GB2415964A - Detergent formulations based on soap and fatty acid N-methyl glucamides - Google Patents

Abstract

Detergent mixtures contain C10-C18 soap and C10-C18 fatty acid N-methyl glucamides where soap forms greater than 40% of the mixture. In another aspect, specified types of auxiliary surfactants are added. These detergent mixtures are for use as laundry detergents where washing is done in soft water or in pre-softened water, using precipitant builders, zeolites or mixtures thereof. Alkali carbonate containing builders can also contain fine calcite particles as crystallisation seed, providing the softening composition. A method of using the composition for washing laundry is claimed and the water-softening composition itself.

Description

DETERGENT FORMULATIONS BASED ON SOAP AND FATTY ACID N

METHYL GLUCAMIDES

The present invention pertains to fatty soap containing laundry detergent formulations.

More particularly this invention pertains to laundry detergent formulations containing soap and fatty acid N-methyl glucamides for fabric washing use in soft water or in water previously softened, using a water softening formulation based on precipitant builders.

The present invention is set against a background of change and urgency in society's attitude as to how the natural resources are used. There is a perception that it may be for the general good of society as well as environment to use natural and renewable feed stocks in consumer products such as laundry detergents. For sometime the detergent industry had been striving to achieve this.

Soaps of C 1 2 to C 18 alkyl chain lengths are very good laundry detergents when used in very soft water. Whereas lower alkyl chain fatty soaps -coca -are fairly soluble in water, longer chain -tallow -soaps are not very soluble. It is these longer chain soaps that are generally preferred for laundry and textile cleaning applications. Therefore their solubility needs to be improved by the addition of co-actives. For granular or flaked detergent formulations it would be desirable to enhance the dissolution of higher chain length soaps in wash liquor. Soaps are very sensitive to water hardness ions with the loss of detergency. For many years, in the past, soaps built with alkaline materials such as carbonates, silicates, borax and orthophosphate had been produced for use in hard water with limited success and hence were superseded by superior built detergent compositions based on sulphonates and sulphates along with non- ionics.

The drawback of soap-based formulations can be eliminated to some extent by softening the water prior to washing. Now a day washing machines can accommodate more than one product such as one for washing and one for softening. Also machines now are electronically controlled and hence manufactures can be persuaded to incorporate other functional cycles such as water softening cycle if a case can be made.

Current environmentally conscious consumers can also be persuaded to soften water first, using softening products and the process should not take more than 2-5 minutes with agitation before wash fabrics and detergent products are added, if they can perceive environmental benefits. This would have additional advantage for the current invention and hence is part of the invention.

As stated above sodium soaps, particularly C 1 4-C 18 range are not very soluble in water. The inclusion of more water-soluble C12-C14 fatty acid N-methyl glucamides, derived from glucose, will increase the dissolution and solubility of soaps in aqueous solutions, particularly under low temperature wash cycle conditions.

In distilled water soaps besides being good laundry detergents, generally show higher soil suspending power than sulphonate and sulphate anionics and ethoxylated non- ionics In this respect soaps containing higher proportion of C18 saturated fatty acid are particularly good.

Soaps do not have the corrosive tendencies of more common synthetic detergents, and have good emulsifying power However the major drawback of soap is that hard water ion soaps are very insoluble in water and hence lost as detergents. Besides they deposit on fabrics making the fabric stiff and hydrophobic. This cannot be eliminated completely by using lime soap dispersing agents since some hard water ion soaps deposit in the interstices of the fabric.

The C12-C14 fatty acid N-methyl glucamides-coco fatty acid derived-are good detergents on their own and being more soluble than C14-C18 soaps, would solubilise them. If incorporated in solid products they would also help dissolution of soap in water. Glucamides being non-ionic would also act as calcium soap dispersing agents.

It is worth noting here that Alkyl Polyglucosides (APGs) of similar chain length are less soluble and hence not preferred.

Fatty acid N-methyl glucamides have been known for many years as detergents -see WO 9206162 and the patents cited therein.

Procter and Gamble have extensively investigated and patented their improved manufacture. They also have extensively patented their use. Following are some of their patents: W0920/6070, 6071, 6072, 6073, 6152, 6153, 6154, 6155, 6156, 6157, 6158, 6159, 6160, 6161, 6162, 6164, 6171, 6172, 6984, 8687 EP103926, 662115, 551415, 548204, 670884, 670885 US5254281 claim soap bar containing 75-85% soap and rest glucamide to harden the bar.

These patents do not claim soap with glucamide formulations for fabric washing, where soap is a major ingredient The calcium and magnesium salts of conventional anionic detergents such as sulphonates and sulphates are relatively more water-soluble compared to the corresponding chain length soaps. Therefore when formulations based on such detergents built with sequestering builders are dissolved in water the equilibrium shifts towards sequestering builders side. However, in the case of soap, since their hard water ion salts are very insoluble the equilibrium shifts towards precipitation side and hence soap based formulations cannot effectively be built with sequestering builders. Here only the precipitant builders such as alkali carbonates, silicates orthophosphate and zeolites are useful. Even so certain amount of hard water ion soaps will precipitate in competition with precipitant builders when used together.

