AU1761092A

AU1761092A - Detergent compositions

Info

Publication number: AU1761092A
Application number: AU17610/92A
Authority: AU
Inventors: Paul Hepworth
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1991-05-24
Filing date: 1992-05-22
Publication date: 1992-12-30
Anticipated expiration: 2012-05-22
Also published as: FI935195A; JP3268597B2; FI935195A0; BR9206050A; CZ250593A3; CA2109832A1; NO934230L; WO1992020772A1; HUT65673A; JPH06510550A; GB2272224A; NZ242884A; NO934230D0; AU672747B2; GB2272224B; HU214041B; HU9303303D0; GB9322610D0; EP0586440A1

Description

DETERGENT COMPOSITIONS

THIS INVENTION relates to detergent compositions. Detergent compositions are known which comprise a suspension of a builder in an organic liquid which comprises a surfactant. Non-aqueous compositions of* this type of good stability are described in European Patents Nos 30096 and 120,659.

It is however difficult to exclude water completely from detergents, and it is desirable that their water-sensitivity should be reduced. It is believed that a reduction in water sensitivity may aid the dispensibility of such materials ie they may make them easier to introduce into a wash liquid.

Detergent compositions may be introduced into a washing machine by placing them in a unit through which water is passed to carry the detergent with the water into a washing zone.

Compositions of low dispensibility may produce solid deposits which remain in the unit. In some cases detergents are placed in containers which are introduced into the washing zone. If the container has restricted access solid deposits may be left in it especially if it was not dry when the detergent was placed in it. It is believed that dispensibility is improved, especially in the latter case, if the water sensitivity of the composition is reduced.

Surprisingly we have found that small quantities of water can be tolerated in such compositions providing that an amine oxide is present. In general the quantity of water should be at most 5 preferably less than 3 and more preferably less than 2 moles per mole for example 0.5 to 1.9 moles of amine oxide and is preferably 1.0 to 1.7 moles of water per mole of amine oxide. By water is meant water which is not included as water of crystallisation of solids, which is irrelevant in this context.

Whilst anhydrous amine oxides are known, in general they are available commercially as aqueous solutions which may contain for example 65% by weight of water. Clearly such solutions are unsuitable for the present purpose and according to one form of this invention means are provided bv which they may be converted into a composition useful for inclv;-: .on in liquid laundry detergent compositions.

SUBSTITUTESHEET This invention comprises a liquid detergent composition which comprises: i) a liquid organic phase which comprises an amine oxide; ii) a solid builder; iϋ) at most 5 and preferably less than 2 for example 0.5 to less than 2 and preferably 1.0 to 1.7 moles of water (other than water of crystallisation of any solid present) per mole of amine oxide.

The builder may suitably be water soluble and if desired a bleach may be present.

The invention also comprises a composition suitable for inclusion in a liquid detergent which comprises: i an amine oxide; ii a polyalkylene glycol, which preferably comprises ethylene glycol residues and optionally propylene glycol residues and more preferably polyethylene glycol; and iii at most 5 and preferably less than 2 moles, for example 0.5 to less than 2 moles and preferably 1 to 1.7 moles of water per mole of the amine oxide. This composition enables liquid laundry detergents of good stability and easy-iron properties to be produced by the addition of a suitable builder. The weight ratio of polyalkylene glycol to amine oxide is suitably 0.5 to 1 to 2:1.

This composition may be produced by distilling an aqueous solution of an amine oxide in the presence of the polyalkylene glycol, preferably polyethylene glycol, preferably under reduced pressure at a temperature of 40 to 80°C and preferably 65 to 75°C. We have surprisingly found that the presence of the polyalkylene glycol serves to reduce the problem of gel formation which occurs and impedes distillation of an aqueous solution of an amine oxide if it is distilled as such.

