Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0047—Detergents in the form of bars or tablets
  • C11D17/0052—Cast detergent compositions
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/66—Non-ionic compounds
  • C11D1/667—Neutral esters, e.g. sorbitan esters
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D10/00—Compositions of detergents, not provided for by one single preceding group
  • C11D10/04—Compositions of detergents, not provided for by one single preceding group based on mixtures of surface-active non-soap compounds and soap
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0047—Detergents in the form of bars or tablets
  • C11D17/0065—Solid detergents containing builders
  • C11D17/0073—Tablets
  • C11D17/0078—Multilayered tablets
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/12—Water-insoluble compounds
  • C11D3/124—Silicon containing, e.g. silica, silex, quartz or glass beads
  • C11D3/1246—Silicates, e.g. diatomaceous earth
  • C11D3/128—Aluminium silicates, e.g. zeolites

Definitions

• the present invention relates to multi-region non-compressed detergent tablets.
• a method for production of the tablets according to the invention is provided.
• the use of a detergent tablet for cleaning fabrics is provided.
• Detergent tablets are known in the art in various forms. Generally tablets are detergent compositions which are solid or semi-solid, and that form a single dose of detergent for a standard wash in a washing machine (or alternatively two tablets form a single dose).
• the advantages of detergent tablets as compared to powdered and liquid detergents include ease of dosing, handling and transport. Most detergent tablets in the art are produced by compressing a particulate material into a solid tablet using a press.
• the particulate materials comprises the normal detergent ingredients like surfactants, builders, perfume, enzymes, etc.
• the compression force on the one hand should be high, in order to produce solid blocks that do not crumble during production, transport, storing, and handling.
• the tablets may also contain pressure sensitive ingredients, that cannot withstand high pressures, and may be damaged during the compaction process. Examples of these are encapsulated enzymes and perfumes.
• Tablets comprising two or more separate regions with different compositions have been described, such as detergent compositions comprising form-stable, solid, and/or transparent smooth or gel-like regions.
• WO 00/61717 describes a detergent tablet of which at least part of its outer surface is semi-solid. Said tablets are constituted from a compressed particulate tablet on top of which a (non- compressed) smooth layer is attached by pouring a mixture of nonionic and PEG followed by hardening.
• WO 99/24549 describes a detergent tablet comprising a compressed solid body and a non-compressed gelatinous portion mounted in a mould of said body.
• EP 1 ,491 ,622 B1 and EP 1 ,511 ,834 B1 disclose detergent tablets comprising a smooth or semi-solid non-compressed region and a solid compressed particulate region, whereby the majority of surfactants is present in the non-compressed region. Therewith compounds which may negatively interact can effectively be separated.
• DE 10121017 B4 exemplifies detergent tablets that are non-compressed.
• the patent describes form-stable detergents in the form of a highly viscous gel, comprising 20- 75 wt% of the combination of water and water-soluble solvent, wherein the concentration of water-soluble solvent is 0.5-10 wt%, 20-75 wt% of ingredients like surfactants, bleach, builders, and possibly other detergent active compounds, and 0.1 -10% polymer thickener.
• the polymer thickeners are for example natural polysaccharides, or polyacrylates, polyethers, polycarboxylates, and also clay minerals like montmorillonite, zeolites and silicates.
• non-compressed detergent tablets comprising a non-compressed gelatinous body, comprising a thickening system and at least one detergent active.
• the gelatinous body comprises one or more gelatinous regions with different compositions.
• the thickening system comprises a non-aqueous solvent or diluent and a gelling agent.
• the non-aqueous solvent include alkylene glycol mono lower alkyl ethers, propylene glycols, and ethoxylated or propoxylated ethylene or propylene.
• the gelling agent may be selected from the group consisting of castor oil derivatives, polyethylene glycol and mixtures thereof and is preferably polyethylene glycol.
