Europâisches Patentamt ê 0 021 752 (D European Patent Office (3) Publication number: B1 Office européen des brevets EUROPEAN PATENT SPECIFICATION (45) Date of publication of patent spécification: 30.05.84 © Intel.3: C 11 D 3/42, C 11 D 1/835, C 11 D 1/62, D 06 M 13/46 (§) Application number: 80302003.1 (2?) Dateoffiling: 13.06.80 (54) Liquid détergent softening and brightening composition. (§) Priority: 14.06.79 US 48411 @ Proprietor: S.C. JOHNSON & SON, INC. 1525 Howe Street Racine, Wisconsin 53403 (US) © Date of publication of application: 07.01.81 Bulletin 81/01 Inventor: Sramek, John A. 3444 Illinois Avenue Publication of the grant of the patent: Racine Wisconsin 53405 (US) 30.05.84 Bulletin 84/22 @ Représentative: Saillie, lain Cameron et al Designated Contracting States: c/o Ladas & Parry Isartorplatz 5 AT BE CH DE FR GB IT LI LU NL SE D-8000 Mùnchen 2 (DE) Références cited: EP-A-0 006 271 FR-A-2295122 US-A-3 954 675 US-A-3 959 157 flû CM lO CM O o Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall Q. be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been LU paid. (Art. 99(1) European patent convention). Courier Press, Leamington Spa, England. This invention relates to an improved liquid detergent having added softener and brightener for use in laundering fabrics. In particular, it relates to a storage stable, single-phase laundry detergent- softener-brightener composition free from phosphates and possessing enhanced softening and brightening properties. In the recent past, laundry was washed by simply placing it in a machine filled with detergent, running the machine through a wash cycle and then through a rinse cycle. Later, cationic fabric softeners were added to the rinse cycle to improve the feel of the laundry and reduce the static charges built up on fabrics during drying. These cationic fabric softeners were not blended with liquid detergents, since they became unstable in the presence of the detergents and tended to form distinct phases during storage. The softeners were not successfully employed in the wash cycle, since they tended to deposit on the clothing as a yellow film. This film also tended to coat fabrics with a water-repellent finish after repeated use. In fabrics, particularly those which needed to breathe or absorb water, this was a serious defect. Fine fabrics were recognized to be particularly susceptible to yellowing, clinging and filming from detergent washing with softening treatment. In an attempt to correct these defects, anionic detergents and phosphate builders were added to detergents to complex the softeners and prevent their yellowing and filming of fabrics. However, these attempts proved unsuccessful, since the softening effect of the fabric softeners, notably the quaternary ammonium salts or "quats", was seriously reduced. In addition, it has been recognized, recently, that phosphates can adversely effect the ecology. Consequently, there has been much clamor for deter- gents, which are free from phosphates. Modern fabrics, including nylons, polyesters, cotton and blends thereof and particularly fine fabrics, are expected to be bright in appearance after washing. Commonly used detergent fluorescent brighteners, such as DASC brighteners (DASC-ASTM designation - those derived from diamino- stilbene disulfonic acid-cyanuric chloride) have two sulfonic acid groups per molecule. These brighteners have been suggested for use with detergents and softeners. However the disulfonate brighteners tend to form unstable opaque products with very poor brightening properties, when combined with laundry detergents and cationic softeners. Monosulfonate, NTS-type stilbenesulfonic acid brighteners have been proposed, but provide very poor brightening when employed with deter- gents and softeners. Diaminostilbene hexa-sulfonate brighteners are used in coatings in the paper industry, but are not recommended for use as brighteners with standard detergents owing to their high level of water solubility. Such hexa-sulfonate brighteners simply do not whiten laundry well, when employed with laundry detergents. Examples of prior art detergent formulations include those disclosed in British Patent 941,993 which utilize detergents and DASC brighteners, but no fabric softeners. These compositions are merely powder mixtures, not liquid compositions. In U.S. Patent 3,625,891, a blend of three different quaternary ammonium ("quats") fabric softeners were employed to overcome detergent compatibility problems. The softener and detergent were added separately to the wash. In U.S. Patent 3,644,203, a minor amount of anionic surfactant was employed with a cationic fabric softener together with a nonionic surfactant and a conventional phosphate builder, forming a multifunctional detergent, in which the anionic surfactant served to neutralize the cationic softener. Optical brighteners were optionally disclosed, but not those employed in this