Laundry additive products

Abstract

 A laundry additive product comprising a solid laundry additive composition containing discrete agglomerated particles of storage sensitive detergency additive water-releasably glued to a unitary, water-insoluble carrier. Preferred storage-sensitive additive are organic peracid bleaches and detergency enzymes. The compositions have improved storage-stability, dust control, reproducibility and convenience of use.

Description

[0001] This invention relates to laundry additive products. In particular, it relates to laundry additive products for cleaning clothes and the like in domestic and commercial washing machines, the additive product containing a storage-sensitive detergency additive material.

[0002] It is widely recognized that the function of a detergency additive material can be significantly impaired in detergent and other laundry compositions by interaction between the additive material and other components of the composition or even with air. For example, detergency enzymes can be deleteriously effected by interaction with bleaches, sequestrants, acids and bases, surfactants and air; perfumes and bleach activators can be deleteriously effected by interaction with bleaches; cationic fabric conditioners can be deleteriously effected by interaction with anionic surfactants; organic bleaches can be deleteriously effected by interaction with moisture, metal contamination, alkalinity etc; fluorescers can be deleteriously effected by interaction with bleaches, cationic surfactants and (in the case of cationic fluorescers) anionic surfactants; and suds-suppressors can also be deleteriously effected by interaction with surfactants. Moreover, the consumer acceptibility of a product can also be significantly reduced as the result of physical interactions between a laundry additive material and other components of a composition. For instance, a speckled detergent containing a water-soluble dye can lose its aesthetic appeal as a result of migration of the dye into the detergent base formula, an effect which can be significantly enhanced by the presence in the detergent composition of a nonionic surfactant component.

[0003] One approach adopted in the art for minimizing storage-stability problems for sensitive ingredients is to agglomerate the sensitive ingredient, for example by extrusion, wet agglomeration, etc and to add the resulting agglomerate to a detergent base powder. British Patents 1,204,123, 1,441,416 and 1,395,006 are representative of this general approach. The technique suffers a number of disadvantages, however. For example, physical segregation problems caused by differences in particle size and/or bulk density between the agglomerate and the base powder can contribute to reduced aesthetic appeal and reproducibility of performance. More importantly, the agglomerates are prone to interparticle abrasion which can lead to partial or even total disintegration of the agglomerates with concomitant problems of reduced storage stability and increased dust formation.

[0004] The Applicants have now discovered that laundry additive materials having improved storage-stability can be provided by affixing particles of the additive material to a water-insoluble, unitary carrier. The resulting laundry additive products have improved storage-stability, convenience and reproducibility in use and reduced problems of dust formation.

[0005] Accordingly, the present invention provides a laundry additive product comprising

(a) a solid laundry additive composition comprising discrete agglomerated particles of storage-sensitive detergency additive water-releasably glued to the surface of

(b) a unitary water-insoluble carrier.

[0006] The storage-sensitive detergent additive is suitably selected from detergency enzymes, bleaches, bleach activators and bleach catalysts, photoactivators, dyes, fluorescers, suds suppressors, perfumes, fabric conditioning agents, and hydrolysable surfactants. Highly preferred are detergency enzymes, especially proteases, amylases and mixtures thereof, and organic bleaches and bleach activators. The laundry additive product will also usually incorporate separately an antagonist material responsible for the deleterious effect on storage stability of the additive; alternatively, the additive material will be sensitive to

[0007] storage in the presence of some environmental factor such as air, moisture, or sunlight. Preferred laundry additive materials and their specific antagonists are listed below:

[0008] The particulate component of the additive product preferably comprises the detergency additive material together with an agglomerating agent. In addition, the agglomerate can contain a solid diluent. The detergency additive and diluent are both preferably particulate in form with a particle size of less than about 250 microns, more preferably less than 150 microns, especially less than 100 microns. A small particle size contributes to improved water release and solubility of the additive material. The physical integrity of the agglomerate should be such, however, to prevent disintegration during glueing to the water-insoluble substrate.

[0009] The average particle size of the agglomerate after glueing to the substrate is preferably at least about 100 microns, more preferably from about 150 microns to about 2000 microns. The agglomerating agent can take the form of a carrier in which the detergency additive and, if present, diluent are dispersed, or the agglomerating agent can simply act to promote physical adhesion of the component particles of the agglomerate. Alternatively the agglomerating agent can function as an encapsulating or coating agent for the detergency additive. Preferred carriers are water-soluble or water-dispersible organic materials having a melting onset temperature of at least 35 C, more preferably at least about 45⁰C, especially at least about 50°C and a melting completion temperature of at least about 40°C, more preferably at least about 45⁰C, especially at least 55^oC, and of less than about 100°C, more preferably less than about 85⁰C, especially less than about 75⁰C. Suitable organic carriers are selected from polyethylene glycols of molecular weight greater than about 1000, C12-C24 fatty acids and esters and amides thereof, polyvinyl pyrrolidone of molecular weight in the range from about 40,000 to about 700,000, and C₁₄-C₂₄ fatty alcohols ethoxylated with from about 14 to about 100 moles of ethylene oxide. Preferred diluents herein are water-soluble salts and include alkali metal, alkaline earth metal and ammonium sulphates, chlorides, and aromatic carboxylates, neutral and acid alkali metal carbonates, orthophosphates and pyrophosphates, and alkali metal crystalline and glassy polyphosphates. Suitable water-insoluble but dispersible diluents include the finely-divided natural and synthetic silicas and silicates, especially smectite-type and kaolinite-type clays such as sodium and calcium montomorillonite, kaolinite itself, aluminosilicates, and magnesium silicates and fibrous and microcrystalline celluloses. Suitable adhesive materials include the organic carrier materials described above, water, aqueous solutions or dispersions of the inorganic diluent materials described above, polymer solutions and latexes such as aqueous solutions of sodium carboxymethylcellulose, methylcellulose, polyvinylacetate, polyvinylalcohol, dextrins, ethylene vinylacetate copolymers and acrylic latexes. In the case of hydrolysable and moisture sensitive additives such as enzymes, however, the final moisture content of the agglomerate should be no more than about 3%.