• WO 01/66683 discloses detergent tablets comprising two or more non- compressed regions. Processing methods for manufacturing the two or more regions are for example sintering, casting, hardening of a shapeable mass (for example gelatinisation). When the tablets are made by a gelatinisation process, the application teaches to use a polymer thickener to make a form-stable tablet.
• polysaccharides like starch, gelatin, casein, arabic gum, and also synthetic polymers like polyacrylates, polyethers, and polycarboxylates.
• the tablets comprise 0.4-1.5 wt% polysaccharide.
• Disadvantages of these cited prior art documents are that compounds are used in the detergent tablets that are not active, often in combination with water. If water is present, then it is required for the polymer thickeners (like polysaccharides) to form a gel network and therewith structure the tablet and make it form stable.
• the use of the polymers and water may lead to tablets with large volumes and low density. Consequently the space required to store the tablets is large, and transport of the tablets requires much energy. Therefore it would be advantageous to make tablets or tablet regions which are free of water and polymers, in order to make the tablets smaller, and therewith save space and energy.
• An object of the present invention is to provide a detergent tablet, wherein the tablet may have one or more distinct regions, wherein the compounds have not been subjected to high pressures, and wherein the tablet dissolves quickly and exhibits a good washing performance. Furthermore the temperature at which the detergent tablet is produced should not be too high, in order to prevent degradation and loss of sensitive compounds (like encapsulated enzymes and perfumes) during the manufacturing process.
• This and other objectives can be achieved by providing a detergent tablet that has not been compressed during production, wherein at least one region is substantially free from polymer thickener, and wherein said at least one region comprises non- electrolyte detergency builder at a concentration of between 10 and 70 wt% based on tablet weight.
• the detergent tablet comprises two or more non-compressed regions with different compositions.
• relatively large amounts of non-electrolyte detergency builder can be incorporated in the tablet, without losing strength and dissolution rate of the tablets.
• a process for manufacturing tablets of the invention wherein at least one region is formed by melting a mixture, pouring the mixture into a mould, followed by a cooling step, and consequently hardening of the tablet. The temperature at which part of the tablet can be produced is relatively low, meaning that sensitive compounds are protected.
• a multi-region non-compressed detergent tablet comprising at least one region that is substantially free from polymer thickener and is substantially free from inorganic electrolyte detergency builder, and wherein said region comprises non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight.
• a method is provided to produce a detergent tablet according to the invention, comprising the following steps:
• step (iv) casting the mix from step (iii) into a mould at a temperature of about 40 to 60°C;
• step (v) casting the mix from step (ii) into the mould onto the mix from step (iv) at a temperature of about 70 to 90 0 C; (vi) cooling down of the regions to form a detergent tablet;
• a further aspect of the invention is the use of a detergent tablet according to the invention for cleaning fabrics in a washing machine.
• Detergent tablet a detergent product which is form stable at room temperature and can be considered, according to the consumer, to be a solid shaped product. Usually one or two of these tablets together form a single dose for a laundry washing cycle in a washing machine, although a tablet also can be used for handwash purposes.
• Weight percentage (indicated as 'wt%'): calculated based upon total weight of the tablet, unless indicated otherwise.
• ⁇ Aspect ratio of the tablets the ratio between the largest dimension of the tablet divided by the shortest dimension of the tablet. For example, if the tablet has the shape of a cylinder, the aspect ratio is defined as the ratio between the diameter and height of the tablet.
• Inorganic electrolyte detergency builder any inorganic water-soluble salt that can be applied as detergency builder; preferably the inorganic electrolyte detergency builder is an inorganic water-soluble builder salt.
• Non-electrolyte detergency builder a detergency builder that is not a water- soluble salt.
• ⁇ Region a part of a detergent tablet that can be considered to be homogeneous on macro (tablet) scale. This does not imply that the region on microscale is necessarily of identical composition, for example the region may comprise small particles and therefore a region may be considered to be heterogeneous on micro scale.
• a multi-region detergent tablet of the present invention comprises two or more regions with different compositions on macro scale.
