GB2229742A

GB2229742A - Liquid detergent composition

Info

Publication number: GB2229742A
Application number: GB9001723A
Authority: GB
Inventors: Massimo Quintini
Original assignee: Sigma Prodotti Chimici SRL
Current assignee: Sigma Prodotti Chimici SRL
Priority date: 1989-01-26
Filing date: 1990-01-25
Publication date: 1990-10-03
Anticipated expiration: 2010-01-25
Also published as: FR2642084B1; FR2642084A1; GB2229742B; GB9001723D0; IT8919200A0; IT1229508B

Abstract

A liquid detergent composition, for hand- and machine-washing, contains from 0.01% to 2% by weight of a fluorescent whitening agent, of general formula: <IMAGE> wherein R and R1 each represent a -C2H5 or -CH3 group, and X represents sodium, potassium, or ammonium cations, an amine or an alkanolamine, and is substantially lacking in conventional builders. The composition also comprises up to 70% by weight of a mixture of ionic and nonionic surfactants, as well as conventional adjuvants. The ionic surfactant can comprises up to a maximum of 3%, of cationic surfactants. The composition provides a uniform and brilliant whiteness in fabrics washed with the composition.

Description

LIQUID DETERGENT COMPOSITION The present invention relates to liquid detergent composition for hand- and machine-washing, containing fluorescent whitening agents. !!ore parsicularqy, the invention concerns isctrcpic and stable liquid detergents, substantially lacking in conventional builders - and especially inorganic phosphorus-based builders - containing fluorescent whitening agents, particularly efficient tor obtaining excellent whitening effects in the washing of fabrics basea on cellulose fibres witnout the forming of bleaching blotches.

The use of fluorescent whitening agents in detergents is well known in practice (see.. for example. the zirk-Othmer Encyclopedia of Chemical Technology - Vol. 4, page 222). By the term fluorescent whitening agents - hereinafter briefly referred to by the acronym FWA - are here meant substances mixed with hand- and machine-washing detergents.both in liquid and in powder form. which act by absorbing ultraviolet radiation and re-emitting it with longer wave lengths. corresponding to olue radiation in the visible field.This phenomenon eliminates or reauces any undesirable yellowish shadings in white fabrics and Jives a shiny effect both to white fabrics and to coiourea fabrics.

The use of suc FWA has also some inconveniences. Among them. ne following should be noted in particular: - the forming of bleaching blotcnes in washed fabrics. due to the uneven spreading of the FWA onto the fabric itself during washing; and - the progressive strengthening of persistent colour shavings on the fabrics, after repearz washings, due to an accumulation of FItA on the fabric itself.

The above inconveniences show up more seriously when using detergents lacking in conventional builders, such as polyphosphates, and to a greater extent with liquid detergents rather than with the ones in powder form.

By the term "builder" - as commonly used in this field - is meant a series of substances added to the soap, or to the surfactants, to facilitate their detergent action. They contribute to this action in several ways, and particularly: 1) by supplying the alkalinity necessary to the washing bath; 2) by removing the bivalent ions, which are harmful both to the washing process and to the sheen imparted by the FWA3 and 3) by keeping in suspension the dirt removed from the fibres, thus preventing it from depositing again and forming blotches; (see, in this respect, the already cited Kirk-Othmer Encyclopedia viol.

7, page 837 and following, and Vol. 22, page 396 and following).

In most recent years, the use of conventional builders basea on inorganic phosphates and polyphosphates has undergone drastic limitations, due to the known consequences of such compounds on aquatic flora (eulrophycation). As a result of such limitations, they have been replaced by non-conventional builders such as, for example, polyacrylic acids, organic sequestering and chelating agents as EDTA, NTA, EDTMPA (ethylenediaminetetramethylene phosphonic acid), and DTMPA (diethylenetriaminepentamethylene phosphoric acid) acids.Nevertheless, such nonconventional builders do not have the same positive effect which conventional builders have an the homogeneous distribution of the FWA on fabrics; with this type of detergent it is therefore hardly possible to avoid the forming of bleaching blotches on the washed articles.

