NO873363L - SOLUTION MIXING. - Google Patents

Abstract

Liquid detergent comprising a non-aqueous liquid base, containing, in solution and/or dispersion and/or emulsion, the other solid and liquid components of the detergent. The detergent comprises two different and separated phases (A,B), to be mixed together at the time of use or just before, wherein one of the two phases (phase A) contains the oxidizing agents and the other phase (phase B) contains enzymes and activation agents for the oxidizing agents contained in the other detergent phase (A). Other components, chosen from the agents listed below are furthermore present in both the detergent phases (A,B): builders, pigments, stabilizers, perfumes, dyes, optical brighteners, anti-redeposition agents, anionic and/or cationic surfactants, anti-foaming agents. The non-aqueous liquid base is formed by a mixture of non-ionogenic surfactants with a possible addition of a polar solvent for viscosity control purposes. By mixing the two phases (A,B), a liquid detergent composition is obtained which is complete in all its cleansing functions, action on oxidizable stains, on protein stains, sequestration of alkaline-earth metal and heavy-metal ions, etc. The solid material content in the two phases (A,B) is suitably comprised in the concentration range between 40-60% by weight.

Description

The present invention relates to heavy-duty and fine-duty liquid detergents.

Liquid detergents have achieved an ever-increasing importance as they are more convenient to use than powdered detergents. They are divided into two main groups, namely water-based liquid detergents and non-aqueous liquid detergents, the basis of which is an organic liquid medium.

Most aqueous, liquid detergents consist of a solution or microsuspension of anionic, cationic

and nonionic surfactants, enzymes, perfumes, stabilizers and various auxiliaries.

They have a limited washing effect as they contain limited amounts of constituents (so-called "builders") which can complex alkaline earth metal ions which cause hardness in washing water, as well as ions of heavy metals.

Furthermore, they do not contain stain removers of the peroxide type (hydrogen peroxide, inorganic peroxides such as perborate, organic peroxides, organic peracids etc.) as such oxidizing agents are not only unstable in aqueous suspension or solution, but they will also affect added enzymes and disable these.

The water-based detergents for machine and hand washing are therefore mainly based on the surface-active effect and the stain-removal effect on protein-type stains, while they do not affect oxidizable stains, which make up the majority of dirt that often occurs.

The oxidizing effect is only possible with non-aqueous detergents consisting of an organic liquid medium based on polar solubilizers and surfactants containing in suspension an oxidizing agent of an organic or inorganic peroxide type, under conditions and in the presence of other "co-formulating" agents such that interaction and therefore cleavage of the oxidizing agent becomes impossible.

DE-C-1 279,878 shows a non-aqueous based liquid detergent comprising a mixture of non-ionic and anionic surfactants, ethyl alcohol, builders such as sodium tripolyphosphate, suspending agents such as calcined silica or calcined alumina, optical brighteners, and sodium perborate.

US-A-3,850,831 mainly relates to anhydrous, liquid detergent mixtures consisting of ionic, anionic and polyhydric alcohol detergents, stain removers of the persalt type, builders such as sodium tripolyphosphate and chelating agents such as polyamino carboxylic acids.

US-A-4,416,812 relates to the use of non-ionic surfactants without any solvents (pour point 10°C), mixed with builders such as sodium tripolyphosphate, stain removers such as sodium percarbonate and perborate, as well as an alkalizing agent such as metasilicate and other typical detergent ingredients, such as CMC, sodium borate, carbonate and bicarbonate, kaolin, bentonite etc. to provide an anhydrous, fine-grained paste detergent.

EP-B-0028,849 relates to a non-aqueous based liquid detergent containing a maleic anhydride copolymer with ethylene or methyvinyl ether and a polyhydric alcohol solvent which acts as a suspending agent together with non-ionic surfactants as well as solid agents such as alkalizing agents, builders, oxidizing agents, bleach activators, enzymes and softeners.

EP-B-0120,659 relates to substantially anhydrous, liquid detergent compositions consisting mainly of non-ionic surfactants, polar solvents with viscosity lowering action and dispersing agents, builders, alkalizing agents, persalts, optical brighteners, carboxymethyl cellulose, enzymes and these compositions are in it substantially anhydrous.