• First region the region of a detergent tablet according to the invention, wherein said first region is substantially free from polymer thickener and is substantially free from inorganic electrolyte detergency builder, and wherein said first region comprises non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight.
• Second and third and other regions other regions of a detergent tablet according to the invention.
• a detergent tablet according to the invention is a multi-region non-compressed detergent tablet comprising at least one non-compressed region that is substantially free from polymer thickener and is substantially free from inorganic electrolyte detergency builder, and wherein said region comprises non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight.
• a detergent tablet according to the invention is a multi-region non-compressed detergent tablet comprising at least one region that is substantially free from polymer thickener and is substantially free from inorganic electrolyte detergency builder, and wherein said region comprises non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight, wherein the maximum concentration of polymer thickener is 0.5 wt% based on the weight of the detergent tablet, wherein the maximum concentration of inorganic electrolyte detergency builder is
• non-electrolyte detergency builder is a detergency builder that is not a water-soluble salt
• inorganic electrolyte detergency builder is an inorganic water-soluble salt that can be applied as detergency builder
• the inorganic electrolyte detergency builder is an inorganic water-soluble builder salt.
• a detergent tablet according to the invention comprises at least two regions with different compositions.
• the detergent tablet may be a two or three-layered product, or may even have up to five or more separate regions.
• the regions of the detergent tablet according to the invention are preferably separate layers within the tablet.
• also different forms are possible, like a discrete region of a tablet could have the form of one or more cores or inserts.
• a first region is a core or insert of smooth material embedded in a second region.
• the cleaning tablets of the invention may optionally comprise further regions, for example the tablet may be partly or completely coated.
• the total weight of the detergent tablet according to the invention is preferably from 10 to 100 gram, more preferred from 20 to 70 gram.
• the weight of the tablets depends on the conditions of intended use, and whether it represents a dose for an average load in a washing machine or a fractional part of such a dose.
• the tablets of the invention constitute a single dose for an average wash load in a washing machine.
• the weight of each of the regions in the tablet is at least 1 gram, preferably at least 2 gram.
• the tablets may be of any shape. However, for ease of packaging they are preferably blocks of substantially uniform cross-section, such as cylinders, cuboids, and spheres. In a more preferred embodiment the tablets have a relatively high aspect ratio, meaning that the height of the tablet is small compared to the diameter or longest side of the tablet. Usually preferred the tablet can be considered to be a disc or thin sheet of detergent material.
• the aspect ratio of a detergent tablet according to the invention is larger than 10, more preferably larger than 15, mostly preferred larger than 20, wherein the aspect ratio is the ratio between the largest dimension of the tablet divided by the shortest dimension of the tablet.
• the whole tablet is coated with a water-soluble polymer film.
• the detergent tablets may be coated with any suitable material, including a packaging material which needs to be removed before applying the tablet in a washing machine. More preferably the packaging material comprises a water-soluble polymer that rapidly dissolves in the wash, so the consumer does not need to unwrap the detergent tablet prior to use.
• a detergent tablet according to the invention is coated with a water-soluble polymer film.
• the tablet can be regarded to be a disc or thin sheet, of which the top and/or the bottom sides are coated with a water-soluble polymer material. This way the tablets can be packed as a pile of discs or sheets, and the consumer can take one disc or sheet at a time for application in the washing machine.
• the overall density of a tablet typically lies in a range from 1050 kg-m "3 up to 1450 kg -m "3 .
• one or more regions of a multi-region detergent tablet of the invention may comprise a detergency builder material, preferably a non- electrolyte detergency builder is contained by only one of the regions of the detergent tablet, while optional other regions are substantially free from non- electrolyte detergency builder.
• concentration of non-electrolyte detergency builder based on the weight of the region that comprises said non-electrolyte detergency builder, may range from 5 to 80 wt%, more preferred from 10 to 60 wt%, mostly preferred from 15 to 50 wt%. Based on total tablet weight the concentration of non-electrolyte detergency builder is between 15 wt% and 70 wt%, more preferred from 15 to 50 wt% based on tablet weight.
