other compounds which are of particular value according to our invention include aminotris (hydroxy succinic acid) and its salts, glycine hydroxy succinic acid and its salts, alkyl amine (especially fatty amine eg dodecylamine) hydroxy succinic acids and their salts, aspartic acid hydroxy succinic acid and its salts, hexane 1 , 6 diamine bis (hydroxy succinic acid) and its salts and ethanolamine bis (hydroxy succinic acid) and its salts.

The corrosion inhibitors of our invention are typically maintained at concentrations in the range 1 to 100 ppm in the water system to be treated, more usually 2 to 80 ppm, especially 5 to 50 ppm, more preferably 7 to 30 ppm eg 9 to 25 ppm.

The corrosion inhibitors are useful for preventing or inhibiting the corrosion of various metals including aluminium and its alloys and ferrous metals, for example, mild steel and are particularly effective in soft water, especially at neutral or acid pH, eg water containing less than 150 mg per litre chloride preferably less than 100 mg per litre and especially water having pH between 5 and 8 particularly 6.5 to 7.8 although the compounds may be used to treat water at pH as high as 9 or even 9.5. They are even effective in base exchange waters. We especially prefer water containing less than 150 mg per litre total of chloride and sulphate, e.g. less than 100 mg per litre. We generally prefer that the water contains less than 150 mg per litre total of strong mineral acid anions including chloride, sulphate, nitrate, phosphate and bromide. Normally soft or moderately soft water, e.g. up to 150 mg per litre calcium hardness can be treated advantageously.

The corrosion inhibitor may be used in conjunction with other water treatment agents, including: scale inhibitors such as acetodiphosphonate, amino tris (methylene phosphonate), ethylenediamine tetrakis (methylenephosphonate), diethylenetriamine pentakis (methylenephosphonate), triethylenetetramine hexakis (methylenephosphonate) or higher members of the series of (n) ethylene (n + 1) amine (n + 3) (methyl enephosphonates), and/or polymaleic acid; one or more other corrosion inhibitors especially phosphono carboxylic acids such as phosphonosuccinic acid, 1 -phosphono- 1, 2,3 ,4-tetracarboxy butane and their higher teleomers, oxygen scavengers such as alkyl hydroxylamines; biocides such as quaternary phosphoniurn salts, eg tetrakis (hydroxymethyl) phosphonium salts, quaternary ammonium salts, eg, dodecyl trimethyl ammonium salts or aldehydes such as formaldehyde or glutaraldehyde, dispersants such as polyacrylates or lignin sulphonates; pH controlling agents such as moφholine, cyciohexylamine or butanolamine; coagulants; flocculating agents and/or freezing point depressants such as ethylene glycol.

De-icing compositions according to the invention typically contain either a concentrated, usually alkaline, aqueous solution of an organic electrolyte, such as sodium acetate, formate or propionate, or an aqueous water miscible organic liquid such as a di-or polyhydric alcohol or alcohol ether. Typically the former type of de-icer contains from 20 to 58% by weight of water and 40 to 75% by weight of dissolved electrolyte. The pH is usually alkaline, e.g., 8 to 10.5 and the composition may contain minor amounts of water miscible organic solvents, polymeric thickeners, and surfactant wetting agents and an effective proportion of corrosion inhibitor, e.g. 5 to 500 ppm. The latter type typically comprises 50 to 97% of an organic water miscible liquid such as ethylene or propylene glycol or other di- or polyhydric alcohol or alcohol ether. The balance may comprise water, surfactant and/or polymer as well as an effective amount of corrosion inhibitor.

Corrosion inhibitors of our invention may be prepared by reacting an amine with a substantially equivalent amount, or small stoichiometric excess, of disodium or other alkali metal epoxysuccinate or epoxyacrylate in an aqueous alkaline medium. The temperature is preferably maintained at an elevated level, eg, between 70 and 100°C preferably 80 to 98°C until the reaction is substantially complete. This usually takes over 10, eg 15 to 150 hours more usually 18 to 30 hours.

We prefer to use a relatively pure, eg, more than 90%, preferably more than 92%, eg, more than 95% pure, epoxysuccinate. Commercial epoxysuccinate is prepared from hydrogen peroxide and maleic acid and is an intermediate in the preparation of tartaric acid. It is often contaminated with unreacted maleate and/or with tartrate. We prefer that maleate and tartrate should each be present in proportions of less than 10% preferably less than 5% especially less than 2.5% based on the weight of epoxysuccinate. We have discovered that this level of purity is attainable by careful temperature control when preparing the epoxysuccinate maintaining the temperature sufficiently high to ensure substantially complete epoxidation of the maleate (eg, greater than 60°C, preferably greater than 62°C) but not so high as to cause substantial degradation to tartrate (eg, below 70°C, preferably below 68°C). The reaction with the amine may be carried out substantially in accordance with DE OS 2241 134 or US 5130052.