We have found that when used together with a builder, polyethylene glycol and preferably another non ionic surfactant amine oxides appear to leave fabrics which have been laundered in them easy to iron. This invention therefore also comprises a detergent composition for example a laundry detergent composition which comprises: i an amine oxide; ii a builder; iii a polyalkylene glycol, having a molecular weight of 100 to 1500 preferably polyethylene glycol, and preferably a non ionic surfactant other than an amine oxide and preferably a bleach. In many parts of the world it is desirable to reduce the concentrations of phosphates in waste water for environmental reasons. The use of phosphates and particularly condensed phosphates for example sodium tripolyphosphate in detergents has been common for many years but in some cases is now restricted by law for environmental reasons. It is, therefore, desirable to formulate detergent compositions of good performance which are free from phosphates.

This invention also comprises detergent compositions which are free from phosphates and which are suitably laundry detergent compositions which comprise:

1) An amine oxide

2) A hydroxy carboxylic acid containing 2 to 6 - COOH groups and 1 to 5 - OH groups and

3) A polycarboxylic acid comprising at least 10 and preferably at least 100 for example 150 to 2000 and preferably 200 to

1000 - COOH groups and which contain at most 5 and preferably less than 2 moles of water per mole of amine oxide (excluding any present as water of crystallisation).

The polycarboxylic acid may be a polyacrylic acid for example a maleinised polyacrylic acid or is more preferably carboxy methyl cellulose which suitably has 100 to 1000 for example 100 to 500 combined glucose units per molecule and suitably has a degree of substitution (proportion of OH groups which have been converted to carboxy methyl form) of 35 to 85% and preferably 45 to 80%. The hydroxycarboxylic acid may be for example a tartrate or preferably a citrate. The composition suitably comprises 2 to 10% by weight of component (3) above and preferably comprises 3 to 9% and more preferably 5 to 8% thereof. It suitably comprises 20 to 50% and preferably 25 to 40% by weight of component (2) above. The composition is preferably substantially neutral or alkaline in reaction and it is preferred that acidic substances be neutralised with ammonium, substituted ammonium or preferably alkali metal ions. It is preferred that at least one part by weight of component 3 be present per eight parts by weight of component 2.

It is preferred that liquid compositions should comprise 25 to 70% and preferably 30 to 60% for example 40 to 60% by weight of total solids. The solids preferably comprise a builder which may be present in an amount of 25 to 60% by weight of the total composition. A bleach for example a perborate or percarbonate of an alkali metal for example sodium may be present in an amount of 0 to 25% for example 1 to 20% and preferably 5 to 20% by weight of the total composition. Optionally a polycarboxylic acid comprising at least 10 and preferably at least 100 for 150 to 2000 and preferably 200 to 1000 COOH groups which is suitably carboxymethyl cellulose may also be present.

The liquid phase suitably comprises a polyalkylene glycol, preferably polyethylene glycol which is for example 5 to 55% by weight of the total composition and which is preferably 10 to 40% by weight of the total composition and a non ionic surfactant which is suitably 5 to 25% and preferably 7 to 20% by weight of the total composition. The amine oxide is preferably 5 to 100% and more preferably 5 to 50% of the organic matter of the liquid phase by weight. The builder may be for example a condensed phosphate, a silicate or a zeolite or a hydroxycarboxylic acid containing 2 to 6 -COOH groups and 1 to 5 -OH groups which may be citric or tartaric acid. It is preferred however that it be a condensed phosphate which may be an alkali metal, preferably sodium, salt for example sodium tripolyphosphate. The molecular weight of the polyethylene glycβl may be 100 to 1500 and is suitably 150 to 500.