• the non-electrolyte detergency builder comprises solid particles that are insoluble in the material from which the tablet is made. More preferred said solid particles comprises alkali metal aluminosilicate. Especially preferred the non-electrolyte detergency builder comprises a zeolite.
• zeolite particles are comprised by a first region of a multi-region detergent tablet according to the invention, in the form of agglomerates, wherein the agglomerates are composed from fine zeolite powder.
• the average particle size of the zeolite powder that is contained in the agglomerates is smaller than 10 ⁇ m, more preferred smaller than 7 ⁇ m, mostly preferred smaller than 2.5 ⁇ m.
• At least one of the regions of a detergent tablet according to the invention is substantially free from solid particles that are insoluble in the materials from which the tablet is made.
• the maximum concentration of said solid particles is 0.5 wt% based on the weight of the detergent tablet.
• a second region of the detergent tablet may comprise a polymer thickener. If present, then preferably the amount of polymer thickener is lower than 15 wt% based on the weight of the tablet, more preferred lower than 10 wt% based on the weight of the tablet. Based on the weight of the second region, the concentration of polymer thickener if present is preferably between 20 and 50 wt%, more preferred between 25 and 45 wt%.
• a preferred polymer thickener is polyethyleneglycol, with an average molecular weight of from 2,000 to 10,000 g/mol, more preferred of from 3,000 to 6,000 g/mol.
• Said second region preferably also comprises surfactants, more preferably nonionic surfactants.
• concentration of nonionic surfactants based on the weight of a second region is preferably from 10 to 50 wt%, more preferred from 20 to 40 wt%, based on the weight of the second region.
• one or more other regions may be present, and the composition of these regions may be according to said first region or according to said second region.
• the detergent tablets of the present invention comprise a non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight.
• the function of the non-electrolyte detergency builder is to bind ions like calcium and magnesium, in order to prevent deposition of calcium and magnesium salts on the textile, as well as prevention of non-optimal functioning of surfactants.
• At least one of the regions of the tablet comprises a detergency builder that is not an inorganic electrolyte.
• the one or more other regions may comprise a detergency builder that is an inorganic electrolyte.
• Preferred non-electrolyte detergency builders are alkali metal aluminosilicates, that are favoured as environmentally acceptable water-insoluble builders for fabric washing.
• Alkali metal (preferably sodium) aluminosilicates may be either crystalline or amorphous or mixtures thereof, having the general formula 0.8-1.5 Na 2 O AI 2 O 3 0.8-6 SiO 2 X H 2 O. These materials contain some bound water (indicated as 'x H 2 O') and are required to have a calcium ion exchange capacity of at least 50 mg CaO per gram.
• the preferred sodium aluminosilicates contain 1.5- 3.5 SiO 2 units (in the general formula above). Both the amorphous and the crystalline materials can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature.
• Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1 ,429,143.
• the preferred sodium aluminosilicates of this type are the well known commercially available zeolites A and X, the zeolite P described and claimed in EP 384,070 and mixtures thereof.
• a water-insoluble detergency builder could be a layered sodium silicate as described in US 4,664,839.
• other layered silicates can be used, such as those having the general formula NaMSi x O 2x+ I .yH 2 O, wherein M is sodium or hydrogen, x is a number from 1.9 to 4, preferably 2, and y is a number from 0 to 20, preferably 0.
• Water-soluble phosphorous-containing inorganic detergency builders that may be present in a second region of a multi-region detergent tablet according to the invention, are the alkali-metal orthophosphates, metaphosphates, pyrophosphates and polyphosphates.
• Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, orthophosphates and hexametaphosphates.
• Non-phosphorous water-soluble builders may also be applied in a second region of a preferred multi-region detergent tablet according to the invention, and may be organic or inorganic.