For these reasons, a high demand has developed in this sector to single out the FWA which could be used in detergent compositions lacking in conventional builders, without the aforespecified incanveniences taking place. The problem of finding such an FWA suited for use in deter- gent comçcsitions lacking in conventional builders has however not been solved up to date, particularly in respect of liquid detergent ccmpositions.

The basic products used in preparing these compositions must in fact be easily soluble or suspensible into aqueous mixtures, so as to avoid any undesirable separations of components during storage of the finished product3 this requirementseverely limits the number of components which can be used as FWA for the intended purposes and thus complicates even further the task of the researcher.

The known chemical compounds, most widely used in practice as FWA to increase the whiteness and sheen of cellulose fabrics subjected to washing, are substantially the salts, and particularly the sodium salts, of the following acids (next to the name of each acid is stated . the respective code number used by the Chemical Abstract Societv = CAS to classify the relevant sodium salt): biphenyl-4,4' bis( styryl-2-sulphonic) acid (CAS N 27344-41-8) (I) 4,4 bis{[4-anilino-6-(N-methyl-N-2-hydroxyethyl)amino-1,3,5 -triazin(2)ylj anino2-stilbene-2,2' disulphonic acid (CAS N 13863-31-5) (II) 4,4' bis[(4-anilino-6-morpholino-1.3.5-triazin(2)yl)amino] -stilbene-2,2' disuiphonic acid (CAS N 16090-02-1) (III) 4,4' bis[(4,6-di-anilino-1,3,5-triazin(2)yl)amino] -stilbene-2,2' disulphonic acid (CAS N 133-66-4) (IV) 4,4' bis[(4-anilino-6-morpholino-1,3,5-triazin(2)yl)amino] -stilbene-2-sulphonic acid (CAS N 102269-58-9) (V) 4-(2H-naphtha01,2-djtriazol-2-yl)-stilbene-2-sulphonic acid (CAS N 6416-68-8) (VI) The salts of acids (I), (II) and (III) are perfectly water soluble, as opposed to the salts of acids (IV), (V) and (VI), which are very scarcely water soluble. These latter correspond to some of the KWA described in the prior art documents cited hereinafter. All of the abclE mentioned compounds in any case provide drawbacks when used in liquid detergent copositions.In particular: - the salts of acid (I) are not apt to confer a sufficiently high whiteness at medium-high temperatures and, furthermore, their cost is too high owing to their chemical structure; - the salts of acid (II) tend to accumulate on fabrics giving rise, after repeated washing, to a persistent shading of a greenish colour; - the salts of acid (III), which are the ones which are airily used in the industrial field, show a tendency to convert to an amorpnous yellow form, causing undesirable colour tones in liquid detergent compositions; and - finally, the salts of acids (IV), (V) and (VI) in no case succeed in conierring on the washed fabrics a sufficiently bright and shiny whiteness.

In known liquid detergent compositions, the aforementioned drawbacks have been eliminated at first,asmentioned abcve,by using conventional builders (see, for example. GB-A-2 028 365, which makes use of organic phosphates). More recently, liquid detergent compositions without conventional builders have instead been proposed (see. or example, Ep-A-167 205 and EP-A-237 119), said compositions containing FWA the characteristics. of which have been selected so as to: - be scarcely water soluble: - have scarce affinity towards cellulose fibres: and - be highly hydrophobic, whereby to hamper the fixing action of FWA to the fabric and thus improve its uniformity of distribution.