It is preferred that compositions according to the invention be formulated as pourable liquids. To this end it is preferred that the liquid detergent composition should comprise a dispersion of solids in a liquid medium. The solids may be of average particle size at most 10 micro metres. The composition suitably has a pour point of less than 10°C. The pour point may be measured by ASTM test method designation D97-66 approved in 1971. It is desirable that at least 90% of the particles should have particle sizes less than 10 micro metres in diameter. The average particle sizes may be determined by either the number average method or the weight average method. A range of 1.2 to 8 micro metres is preferred. The surfactant component of the composition may comprise for example a non ionic surfactant. It is suitably an alkylene oxide derivative, the alkylene oxide preferably being ethylene and/or propylene oxide. It may very suitably be a product of reaction of an amine, alkyl phenol or alkanol with ethylene and/or propylene oxide. The alkyl group in the alkyl phenol may be straight chain or branched chain and may contain from 6 to 20 carbon atoms for example six to twelve carbon atoms. The alkanol may contain 6 to 20 carbon atoms and preferably 10 to 16 carbon atom. The alkanol is preferably a primary or secondary alkanol having a linear or mono branched alkyl chain. Suitably the non ionic surfactant comprises a chain of 1 to 10, preferably 3 to 8 alkylene glycol residues, it being understood that this is an average value.

The surfactant may consist essentially of an amine oxide which preferably comprises an alkyl group having 10 to 18 carbon atoms and preferably 12 to 16 carbon atoms and 2 other groups selected individually from the C. to C, alkyl or hydroxyalkyl group. The composition may if desired comprise two or more non ionic surfactants. The pour point may be adjusted by varying the liquid phase composition, for example, by including surfactants and/or polyethylene glycol of low pour point. Suitably, 10 to 50% and preferably 15 to 30% by weight of surfactant is present. The surfactant may alternatively be anionic or cationic. Such anionic or cationic surfactants may be of known type for example the anionic detergents may be soaps, alkylbenzene or olefine sulphonates, alcohol sulphates or alcohol alkoxylate sulphates; the cationic surfactants are suitably di-C and preferably di-C_{1c 10} alkyl,*di-lower alkyl ammonium salts or lb—lo hydroxides for example chlorides or sulphates or for example fabric softeners of the C.. ,_c alkyl, di lower alkyl (for example lU—lb methyl), substituted ethyl ammonium salts. The substituent on the ethyl group may be an -OOCR group where R is a C.____ alkyl group, and the anion of the salt may be a RSO - group where R is lower alkyl for example methyl. The lower alkyl groups are suitably methyl groups.

It is preferred that a polyalkylene glycol, for example a polyethylene/polypropylene glycol or preferably a polyethylene glycol should be present. This contributes to the effectiveness of the compositions in washing fabrics and is of favourable biodegradability. Polyalkylene glycols of average molecular weight 100 to 400 and preferably 150 to 300 are preferred as they tend to reduce the pour point of liquid compositions thus making them more easily usable in a cold environment. Suitably 10 to 50 and preferably 25 to 45% by weight of polyalkylene glycol is present.

Very suitably the composition comprises a bleach which is suitably a perborate or percarbonate of an alkali metal. If desired bleach activators may be incorporated. Suitably 1 - 20% and preferably 2 - 15% by weight of bleach is present.

The composition may also contain additives conventionally found in detergent compositions, for example optical brighteners, ethylene diamine tetra acetic acid, dyes, perfumes and/or enzymes. In compositions according to the invention the dispersion of the solids in the non-ionic surfactant is remarkably stable especially if the particle size of the solids is at most 10 micro meters. If the solids separate at all then the resulting phase is usually loosely flocculated and is readily redispersible while if the relative amounts of the solids, polyethylene glyclol and surfactant in the composition are correctly chosen there is little phase separation as the liquid fills the space between the loosely packed solid particles.

Compositions according to the invention may suitably be ^"made by a process which comprises milling ingredients together.

The percentages by weight given herein are based on the total weight of the composition unless the context requires otherwise. EXAMPLE 1 : Dehydration of Alkyl Dimethyl Amine Oxide

The following procedure produces a 50% w/w solution of an amine oxide having an alkyl group of chain distribution 70%- C12, 27%- C14 and 3%- C16 and two methyl groups substituted on its nitrogen atom (DMAO) in polyethylene glycol (MW200) (PEG 200).

1 equivalent of PEG200 is added to 4 equivalents of DMAO in aqueous solution. (Approx 33% by weight DMAO). The water is removed by distillation at reduced pressure in a 20L Quickfit flask fitted with a N_ bleed to bottom and a 2 foot froth disengagement column or a splash head, then via a water condenser to a collection vessel and vacuum control.