• Inorganic builders that may be present include alkali metal (generally sodium) carbonate.
• Organic builders include polycarboxylate polymers, such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphonates.
• Examples of organic builders are also monomeric carboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and tri-succinates, carboxymethyloxysuccinates, carboxymethyloxymalonat.es, dipicolinates and hydroxyethyliminodiacetates.
• the detergent tablets of the invention comprise surfactants.
• the surfactants may be the usual compounds known in the art, in any combination and any weight ratio, such as soap, anionic, non-ionic, zwitterionic or cationic surfactants.
• concentration of surfactants is between 5 wt% and 60 wt% based on the weight of the tablet, more preferred between 15 wt% and 50 wt%.
• the majority of surfactants is preferably comprised by a first region, wherein said first region also comprises comprises non-electrolyte detergency builder at a concentration of between 15 wt% and 70 wt% based on tablet weight, and wherein said region is substantially free from polymer thickener and inorganic electrolyte detergency builder.
• the weight ratio of total amount of surfactants in a first region relative to a second region is preferably from 1 :1 to 20:1 , more preferred from 1 :1 to 10:1 , mostly preferred from 1 :1 to 6:1.
• anionic surfactants are comprised by the detergent tablet, preferably the second region is substantially free from these anionic surfactants.
• soaps if these are comprised by the detergent tablet, then preferably the second region is substantially free from these soaps. It has been found that the difference in concentrations of surfactants in the regions of the tablets provide very good dispersing and cleaning properties to the detergent tablet.
• Soaps for use in accordance with the invention are preferably sodium soaps derived from naturally occurring fatty acids, for example but not limited to the fatty acids from beef tallow, coconut oil, sunflower oil or hardened rapeseed oil.
• the first region comprises soap for example at a level of 0.1 to 10 wt% based on the weight of the first region.
• the soap is present in a level of at least 1 wt% of the first region.
• Anionic surfactants may be present in an amount from 0 to 50 wt%, preferably from 1 wt% up to 30 wt% or 40 wt% by weight of the tablet composition.
• Synthetic (i.e. non-soap) anionic surfactants are well known to those skilled in the art. Examples include but are not limited to alkylbenzene sulphonates, particularly sodium linear alkylbenzene sulphonates having an alkyl chain length Of C 8 -Ci 5 ; olefin sulphonates; alkane sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.
• Other examples of commercially important anionic surfactants are primary alkyl or alkenyl sulphates, having a chain length of 8 to 18 carbon atoms.
• Linear alkyl benzene sulphonate or primary alkyl sulphate, or a mixture thereof will be the preferred (combination of) anionic surfactants and may provide 75 to 100 wt% of any anionic non-soap surfactant in the composition.
• Suitable nonionic surfactant compounds which may be used include in particular the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide and propylene oxide.
• nonionic surfactant compounds are alkyl (C8-22) phenol-ethylene oxide condensates, the condensation products of linear or branched aliphatic C 8 -2o primary or secondary alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylene-diamine.
• Preferred are the primary and secondary alcohol ethoxylates, especially the C 9- n and C-12-15 primary and secondary alcohols ethoxylated with an average of from 5 to 20 moles of ethylene oxide (EO) per mole of alcohol.
• EO ethylene oxide
• the use of ethoxylated nonionic surfactants based on branched alcohols is sometimes preferred.
• the concentration of nonionic surfactants preferably lies in a range from 3 to 40%, more preferred 4 or 5 to 30% by weight of the whole tablet.
• the surfactants in the first region comprise a combination of anionic surfactants and nonionic surfactants in a weight ratio of from 5:1 to 1 :5, more preferred 3:1 to 1 :3, more preferred 2:1 to 1 :2.
• the first region comprises relatively high levels of nonionic surfactants, preferably the non-soap surfactants are predominantly nonionic surfactants, most preferred all the nonsoap surfactants are nonionic surfactants.