[0010] The agglomerates herein are water-releasably glued to the surface of the water-insoluble carrier, preferably using a polymeric adhesive. It will be understood that both the substrate and the individual agglomerates carry a surface coating of adhesive which acts directly as the glue bond between agglomerate and substrate. Preferably, however, the agglomerates carry only a partial coating of adhesive, the adhesive being limited to a glue bond region intermediate agglomerate and substrate, the outer surface of the agglomerate distal from the glue bond region being free of adhesive coating.

[0011] The substrate/agglomerate adhesive herein is suitably a hot-melt adhesive, a solvent-releasing adhesive, a pressure-sensitive adhesive or a reactive adhesive. Hot-melt adhesives and water-based polymeric solutions and latexes are preferred. Particularly suitable adhesives are polymer-based glues, especially thermoplastic polymers, which are soluble or dispersible in water, particularly those based on sodium carboxymethylcellulose, methyl cellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinylacetate, polyvinylalcohol, dextrins, starches ethylenevinyl copolymers, styrene-butadiene and acrylic copolymers. The invention is not limited to water-dispersible polymers, however, water-insoluble heat-setting resins being equally suitable providing the adhesive is limited to the intermediate glue bond region as described above.

[0012] The polymeric adhesive can be applied to the substrate using conventional roller, knife, flow or curtain coating technology or by a hot or cold spray system and the agglomerates, where stability and water-release considerations allow, can be incorporated directly in the adhesive or can be applied using a separate coating or spraying step, preferably after application of the adhesive and prior to setting thereof.

[0013] In a highly preferred embodiment, the additive composition comprises agglomerates glued to a flexible, sheet-like substrate at a weight ratio of composition: substrate (ie loading ratio) of at least about 1:1, more preferably at least 3:1, especially at least about 5:1. Alternatively, the substrate can take the form of a laminate or pouch wherein the agglomerates are glued to an inner or outer surface of the laminate or pouch.

[0014] The laundry additive products of the invention can also comprise additional, non-agglomerated ingredients, these preferably being carried by the substrate in the form of an organic matrix having a softening temperature of at least about 35°C, more preferably at least about 40°C, especially at least about 50°C. Such organic matrices preferably comprise at least about 40%, more preferably at least about 50%, especially at least about 60% of matrix materials having a melting completion temperature of less than 85⁰C. The organic matrix can further act as a carrier for agglomerated storage sensitive ingredients over and above those agglomerated ingredients which are directly glued to the substrate as described above.

[0015] The laundry additive products of the invention suitably contain at least about 5%, preferably at least about 20% of additive composition of organic detergent selected from anionic, nonionic and cationic surfactants and mixtures thereof. Preferred nonionic surfactants have melting completion temperatures of less than about 85 C and form part of the matrix of organic materials. Preferred cationic surfactants have melting onset temperatures of at least about 35⁰C and can either form part of the matrix of organic materials or be dispersed in the organic matrix. Preferred anionic surfactants have melting completion temperatures in excess of about 100°C and are dispersed in the organic matrix. Surfactants which are sensitive to alkaline or acid hydrolysis (eg alkyl sulphates), however, can be incorporated in the organic matrix in the form of agglomerates. Of the above surfactants, highly preferred from the viewpoint of optimum detergency and agglomerate stability are anionic sulphonate and sulphate surfactants and/or water-soluble cationic surfactants and mixtures of these anionic and/or cationic surfactants with water-soluble ethoxylated nonionic surfactants.

[0016] The laundry additive products of the invention will now be discussed in detail.

[0017] A preferred class of detergency additive material is a detergency enzyme. The enzyme is preferably a hydrolysing enzyme and can be selected generally from proteases, esterases, carbohydrases, and mixtures thereof. Examples of proteases suitable for use herein are pepsin, trypsin, chymotrypsin, collagenase, keratinase, elastase, subtilisin, papain, bromelin, carboxypeptidase A and B, aminopeptidase, and aspergillopeptidase A and B. Preferred proteases are serine proteases which are active in the neutral to alkaline pH range and are produced from microorganisms such as bacteria, fungi or mould. A highly preferred protease is prepared by fermentation of a strain of Bacillus Subtilis.

[0018] Specific examples of carbohydrases are maltase, saccharase, amylases, cellulase, pectinase, lysozyme, of-glucosidase, and β-glucosidase. Preferred are α-amylases of mould, cerial or bacterial origin.

[0019] Specific examples of esterases are gastric lipase, pancreatic lipase, plantlipases, phospholipases, cholineesterases and phosphotases.

[0020] A valuable feature of the enzyme embodiments of the invention is that the laundry additive product provides, in unitary form, the entire enzyme dosage for a single laundering operation. This is highly beneficial from the view-point of enzyme handling and stability. Accordingly, the laundry additive products preferably comprise from about 0.001 to about 0.5, more preferably from about 0.003 to about O.lg of enzyme per unit of product (enzyme expressed in pure form). For protease andol-amylase specifically, the laundry additive products preferably comprise from about 0.075 to about 15, more preferably from about 0.15 to about 4.5 Anson units of protease per unit of product, and from about 2,000 to about 400,000, more preferably from about 4,000 to about 120,000 maltose units ofo(-amylase per unit of product. Protease activity is measured against Novo Alcalase protease as standard using the method of Dunn & Brotherton, Analyst, 96, 159-163 (1971). Amylase activity is measured as described in P. Bernfeld, Adv. in Enzymol., 12,379 (1959), but using starch substrate buffered to pH 6 with a sodium acetate (4.1%)/acetic acid buffer solution, a sample concentration of 0.05g/litre or a multiple dilution thereof, a digestion temperature of 37⁰C and a digestion time of 5 minutes. The amylase then has one activity unit for each 0.4mg of maltose hydrate produced during hydrolysis.