DE-A-3 511 516 mainly relates to an anhydrous laundry detergent, comprising non-ionic surfactants, acidic surfactants, sodium tripolyphosphate, sodium perborate, TAED and a copolymer such as "SOKALAN CP5^

DE-A-3 511 515 relates to a substantially anhydrous laundry detergent comprising nonionic surfactants, acidic surfactants, sodium phosphonate, sodium perborate, "SOKALAN CP5" copolymer, sodium carbonate, TAED, optical brighteners and protease.

The above-mentioned patents DE-C-1 279,878, US-A-3,850,831 and US-A-4,316,812 all relate to non-aqueous, liquid detergent compositions with stain-removing action based on non-activated persalts. These mixtures have a limited effect on oxidizable stains at low temperatures, due to the absence of bleach activators. Furthermore, they have limited stain removal properties, due to the absence of enzymes, especially of the proteolytic type. The absence of enzymes washes away the difficulty of introducing enzymes into this type of mixture as they will be quickly deactivated as a result of the action of the oxidizing agent, this enhanced by traces of moisture which will inevitably be present in the raw materials during manufacture and packaging and which in all add- traps will easily be picked up during use by the user.

The patents EP-B-0 028 849, EP-B-0120 659, DE-A-3 511 515 and DE-A-3 511 516 are based on the combined use of oxidizing agents, bleach activators and enzymes to achieve the desired cleaning effect .

It is known, however, that bleach activator and persalt, if they are simultaneously present in detergent mixtures based on solvents and polar surfactants, will lead to early reactions with the formation of peracid and water and eventual evolution of the oxygen. This reaction is promoted both by the partial solubility of the two components, but mainly by the presence of traces of water.

It is also well known that the simultaneous presence of enzymes in a system containing oxidizing agents in non-protected form causes the enzyme to be quickly deactivated.

Consequently, the detergent compositions described in the patents EP-B-0028 849, EP-B-0120 659, DE-A-3 511 515 and DE-A-3 511 516 will not provide any satisfactory solution to the problem of composition of a completely liquid detergent.

It is therefore an aim of the present invention to provide a non-aqueous, liquid detergent which is able to remove oxidizable stains, as well as protein stains and which is not burdened with the disadvantages of the known detergents of this type.

According to the distinctive feature of the present invention, this purpose can be achieved by providing detergents in the form of two physically separated phases, one containing the oxidizing agent and the other bleach activator and enzyme in combination with surface-active agents, builders, optical bleachers, anti-redeposition agents, alkalizing ingredients, colors, perfumes, stabilizers, etc., all the ingredients being dissolved and/or dispersed and/or emulsified in a suitable non-aqueous, liquid base.

The liquid base is preferably prepared from mixtures of liquid non-ionic surface-active agents and solvents of the polar type, the latter being intended to lower the viscosity and freezing point, as well as to enhance dispersibility in water during washing.

Surface-active agents of the anionic or cationic type can also be included if the textiles' softening effect is desired.

The builders consist of anhydrous salts of the polyphosphate type, NTA , sodium citrate, zeolites, bentonites, montmor i1lonites, etc.

The oxidizing agent is selected from inorganic persalts of the type sodium perborate monohydrate, sodium perborate tetrahydrate, sodium percarbonate, sodium, potassium and ammonium persulphate, sodium and potassium monopersulphate, perphosphate, perurea, peroxides and organic peroxides, etc.

The bleach activator, which is always used when inorganic persalts are used, can consist of TAED, PAG, EBA, TAGU-NAOFS and other known bleach activators.

The enzymes are mainly of the protolytic type, also in combination with lipase, amylase and cellulase.

The optical brighteners used are of the stilbene-morpholine, distril diphenyl and pyrazole type, and generally of a type normally used in detergents.

The preferred anti-redeposition ingredients are of the cellulose derivative type, such as carboxymethyl cellulose and etherified, nonionic celluloses. Acrylic acid homopolymers and acrylic acid copolymers with maleic anhydride and maleic anhydride polar copolymers with methyl vinyl ether, methyl porenyl ether etc. are also used.

Persalt stabilizing agents are of the phosphonate type and amino polycarboxylic acid complex formers, such as EDTA, DTPA etc.

The enzymes used in the present invention, namely protease, lipase, amylase, cellulase can be introduced into the detergent in solid form, as a slurry or in the form of a solution in an organic liquid.

With regard to the presence of water and other components that have a destabilizing effect on the enzymes, the stabilizers can advantageously be added such as calcium and magnesium organic and inorganic salts, polar solvents such as ethyl alcohol and polyglycols, organic boron compounds and inorganic such as boric acid and borates, nitrogenous compounds such as EDTA, NTA, glycine, monoethanolamine, diethanolamine, triethanolamine, acetamide, and glutamic acid.