Typically the corrosion inhibitor is used as the sodium salt although, for example, potassium or ammonium salts could be used instead. According to a further embodiment our invention provides a corrosion inhibiting pigment which is a solid composition which may be prepared by reacting a concentrated aqueous solution of any of the water soluble corrosion inhibitors according to the invention with a base or salt of calcium, zinc, barium, aluminium or other polyvalent metal and precipitating a solid salt according to any of the foregoing formulae (mutatis mutandis) wherein X represents a polyvalent metal.

According to a further embodiment our invention provides a corrosion inhibiting coating composition containing a pigment according to the invention.

The corrosion inhibiting pigment may be dissolved or dispersed in an anti-corrosive paint, varnish, enamel, lacquer, or other coating formulation. The formulation may comprise a volatile liquid vehicle, such as water or a volatile organic solvent including petroleum spirit, tuφentine, ketones, esters and/or aromatic hydrocarbon solvent, and/or a drying oil, such as linseed oil, soya oil, rung oil or dehydrated castor oil, which may optionally be dissolved in said volatile organic solvent or emulsified in said water.

The formulation typically may also comprise a resin, eg a polyester, urea formaldehyde, melamine, acrylic, alkyd, polyurethane, vinyl chloride, vinyl acetate, phenolic or epoxy resin dissolved or dispersed therein and/or a dispersed pigment. We prefer that the pigment should be or should comprise other corrosion inhibiting pigments such as red lead, potassium zinc chromate, metallic zinc or aluminium powder or zinc oxide and/or that the formulation should contain one or more of the other corrosion inhibitors referred to above in addition to the corrosion inhibiting pigment of the invention.

The coating compositions may additionally contain any of the conventional paint ingredients, including pigments such as titanium oxide, iron oxide, carbon black, phthalocyanine pigments or aluminium stearate, chlorinated rubber, polystyrene, silicone, asphalt, wetting agents. dispersants, emulsifiers, biocides, flocculants. marine antifoulants. antifoams, viscosifiers, fire retardants, fluorescers, aerosol propellants, talc, clay and/or plasticisers.

Alternatively the water soluble corrosion inhibitors of the invention may be used to provide a corrosion inhibiting treatment for metal surfaces such as steel, aluminium and aluminium alloys after any machining and prior to storage, coating, electroplating, polishing or etching. Typically the work is coated with an aqueous solution containing at least an operative amount of said corrosion inhibitor eg, 10 to 500 ppm preferably 25 to 300 eg 20 to 200 especially 25 to 100, more especially 30 to 80 ppm.

After contacting with the corrosion inhibiting solution the work may be rinsed and/or subjected to one or more coating or finishing operations such as resin coating, lacquering, enamelling, painting, electrophoretic coating, spattering, vapour deposition, electrodeposition, etching chemical or electrical polishing or may be put aside for storage.

The work may be greased for storage, but an advantage of the treatment is that greasing and hence subsequent degreasing may be avoided.

The liquid detergent of our invention preferably contains 5 to 50% e.g. 10 to 40% by weight surfactant, 5 to 60% e.g. 10 to 40% builder, 20 to 75% e.g. 40 to 70% by weight water and 0.1 to 2.5% of said polymer. The liquid detergent preferably also contains conventional amounts of minor adjuncts including enzymes, soil suspenders such as sodium carboxymethyl cellulose, optical brighteners, dyes, perfumes, preservatives and foam modifiers.

The builder preferably comprises non-phosphate builders such as zeolite, carbonate, citrate, nitrilotriacetate and ethylene diamine tetracetate. The stain remover is preferably a reaction product of epoxysuccinic acid or its salts with a mixture of amines, e.g. a polymeric mixture of amines with having four or more amine nitrogen atoms, especially amines of the formula NH₂(CH₂CH₂NH)_nH where n is greater than 2, e.g. 3 to 6. The product typically has two or more 1, 2-dicarboxy-2-hydroxyethyl groups. Particularly preferred are the reaction products of from 3 to (n) molar proportions epoxysuccinic acid or its salts with mixtures of polyamines of the formula H[NHCH₂CH₂]_nNH₂ where (n) is the average value of n and lies between 4 and 6.

Alternatively the individual amine components of the above mixture of polyamines may be separately reacted with epoxysuccinate and then mixed.

Polymers of our invention are preferably prepared by reacting a polymeric mixture of amines or its separate components with a substantially equivalent amount, or small stoichiometric excess, of disodium or other alkali metal epoxysuccinate in an aqueous alkaline medium. The temperature is preferably maintained at an elevated level, e.g. between 70 to 100°C preferably 80 to 98°C until the reaction is substantially complete. This usually takes over 10, e.g. 15 to 150 hours, more usually 18 to 30 hours.

We prefer to use a relatively pure, e.g. more than 90% preferably more than 92%, e.g. more than 95% pure, expoxysuccinate. Commercial epoxysuccinate is prepared from hydrogen peroxide and maleic acid and is an intermediate in the preparation of tartaric acid. It is often contaminated with unreacted maleate and/or with tartrate. We prefer that maleate and tartrate should each be present in proportions of less than 10% preferably less than 5% especially less than 2.5% based on the weight of epoxysuccinate. We have discovered that this level of purity is attainable by careful temperature control when preparing the epoxysuccinate maintaining the temperature sufficiently high to ensure substantially complete epoxidation of the maleate (e.g. greater than 60°C, preferably greater than 62°C) but not so high as to cause substantial degradation to tartrate (e.g. below 70°C, preferably below 68°C). The reaction with the amine may be carried out substantially in accordance with DE OS 2241 134 or US 5130052.