invention. A non- phosphate softener-detergent composition is set forth in U.S. Patent 3,959,157. A DASC brightener is employed having only two sulfonate groups. To stabilize the "quat" softeners, up to 20% of an alcohol is disclosed to be necessary. This adds to the expense of the composition. Further, the level of "quat" softeners employed in the patent is from 3% to 1 5% by weight of the composition. It is most desirable to reduce this level, while maintaining softening properties, to reduce the costs of the product to the consumer and reduce yellowing and filming tendencies. Therefore, the present invention provides a storage stable, liquid detergent composition having softening and brightening properties which permits a single-step laundering, softening and brightening treatment; provides a stable, single phase liquid laundering composition providing balanced cleansing, softening and brightening with a capacity to resist static cling, filming and yellowing of fabrics; provides an economical, clear detergent composi- tion for fine fabrics with balanced softening and brightening; and provides an easily pourable, storage stable, phosphate-free, detergent-softener aqueous composition which will not impart a water-repel- lent finish to fabrics. Accordingly the present invention provides an aqueous, stable, liquid aqueous detergent composition having enhanced softening and brightening properties, including a surfactant, a quaternary ammonium softener and a sulfonated diaminostilbene brightener, characterized in that it comprises, based on the total weight of the composition, (a) from 10 to 50% by weight of a water soluble non-ionic surfactant system; (b) from 0.75 to 6% by weight of at least one quaternary ammonium fabric softener having an equivalent weight from 400 to 2000 of the formula: wherein Z is a water soluble, salt-forming anion, R1 is a C10-C20 alkyl radical, R2 is R' or a C10-C20 alkyl radical, X and Y are the same or different and are methyl, ethyl, 2-hydroxyethyl, 2-hydroxy propyl, (R")-CH2-CH2-O-H or wherein R" is a group or a polymer radical having from 1 to 10 ethoxy, isoproxy or mixed ethoxy-iso- propoxy units, and R' is an ethoxy- or a polyethoxy-ethanol group having from 1 to 10 ethoxy units only when: i) X and Y are both methyl, or (ii) X is methyl and Y is an ethoxy- or a polyethoxy-ethanol group having from 1 to 10 ethoxy units, iii) X is ethyl and Y is an ethoxy- or a polyethoxy-ethanol group having from 1 to 10 ethoxy units; c) from 0.15 to 6% by weight of an optical brightener of the formula: wherein A and A are the same or different and are hydrogen, methyl, ethyl, isopropyl, 2-hydroxyethyl, propanamido or taken together are morpholino or anilino; B is H, m-S03H or p-S03H wherein the total number of -S03H groups is from 3 to 5, and the water soluble salts thereof; (d) a hydrotrope in a ratio of at least one equivalent hydrotrope per equivalent weight of softener employed; (e) an aqueous solvent medium. When the term "brightening" is employed herein it is meant to include both the whitening of fabrics and the optical brightening of fabrics as these conventional terms are understood by those skilled in the art. As employed herein the term "nonionic surfactant system" includes a single nonionic surfactant or detergent or a blend of nonionic surfactants (or detergents). For the purpose of this invention the term "hydrotrope" is employed in its art-recognized context and includes a substance which increases the solubility of a compound in aqueous solution. An important feature of the invention is the use of a specified quaternary ammonium compound having an equivalent weight between 400 and 2000 in combination with the diamino distilbene optical brighteners having 3 to 5, and particularly 4, sulfonate groups. From this, it has been found that both brightening and, unexpectedly, softening are enhanced. It has been postulated that the cationic quaternary ammonium compound and anionic optical brightener interact to form a complex based on charge attraction and neutralization. It is postulated that when the brightener, according to the present invention, provides sufficient negative charges attributable to sulfonates and the quaternary softener according to the present invention provides suffi- cient positive charge attributable to ionized nitrogen to create a charge complex, then enhanced brightening and softening are obtained. This effect is unexpected, since one skilled in this art would expect softening to be reduced as the amount of quaternary softener in the formulation is reduced. The nonionic surfactant system includes commercially known compounds. These include the water-soluble products which are derived from the condensation of an alkylene oxide or equivalent reactant and a reactive-hydrogen hydrophobe. The hydrophobic organic compounds may be aliphatic, aromatic or heterocyclic, although the first two classes are preferred.