According to a preferred embodiment of introducing the enzyme into the detergent mixture, the protolytic enzyme is introduced in the form of a slurry in the non-ionic surfactant or polar solvent in fine particles in post-mixing to the remaining components, after grinding to avoid unwanted degradation. The simultaneous presence of oxidizing agents such as inorganic persalts and peracids or organic peroxides can lead to an interaction between the activator and the enzyme, respectively, which will quickly break down these compounds.

Also the simultaneous presence of persalt and bleach activators, in unprotected form, leads to an exothermic decomposition reaction.

The two phases can be prepared according to any suitable method.

Dosing of the liquid detergent in the washing machine can be carried out using the dosing cup, which comes with the machine, or directly into the washing machine.

The composition of the liquids and solids in the two separate phases must be such that an equal final density, viscosity and pour point is obtained, so that the same physical stability is ensured at low temperature and constant supply ratio.

The various solid components of the detergent can be partially soluble or insoluble in the liquid system. To ensure perfect physical time stability, the undissolved solids must have a very fine grain size, for example less than 10 µm. Each phase consists of liquid components, solvents and ionic surfactants, solid components that can be dissolved in the system and suspended solid components as well as emulsified liquid components. The ratio between solids and liquids is in the range 1:3 and 9:1, preferably in the range 1:1.5 and 3:1.

The liquid phase consists of preferably non-ionic surfactants and polar solvents. The ratio between the solvents and the surfactants is in the range of 1:9 and 3:1.

C^-C^ lower alcohols, ethylene, propylene glycols, oligomers and copolymers thereof, also partially esterified with ^ alcohol, glycerol and aprotic polar solvents such as dimethyl sulfoxide are particularly suitable solvents.

The most suitable non-ionic surfactants are primary and secondary, natural or synthetic alcohol derivatives where the number of carbon atoms is in the range cg~C22'

and preferably in the range Cg-^g* condensed with ethylene oxide and containing 3-25 monomer units and preferably 5-15 monomer units, or condensed with propylene oxide with the content of monomer units in the range 2-10, and preferably in the range 3-6 or condensed together with oxyethylene and oxypropylene units. Non-ionic surfactants of the aforementioned type may contain a final hydroxide esterification with C-^-C-^ organic acids.

Other non-ionic surfactants suitable for the production of the liquid detergents according to the invention are those derived from the condensation of alkylphenols with alkylene oxides and where the type and content of monomeric units correspond to the above-mentioned alcohol-based non-ionic surfactants.

The physical and chemical stability of the two phases that make up the detergent must be suitably ensured by limiting the water content in the two phases. Therefore, with regard to the phase in which, among other things, the oxidizing agent in the mixture is present, the free water content should not exceed 6% and preferably be lower than 3%.

For the production of the two phases of the detergent, the liquid and solid components containing free water of crystallization should be dehydrated to satisfy the above-mentioned conditions.

The two phases that make up the detergent are in the form of suspensions of solids in liquids, and have a viscosity • in the range 100 - 2000 mPa, preferably in the range 500-100 mPa. To satisfy this requirement and to achieve the same viscosity for the two phases to ensure uniform delivery, the solid particles must be suitably fine, for example less than 10 pm.

This result is achieved by grinding the suspension in a suitable machine, such as a ball mill or bed mill for a period of time and a number of steps suitable to ensure that the desired result is achieved.

A modification of the above-mentioned method can consist of grinding the individual solid components in a single phase, and then bringing the same with the liquid so that a fine suspension is obtained (grain size see less than 10 pm) which is stable against deposition.

The physical stability, i.e. non-settling of the suspensions corresponding to the two detergent phases, must be ensured for a period of time between production and consumption, i.e. at least for a period of time in the range of 6-12 months.

It is therefore useful to add suspending agents such as calcined silica, calcined alumina, water-soluble polymers such as polyvinylpyrrolidone to the suspension, before or after painting. The added amounts are in the range 0.1 - 2%, and preferably in the range 0.3-1%.

Calcined silica is silicon dioxide obtained by pyrohydrolysis of chlorosilanes and is marketed as a powder with low density and insoluble in water, with very small particles and with a surface area in the range of 50-400 m 2 /g. Commercially available types of fumed silica are "HDK" (rtaker) and "AEROSIL" (Degussa).