The detergent formulations of the invention may contain from 1% to 90% by weight of surfactant, more usually 2% to 70% e.g. 3% to 60% especially 4% to 50%, preferably 5% to 40%, more preferably 6% to 30%, most preferably 7% to 20%.

For example the surfactant may be, or may comprise, one or more anionic surfactants such as an alkyl benzene sulphate, alkyl sulphate, alkyl ether sulphate, paraffin sulphonate, olefin sulphonate, alkyl ether sulphonate, alkylphenyl sulphate, alkyl phenyl ether sulphate, alkyl sulphonsuccinate, alkyl sulphosuccinamate, alkyl isethionate, alkyl sarcosinate, soap, alkyl ether carboxylate, alkyl ether polycarboxylate, alkyl tauride, alkyl phosphate, alkyl ether phosphate or alkyl or thiol capped polyelectrolytes such as an alkylthiol capped polymaleic acid.

All references to "alkyl" groups in this context refer to C8 to 22 straight or branched chain alkyl or alkenyl groups. "Ether" refers to glyceryl, mono- or poly- ethyleneoxy, mono or poly propyleneoxy, or mixed ethyleneoxy/propyleneoxy, glyceryl/ethyleneoxy, glyceryl/propyleneoxy or glyceryl/ethyleneoxy/propyleneoxy.

The cation of the aforesaid anionic surfactants is usually sodium but may also be potassium or mono-, di-or tri-alkylolamine. Less commonly the cation may be lithium, ammonium, calcium, magnesium, zinc or a mono- di- or tri- alkyl amine such as isopropylamine or trimethylamine.

The surfactant may also be, or may comprise, one or more non-ionic surfactants such as the polyalkoxylated derivatives of alcohol's, carboxylic acids, alkyl phenols, alkylamines, alkanolamides. or glyceryl or sorbitan esters, wherein each compound has an "alkyl" group as hereinbefore defined, and the polyalkylene oxy group comprises from 1 to 50 ethyleneoxy and/or propyleneoxy groups.

Alternatively the non-ionic surfactant may be an alkanolamide, e.g. a mono- or di-alkanolamide, a lactobionamide, an alkylpolyglycoside or an amine oxide, or an alkyl or thiol capped polyvinyl alcohol or polyvinylpyrrolidone, or a sugar ester.

The surfactant may be, or may comprise, one or more amphoteric surfactants such as a betaine or sulphobetaine, and/or one or more cationic surfactants such as an alkyl trimethyl ammonium, alkyl pyridinium, alkyl dimethylbenzylammonium, alkyl isoquinolinium. alkyl imidazoline or alkylamido amine. The counter ion of the cationic surfactant may typically be chloride, methosulphate, formate, acetate, citrate, lactate, tartrate or bromide.

Mixtures or anionic surfactants and non-ionic surfactants are particularly favoured: mixtures of anionic and/or non-ionic surfactants with amphoteric surfactants are also favoured, as are mixtures of cationic with amphoteric surfactants, with or without non-ionics. Mixtures of anionic with cationic surfactants are not normally favoured.

The detergent composition may contain a total of up 90% by weight of builder. Most commonly the detergent formulation contains from 1% to 80% builder, e.g. 5% to 75%, more usually 10% to 70% preferably 15% to 60%, more preferably 20% to 50%, most preferably 25% to 40% by weight based on the total weight of the composition.

The builder may be any substances that assists the action of the surfactant by ameliorating the effects of calcium in the wash liquor and/or maintaining alkalinity in the wash. The builder could for example, be or comprise, an alkali metal orthophosphate or condensed phosphate, especially sodium tripolyphosphate, tetrasodium or tetrapotassium pyrophosphate or sodium tetraphosphate, or a phosphonate. But we prefer that the builder is a non-phopshate builder such as zeolite, citrate, ethylenediamine tetracetate. nitrilotriacetate. silicate or carbonate.

The detergent compositions of this invention usually contain a filler or diluent which is typically sodium sulphate, in proportions up to 80%, more usually 10 to 60% by weight. Liquid detergents containing water as diluent are also provided.

The detergent formulations of this invention may optionally contain any of the detergent ancillary ingredients. For convenience the term "detergent ancillary ingredients" will be used herein to include all those ingredients, other than surfactant, polymeric stain remover, builder and any filler or diluent, which have been or may be used to enhance the performance, appearance, pourability, stability, fragrance or ease of use of detergent compositions.

The term includes, for instance, soil suspending agents such as sodium carboxymethyl cellulose, optical brighteners, photoactive bleaches, sequestrants, buffers, foaming agents, foam stabilisers, antifoams, preservatives, biocides, enzymes, enzyme stabilisers, hydrotropes, polymers, dyes, vegetable oils, mineral oils, pigments, fragrances, abrasives, perfume enhancers and fabric conditioners, including cationic fabric conditioners and inorganic fabric conditioners such as bentonite.

