WO1992011346A1

WO1992011346A1 - A detergent and its manufacture

Info

Publication number: WO1992011346A1
Application number: PCT/SE1991/000896
Authority: WO
Inventors: Ingemar Lejon
Original assignee: Kommentus Ecogreen Aktiebolag
Priority date: 1990-12-21
Filing date: 1991-12-20
Publication date: 1992-07-09
Also published as: AU9129991A; SE9004130D0; SE467927B

Abstract

There is provided a detergent which contains surfactants and sequestering agents and which includes a combination of a) one or more nonionic surfactants, and b) one or more amphoteric surfactants, said surfactants a) and b) functioning well in hard water, do not precipitate calcium carbonate during the washing process, and have a low foaming profile, and c) a sequestering agent in the form of a mixture of c1) sodium carbonate and c2) a sodium salt or potassium salt of a carboxylic acid capable of functioning as a sequestering agent, or a mixture of such salts. The detergent can be produced by a method of mixing the solid detergent components and fluidizing the mixture in air, and subsequently spraying the liquid components onto the solid components in a finely divided form.

Description

A Detergent and Its Manufacture

The present invention relates to a detergent containing surfactants and sequestering agents, and a method for manufacturing the detergent.

Many different types of detergents for use in clothes-washing machines are commercially available, which detergents are composed of surfactants and sequestering agents as active cleaning substances and softeners and detergent amplifiers respectively. The majority of conventional detergents also include bleaching agents, optical brighteners, protective colloids, anti-corrosion agents, fillers and binders. The detergents may also include dyes, perfume and enzymes.

Conventional, commercially available detergents include many substances which pollute the environment. Many different forms of surfactants are available with varying degrees of toxiσity with respect to marine life and also varying degrees of biological degradability. Many surfactants consume considerable quantities of oxygen as they degrade, and certain surfactants form toxic substances which are liable to be imbibed by plants and animals. In order to reduce the pollution load on the environment created by these substances, there is a trend towards the use of readily degradable surfactants of low toxic effect.

Phosphates, which are used as sequestering agents, function as a fertilizer and are a contributory cause to the overgrowth of lakes and waterways and to oxygen deficiencies. Manufacturers have begun to use other types of sequestering agents-softeners, in order to obviate the problem created by the phosphates. Frequent substitutes for phosphates are zeolites and polyacrylates, which are often used in different combinations. Other sequestering agents used are EDTA, NTA and phosphonate. The problem with these sequestering agents is that they can create a flow of heavy metals from the purifying plant to the surroundings .

The use of zeolites and polyacrylates has also been questioned in recent times.

Perborate is included in many detergents as a bleaching agent and can have a negative effect on the growth of marine plants, due to its boron content.

In order to reduce the pollution load on the environment, detergents which are more or less environmentally adapted have been developed and introduced onto the market in recent years. The object of the different manufacturers with these "environmentally adapted" detergents is to replace environmentally harmful substances with other, less environmentally disturbing components. These detergents normally comprise surfactants which degrade more readily. The phosphate concentration is low, or has been replaced totally by, for instance, zeolites, polyacrylates and phosphonate. The most "environmentally adapted" detergents often lack a bleaching agent and enzymes, which is reflected in a poorer washing result.

One object of the present invention is to provide a detergent which can be used to launder all textiles in a washing machine at temperatures between 30ºC and 95°C, and which will produce a washing result which is comparable with traditional detergents which are not environmentally adapted, but which, at the same time, will fulfil very high demands placed on environmental adaptation. Another object of the invention is to provide a detergent which can be manufactured in a simple and energylean fashion.