The boiler is charged at no more than 1/3 to 1/2 fill (to give froth space). The contents are agitated at 100 rpm with a strirrer paddle and a nitrogen bleed introduced. A vacuum is applied and the nitrogen bleed adjusted to maintain a minimum flow. When the vacuum is established the temperature is slowly increased to 60-75°C. Frothing can be controlled by fine adjustment of the vacuum or optionally a silicon antifoam at a level of 0.-05 to 0.1 equivalents can be added to the reaction mixture.

When the theoretical water has been removed, the water content of the boiler is measured. Distillation conditions,

20L scale, 12 hours, 50 mm Hg at 60°C 500ml scale, 3 hours, 45 mm Hg at 75°C. Under these conditions, but making a 60% DMAO composition (less PEG 200 being added) the product is a solid at room temperature, the 50% Amine Oxide material being a liquid.

EXAMPLE 2

Formulation A was produced as follows:

The liquid components were mixed and seven parts by weight mixed with the enzyme and bentonite and the remainder was mixed with the other solid components with a homogeniser and the product milled to a mean particle size of 3 micrometers (weight average). The two mixtures were then mixed together using a homogeniser. Formulation B was produced as follows:

The components other than the enzyme were mixed using a homogeniser and milled to a weight average particle size of 3 micrometers. The enzyme was then added and mixed in using a homogeniser.

TABLE 1

Sodium Citrate

Sodium Tripolyphosphate

Sodium Carbonate

Carboxymethyl cellulose

Sodium Disilicate

"Leukophor" DUK Optical Brightener

Enzyme (Protease and amylase)

"Synperonic" A3

"Synperonic" 87K

Polyethylene glyclol, molecular weight 200 (PEG 200) DMAO (as 100%)

Sodium perborate monohydrate Tetra acetyl ethylene diamine Bentonite Clay 3% Water 0.753

Commercial product sold as "Courlose" A610, degree of substitution 0.5 to 0.7 molecular weight believed to be 60,000 to 100,000.

"Synperonic" A3 and "Synperonic" 87K are the products of condensing respectively an average of 3 moles ethylene oxide and seven moles of a mixture of 92% ethylene oxide and 8% propylene oxide with a mixture of two parts C primary alkanol to one part C,_ primary alkanol, both having some 2-methyl branching, lb

The above percentages are all by weight.

The formulations were tested as laundry detergents as follows:

The performance of formulations A and B was compared with that of a commercial detergent as follows. The wash tests were carried out using a Zanussi FL1030 washing machine run at 40°C and 60°C in water with 90 ppm Ca hardness. Standard cloths from EMPA or Krefeld were used to assess the performance of each product. The machine was filled with four test pieces (lOxlOcm) of each different type of test cloth together with 2 kg of clean cloth as ballast for each wash. Each test cloth was measured in ten different places to assess the increase in reflectance of each cloth. The dose levels of detergent were 60g for formulations A and B and 180g of the commercial product per load. The results were as follows:

The numerical values given are the percentage increase in reflectance after washing.

The above results show good performances compared with the use of three time the weight of a commercial product. Easy Iron Properties

After using Formulation A for a fortnight, 27 out of 29 people answered yes to the question "Did the clothes handle well during ironing?"

A formulation substantially equivalent to formulation A but modified for greater consumer appeal may be made up as follows:

EXAMPLE 3

Liquid suspensions comprising the ingredients of the following Table and which comprised about 50% solids were made up. Formulation C was milled to a mean particle size of 3 micrometres by weight average. The other formulations were made by mixing solid pre-ground particles with liquid components the size of the particles not having been determined.

Formulation Formulation Formulation A B C "Dequest" 2016D

Polyethylene glycol. Molecular weight 200 25.5% 25.5% 34.5%

Tetra acetyl ethylene diamine 3%

"Synprolam" 35DMQ 10% 10% Sodium Perborate Monohydrate 7%

Commercial Product sold as "Courlose" A161, degree of substitution 0.5 to 0.7 molecular weight believed to be 60,000 to 100,000.