Compositions of the invention preferably contain soil suspending agents such as sodium carboxymethyl cellulose typically in proportions of from 0.01% to 3% by weight based on the weight of the composition, especially 0.1% to 2% e.g. 0.5% to 1.5%. The compositions typically contain fragrances, dyes, pigments and/or preservatives in a total proportion of from 0.1% to 5% by weight, e.g. 0.2% to 3% by weight based on the total weight of the composition.

The polymers of the invention may be used in conjunction with oxidising bleach, in the presence of which they tend to inhibit the loss of available oxygen from the formulation during storage. They, however, are more commonly used in bleach-free formulations. In the former case the compositions of the invention may also comprise conventional amounts of bleach activators such as tetracetylethylenediamme. The formulation may also contain foam control agents such as silicone antifoams and/or mineral oils where the compositions are intended for use in front loading washing machines, or foam boosters where the products are intended for hand washing or use in top loading washing machines.

Detergent ancillary ingredients, are normally present in a total concentration below 10% by weight based on the total composition.

The polymers of the invention in addition to acting as stain removers and bleach stabilisers also reduce the corrosion of steel or aluminium trim on washing machines.

The invention will be illustrated by the following examples :-

Example 1

Pentaethylene hexamine was epoxysuccinated as follows:

har es

Charge Weight(g) Moles

Di-sodium epoxy succinate 20 0.114

Pentaethylene Hexamine 4.4 0.019

Water 30 0.6 Equipment

250cm round bottom flask, reflux condenser, heater, stirrer mantle and oil bath.

Method

Di-sodium epoxy succinate (20g, 0.114m) referred to hereinafter as "DSES" was dissolved in water (30g, 0.6m) by gentle heating at 40°C. This was followed by the addition of pentaethylene hexamine (4.4g, 0.019m). The temperature was then raised to 95°C to give a clear pale yellow solution. Heating and stirring was then continued for a further 8 hours. The reaction was monitored by 1H-NMR (in D₂O) for the disappearance of DSES peak at 3.6ppm.

The final solution is clear, light yellow with a solid concentration of 44.9%.

Analysis: Was carried out by 'H-NMR(in D₂O). Which showed small amount s of DSES at 3.6 ppm, di sodium maleate at 5.9 ppm, di sodium tartrate at 4.3 ppm, hydroxy succinate peaks at 4.25, 4.1 and 3.4, 3.3 ppm respectively. Amine CH₂'s peaks at 2.4-3.0 ppm.

The product was believed to have the formula:

COONa

I

H — [N CH,CH₂]₅ NHCHCHOH

I I

CHCOONa COONa

I HOCHCOONa Example 2

Epoxysuccinated amido amine was prepared as follows:

Coconut -N- hydroxyethyl imidazoline sold under the Registered Trade Mark "Empigen" 5104 (80.4g, 0.3 moles) was hydrolysed with sodium hydroxide (47.2%. 3.8 lg, 0.045 moles), in water (141.6g), for 2 hours at 85°C. Disodium cis epoxysuccinate (79.2g, 0.45 moles) and water (60g) was then added, and the reaction continued at 95°C and with daily sampling, until completion.

The following results were obtained.

Time (Hrs) Ether Extr

0 23.5 (theo.)

24 3.97

48 2.01

72 2.05

96 1.26

120 1.39

144 0.6

The product was diluted to 35% by weight solids. A sample diluted to 10% by weight solids had a pH of 10.1.

The product has been confirmed by FAB mass spectroscopy and by Proton and C¹³ NMR as having the formula:

O II

C„H₂₃ C-NH CH₂CH₂ — N CH₂CH₂OH

CHCOONa

I HOCHOONa Example 3

Carboxyethylated amido amine was prepared as follows:

Lauryl hydroxyethyl imidazoline was reacted with ethyl acrylate and the intermediate product hydrolysed in aqueous alkaline solution.

The product was believed to have the formula:

O

II C_πH₂₃ CNH CH₂CH₂— N CH₂CH₂OH

I CH₂CH₂COONa

Example 4

Di sodium epoxy succinate (17.6g, 0.1m) was dissolved in water (eg, 1.57m) at room temperature with stirring. This was followed by the addition of "Polyamine" B, a polyethylene polyamine still residue comprising a mixture of higher polyethylene polyamines (5g, 0.1m). The mixture was then heated at 90-95°C for 20 hours to give a clear solution. pH mixture remained at 13 throughout reaction. Ratio of DSES to amine (NH's) was 1 :1.

Analaysis: Was carried out by 'H-NMR (in D₂O).

Example 5

Di sodium epoxy succinate (13.2g, 0.075m) was dissolved in distilled water (20g, 1.1m) with stirring at room temperature. This was followed by the addition of ethylene diamine (2.25g, 0.0375m) to give a pale yellow solution (clear). This was heated at 95-100°C for 20 hours. pH of solution remained at 12-13 throughout reaction. Ratio of DSES to amine was 2:1.