It has been found, in accordance with the invention, that these objects can be achieved when starting from a mixture of nonionic surfactants and amphoteric surfactants, which function well in hard water, do not precipitate calcium carbonate during the laundering process, and have a low foam profile. By using such surfactants, it is possible to use non-environmentally harmful sequestering agents, such as sodium carbonate, in combination with sodium carboxylates and/or potassium carboxylates. In accordance with the aforesaid, the inventive detergent is characterized in that it contains a combination of a) one or more nonionic surfactants, and

b) one or more amphoteric surfactants, which surfactants a) and b) function well in hard water, do not precipitate calcium carbonate during the laundering process, and have a low foam profile, and c) as sequestering agent, a mixture of

c1) sodium carbonate, and

c2) a sodium or potassium salt of a carboxylic acid

capable of functioning as a sequestering agent, or a mixture of such salts. According to the invention, the component a) may comprise one or more fatty alcohol ethoxylates, one or more fatty alcohol polyethylene-polypropylene glycol ethers, oxoalcohol polyethylene glycol ethers, or a mixture of such substances. The fatty alcohol ethoxylates used are those which have a straight carbon chain in the alcohol part containing 8-18, preferably 10-14, carbon atoms, and a degree of ethoxylation of 3-25, preferably 3-10, mole ethylene oxide units.

Fatty alcohol ethoxylates having, for instance, 13

carbon atoms in the chain, and degrees of ethoxylation from 7 to 25 function well in hard water, have a relatively low foam profile, are stable in alkaline systems, can be admixed with a powder detergent at low temperatures, and are biologically degradable in accordance with OECD's guidelines. The combination of fatty alcohol ethoxylates with different degrees of ethoxylation, provides good wetting and washing properties with respect, for instance, to cottons, polyesters and mixtures of cottons and polyesters in temperatures ranging from 30ºC to 95ºC. An optimal wetting effect and detergent effect is obtained with a carbon-chain length of 2-16, preferably 13 carbon atαπs, by ccmbining fatty alcohols which have a degree of ethoxylation of from 3 to 12, preferably 6 to 9. These fatty alcohol ethoxylates are liquid at room temperature. In order to obtain the requisite surfactant concentration in the detergent solution and a detergent powder which can be handled technically both from a production and a storage aspect, surfactants must also be added in solid form. Solid fatty alcohol ethoxylates have a degree of ethoxylation of 17 or more. Their carbon chains may

also be longer than 13 carbon atoms. From a laundering aspect, the best result is obtained by adding solid fatty alcohol ethoxylate with 13 carbon atoms in the chain and with 17 mole ethylene oxide. Good results have also been achieved with fatty alcohols with 16-18 carbon atoms and 25 mole ethylene oxide.

The component b) of the inventive detergent may comprise a tallow amphopolycarboxy glycinate, mixed C8-amphocarboxylates, a caprylo-ampho-carboxy-glycinate, a capryloamphocarboxy propionate or a mixture of such substances.

The above mentioned substances examplifying component b) are low foaming, biologically degradable, amphoteric surfactants, which in combination with the aforesaid fatty alcohol ethoxylates increase the wetting ability and detergent effect of the detergent solution by synergism.

This is necessary, since the sequestering agents used in the detergent have an insignificant dispersing effect in comparison, for instance, with sodium tripolyphosphate. The above mentioned component b) substances are stable in alkaline systems, are insensitive to hard water, and can be readily mixed into the detergent at low temperature.

Each of the components a) and b) may be present in the detergent in a concentration of 1-15, preferably 2-8 per cent by weight, calculated on the total weight of the detergent.

In addition to functioning as a sequestering agent, sodium carbonate, added as component c1), also functions as an alkali donor and surfactant carrier and, in accordance with the invention, is present in the detergent in an amount of 5-40, preferably 20-40 per cent by weight, calculated on the total weight of the detergent. The component c2) is advantageously a sodium or potassium citrate or a sodium or potassium tartrate or a sodium or potassium gluconate or a mixture of at least two of said substances. A mixture of sodium citrate, sodium tartrate and potassium tartrate is particularly preferred.

The component c2) will normally be present in an amount of 5-40, preferably 10-30 per cent by weight, calculated on the total weight of the detergent.