The FWA used for this purpose are the acid salts (IV), V) and (VI), nevertheless, the results obtained with the detergent compositions described in EP-A-167 205 and in EP-A-237 119 are very unsatisfactory. In fact, though on one hand it has been possible to avoid the inconvenience of the forming of bleaching blotches, on the other hand the whiteness obtained - owing to the intrinsic characteristics of the FWA employed is very poor, and in any case quite unsatisfactory as compared to the results which can be obtained with liquid detergents containing conventional builders, and with powder detergents.

The object of the present invention is to supply a liquid detergent composition containing a fluorescent whitening agent, but lacking or substantially lacking in conventional builders, which is free from the above mentioned inconveniences of known liquid detergent compositions of this type.

Said object has been met by the Applicant on the basis of a discovery made while carrying out tests, said discovery forming the basis of the present invention. The Applicant has in fact discovered - quite surprisingly, considering the teachings of the prior art that fluorescent whitening agents of general formula:

wherein R and R1 each represent a -çH; or -H group, and X represents sodium, potassium, or ammonium cations. an amne or an alkanolamine: and, in particular. the water soluble salts of the following acids: 4,4' bis[(4-anilino-6-ethylamino-1,3,5-triazin(2)yl)amino] -stilbene-2,2' disuiphonic acid (CAS NO of the acid sodium salt 24565-13-7) (VII) 4, 4' bis 24-anilino-6-methylamino-1,3,;-triazin(2)yl)amino3 -stilbene-2, 2' disulphonic acid (CAS N of the acid :35632-99-6) (VIII) already known for a long time and 9:ppertnted with little success in the field of powder detergent compositions, turn out instead to be particularly efficient when used in liquid detergent compositions - both of the limpid and transparent type and of the non-transparent type - due to the presence of evenly dispersed bodies, also if substantially lacking in conventional builders, such as phosphates and polyphosphates.

The FWA derived from the acids (VII) and (VIII) - though having physical characteristics diametrally opposed to those selected by known technique, that is, being perfectly water soluble and thus particularly hydrophilic and showing, furthermore, an excellent affinity towards cellulose fibres - when incorporated into a liquid detergent composition according to the teachings of the present invention, confer on the washed fabrics a bright whiteness, with the total absence of bleaching blotches the bleached fabric assumes, furthermore, a particularly shiny and pleasant appearance.Said unexpected result, even in the absence of the promoting action of conventional builders, is deemed to be due - though this expianation should not be considered as limiting the invention - to the self-levellingpower of the FWA of the present invention, which allows a uniform spreading thereof onto the fabric, even when the initial distribution is not homogeneous.

The object of the present invention has thus been met on the basis of the aforementioned discovery, by means of a liquid detergent composition for hand- and machine-washing, characteri:ed b being substantially lacking in conventional builders, and by comprising: a) up to 70% by weight of surfactants selected fran ionic and nonionic surfactants, and mixtures thereof b) from 0.01 to 2 by weight of a fluorescent whitening agent of general formula:

wherein R and R1 each represent a -C2H5 or -CH3 group, and X represents sodium, potassium, or ammonium cations, an amine or an alkanolamine; and c) organic and inorganic adjuvants of known type.

The invention will now be described in further detail with reze- rence to some examples of detergent compositions containing the FWA of the present invention, and to some comparison examples of detergent compositions containing the FWA in accord with known technique.

In the following examples, the sodium salts of the acids (VII) and (VIII) are compared to those of the acids (I), (II), (III), tIV), using weight ratios between those of the various products found on the market, which approximately correspond to the ratios of the specific extinctions measured at the wave length of 349 nm, corresponding to the highest absorption in the ultraviolet field, according to the following Table: Compounds E1 1 502 II 520 III 1024 IV 361 v 441 VI 513 Example 1 To a liquid detergent composition having the following composition: water 44.7 g dodecylbenzene sulphonic acid 4.0 g sodium lauryl ether sulphate 4.0 g triethanolamine lauryl sulphate 4.0 g ethoxylated C10-C12 natural alcohol (9 moles ETO) 20.0 g polyglycol (PM 400) 20.0 g triethanolamine 2.3 g was added the sodium salt of the acid (VII) in a weight ratio of o.iS.