Analysis: Was carried out by Η-NMR(in D₂O). Which showed small amount so DSES at 3.6 ppm, di sodium maleate at 5.9 ppm, di sodium tartarate at 4.3 ppm, hydroxy succinate peaks at 4.25, 4.1 and 3.4, 3.3 ppm respectively. Amine CH₂'s peaks at 2.4-3.0 ppm. Example 6

Di sodium epoxy succinate (17.6g, 0.1m) was dissolved in distilled water (30g. 1.67m) with stirring at 45°C. This was followed by the addition of "Berolamine 20" a polyethylene polyamine still residue containing a mixture of higher polyethylene polyamines and ethanolamines (5.8g, 0.1m). The mixture was then heated at 90-95°C for 20 hours to give a brown solution. The pH of reaction throughout was 13. Ratio of DSES to amine (NH's) was 1 :1.

Analysis: Was carried out by Η-NMR(in D₂O).

("Berolamine" is a trademark of Berol Nobel).

Example 7

Di sodium epoxy succinate (20g, 0.114m) was dissolved in distilled water (30g, 1.67m) with stirring at room temperature. This was followed by the addition of pentaethylene hexamine (6.6g, 0.028m) to give a pale yellow solution (clear). This was heated at 95-100°C for 20 hours. pH of solution remained at 13 throughout reaction. Ratio of DSES to amine was 4:1.

Analaysis: Was carried out by Η-NMR(in D₂O). Which showed small amounts of DSES at 3.6 ppm, di sodium maleate at 5.9 ppm, di sodium taratrate at 4.3 ppm, hydroxy succinate peaks at 4.25, 4.1 and 3.4, 3.3 ppm respectively. Amine CH₂ peaks at 2.4-3.0 ppm.

Example 8

Di sodium epoxy succinate (8.8g, 0.05m) was dissolved in distilled water (30g, 1.67m) with stirring at 45°C. This was followed by the addition of D-glucamine (9.5g, 0.05m) to give a clear light pale yellow solution. The mixture was then heated at 90-95°C for 22 hours, to give a clear pale yellow solution. pH of reaction throughout remained at 13. Ratio of DSES to D-glucamine was 2:1. Example 9

Di sodium epoxy succinate (17.6g. 0.1m) was dissolved in distilled water (30g. 1.67m) with stirring at 45°C. This was followed by the addition of N-methyl D-glucamine (19.3g. 0.1m) to give a thick white suspension, which went clear after 1 hour. The mixture was then heated at 90-95°C for 20 hours, to give a clear light yellow solution. pH of reaction throughout remained at 13. Ratio of DSES to N-methyl D-glucamine was 1 :1.

Example 10

Delta-gluconolactone (7.5g, 0.042m) was dissolved in methanol (150g, 4.69m) by refluxing over 45mins. Pentaethylene hexamine (4.9g, 0.021m) was then added in one portion and reaction mixture was then heated for a further 30 min, with stirring. The light yellow coloured solution was then evaporated under reduced pressure to give a white foam.

Example 11

Di sodium epoxy succinate (9.87g, 0.056m) was dissolved in distilled water (22.5g, 1.25m) with stirring at 45°C. This was followed by the addition of the product of Example 11(a) (5.5g, 0.0093m) to give a thick white suspension, which went clear after 1 hour. The mixture was then heated at 90-95°C for 20 hours, to give a clear light yellow solution. pH of reaction throughout remained at 13. Ratio of DSES to N,N Bis D-gluconamide pentaethylene hexamine was 1:1.

Example 12

Di-sodium epoxy succinate (176g, lm) is added to polyethylene polyamine (lm, based on NH groups). This is followed by the addition of water to give a 50% w/w solution. The mixture is then stirred and heated at 95°C for 8 hours to give a clear pale yellow solution. Example 13

Di sodium epoxy succinate (lOg, 0.057m) was dissolved in distilled water (20g. 1.1 1m) with stirring at 45°C. This was followed by the addition of DL-glutamic acid (4.7g, 0.029m). The mixture was then heated at 90-95°C for 20 hours to give a clear solution. However, on cooling to room temperature some crystals dropped out, these are currently been analysed. pH of reaction throughout was 13. Ratio of DSES to amino acid was 1 :1.

Example 14

Di sodium epoxy succinate (20g, 0.114m) was dissolved in distilled water (30g, 1.67m) with stirring at 45°C. This was followed by the addition of triethylenetetramine (4.16g, 0.028m) to give a clear light pale yellow solution. The mixture was then heated at 90-95°C for 18 hours, to give a clear pale yellow solution. pH of reaction throughout remained at 13. Ratio of DSES to amine was 4:1.

Analysis: Was carried out by 'H-NMR which showed that most epoxide had reacted.

The product was believed to have the formula

OH

H N CH, CH₂ NH-CH CH COONa

I ^' I

CHCOONa COONa

I HOCHCOONa „

where n=3 Example 15

Di sodium epoxy succinate (15g, 0.085m) was dissolved in distilled water (22.5g. 1.25m) with stirring at 45°C. This was followed by the addition of diethylenetriamine (2.93g. 0.028m) to give a thick white suspension, which went clear after 1 hour. The mixture was then heated at 90-95°C for 18 hours, to give a clear light yellow solution. pH of reaction throughout remained at 13. Ratio for DSES to amine was 3:1.