In addition to the aforesaid components a)-c), the inventive detergent may also include d) one or more bleaching agents selected from the group consisting of percarbonates, persulphates and TAED, preferably sodium percarbonate. This component may be present in the detergent in an amount of 0-30, preferably 1-20 per cent by weight, calculated on the total weight of the detergent.

In addition to components a)-c) and possibly also

component d), the inventive detergent may further

include e) one or more anti-corrosion agents and

f) component carriers, anticaking agents, fillers and

optionally

g) one or more protective colloids and/or

h) enzymes.

i) one or more anionic surfactants selected from the

group consisting of paraffinic sulphonates, sodium lauryl sulphate and sodium lauryl ether sulphate.

The anti-corrosion agent used is preferably sodium disilicate and/or sodium metasilicate and/or potassium metasilicate. A suitable quantity is 1-15, preferably 5-12 per cent by weight, calculated on the total weight of the detergent. Examples of component carriers, anticaking agents and fillers are sodium disilicate and/or sodium sulphate, which can be added in a quantity of 5-30, preferably 10-30 per cent by weight, calculated on the total weight of the detergent.

The protective colloid used may be carboxy methyl cellulose (CMC) or similar substances having a corresponding function, said colloid being present in an amount of 0-5, preferably 0.1-2 per cent by weight, calculated on the total weight of the detergent.

The enzymes used may be encapsulated enzymes used conventionally within the detergent industry and assisting to dissolve and remove stains, such as blood, egg, milk and cocoa stains. The enzymes may be

present in quantities of 0-5, preferably 0.1-2 per cent by weight, calculated on the total weight of the detergent.

Component i) may be added in order to improve the washing results of the detergent. It is generally added to a concentration of 0.2 - 6, preferably 0.3-3.0 per cent by weight of the detergent.

The inventive detergent can be produced by a method which is characterized by mixing the solid detergent components of the detergent and fluidizing the mixture in air, and by then spraying the liquid components in a finely divided form onto the solid components.

While the component b) will always consists of a liquid substance, the component a) may consist of both solid and liquid substances, as mentioned above. When producing the detergent, the ratio of solid components to liquid components is selected so as to obtain a readily pourable, dust-free powder having a desired high surface concentration. In general, this implies that the proportion of liquid surfactants present will lie within the range of 6-10 per cent by weight, calculated on the weight of the detergent. If desired, the resultant powder can be converted to tablet form, with the aid of known techniques, while adding a suitable auxiliary agent as a binder.

The inventive detergent can also be given a paste form, in which case manufacture is effected by stirring the various ingredients while using liquid surfactants or additions of, for instance, propylene glycol or glycerol in sufficient quantities to obtain a paste form.

Consequently, the inventive detergent can be produced by means of an energy-lean process and the resultant product is a compact detergent, preferably having a density of 700-900 g/l, which takes-up little space, which saves on packaging material and the need for space, both when transporting and storing the detergent. The detergent can be used for all machine washes between 30ºC and 95ºC.

The inventive detergent may also contain other components in addition to components a)-h) recited above, and also other substances than those substances specifically recited in conjunction with the components d)-h) without departing from the inventive concept.

Similarly, it should be borne in mind that the above recited weight limits for the various components are not critical in general terms, in the sense that the detergent effect would totally disappear immediately these limits were transgressed.

The invention will now be described with reference to a number of working examples. A number of detergents were prepared, which detergents have the following composition, given in parts by weight:

Example No.