[0021] The storage-sensitive detergency additive can also be represented by bleaches, bleach activators and bleach catalysts. Suitable inorganic peroxygen bleaches include sodium perborate mono- and tetrahydrate, sodium percarbonate, sodium persilicate and urea-hydrogen peroxide addition products and the clathrate 4Na2so4:2H202:lNaCl. Suitable organic bleaches include peroxylauric acid, peroxyoctanoic acid, peroxynonanoic acid, peroxydecanoic acid, diperoxydodecanedioic acid, diperoxyazelaic acid, mono- and diperoxyphthalic acid and mono- and diperoxyisophthalic acid. Naturally, the above organic bleaches can be made in form of their salts or hydrates or in combination with suitable stabilizers, for example borax or magnesium compounds. Peroxyacid bleach precursors suitable herein are disclosed in UK-A-2040983, highly preferred being peracetic acid bleach precursors such as tetraacetylethylenediamine, tetraacetylmethylenediamine, tetraacetylhexylenediamine, sodium p-acetoxybenzene sulphonate, tetraacetylglycouril, pentaacetylglucose, octaacetyllactose, and methyl O-acetoxy benzoate. Bleach precursors can be used at a precursor: unitary carrier ratio within the range from about 30:1 to about 1:10, preferably from about 8:1 to about 1:2, while bleaches can be used at a bleach:unitary carrier ratio from about 30:1 to about 1:4, preferably from about 10:1 to about 1:1. Bleach catalyst systems suitable for use herein include chelated transition metal catalysts as described in British Patent Application 8215890.

[0022] The storage sensitive detergency additive can also be represented by sud-suppressors, especially materials of the silicone, wax, vegetable and hydrocarbon oil and phosphate ester varieties. Suitable silicone suds controlling agents include polydimethylsiloxanes having a molecular weight in the range from about 200 to about 200,000 and a kinematic viscosity in the range from about 20 to about 2,000,000 mm²/s, preferably from about 3000 to about 30,000 mm²/s, and mixtures of siloxanes and hydrophobic silanated (preferably trimethylsilanated) silica having a particle size in the range from about 10 millimicrons to about 20 millimicrons and a specific surface area above about 50 _m²/g. Suitable waxes include microcrystalline waxes having a melting point in the range from about 65⁰C to about 100° a molecular weight in the range from about 400-1000, and a penetration value of at least 6, measured at 77⁰C by ASTM-D1321, and also paraffin waxes, synthetic waxes and natural waxes. Suitable phosphate esters include mono- and/or di-C16-C22alkyl or alkenyl phosphate esters, and the corresponding mono- and/or di alkyl or alkenyl ether phosphates containing up to 6 ethoxy groups per molecule.

[0023] Other storage-sensitive detergency additives include bleach-sensitive flourescers such as Blackophor MBBH (Bayer AG) and Tinopal CBS and EMS (Ciba Geigy); nonionic surfactant-soluble dyes and photoactivators as disclosed in European Application No 82300309, highly preferred materials being zinc phthalocyanine tri- and tetrasulphonates; bleach-sensitive perfumes; anionic surfactant-sensitive fabric conditioning agents such as di-C12-C24 alkyl or alkenyl amines and ammonium salts; and hydrolysable surfactants such as the C₁₀-C₁₆ alkyl and alkyl ether sulphates.

[0024] The agglomerates of storage-sensitive detergency additive can be prepared by any appropriate agglomeration technique, for example by extrusion with a molten organic carrier or by dispersing liquid organic carrier or adhesive onto a moving bed of the storage sensitive additive, optionally in admixture with a solid diluent, in for example a pan agglomerator, Schugi mixer or fluidized bed apparatus.

[0025] In the case of a laundry additive composition comprising an organic matrix component, such a composition is in solid form at ambient temperatures (25°C and below) and preferably has a softening temperature of at least about 35⁰C, more preferably at least about 40°C, especially at least about 50°C. By softening temperature is meant the temperature at which there is transition from plastic-flow to viscous-flow properties; at ambient temperatures, therefore, the composition takes the form of a plastic solid having a non-zero yield stress. The hardness of the compositions at ambient temperatures can be determined by standard methods, for example, by the penetrometer-based technique of IP49 (or the technically equivalent ASTM-D5 or BS4691). Thus, laundry additive compositions preferred for use herein have a penetration under a 100g load at 25°C after 15 seconds under IP49 of less than about 10 (measured in tenths of a millimetre), more preferably less than about 7. The softening temperature of the composition, on the other hand, is taken herein to be the temperature at which the IP49 15 second penetration exceeds about 30.

[0026] The thermal characteristics of the matrix of organic materials can be determined as follows. Melting completion temperatures are determined using a Dupont 910 Differential Scanning Calorimeter with Mechanical Cooling Accessory and R90 Thermal Analyser as follows. A 5-10 mg sample of the organic material containing no free water or solvent is encapsulated in a hermetically sealed pan with an empty pan as reference. The sample is initially heated until molten and then rapidly cooled (at about 20-30°C/min) to -7₀°_C.

[0027] Thermal analysis is then carried out a a heating rate of 10 C/minousing sufficient amplification ofΔT signal (ie temperature difference between sample and reference - vertical axis) to obtain an endotherm-peak signal:baseline noise ratio of better than 10:1. The melting completion temperature is then the temperature corresponding to the intersection of the tangential line at the steepest part of the endotherm curve at the high temperature end of the endotherm, with the horizontal line, parallel to the sample temperature axis, through the highest temperature endotherm peak. The melting onset temperature can once again be determined by thermal analysis as described above and is taken to be the sample temperature at the point of intersection of the base line with a tangent to the steepest part of the endotherm nearest the low temperature end of the endotherm.