Analysis: Was carried out by 1H-NMR which showed that most epoxide had reacted

The product was believed to have the formula of Example 14 wherein n=2.

Example 16

Di sodium epoxy succinate (20g, 0.114m) was dissolved in distilled water (30g, 1.67m) with stirring at 45°C. This was followed by the addition of tetraethylenepentamine (4.3g, 0.023m) to give a clear light yellow solution. The mixture was then heated at 90-95°C for 18 hours, to give a clear pale yellow solution. pH of reaction throughout remained a tl3. Ratio for DSES to amine was 5:1.

Analysis: Was carried out by 1 H-NMR which showed that most epoxide had reacted.

The product was believed to have the formula of Example 14 where n=4.

Example 17

Di sodium epoxy succinate (5.24g, 0.0.3m) was dissolved in water (lOg, 0.55m) at 45°C with stirring. This was followed by the addition of sodium salt of glycine ( 1.46g, 0.015m) previously dissolved in water (5g, 0.27m). The reaction mixture was heated at 75-80°C for 8 hours; when a pale clear solution resulted.

Analysis: by 1 H-NMR and FAB mass spec, showed that mono (M+Na)=296 and di (M+Na)=472 substituted products had been formed. However, a peak at 199 (M+Na) for the epoxide showed that reaction had not gone to completion. The product was believed to comprise a component of the formula:

OH

NaOOCCH- CHCOONa

H NCH,COONa

Example 18

Charges

Charge Mol. Wt Weight Moles

Di-sodium epoxy succinate 176 35.79 0.203

Pentaethylene Hexamine 232.38 3.97 0.017

Tetraethylene Pentamine 189.31 3.24 0.017

Triethylene Tetramine 146.24 0.56 0.004

Water 18 55 3.1

Equipment

250CM fi round bottom flask, reflux condenser, heater, stirrer mantle and oil bath.

Method

Di-sodium epoxy succinate (35.79g, 0.203m) was dissolved in water (55g, 3.1m) by gentle heating at 40°C. This was followed by the addition of pentaethylene hexamine (3.97g, 0.017m), tetraethylene pentamine (3.24g, 0.017m) and triethylene tetramine (0.56g, 0.0038m). The temperature was then raised to 95°C to give a clear pale yellow solution. Heating and stirring was then continued for a further 8 hours. The reaction was monitored by 1H-NMR (in D₂O) for the disappearance of DSES peak at 3.6ppm.

The final solution was a clear, light yellow solution, solids concentration being 44.2% Example 19

Various corrosion inhibitors were added to water containing 325mg per litre total dissolved solids, 163mg per litre hardness (as calcium carbonate) calcium hardness 127mg per litre as calcium carbonate, bicarbonate alkalinity 75mg per litre as calcium carbonate and chloride content 46mg per litre CL-ion which had been diluted with 19 parts by volume deionised water to 6ppm calcium hardness in contact with mild steel at total inhibitor concentrations of 50 ppm. The control was a phosphono oligomaleate which was selected as the most effective commercially available prior art corrosion inhibitor known to the applicant. Comparison is made with the results quoted in US 5130052 for its best performing product at equivalent concentration in relatively hard water.

This corrosion was measured and reported in the following table:

Table

Inhibitor Corrosion Rate

mls/yr

Control 0.5

Product of Example 1 0.05

Product of Example 2 0.05

Product of Example 3 0.05

Best quoted rate in US 5183590 at 50 ppm 2.3 Example 20

2-bromo-2-nitropropane-l,3-diol(BNP) is manufactured and marketed as an antimicrobial agent for industrial use. It is known to be aggressive towards aluminium, which is of concern as one use for the product is in aircraft toilet cleaning formulations.

Coupon tests were performed on a typical aluminium alloy to determine whether .amine hydroxysuccinate derivatives, could inhibit corrosion by a 5% w/v BNP solution in synthetic tap water at pH 4.5

The results are expressed in the following Table.

Corrosion rates are expressed in mils/year using 5% by weight BHP and various concentrations (A) of the product of Example 18 and (B) the product of Example 2 on alloy type 2024.

TABLE

Oppm lOOppm lOOOppm

A 18.9 3.6 3.5

B 18.9 0.4 0.7

Example 21

A de-icer composition comprises water and 60% by weight of sodium acetate adjusted to a pH of 9.5, together with 0.5% of a surfactant mixture comprising, by weight, 3 parts alkyl benzene sulphonate and 1 part C₁₂._M alkyl 3 mol ethoxylate. The composition has been observed to cause pitting of aluminium surfaces.

To the above composition is added 50 ppm of the product of Example 18. The incidence of corrosion is substantially reduced.

Example 22

A de-icer composition consists of ethylene glycol, 3% by weight water, 1% by weight of a polymaleate and 1% by weight of C_I2._]4 alkyl 2 mole ethoxylate. Addition of 50 ppm of the product of Example 18 substantially reduced corrosion of the formulation towards aluminium surfaces.