• Further surfactants, for example cationic surfactants may equally be present for example at a level of 0.1 to 10 wt% based on the weight of the smooth or semi-solid part.
• the first region additionally comprises a material selected from polyalkoxylated carbohydrates, as defined in EP 1 ,405,901 A1.
• alkoxylated carbohydrate materials are polyoxyethylene sorbitan mono fatty acid esters (for example Tween 20, Tween 40 and Tween 60, supplied by Uniqema, Gouda, The Netherlands), polyoxyethylene-sorbitol fatty esters, polyoxyethylene glycerol esters, polyoxyethylene glycerol sorbitan isostearate (for example Arlacel 582), polyoxyethylene sorbitan (for example obtainable by hydrolysing Tween 20, Tween 40 and Tween 60), polyoxyethylene sorbitol, polyoxyethylene glycerol, polyoxyethylene glycerol sorbitan, polypropoxylated sorbitan (for example Atlas G- 2330 and Atlas G-2401 , supplied by Uniqema, Gouda, The Netherlands).
• Both the first and second region of the tablet may contain diluent materials, that are characterised by having a dielectric constant of about 10 to about 40 (as defined in EP 1 ,676,904 A1 ).
• these diluents are polyethyleneglycol 400, dipropyleneglycol, monopropyleneglycol, and isopropanol.
• the level of these diluents is from 0 to 40 wt%, more preferred 4 to 30 wt%, based on the weight of the tablet.
• the diluents used preferably have a flashpoint of at least 75°C, most preferred above 80 0 C or even above 90 0 C.
• the weight ratio between diluents in the first and second region may range from 5:1 to 1 :5, more preferred from 3:1 to 1 :3.
• the first region comprises no or only low levels of water.
• the level of water is less than 20 wt% based on the weight of the first region.
• the first region is free from added water, which means in this context that apart from low levels of moisture (e.g. for neutralisation or as crystal water) no additional added water is present.
• the tablet may comprise active ingredients like enzymes, perfume, fluorescer, polymers, or dyes, and various other compounds, that will be exemplified later.
• bleach systems for example bleach systems, enzymes, perfumes, and various other compounds, that will be exemplified here.
• said first region is substantially free from enzymes, perfumes, and bleach system.
• Detergent tablets according to the invention may comprise a bleach system, although preferably the detergent tablets of the invention are substantially free from a bleach system. If a bleach system is present, then it is preferably predominantly present in the second region. If present then the bleach system preferably comprises one or more peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, which may be employed in conjunction with activators to improve bleaching action at low wash temperatures. If any peroxygen compound is present, the amount is likely to lie in a range of from 10 to 25% by weight of the tablet.
• Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate, advantageously employed together with an activator.
• persalt crystals are coated with water-soluble inorganic salts.
• Bleach activators also referred to as bleach precursors, have been widely disclosed in the art.
• Preferred examples include peracetic acid precursors, for example, tetraacetylethylene diamine (TAED), and perbenzoic acid precursors.
• a bleach system may also include a bleach stabiliser (heavy metal sequestrant) such as ethylene diamine tetra (methylene phosphonic acid), diethylenetriamine pentamethylene phosphonate, and tetrasodium 1 -hydroxyethylidene biphosphonate.
• the detergent tablets of the invention may also contain one or more of the detergency enzymes well known in the art for their ability to degrade and aid in the removal of various soils and stains.
• the first region is substantially free from enzymes.
• Suitable enzymes include the various proteases, cellulases, lipases, amylases, and mixtures thereof, which are designed to remove a variety of soils and stains from fabrics. Examples of suitable proteases are Alcalase (trademark), and Savinase (trademark), as supplied by Novozymes A/S (Bagsvaerd, Denmark).
• the detergency enzymes are employed in liquid form.
• the detergent tablets of the invention may also contain a fluorescer (optical brightener), for example, Tinopal (trademark) DMS or Tinopal CBS available from Ciba Speciality Chemicals AG (Basel, Switzerland).