[0028] In a highly preferred embodiment, the additive composition comprises agglomerates glued to a flexible sheet-like substrate at a weight ratio of composition: substrate of at least about 1:1, preferably at least about 3:1. Preferred substrates for use herein are apertured nonwoven fabrics which can generally be defined as adhesively bonded fibrous or filamentous products, having a web or carded fibre structure (where the fibre strength is suitable to allow carding) or comprising fibrous mats, in which the fibres or filaments are distributed haphazardly or in random array (i.e. an array of fibres in a carded web wherein partial orientation of the fibres is frequently present as well as a completely haphazard distributional orientation) or substantially aligned. The fibres or filaments can be natural (e.g. wool, silk, wood pulp, jute, hemp, cotton, linen, sisal, or ramie), synthetic (e.g. rayon, cellulose, ester, polyvinyl derivatives, polyolefins, polyamides, or polyesters) or mixtures of any of the above.

[0029] Generally, non-woven cloths are made by air or water laying processes in which the fibres or filaments are first cut to desired lengths from long strands, passed into a water or air stream, and then deposited onto a screen through which the fibre-laden air or water is passed. The deposited fibres or filaments are then adhesively bonded together, dried, cured and otherwise treated as desired to form the non-woven cloth.

[0030] Preferably, the non-woven cloth is made from cellulosic fibres, particularly from regenerated cellulose or rayon, which are lubricated with standard textile lubricant such as sodium oleate. Preferably the fibres are from about 4 to about 50 mm, especially from about 8mm to about 20mm, in length and are from about 1 to about 5 denier (Denier is an internationally recognised unit in yarn measure, corresponding to the weight in grams of a 9,000 meter length of yarn). Preferably the fibres are at least partially orientated haphazardly, particularly substantially haphazardly, and are adhesively bonded together with hydrophobic or substantially hydrophobic binder-resin, particularly with a nonionic self-crosslinking acrylic polymer or polymers. In highly preferred embodiments, the cloth comprises from about 75% to about 88%, especially from about 78% to about 84% fibre and from about 12% to about 25%, especially from about 16% to about 22% hydrophobic binder-resin polymer by weight and has a basis weight of from about 10 to about 70, preferably from 20 to 50 g/m . Suitable hydrophobic binder-resins are ethylacrylate resins such as Primal HA24 Rhoplex HA8 and HA16 (Rohm and Haas, Inc) and mixtures thereof.

[0031] The flexible substrate for use herein is preferably an apertured substrate having an aperture density of from about 10 to about 30, preferably from about 13 to about 26, more preferably from 16 to about 23 apertures per sq cm of sheet, wherein the apertures, on average, have a width of from about 0.5mm to about 5mm and a length of from about 0.8mm to about 5mm, the substrate carrying a coating of the laundry additive composition and having areas of uncoated apertures and areas wherein the coating covers the apertures and extends between opposing surfaces of the substrate, the ratio of areas of uncoated to coated apertures being in the range from about 15:1 to about 1:3. The apertures themselves are generally symmetrical about a longitudinal axis (ie they have mirror symmetry) and preferably have, on average, a width of from about 0.7 to about 2.5mm and a length of from about 1.7mm to about 4mm. The area of the apertures, on the other hand, is preferably from about 0.7mm to about 7mm , more preferably from 2 2 about 0.8mm to about 3.5mm , and the ratio of length:width is from 1:1 up to preferably about 6:1, more preferably about 4:1. These parameters are highly preferred from the viewpoint of achieving the optimum ratio of areas of uncoated to coated apartures and the complete filling of coated apertures from one surface of the substrate to the other.

[0032] The substrate apertures herein can be elongate in shape (for example, generally elliptical or diamond-shaped) in which case the apertures preferably have a width of from about 0.8mm to about 1.5mm and a length of from about 2mm to about 3.5mm.In preferred embodiments, however, the apertures are generally square-shaped with a side dimension of from about 1 to 2.5mm. As used herein, "length" refers to the dimension of the principal (ie longest) longitudinal axis, and "width" is the maximum dimension perpendicular to this axis.

[0033] As far as loading ratio is concerned (ie the weight ratio of composition:substrate) this preferably is at least about 5:1 and more preferably at least 6:1. Moreover the ratio of the areas of uncoated to coated apertures in the final product is preferably from about 6:1 to about 1:2, more preferably from about 4:1 to about 1:1.

[0034] An example of an apertured non-woven substrate suitable herein is a regenerated cellulose sheet of 1.5 denier fibres bonded with Rhoplex HA 8 binder (fibre:binder ratio of about 77:23) having a basis weight of about 35 2 2 g/m and about 17 apertures/cm . The apertures are generally ellipitical in shape and are in side-by-side arrangement. The apertures have a width of about 0.9mm and a length of about 2.5mm measured in a relaxed condition. Another highly preferred substrate based on 1.5 denier regenerated cellulose fibres with Rhoplex HAS binder has a fibre:binder ration of about 82:18, a basis weight of about 2 2 35g/m², and about 22 apertures/cm². In this example, the apertures are generally square-shaped with a width (relaxed) of about l.lmm. The apertures are again disposed in side-by-side arrangement.

[0035] The size and shape of the substrate sheet for each unit of product is a matter of choice and is determined principally by factors associated with the convenience of its use. Thus the sheet should not be so small as to become trapped in the crevices of the machine or the clothes being washed or so large as to be awkward to package and dispense from the container in which it is sold. For the purposes of the present invention sheets ranging in plan area from about 130 cm² to about 1300 cm ² are acceptable, the preferred area lying in the range of from about 520 cm 2 to about 780 2 cm .