Example 23

To illustrate calcium tolerance in the absence of chloride a synthetic hardwater was prepared containing 1000 ppm calcium hardness as calcium acetate. The product of Example 18 gave excellent corrosion inhibition and showed good stability with no evidence of precipitation.

Example 24

Base exchange water, softened by passing hard water through an ion exchange membrame to replace calcium with sodium gave a corrosion rate of 37 mils per year. 100 ppm of the product of Example 1 reduced the corrosion rate to below 1 mil per year. Example 25

Wastwater, a very soft natural water was tested on mild steel coupons with varying proportions of the product of Example 18 the results were recorded in the following table.

TABLE

Inhibitor Concentration (ppπ Corrosion Rate (mils per year)

0 46

10 1.03

25 0.44

50 0.61

EXAMPLE 26 :- PREPARATION OF POLYMERIC STAIN REMOVER

A polymeric mixture of alkylene amines comprising pentaethylene hexamine, tetraethylene pentamine and triethylene tetramine was reacted with epoxysuccinate as follows :-

Equipment

5 Litre jacketed vessel, oil heating circulator, reflux condenser and stirrer.

Method

1. Di-sodium epoxy succinate (1330.9g, 8.56m) was dissolved in water (1730.9g, 96.2m) by gentle heating at 40°C. 2. 400gms of a mixture of pentaethylene hexamine (47.1 % by weight), tetraethylene pentamine (44.2% by weight) triethylene tetramine (8.3% by weight) and diethylene triamine (0.4% by weight) was added.

3. Oil heater circulator was then set at 95°C and stirring continued.

4. Heating and stirring were continued for a further 8 hours, monitoring the reaction by 1H-NMR (in D20) for the disappearances of DSES peak at 3.6ppm.

The final solution was a clear, amber coloured solution, with solids concentration being 50%.

Comments

Care was taken to maintain the temperature below 95°C to minimise formation of di-sodium tartrate.

EXAMPLE 27 :- A BUILT LIQUID DETERGENT COMPOSITION COMPRISING POLYMERIC STATN REMOVER

The following composition was prepared, all weights being expressed as the percentage of active ingredient by weight, based on the total weight of the composition :-

Sodium C₁₂-C₁₄ alkyl benzene sulphonate 10%

Sodium tripolyphosphate 25%

Antifoam 0.2%

Polymeric stain remover of Example 1. 0.6%

Water balance On storage the stain remover was found to be stable in. and compatible with, the built liquid detergent composition.

EXAMPLE 3 :- EVALUATION OF THE EFFECTIVENESS OF THE POLYMERIC STAIN REMOVER

The stain removal ability of the polymeric stain remover of Example 26 was determined according to the method given below. As a standard, the stain remover was omitted from the composition of Example 2.

Method of evaluation of stain removal performance

1. The performance of Example 2 and of the standard on bleachable stains was tested on each of the following four types of test cloths:-

1) Empa 114 (red wine stained cotton)

2) Tea stained cotton

3) Coffee stained cotton

4) Blackcurrant juice stained cotton

The ΕMP114' cloth is a pre-stained cotton cloth supplied by the 'Swiss Federal Laboratories for materials testing and research - Switzerland' and is recognised as a standard test cloth in the detergent industry. Tea, coffee and blackcurrant juice test cloths were prepared in-house, by manual staining of cloth. The test fabrics are measured for reflectance values before and after laundering. 2. Four 3 inch square pieces of each standard pre-stained cloth (see above) were placed into a Micle, Novotronic W820 automatic washing machine, set for short programme cotton wash at 60°C.

3. The test cloths were washed together at 60°C in the washing machine, with 1 OOmls (10 grams per litre of wash water) of the detergent sample. The water used was of an approximate water hardness of 200 parts per million of calcium carbonate. After the washing cycle the test cloths were rinsed in water of the same hardness.

R sul s

After air drying and ironing, two light reflectance readings were taken on each side of every cloth, using a Minolta light reflectance meter model CR200 to determine the degree

of whiteness of the cloths. The sixteen light reflectance readings thus obtained were averaged and converted to percentage stain removal by the formula below:

% removal = W,-W₂

x lOO

W-W₂

where:

W, is the reflectance reading of the laundered fabric.

W₂ is the reflectance reading of stained fabric.

W is the reflectance reading of unstained fabric of the same type. The respective actual % stain removal for Example 27 and the standard is given below in

Table 1.

Table 1 : % stain removal

TEST CLOTH % STAIN REMOVAL

EXAMPLE 2 STANDARD

EMP114 70.02 59.55%

TEA 82.06 69.26%

COFFEE 40.26 23.22%

BLACKCURRANT JUICE 59.26 44.21%

MEAN % STAIN REMOVAL 62.9 49.06%

Claims

H1073/74 - CLAIMS

1. A method of inhibiting corrosion of ferrous metals, by aqueous systems containing less than 150 mg chloride per litre which comprises adding to said systems a corrosion inhibiting amount of a carboxy amine corrosion inhibitor of the formula: R, NCHRCHRCOOH wherein each R is hydrogen, hydroxyl, amino or an organic group, provided that the total number of N linked [CHRCHRCOOH] groups equals or, preferably, exceeds the total number of amine hydrogen atoms; or a salt thereof.