The mixturewas stirred until the FWA had totally dissolved. A S gil concentration washing bath was then prepared with the mixture thus obtained.

Pieces of dirty cotton fabric EMPA/302, having dimensions of lOx10 c.=.were subjected to ten washing cycles repeated in succession, in a Linitest apparatus, in a 1/10 weight ratio in respect of the described washing bath, at temperatures of 300 and 600C.

The whiteness of the fabrics, after 2, 5 and 10 washing cycles.was checked by means of an Elrepho Zeiss reflection spectrophotometer and the respective worth (W) expressed according to the Berger formula for the degree of whiteness.

The results of these tests and of those of the following Examples 2 and 3, as well as of the tests of comparative Examples A, 3, ç and D. are shown in Table 1.

The cotton pieces were moreover subjected, after washing, to a visual examination under ultraviolet light, so as to check the uniformity of the bleacn.

The results of this check are also shown in Table 1.

Example 2 To the detergent composition of Example 1 was added 0.9% of a 20% solution of the sodium salt of the acid (VII) in diethylene glycol.

The mixture thus obtained was then used in washing cycles as described in Example 1 according to the modes, weight ratios and concentrations indicated in Example 1.

Example 3 To the detergent camposition of Example 1 there was added 0.18% of the sodium salt of the acid (VIII).

Comrarative Example A To the detergent composition of Example 1 there was added 0.10% of the sodium salt of the acid (I).

Comparative ExamleB To the detergent composition of Example 1 there was added 0.25% of the sodium salt of the acid (II).

Comparative Example C To the detergent composition of Example 1 there was added 0.20% of the sodium salt of the acid (III).

Comrarative Example D To the detergent composition of Example 1 there was added 0.175% of the sodium salt of the acid (IV).

TABLE 1

EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash.

W(30 C) 159,0 170,5 178,8 159,2 170,1 179 158,8 170,0 178,5 W(60 C) 161,0 171,7 180,3 161,7 172,2 180,1 160,5 170,8 179,3 Visual Uniform, bluish Uniform, bluish Uniform, bluish test A B C D 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash W(30 C) 156,1 162,1 171,4 159,1 169,7 178,3 157,8 169,3 178 148,2 153,4 165,1 W(60 C) 156,3 163,2 168,0 160,0 170,3 179,2 159,8 171,7 180,1 151,2 157,4 169,0 Visual Uniform, pinkish Blotted, greenish Blotted, bluish Uniform, neutral test Example 4 To a liquid detergent composition having the following composition: water 38.3 g todecylbenwene sulphonic acid 3.0 g sodium lauryl ether sulphate j.o g triethanolamine lauryl sulphate 3.0 e ethoxylated C10C12 synthetic alcohol (9 moles ETO) 20.0 g sodium soap 10.0 g triethanolamine 1., g therewas added the sodium salt of the acid (VII) in a weight ratio of 0.18%.

The mixturewas stirred until the FWAhad completely dissolved. A 5 g/l concentration washing bath was then prepared with the mixture thus obtained.

Pieces of dirty cotton fabric EMPA/302, having dimensions of 10x10 cm,were subjected to ten washing cycles repeated in succession. in a Linitest apparatus, in a 1/10 weight ratio in respect of the described washing bath, at the temperatures of 300 and 600C.

The whiteness of the fabrics, after 2, 5 and 10 washing cncies.was checked by means of an Elrepho Zeiss reflection spectropnotometer and the respective worth (W) expressed according to the Berger formula for the degree of whiteness.

The results of these tests and of those of the following Dxampies 5 and 6, as well as of the tests to comparative Examples E? F, G and H, are shown in Table 2.

The cotton pieces z s were additionally subjected, after washing, to a visual exmination under ultraviolet light, so as to check the uniformity of the bleach.