Polyvinylpyrrolidone is used with a molecular weight in the range of 30,000.

The invention shall be further described by the following examples. In the examples, the detergent phase containing the oxidizing agent will be referred to as "phase A", and the one containing enzymes and bleach activator will be referred to as "phase B".

EXAMPLE 1

Phase A and phase B are prepared separately as described below by mixing the liquid and solid components in a mixing device equipped with tubes.

In order to achieve a sufficient physical stability, the solid components in the two phases are then ground in a ball mill until an average particle size of 6.6 pm for the solid particles is obtained.

The composition of the two phases was as follows, expressed in % by weight:

The two phases had the following physical properties:

EXAMPLE 2

By following the same procedure as in example 1, phase A and phase B were prepared with the following compositions:

The two phases in example 2 have the following chemical-physical properties:

EXAMPLE 3

After painting, the two parts of phase A and phase B in example 1 are carefully mixed in a 1:1 ratio to obtain a single-phase liquid detergent with the following composition:

Single-race liquid detergent according to example 1

EXAMPLE 4

After painting, the two parts of phase A and phase B prepared according to example 2 are carefully mixed in a ratio of 1:1 to obtain a single phase liquid detergent with the following composition in % by weight

Single-phase detergent according to example 2

EXAMPLE 5

The mixtures A and B according to examples 1 and 2 and the new mixtures obtained by their mixing according to examples 3 and 4 were examined over time and at different temperatures with regard to sodium perborate, bleach activators and protolytic enzyme stability. The products were kept in sealed glass containers. It should be noted that upon opening the containers where the mixture according to example 3 and example 4 was stored to carry out the analyses, an overpressure caused by gas formation as a result of a remarkable decomposition of the oxidizing agent was observed.

EXAMPLE 6

With the liquid detergents according to examples 1,2,3 and 4, stored for two months at 23°C, washing trials were carried out in a washing machine. At the same time, washing tests were carried out using a marketed, water-based detergent containing enzymes carried out under the same test conditions. The amounts of detergent used in the washing trials are shown in the following table:

The detergents A + B according to examples 1 and 2 were dosed by mixing equal amounts by weight of the two phases just before the examination.

Claims (40)