The most environmentally friendly builders are sodium carbonate, sodium silicates and zeolites. However the problem with sodium carbonate is that the precipitated calcium carbonate fine particles, deposit in the interstices of the fabric and cannot, easily, be washed away. This causes encrustation, increasing the so-called ash content of the fabric, damaging the fabric after many laundering cycles. This can be eliminated to a great extent by the addition of fine calcite particles to the builder to act as nucleating agents in the aggregation of carbonate precipitates. Now the aggregates become particulate dirt, which can easily be washed away during, wash and rinse cycles. However the nucleating agent gets deactivated in the presence of anionic actives including soap, as disclosed in GB1424406 and US3957695, the disclosure of which is incorporated herein by reference. Since calcium and magnesium carbonates are insoluble in water they would not interact with soap during the wash cycle time period.

Silicates also soften water by the formation of precipitates. Since the silicates are polymers the precipitates do not deposit on the fabric. They also suspend soil in solution and prevent their re-deposition on the cloth. Silicates are also good buffers.

The best silicates are in the Na20: SiO2 ratio of 1:1.6 to 1:2.4. Therefore a combination of alkali carbonates and silicates have good building property.

Summag of the invention This invention provides detergent mixtures for use in cleaning fabrics, based on soap as major ingredient but also containing glucose based surfactants as co-actives for use in soft or pre -softened water. They are naturally derived. environmental friendly and highly biodegradable The C 1 2-C 14 fatty acid N-methyl glucomide co- active, besides being good cleaner on its own right, being more soluble would assist in the dissolution of soap in water at low temperatures and in the dissolution of soap from formulated products. Being non- ionic in nature they would also have calcium soap dispersing effect and hence prevent any residual calcium soap deposition on fabrics. Glucamides, being, solids, would also have beneficial effect in product formulations in solid forms such as granules or flakes and they will have plasticizing effect The soap used can be based on C10-C18 fatty acids such as coco, tallow and palm oil and palm kernel oil. The active composition can contain from 40% to 75% soap.

It should be understood that in the process of glucamide production certain by- products are produced such as ester amides and cyclic polyLydroxy fatty acid amides.

The level of such by-products should be less than 10% preferably less than 4% tin the glucamide raw material.

Auxiliary Surfactanb The detergent mixture can further include an auxiliary surfactant component, to improve the performance further, which comprises anionic and non-ionic surfactants other than soap and glucamides. If present such auxiliary surfactants will typically be present in an amount less than 30% of the mixture.

Such auxiliary surfactants include C12-C18 alkyl sulphate, coco alcohol E04-E012 ethoxylates, coco alkyl polyglucosides, coco mono- and di ethanolamides, their ethoxylates and mixtures thereof. Lit

The formulations are tailored and targeted to washing in water at different hardness levels.

For water hardness <5dH the formulation can be used as is without any builders, where certain amount of soap will act as self builder and the small amount of calcium soap produced will be dispersed by the co-active present. However in such formulations the presence of alkaline builders would enhance detergency because of their alkalinity For use in water hardness <I OdH a mall amount builders such as sodium carbonate or a combination of sodium carbonate and alkaline silicates, zeolite or mixtures thereof should be used However, for hard water wash, the water needs to be softened first before the detergents are added. Further advantages can be gained when both the clothes and detergents are added after softening the water.

Other conventional ingredients such as lather suppressants, optical brighteners etc can either be added to the active mixture or WatersoRening mixture when they are used separately.

Typical Formulations A) Water Softening Formulation 1. Sodium Carbonate 50% Sodium Silicate (SiO2: Na20 = 2) 20% Calcite (<10 micron) 30% B) Detergent Formulation 1. Sodium Tallow Soap 70% Coco fatb acid N-methyl Glucamide 30% 2. Sodium Tallow soap 50% Coco fatty acid N-Methyl Glucamide 30 % C12-C14 EO7 20%

Claims (4)

1. Claims 1. A fabric washing detergent mixture containing a) C10-C18 soap

   and b) CIO-C18 fatly acid N-methyl glucamide for washing in soft water or in water previously softened
2. 2. A method of laundering comprises adding the detergent mixture of Claim I along with the fabrics to be washed to previously softened wash water, using a water softening product.
3. 3. A detergent mixture as in Claim I where the soap content is 40% to 7S%.
4. 4. A detergent mixture as in claim I, that further contains from 1 to 30% of an auxiliary surfactant component se l ected from alkyl polyglucosi de, alkyl ethoxyl ate, fate alkanolamide ethoxylate and alyl sulphate or mixtures thereof.

   4. A detergent mixture as in Claim I where the glucamide content is 60% to IS%.

   5. A detergent mixture as in Claim 1 where the soap fatty acid is derived from coca, tallow or mixtures thereof.

   6. A detergent mixture as in Claim I where the fatty acid N-methyl glucamide is based on coca fatty acid.

   7. A detergent mixture as in Claim I which further contains from I to 30% of an auxiliary surfactant component selected from alkyl polyglucosides, alkyl ethoylates, fatty alkanolamide ethoylates, alkyl sulphates, or mixtures thereof 8. The water softening product as in Claim 2 is a precipitant builder, silicate, Polite or mixtures thereof.

   9. When the precipitant builder as in Claim 8 is an alkali carbonate, it additionally can contain fine calcite particles Amendments to the claims have been filed as follows Claims 1. A detergent mixture, for fabric washing use in soft water, consisting essentially of C10 - C18 soap and from 21 to 60% of C10 - C18 fatty acid N-methyl glucamide.

   2. A mixture as in claim 1, where the soap is derived from coco, tallow, hydrogenated tallow or mixtures thereof.

   3. A mixture as in claim 1, where the fatty acid N-methyl glucamide is preferably based on coco fatty acid.