The results of this check are also shown in Table 2.

Example 5 To the detergent composition of Example 4 there was added 0.9% of a 20% solution of the sodium salt of the acid (VII) in diethylene glycol.

The mixture thus obtained was then used in washing cycles as described in Example 4 according to the modes, weight ratios and concentrations indicated in Example 4.

Example 6 To the detergent composition of Example 4 there was added 0.18% of the sodium salt of the acid (VIII).

Comnarative Example E To the detergent composition of Example 4 there was added 0.108 of the sodium salt of the acid (I).

Comcarative Example F To the detergent composition of Example 4 there was added 0.25% of the sodium salt of the acid (II).

ComDarative Example G To the detergent composition of Example 4 there was added 0.20% of the sodium salt of the acid (III).

Comparative Example H To the detergent composition of Example 4 there was added 0.1758 of the sodium salt of the acid (IV).

The mixture thus obtained was then used in washing cycles as described in Example 4 according to the modes, weight ratios and concentrations indicated in Example 4. TABLE 2

EXAMPLE 4 EXAMPLE 5 EXAMPLE 6 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash.

W(30 C) 157,8 169,5 178,0 157,9 169,7 178,2 157,5 169,3 177,0 W(60 C) 160,1 171,3 179,9 160,0 171,4 179,5 159,3 169,2 178,1 Visual Uniform, bluish Uniform, bluish Uniform, bluish test E F . G H 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash. 2 wash. 5 wash. 10 wash.

W(30 C) 154,8 160,2 170,5 157,6 168,1 176,0 156,5 167,1 176,4 145,1 149,7 162,8 W(60 C) 155,2 161,3 171,7 158,5 170,5 178,8 158,3 169,6 179,1 148,5 152,2 165,3 Visual Uniform, pinkish Blotted, greenish Blotted, bluish Uniform, neutral test From the previous description, and from the results of the examples reported thereabove, it can be clearly appreciated how the liquid detergent compositions of the present invention have fully reached the intended purpose, allowing a whiteness of washed pieces of fabric to be achieved which is particularly satisfactory and totally fret from bleaching blotches.

Said positive result has been reached due to the use. in said detergent compositions. of the FWA comprising the water-soluble salts of the general formula described heretofore. Said FWA provide in fact. when incorporated into liquid detergent compositions even substantially lacking in conventional builders, the following advantages relative to the known type FWA: : a) they have been disccvered to be fully compatible therewith, without giving rise to any separation of phase, or precipitation; b) they spread evenly onto the fabric, producing a whiteness of high intensity and having a pleasant and shiny effect; c) hey do not accumulate on fabrics, and so do not cause a reenisn snaring in said fabrics after repeated washing; and d) they can easily be incorporated into detergent formulations. as they are easily soluble in most solvents introduced into formulations such as, for example, ethylene glycol, diethylene glycol, propylene glycol, the monoesters thereof with the lower alcohols. liquid polyglycols with low molecular weight. or mixtures thereof.

Claims

1. A liquid detergent composition, for hand- and machine-washing, sub stantially lacking in conventional builders, and comprising: a) tp to 70% by weight of surfactants selected fran icnic and nonionic surfactants, and ndxtures thereof; b) fran 0.01% to 2% by weight of a fluorescent whitening agent, of the general formula:

wherein R and R1 each represent a -C2H5 or -CH3 group, and X represents sodium, potassium, or ammonium cations, an amine or an alkanolamine; and c) organic and incrganic adjuvants of known type

2. A liquid detergent composition as claimed in claim 1, wherein R and R1 both represent the -C2H5 group, and X represents the sodium cation.

3. A liquid detergent ocpoositicn as claimed in claim 1 or claim 2, wherein said surfactants comprise up to 3% of cationic surfactants.

4. A liquid detergent composition as claimed in claim 1 substantially as described in any one of Examples 1 to 6.