"Synperonic" A3 and "Synperonic 87K are the products of condensing respectively an average of 3 moles ethylene oxide and seven moles of a mixture of 92% ethylene oxide and 8% propylene oxide with a mixture of two parts C primary alkanol to one part C._ς primary alkanol, both having some 2-methyl branching, and "Synprolam" 35DMO is an amine oxide having an alkyl group corresponding to the said mixture of C._ and C... alkanols and two methyl groups substituted on its nitrogen atom. The above percentages are all by weight. The formulations were tested as laundry detergents as follows:

The performance of formulations A, B and C was compared with that of a commercial detergent as follows. The wash tests were carried out using Miele W451 washing machines run at 40°C and 60°C in hard water (36°C French specification hardness). Standard cloths from EMPA or Krefeld were used to assess the performance of each product. Three machines were filled with four test pieces (lOxlOcm) of each different type of test cloth together with 2 kg of clean cloth as ballast for each wash. Each test cloth was measured in twelve different places to assess the increase in reflectance of each cloth. The dose levels of the detergent were 60g for formulations A, B and C and 180g of the commercial product per load.

The results were as follows:

The above results show good performances compared with the use of three times the weight of a commercial product. The commercial product contained about one third by weight of water and the comparison on a total chemicals content is thus at a ratio of about one to two. EXAMPLE 4

Two liquid detergent compositions comprising solids suspended in liquids of the following composition were tested as follows:

Water was then added to both compositions in amounts of 1%, 1.5%, 2%, 2.5% and 3% by weight. The viscosity after 45 minutes and (where shown) one day at 20°C is shown below:

A B se) Viscosity (Poise) day 45 min day

46.0 70.8 139.0 70.9 304.0 340 706,000.0

These data show that the amine oxide containing composition was more resistant to degradation by water.

Compositions A and B were also tested for dispensibility in a commercial Zanussi washing machine with a draw dispenser. 2.5 times more residue was left in the tray at the commencement of the washing process in the case of composition B than in the case of composition A.

Claims

1 A liquid detergent composition which comprises a liquid organic phase which comprises an amine oxide and a solid phase which comprises a builder at most 5 for example 0.5 to less than

2 and preferably 1.0 to 1.7 moles of water being present per mole of amine oxide excluding any water present as water of crystallisation of any solid present.

2 A composition suitable for inclusion in a liquid detergent which comprises an amine oxide and a polyalkylene glycol in which at most 5 and preferably less than 2 for example 0.5 to 5 and preferably 1 to 1.7 moles of water per mole of the amine oxide is present.

3 A detergent composition which comprises an amine oxide, a builder and a polyalkylene glycol having a molecular weight of 100 to 1500.

4 A liquid detergent composition which is substantially free from phosphates which comprises an amine oxide, a hydroxycarboxylic acid containing 2 to 6 COOH groups and 1 to 5 OH groups and a polycarboxylic acid comprising at least 10 COOH groups which composition comprises at most 5 and preferably less than 2 moles of water per mole of amine oxide excluding any water present as water of crystallisation of any solid substance present.

5 A composition as claimed in any preceding claim in which the amine oxide comprises an alkyl group having 10 to 18 carbon atoms and two other groups selected individually from Cl to C3 alkyl or hydroxy alkyl groups.

6 A composition as claimed in any preceding claim in which the builder is a condensed phosphate, a zeolite, a silicate or a hydroxycarboxylic acid containing 2 to 6 COOH groups and 1 to 5 OH groups.

7 A composition as claimed in claim 6 in which the builder is a condensed alkali metal phosphate.

8 A composition as claimed in any preceding claim in which the builder is citric or tartaric acid. 9 A composition as claimed in any preceding claim which comprises polyethylene glycol of molecular weight 150 to 500.

10 A composition as claimed in any preceding claim in which the weight ratio of polyalkylene glycol to amine oxide is suitably 0.5 to 1 to 2 to 1.

11 A composition as claimed in any preceding claim which comprises a bleach.