[0036] The agglomerates herein can be distributed over the entire surface of the water-insoluble carrier or can be localized in smaller, finite regions thereof, for example in stripes or spots. Laundry additive products wherein different particulate components are glued to different regions of the substrate, possibly using glues of differing setting characteristics, are also within the scope of the invention.

[0037] The laundry additive products of the invention can be supplemented by all manner of laundering and detergency components. Suitably, the additive products can contain at least about 5%, preferably from about 20% to about 90%, more preferably from about 35% to about 75% of organic detergent selected from anionic, nonionic and cationic surfactants and mixtures thereof. Anionic surfactants preferably comprise from about 7% to about 38%, more preferably from about 15% to about 30% by weight of composition; nonionic surfactants from about 8% to about 32%, more preferably from about 12% to about 25% by weight of composition; and cationic surfactants from about 5% to about 30%, more preferably from about 8% to about 20% by weight of composition.

[0038] The anionic surfactant can be any one or more of the materials used conventionally in laundry detergents. Suitable synthetic anionic surfactants are water-soluble salts of alkyl benzene sulphonates, alkyl sulphates, alkyl polyethoxy ether sulphates, paraffin sulphonates, alpha-olefin sulphonates, alpha-sulpho-carboxylates and their esters, alkyl glyceryl ether sulphonates, fatty acid monoglyceride sulphates and sulphonates, alkyl phenol polyethoxy ether sulphates, 2-acyloxy alkane-l-sulphonate, and beta-alkyloxy alkane sulphonate.

[0039] A particularly suitable class of anionic surfactants includes water-soluble salts, particularly the alkali metal, ammonium and alkanolammonium salts or organic sulphuric reaction products having in their molecular structure an alkyl or alkaryl group containing from about 8 to about 22, especially from about 10 to about 20 carbon atoms and a sulphonic acid or sulphuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups). Examples of this group of synthetic detergents which form part of the detergent compositions of the present invention are the sodium and potassium alkyl sulphates, especially those obtained by sulphating the higher alcohols (C8-18) carbon atoms produced by reducing the glycerides of tallow or coconut oil and sodium and potassium alkyl benzene sulphonates, in which the alkyl group contains from about 9 to about 15, especially about 11 to about 13, carbon atoms, in straight chain or branched chain configuration, e.g. those of the type described in U.S.P. 2,220,099 and 2,477,383 and those prepared from alkylbenzenes obtained by alkylation with straight chain chloroparaffins (using aluminium trichloride catalysis) or straight chain olefins (using hydrogen fluoride catalysis). Especially valuable are linear straight chain alkyl benzene sulphonates in which the average of the alkyl group is about 11.8 carbon atoms, abbreviated as C11.8 LAS, and C₁₂-C₁₅ methyl branched alkyl sulphates.

[0040] Other anionic detergent compounds herein include the sodium C_10-18 alkyl glyceryl ether sulphonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphonates and sulphates; and sodium or potassium salts of alkyl phenol ethylene oxide ether sulphate containing about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl groups contain about 8 to about 12 carbon atoms.

[0041] Other useful anionic detergent compounds herein include the water-soluble salts or esters of α-sulphonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-1-sulphonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; alkyl ether sulphates containing from about 10 to 18, especially about 12 to 16, carbon atoms in the alkyl group and from about 1 to 12, especially 1 to 6, more especially 1 to 4 moles of ethylene oxide; water-soluble salts of olefin sulphonates containing from about 12 to 24, preferably aout 14 to 16, carbon atoms, especially those made by reaction with sulphur trioxide followed by neutralization under conditions such that any sultones present are hydrolysed to the corresponding hydroxy alkane sulphonates; water-soluble salts of paraffin sulphonates containing from about 8 to 24, especially 14 to 18 carbon atoms, andfl-alkyloxy alkane sulphonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane moiety.

[0042] The alkane chains of the foregoing non-soap anionic surfactants can be derived from natural sources such as coconut oil or tallow, or can be made synthetically as for example using the Ziegler or Oxo processes. Water solubility can be achieved by using alkali metal, ammonium or alkanolammonium cations; sodium is preferred. Suitable fatty acid soaps can be selected from the ordinary alkali metal (sodium, potassium), ammonium, and alkylolammonium salts of higher fatty acids containing from about 8 to about 24, preferably from about 10 to about 22 and especially from about 16 to about 22 carbon atoms in the alkyl chain. Suitable fatty acids can be obtained from natural sources such as, for instance, from soybean oil, castor oil, tallow, whale and fish oils, grease, lard and mixtures thereof). The fatty acids also can be synthetically prepared (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Napthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from tallow and hydrogenated fish oil.

[0043] Mixtures of anionic surfactants are particularly suitable herein, especially mixtures of sulfonate and sulfate surfactants in a weight ratio of from about 5:1 to about 1:5, preferably from about 5:1 to about 1:1, more preferably from about 5:1 to about 1.5:1. Especially preferred is a mixture of an alkyl benzene sulfonate having from 9 to 15, especially 11 to 13 carbon atoms in the alkyl radical, the cation being an alkali metal, preferably sodium; and either an alkyl sulfate having from 10 to 20, preferably 12 to 18 carbon atoms in the alkyl radical or an ethoxy sulfate having from 10 to 20, preferably 10 to 16 carbon atoms in the alkyl radical and an average degree of ethoxylation of 1 to 6, having an alkali metal cation, preferably sodium.