1 2 3 Liquid Components

Fatty alcohol ethoxylate having a straight

carbon chain (C13) and 7 ethylene oxide

units (Marlipal^R 013/70 from Hϋls AG,

Marl, Germany). 3.0 5.0 4.0

Fatty alcohol ethoxylate having a

straight carbon chain (C13) and 12

ethylene oxide units (Marlipal 013/120

from Hϋls AG, Marl, Germany). 1.5 - -

Tallow amphopolycarboxy glyσinate

(Beraid ^R 7557 from Berol Nobel AB,

Stenungsund, Sweden). 3.0 5.0 4.0

Sodium paraffinsulfonate (Marlon^® PS 60

from Hϋls AG, Marl, Germany) - - 3.0

Sodium laurylether sulfate (LES 28) - - 0.4

Solid Components Fatty alcohol ethoxylate having a

straight carbon chain (C13) and 17

ethylene oxide units (Marlipal^R 013/170

from Hϋls AG, Marl, Germany). 1.5 - -

Fatty alcoholethoxylate (C16-18; EO 25) - 2.5 2.5 Sodium disilicate 22.5 15.0 10.0

Sodium metasilicate 5H₂O 7.5 - -

Sodium carbonate 27.5 35 41.6

Sodium citrate 15.0 17.5 10

Sodium gluconate - - 5.0 Sodium/potassium tartrate 2.5 1.5 1.0

Sodium percarbonate 5.0 10 10

Carboxy methyl cellulose 0.75 2.0 1.5

Enzyme granulate 0.25 1.5 1.0

Sodium sulphate 10.0 5.0 6.0 Manufacture was effected in an agglomerating process, utilizing an agglomerator of the type Forberg mixer from Halvor Forberg A/S, Larvik, Norway, in which the solid components were mixed and fluidized in air, whereafter the liquid components were sprayed onto the solid components in the form of fine droplets.

Example 3 represents the best mode contemplated at present for carrying out the invention.

Claims

1. A detergent containing surfactants and sequestering agents, c h a r a c t e r i z e d in that it includes a combination of a) one or more nonionic surfactants, and

b) one or more amphoteric surfactants, said surfactants a) and b) functioning well in hard water, do not precipitate calcium carbonate during the washing process, and have a low foaming profile, and

c) a sequestering agent in the form of a mixture of c1) sodium carbonate and

c2) a sodium salt or potassium salt of a carboxylic

acid capable of functioning as a sequestering agent, or a mixture of such salts.

2. A detergent according to Claim 1, ch a r a c t e r i z e d in that the component a) consists of one or more fatty alcohol ethoxylates, one or more fatty alcohol polyethylene polypropylene glycol ethers, oxoalcohol polyethylene glycol ethers or a mixture of such substances.

3. A detergent according to Claim 2, c h a r a c t e r i z e d in that the fatty alcohol ethoxylates have a straight carbon chain in the alcohol part containing 8-18, preferably 10-14 carbon atoms and a degree of ethoxylation of 3-25, preferably 3-10 mole ethylene oxide units.

4. A detergent according to one or more of Claims

1-3, c h a r a c t e r i z e d in that the component b) consists of a tallow amphopolycarboxy glycinate,

mixed C8-amphocarboxylates, a caprylo amphocarboxy-glycinate, a caprylo amphocarboxy propionate or a mixture of such substances.

5. A detergent according to one or more of Claims

1-4, c h a r a c t e r i z e d in that the component c2) is a citrate or tartrate or gluconate or a mixture of at least two of said substances.

6. A detergent according to one or more of Claims

1-5, c h a r a c t e r i z e d in that it further

includes d) one or more bleaching agents selected from the

group consisting of percarbonates, persulphates

and TAED, preferably sodium percarbonate.

7. A detergent according to one or more of Claims

1-6, c h a r a c t e r i z e d in that in addition to components a)-c) and optionally d), the detergent also includes e) one or more anti-corrosion agents and

f) component carriers, anticaking agents, fillers,

and optionally

g) one or more protective colloids and/or

h) enzymes.

i) one or more anionic surfactants selected from the

8. A method for producing a detergent in accordance

with any one of Claims 1-7, c h a r a c t e r i z e d by mixing the solid detergent components and fluidizing the mixture in air, and subsequently spraying the

liquid components onto the solid components in a finely divided form.