1. Detergent mixture comprising a non-aqueous liquid base containing in solution and/or dispersion and/or emulsion in liquid and solid components of the detergent, characterized in that it consists of two different and separate detergent-based phases which must be combined at the time of use or immediately before and where one phase, the first phase, contains oxidizing agents and the second phase contains enzymes and activators for the oxidizing agents, both phases containing a number of additional components water among builders, pigments, dyes, stabilizers, optical brighteners, perfumes and anti-deposition agents, anionic and/ or cationic surfactants and anti-foam agents. 2. Detergent according to claim 1, characterized in that the non-aqueous liquid base consists of one or more non-ionic surfactants and one or more polar solvents. 3. Liquid detergent according to claim 1, characterized in that the oxidizing agents are present in the first phase in amounts in the range of 2-35% by weight, preferably 10-25% by weight. 4. Liquid detergent according to claim 1, characterized in that the bleach activators are present in the second phase in an amount in the range 1-15 weight/e, preferably 5-10% by weight. 5. Detergent according to claim 1, characterized in that the enzymes present in the second phase are of the proteolytic and/or amyolytic and/or lipolytic and/or cellulase type and are present in amounts in the range 0.2-5%, preferably in the range 0.5-2% . 6. Detergent according to claims 1-5, characterized in that the oxidizing agents, bleach activators and enzymes present in the liquid bases in the first and second phases are in the form of a suspension of solid particles with an average diameter of less than 10 µm. 7. Detergent according to the preceding claims, characterized in that the ratio between the liquid base and the solid components suspended and/or dispersed and/or emulsified in the two phases is in the range 1:3 - 9:1 and preferably in the range 1:1, 5 and 3:1. 8. Detergent mixture according to claim 2, characterized in that the ratio between solvents and surfactants in the liquid base is in the range 0.5:9 and 3:1, and preferably in the range 1:9 and 1:1. 9. Detergent mixture according to any of the preceding claims, characterized in that the amount of builders contained in the first and second phases is in the range 5-50% by weight, and preferably in the range 10-30% by weight. 10. Detergent mixture according to the preceding claims, characterized in that the optical brighteners are present in the two phases in amounts in the range of 0.01-0.5% by weight, preferably in the range of 0.05-02% by weight. 11. Detergent according to the preceding claims, characterized in that the first phase contains a persalt stabilizer of aminopolycarboxylic acid and/or potassium phosphonate type. 12. Detergent according to the preceding claims, characterized in that the two phases further contain stabilizers of the type calcined silica, calcined aluminum oxide or suspending polymers. 13. Detergent type according to the preceding claims, characterized in that the content of free water in the first phase is less than 2%, and preferably less than 1%. 14. Detergent according to the preceding claims, characterized in that the content of free water in the second phase is lower than 5%, and preferably lower than 3%. 15. Detergent according to claim 2, characterized in that the liquid base of the solution and/or the dispersion and/or the suspension in the two phases consists of a non-ionic surfactant formed from primary or secondary alcohols condensed with alkylene oxides. 16. Detergent mixture according to claim 2, characterized in that the liquid base or the solution and/or the dispersion and/or the suspension of the components in the two phases consists of a non-ionic surfactant, formed from alkylphenol condensed with alkylene oxides. 17. Detergent mixture according to claim 2, characterized in that the solubilizing agent in the liquid base of the solution and/or dispersion and/or suspension in the components of the two phases is propylene glycol, ethylene glycol or oligomers with 3-100 monomeric units, preferably 5-20 monomeric units. 18. Detergent according to claim 2, characterized in that the solvent is an anol. 19. Detergent according to claim 2, characterized in that the solvent is dimethyl sulfoxide. 20. Detergent according to claim 15, characterized in that the alcohol which constitutes the non-ionic surface-active agent has a carbon content in the range C2-C0_, and preferably C0-C10. o ZZo laughed 21. Detergent according to claims 15 and 16, characterized in that the primary and/or secondary alcohol and the alkylphenols are condensed with 3-25 ethylene oxide units, and preferably 5-15 units. 22. Detergent according to claims 15 and 16, characterized in that the primary and/or secondary alcohol and the alkylphenols are condensed with 2-10 propylene oxide units, and preferably 3-6 units. 23. Detergent according to claims 15 and 16, characterized in that the primary and/or secondary alcohol and the alkylphenols are condensed with 3-25 units of ethylene oxide with the simultaneous presence of propylene oxide in an amount of preferably 5-15 units. 24. Detergent mixture according to claims 15 and 16, characterized in that the primary and/or secondary alcohol and the alkylphenols are condensed with ethylene oxide and/or propylene oxide and are optionally esterified on the terminal hydroxyl groups with organic acids containing 1-3 carbon atoms. 25. Detergent according to claim 3, characterized in that the oxidizing agent used as stain remover is sodium perborate monohydrate. 26. Detergent mixture according to claim 4, characterized in that the bleach activator used is tetraacetyldiamine. 27. Detergent according to claim 4, characterized in that the bleaching activator used is pentaacetylglucose. 28. Detergent mixture according to claim 9, characterized in that the builder used is Az eoli 11. 29. Detergent according to claim 9, characterized in that the builder used is potassium or sodium polyphosphate or pyrophosphate. 30. Detergent according to claim 29, characterized in that the polyphosphate is sodium or potassium tripolyphosphate. 31. Detergent according to claim 9, characterized in that the builder is NTA sodium salt. 32. Detergent according to claim 9, characterized in that the builder is sodium citrate. 33. Detergent according to the preceding claims, characterized in that the anti-precipitating agent is sodium polyacrylate. 34. Detergent according to the preceding claims, characterized in that the anti-deposition agent is maleic anhydride copolymer with methyl vinylene. 35. Detergent according to the preceding claims, characterized in that the anti-deposition agent is maleic anhydride copolymer with acrylic acid. 36. Detergent according to claim 5, characterized in that the enzymes are re-mixed with detergent mixture after painting in the form of a solution or a fine particle slurry in a non-ionic surfactant or an inert polar solvent. 37. Detergent according to claim 36, characterized in that the enzymes are proto-lytic enzymes of the type maxatase, mexacal, savinase, espernase, alkalase, cellulase "SP 227", termanyl L type A. 38. Detergent according to the preceding claims, characterized in that the two phases contain anionic and/or cationic surfactants. 39. Use of the detergent according to claims 1-38 in that the two phases that make up the detergent are mixed in a fixed ratio in the range 1:4 and 4:1, and preferably in the range 1:1.5 and 1.5:1. 40. Use of the detergent according to claims 1-38 by mixing the two phases that make up the detergent takes place when the detergent is introduced into the washing machine or immediately before.