[0044] The nonionic surfactants useful in the present invention are condensates of ethylene oxide with a hydrophobic moiety to provide a surfactant having an average hydrophilic-lipophilic balance (HLB) in the range from about 8 to 17, preferably from about 9.5 to 13.5, more preferably from about 10 to about 12.5. The hydrophobic moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

[0045] Examples of suitable nonionic surfactants include:

1. The polyethylene oxide condensates of alkyl phenol, e.g. the condensation products of alkyl phenols having an alkyl group containing from 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 3 to 30, preferably 5 to 14 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived, for example, from polymerised propylene, di-isobutylene, octene and nonene. Other examples include dodecylphenol condensed with 9 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 11 moles of ethylene oxide per mole of phenol; nonylphenol and di-isooctylphenol condensed with 13 moles of ethylene oxide.

2. The condensation product of primary or secondary aliphatic alcohols having from 8 to 24 carbon atoms, in either straight chain or branched chain configuration, with from 2 to about 40 moles, preferably 2 to about 9 moles of ethylene oxide per mole of alcohol. Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms and is ethoxylated with between 2 and 9, desirably between 3 and 8 moles of ethylene oxide per mole of aliphatic alcohol. The preferred surfactants are prepared from primary alcohols which are either linear (such as those derived from natural fats or, prepared by the Ziegler process from ethylene, e.g. myristyl, cetyl, stearyl alcohols), or partly branched such as the Lutensols, _Dobanols and Neodols which have about 25% 2-methyl branching (Lutensol being a Trade Name of BASF, Dobanol and Neodol being Trade Names of Shell), or Synper- onics, which are understood to have about 50% 2-methyl branching (Synperonic is a Trade Name of I.C.I.) or the primary alcohols having more than 50% branched chain structure sold under the Trade Name Lial by Liquichimica. Specific examples of nonionic surfactants falling within the scope of the invention include _Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-2.5, Dobanol 91-3, Dobanol 91-4, Dobanol 91-6, Dobanol 91-8, Dobanol 23-6.5, Synperonic 6, Synperonic 14, the condensation products of coconut alcohol with an average of between 5 and 12 moles of ethylene oxide per mole of alcohol, the coconut alkyl portion having from 10 to 14 carbon atoms, and the condensation products of tallow alcohol with an average of between 7 and 12 moles of ethylene oxide per mole of alcohol, the tallow portion comprising essentially between 16 and 22 carbon atoms. Secondary linear alkyl ethoxylates are also suitable in the present compositions, especially those ethoxylates of the _Tergitol series having from about 9 to 15 carbon atoms in the alkyl group and up to about 11, especially from about 3 to 9, ethoxy residues per molecule.3.

[0046] The compounds formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The molecular weight of the hydrophobic portion generally falls in the range of about 1500 to 1800. Such synthetic nonionic detergents are available on the market under the Trade Name of "Pluronic" supplied by Wyandotte Chemicals Corporation.

[0047] Especially preferred nonionic surfactants for use herein are the C₉-C₁₅ primary alcohol ethoxylates containing 3-8 moles of ethylene oxide per mole of alcohol, particularly the C₁₂-C₁₅ primary alcohols containing 6-₈ moles of ethylene oxide per mole of alcohol.

[0048] Cationic surfactants suitable for use herein include quaternary ammonium surfactants and surfactants of a semi-polar nature, for example amine oxides.

[0049] Suitable surfactants of the amine oxide class have the general formula I

wherein _R¹ is a linear or branched alkyl or alkenyl group having 8 to 20 carbon atoms, each _R² is independently selected from C_1-4 alkyl and (C_nH_2nO)_mH where i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to 7, the sum total of C_nH_2nO groups in a molecule being no more than 7.

[0050] In a preferred embodiment R¹ has from 10 to 14 carbon atoms and each _R² is independently selected from methyl and -(C_nH_2nO)_mH wherein m is from 1 to 3 and the sum total of C_nH_2nO 0 groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred embodiment, _j is ₀ and each R is methyl, and R is C₁₂-C₁₄ alkyl.

[0051] Another suitable class of amine oxide species is represented by bis-amine oxides having the following substituents. j : 1

R¹: tallow C₁₆-C₁₈ alkyl; palmityl; oleyl; stearyl

^R₂: hydroxyethyl

i : 2 or 3

[0052] A specific example of this preferred class of bis-amine oxides is: N-hydrogenated C₁₆-C₁₈ tallow alkyl-N,N',N'tri-(2-hydroxyethyl) -propylene-1,3-diamine oxide.

[0053] Suitable quaternary ammonium surfactants for use in the present composition can be defined by the general formula II:

wherein R is a linear or branched alkyl, alkenyl or alkaryl group having 8 to 16 carbon atoms and each _R⁴ is independently selected from C_1-4 alkyl, C_1-4 alkaryl and -(C_nH_2nO)_m wherein i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to 7, the sum total of C_nH_2nO groups in a molecule being no more than 7, and wherein Z represents counteranion in number to give electrical neutrality, In a preferred embodiment, R has from 10 to 14 carbon atoms and each R⁴ is independently selected from methyl and (C_nH_2nO)_mH wherein m is from 1 to 3 and the sum total of C_nH_2nO groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred embodiment j is 0, _R⁴ is selected from methyl, hydroxyethyl and hydroxypropyl and R³ is C₁₂-C₁₄ alkyl. Particularly preferred surfactants of this class include C₁₂ alkyl trimethylammonium salts, C₁₄ alkyltrimethylammonium salts, coconutalkyltrimethylammonium salts, coconutalkyldimethyl- hydroxyethylammonium salts, coconutalkyldimethylhydroxy- propylammonium salts, and c12 alkyldihydroxyethylmethyl ammonium salts.

[0054] Another group of useful cationic compounds are the diammonium salts of formula II in which j is 1, R is C₁₂-C₁₄ alkyl, each R⁴ is methyl, hydroxyethyl or hydroxypropyl and i is 2 or 3. In a particularly preferred surfactant of this type, R is coconut alkyl, R 4 is methyl and i is 3.