A method of inhibiting the corrosion of aluminium and its alloys in aqueous systems which comprises adding to said systems a corrosion inhibiting amount of a carboxy amine corrosion inhibitor as defined in Claim 1.

A composition for cleaning and disinfecting aluminium surfaces comprising a bacterocidally or bacterostatically effective amount of a disinfectant which tends to promote corrosion of aluminium and an amount of a corrosion inhibitor as defined in Claim 1 sufficient to inhibit said corrosion.

A method of inhibiting scale formation in or around drill pipes in the presence of formation water containing barium salts, which comprises injecting a corrosion inhibitor as defined in Claim 1 into the formation.

5. A compound of the formula H[NXCH₂CH₂]NHX where X is a

CHCOOMCHOHCOOM group, n is from 3 to 10 and M is hydrogen or an alkali metal, alkaline earth metal or ammonium or a base such that said compound is water soluble.

6. A method of inhibiting the corrosion of metals by aqueous systems which comprises adding to said systems a corrosion inhibiting amount of a carboxy amine corrosion inhibitor of the formula (R₃C), NCHRCHRCOOH wherein each R represents hydrogen, a hydroxyl or organic group, provided that the total number of N linked [CHR CHR COOH] groups exceeds the total number of amine hydrogen atoms; or a salt thereof.

7. A hydroxysuccinate derivative of an alkyl amido amine of the formula RCONH (CH₂CH₂NH)_a CH₂CH₂A, where R is a C₈.₂₀ alkyl or alkenyl group, a is 1 to 30 and A is OH or NH₂.

8. A novel polymer composition for reducing the intensity of bleachable stains, which polymer has the formula

wherein :

(i) each R is hydrogen, methyl, ethyl, hydroxyethyl, hydroxy propyl,

polyoxyethylene, carboxyethyl or carboxymethyl;

(ii) each R¹ is a mono or di-carboxy substituted ethyl group, optionally also substituted with a hydroxyl group e.g. a CHCOOM CHOHCOOM group, or hydrogen, provided that more than 50% and preferably all, of the R¹ groups are said substituted ethyl groups;

(iii) n has an average value between 2 and 10;

A laundry detergent composition comprising a surfactant a builder and a polymer according to Claim 8.

10. A method of treating bleachable stains which comprises applying thereto a polymer according to Claim 1 or a laundry detergent according to Claim 9.

11. A polymer of the formula HRN[CH₂CH₂NR]_n H wherein each R is a

-CHCOOMCHOHCOOM group, M is as hereinbefore defined, and the polymer consists essentially of: 10 to 45% by weight, based on the total weight of the polymer, of molecules with n=3; 10 to 45% by weight, based on the total weight of the polymer, of molecules having n=4; 10 to 45% by weight, based on the total weight of the polymer, of molecules having n=5: and optionally up to 30% by weight total, based on the total weight of the polymer, of molecules having n from 6 to 8.

12. A composition according to Claim 9 comprising 2 to 60% by weight surfactant, 10 to 70% by weight builder, up to 70% by weight of a filler or diluent and 0.1 to 5% by weight of said polymer.

13. A liquid detergent composition according to either of Claims 9 and 12 wherein which comprises water.

14. A liquid detergent composition according to Claim 13 comprising 10 to 40% by weight surfactant, 10 to 40% by weight builder, 40 to 70% by weight water and 0.1 to 2.5% by weight of said polymer.

15. A detergent composition according to any of claims 9, 12, 13 or 14, wherein said builder comprises zeolite and/or water soluble carbonate, citrate, nitrilotriacetate and/or etlhylene diamine tetracetate.

16. A composition according to any of claims 9, 12, 13, 14 or 15 wherein said polymer is a reaction product of epoxysuccinic acid or its salts with a mixture of amines having four or more amine nitrogen atoms.

17. A composition according to Claim 16 wherein said mixture of -amines comprises amines of the fonnula NH₂[CH₂CH₂NH]_n H where R is 3 to 6.

18. Aa novel surfactant of the general formula :-

R[R^]]_n— N - R²

I CHA

I

HO-CHCOOOX

Wherein R is a C₈ to ₂₅ alkyl or alkenyl group; R¹ is CO, CONHCH,CH₂, CONCH,CH₂CH₂ or (OCH₂CH₂)_a ; R² is (CH₂CH₂O)_b(CH,CH₂N)_c R³ ; ^H

R³

R³ is [CHACHOHCOOX] or a C, to ₄ alkyl or C₂ to ₄ hydroxy alkyl group; A is H or COOX;X is hydrogen or an alkali metal, alkaline earth metal, ammonium or C, to ₆ alkylammonium or alkanol ammonium; n is 0 or 1 ; a is 1 to 50; b and c are each 0 to 50;

na +b + c < 50 and, where b and c are both greater than O, the respective monomer units to which they are subscribed may be distributed either at random or in any order within the R² chain.