[0055] Chelating agents that can be incorporated include citric acid, nitrolotriacetic and ethylene diamine tetra acetic acids and their salts, organic phosphonate derivatives such as those disclosed in Diehl US Patent No. 3,213,030 issued 19 October, 1965; Roy US Patent No. 3,433,021 issued 14 January, 1968; Gedge US Patent No. 3,292,121 issued 9 January, 1968; and _Bersworth US Patent No. 2,599,807 issued 10 June, 1952, and carboxylic acid builder salts such as those disclosed in _Diehl US Patent No. 3,308,067 issued 7 March, 1967. Preferred chelating agents include nitrilotriacetic acid (NTA), nitrilotrimethylene phosphonic acid (NTMP), ethylene diamine tetra methylene phosphonic acid (EDTMP) and diethylene triamine penta methylene phosphonic acid (DETPMP), and these are incorporated in amounts such that the substrate chelating agent weight ratio lies in the range from about 20:1 to about 1:5, preferably from about 5:1 to about 1:5 and .most preferably 3:1 to 1:1.

[0056] Antiredeposition and soil suspension agents also constitute preferred components of the additive product of the invention. Cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose are examples of soil suspension agents and suitable antiredeposition agents are provided by homo- or co-polymeric polycarboxylic acids or their salts in which at least two carboxyl radicals are present separated by not more than two carbon atoms.

[0057] Highly preferred polymeric polycarboxylic acids are copolymers of maleic acid or maleic anhydride with methyl vinyl ether, ethyl vinyl ether, ethylene or acrylic acid, the polymers having a molecular weight in the range from 12,000 to 1,500,000.

[0058] A further description of suitable polymeric polycarboxylic acids is provided in the Applicants' European Patent Application No. 82301776.9.

[0059] In a method of making the laundry additive products of the invention, the particles or agglomerated particles of storage-sensitive detergency additive are dispersed in an aqueous adhesive polymer solution or latex, the dispersion is coated on the water-insoluble substrate, and the adhesive is set by removing water from the substrate by evaporation, filtration, centrifuging or pressing. In another method of making the laundry additive products of the invention, an aqueous adhesive polymer solution or latex is coated on the water-insoluble substrate and prior to the adhesive setting, the particles or agglomerated particles of storage-sensitive detergency additive are coated or sprayed onto the adhesive coated substrate which is finally set by removing water therefrom by evaporation, filtration, centrifuging or pressing. In a further method of making the laundry additive products of the invention, the substrate is coated with a temperature or pressure-sensitive adhesive and the particles or agglomerated particles of storage-sensitive detergency additive are coated or sprayed onto the adhesive-coated substrate at a temperature or pressure above the setting temperature or setting pressure respectively of the adhesive. In the above process embodiments, the spraying step is preferably carried out using a fluidized bed.

[0060] The invention is illustrated in the following non-limitative Examples in which parts and percentages are by weight unless otherwise specified.

[0061] In the Examples, the abbreviations used have the following designation:

LAS : Linear C₁₂ alkyl benzene sulphonate

C_12/14AS : Sodium C₁₂-C_l4 alkyl sulphate

TAE_n : Hardened tallow alcohol ethoxylated with n moles of ethylene oxide per mole of alcohol

MAO : C₁₂-C_l4 alkyl dimethyl amine amide

C₁₂TMAB : C₁₂ alkyl trimethyl ammonium bromide

C₁₂ Amide : Coconut monoethanolamide

Dobanol 45-E-7 : A C₁₄-C₁₅ primary alcohol condensed with 7 moles of ethylene oxide, marketed by Shell

Clay : Sodium montmorillonite

PEG : Polyethylene glycol (MWt normally follows)

PVA : Polyvinylalcohol

TAED : Tetraacetylethylenediamine

PPA : Peroxyphthalic acid, magnesium salt

Silicone/Silica : 20:1 mixture of polydimethylsiloxane and silanated silica

Wax : Microcrystalline wax - Witodur 272-M.pt871C

Porphine : Tri/tetra sulphonated zinc phthalocyanine

Gantrez AN119 : Maleic anhydride/vinyl methyl ether copolymer, believed to have an average molecular weight of 240,000, marketed by GAF. This material was prehydrolysed with NaOH before addition.

Perborate : Anhydrous sodium perborate bleach of empirical formula NaB0₂.H₂0₂

MA/AA : Maleic acid/acrylic acid copolymer, 1:4 mole ratio, m.wt 80,000.

EDTA : Sodiumethylenediaminetetraacetate

Brightener 1 : Disodium 4,4'-bis(2-morpholino-4-anilino-s-triazin-6-ylamino) stilbene-2:2'-disulphonate

Brightener 2 : Disodium 4,4'-bis(2-sulphonato styryl)biphenyl

DETPMP : Diethylenetriamine penta(methylene phosphonic acid), marketed by Monsanto under the Trade name Dequest 2060

EDTMP : Ethylenediamine tetra(methylene phosphonic acid), marketed by Monsanto, under the Trade name Dequest 2041

Substrate 1 : Non-woven fabric formed of 100% unbleached crimped rayon fibres of 1.5 denier bonded with 23% polyacylate binder; basis weight 35 g/m²; 17 elliptical apertures/cm²; aperture width 0.9mm; aperture length 2.5mm

Substrate 2 : Non-woven fabric formed of 100% unbleached crimped rayon fibres of 1.5 denier bonded with 18% polyacylate binder; basis weight 35g/m²; 22 square-shaped apertures/cm²; side dimension 1.1mm

Substrate 3 : Non woven non-apertured fabric formed of 100% unbleached crimped rayon fibres of 1.5 denier bonded with 15% polyacylate binder; basis weight 32 g/m².

EXAMPLES 1 TO 4

[0062] Laundry additive products according to the invention are prepared by a slurry process as follows:

A slurry is prepared containing agglomerate (50% of slurry) suspended in an aqueous solution of adhesive. A porous non-apertured web (Substrate 3) made from rayon and having the strength to withstand the laundering process is passed over a mesh conveyor and the slurry fed on to the web at a uniform application rate. Excess fluid is filtered through the mesh, the flow being accelerated by vacuum. The resulting thin 'cake' of agglomerates on the web is then dried in a continuous drying tunnel where the water is evaporated to leave the agglomerates bound to the substrate by the adhesive. Thereafter, the web is wound into rolls and passed to equipment for preparing individual cut sheets of size 35 x 23 cm ready for packing.

EXAMPLES 5 TO 8

[0063] Further laundry additive products according to the invention are prepared as follows. The web of substrate leaving the unwinding station is sprayed with hot melt adhesive and thereafter a curtain of the agglomerated material is fed onto the web. The web is then passed through compression rolls to press the agglomerates into the adhesive and the substrate is then passed through a second set of glue spray, powder feed and compression roll stations. Thereafter, the web is wound into rolls and passed to equipment for preparing individual cut sheets of size 35 x 23 cm ready for packing.

EXAMPLES 9 TO 14

[0064] Additional laundry additive products according to the invention are prepared as follows.

[0065] The agglomerates are first glued to substrate following the glue spray, powder feed and compression roll procedure of Examples 5 to 8. Separately, the remaining components of the laundry additive composition are mixed at a temperature of about 60°C and passed through a Fryma Colloid Mill, Model MK95-R/MZ 80R (made by M.M. Process Equipment Ltd of M.M. House, Frogmore Road, Hemel Hempstead, Herts, U.K.)

[0066] in which the grinding faces are set to a separation of about 180 microns. The melt is then fed through a pair of counterrotating rolls heated to 76⁰C and having a nip setting of 250 microns and is transferred to the agglomerate-treated substrate moving counter to one of the rollers by wiping. The coated substrate is finally passed between a pair of static plates having a spacing of 180 microns, air-cooled, and cut into sheets of size 35 X 23cm.

[0067] In the Examples, the agglomerates have the following composition:

[0068] In the above, Agglomerate 1 is prepared by extrusion and has a protease activity of 2 Anson units/g and an amylase activity of 48,000 maltose units/g; Agglomerate 2 is prepared by spray-on of PVA onto bleach and diluent in a fluidized bed; Agglomerate 3 is prepared by extrusion in a radial extruder as described in European Patent Application No 82301775.1; Agglomerate 4 is prepared by spray-on of storage-sensitive ingredient and organic carrier onto a fluidized bed of granular sodium tripolyphosphate (hydrated); and Agglomerates 5 and 6 and prepared by spray-on of organic carrier and, where appropriate water, onto the remaining granular components in a drum agglomerator.

[0069] The compositions of Examples 1 to 14 have excellent storage-stability, convenience and reproducibility in use, and improved dust control.

Claims

1. A laundry additive product characterized by:

(a) a solid laundry additive composition comprising discrete agglomerated particles of storage-sensitive detergency additive water-releasably glued to the surface of

(b) a unitary water-insoluble carrier.

2. A product according to Claim 1 characterized in that the storage-sensitive detergency additive is selected from detergency enzymes, bleaches, bleach activators, bleach catalysts, photoactivators, dyes, fluorescers, suds suppressors, perfumes, fabric conditioning agents, and hydrolysable surfactants.

3. A product according to Claim 1 or 2 incorporating therein an antagonist for the storage-sensitive detergency additive, and wherein the detergency additive/antagonist combination are selected from at least one of the following:

4. A product according to any of Claims 1 to 3 characterized in that the storage-sensitive detergency additive is an enzyme selected from the group consisting of proteases, amylases and mixtures thereof.

5. A composition according to any of Claims 1 to 3 characterized in that the storage sensitive detergency additive is an organic peroxy bleach selected from mono and diperoxyphthalic acid, mono and diperoxyisophthalic acid, peroxylauric acid, peroxyoctanoic acid, peroxynonanoic acid, peroxydecanoic acid, mono and diperoxydodecanedioic acid, mono and diperoxyazelaic acid and salts thereof.

6. A product according to any of Claims 1 to 5 characterized in that the agglomerated particles are glued to the substrate surface by a polymeric adhesive, preferably a thermoplastic polymer based on sodium carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinylacetate, polyvinyl alcohol, dextrins, ethylenevinyl copolymers, and acrylic copolymers.

7. A product according to any of Claims 1 to 6 characterized in that the agglomerated particles comprise an agglomerating agent and optionally a solid diluent, the agglomerating agent being in the form of a water-soluble or water-dispersible organic carrier, an adhesive, or an encapsulating or coating agent.

8. A product according to any of Claims 1 to 7 characterized in that the weight ratio of additive composition:substrate is at least about 1:1, preferably at least about 3:1.

9. A product according to any of Claims 1 to 8 characterized in that the particles of storage-sensitive detergency additive have an average particle size of less than about 250 microns, preferably less than about 150 microns, and that the agglomerates have an average particle size of at least about 100 microns, preferably from about 150 to about 2000 microns.

10. A product according to any of Claims 1 to 9 characterized by at least 5%, preferably at least 20% of organic detergent selected from anionic, nonionic and cationic surfactants and mixtures thereof.

11. A product according to Claim 10 characterized in that the organic detergent is selected from anionic sulphonate or sulphate surfactants and/or water-soluble cationic surfactants and mixtures of said anionic or cationic surfactants with water-soluble ethoxylated nonionic surfactants.