• Tinopal DMS is disodium 4,4'bis- (2-morpholino-4-anilino-s-triazin-6-ylamino) stilbene disulphonate
• Tinopal CBS is disodium 2,2'-bis-(phenyl-styryl) disulphonate.
• Any of the regions of the detergent tablet of the invention may contain fluorescer.
• An antifoam material may be included in the detergent tablet (in any of the regions, if present), especially if a detergent tablet is primarily intended for use in front-loading drum-type automatic washing machines.
• a detergent tablet of the invention includes an amount of an alkali metal silicate, particularly sodium ortho-, meta- or disilicate.
• an alkali metal silicate particularly sodium ortho-, meta- or disilicate.
• a detergent tablet for fabric washing will generally not contain more than 15 wt% silicate.
• ingredients which can optionally be employed in a detergent tablet of the invention include anti-redeposition agents such as sodium carboxymethylcellulose, straight-chain polyvinyl pyrrolidone and the cellulose ethers such as methyl cellulose and ethyl hydroxyethyl cellulose, heavy metal sequestrants such as EDTA, perfumes, colourants, dyes, or coloured speckles.
• anti-redeposition agents such as sodium carboxymethylcellulose, straight-chain polyvinyl pyrrolidone and the cellulose ethers such as methyl cellulose and ethyl hydroxyethyl cellulose
• heavy metal sequestrants such as EDTA
• perfumes, colourants, dyes, or coloured speckles such as EDTA
• a manufacturing process for a preferred detergent tablet according to the invention preferably comprises the following steps: (i) mixing the ingredients of a first region at a temperature of about 70 to 90 0 C, wherein said ingredients exclude non-electrolyte detergency builder; (ii) mixing of a non-electrolyte detergency builder into the mix from step (i); (iii) mixing the ingredients of a second region at a temperature of about 40 to 60 0 C; (iv) optionally mixing the ingredients of a third region at an elevated temperature; (v) casting the mix from step (iii) or (iv) into a mould at a temperature of about 40 to 60 0 C, therewith forming the bottom region of the tablet;
• step (vi) casting the mix from step (ii) into the mould onto the mix from step (v) at a temperature of about 70 to 90°C, therewith forming a second region of the tablet;
• step (vii) optionally casting the mix from step (iv) into the mould onto the mix from step (vi), therewith forming a new top region of the tablet;
• both steps (i) and (iii) and optional step (iv) take place in a stirred batch vessel.
• more regions can be cast onto the tablet by repeating the steps (iv) and (vii) for applying additional regions to the tablets.
• the invention provides a method to produce a detergent tablet comprising the following steps:
• step (iii) mixing the ingredients of a second region at a temperature of about 40 to 60°C; (iv) casting the mix from step (iii) into a mould at a temperature of about 40 to 60°C; (v) casting the mix from step (ii) into the mould onto the mix from step (iv) at a temperature of about 70 to 90 0 C; (vi) cooling down of the regions to form a detergent tablet; (vii) removal of the detergent tablet from the mould; wherein steps (iv), (v), (vi), and (vii) take place consecutively.
• said ingredients exclude non-electrolyte detergency builder.
• the detergent tablets according to the invention can be used for cleaning fabrics in a washing machine. Usually one or two tablets constitute a single dose for average household use in the washing cycle of a washing machine. However the tablet may also be used for hand-washing of laundry, or treatment of stains on the textile prior to the washing process, by rubbing part of the tablet onto the stain.
• the dissolution rate of single regions from which the tablets may be composed is determined by measuring the amount of dissolved single region after 5 minutes of dissolution under standard conditions.
• a single-region form-stable (gel-like) disc is used for this measurement.
• the weight of the single region is about 5.3 ⁇ 0.1 gram, having a diameter of 44 mm and thickness of 4.7 mm.
• the disc is dissolved in 500 gram water of 20 0 C while stirring at 100 rpm with a turbine-stirrer R1313. The stirrer is positioned just below the water surface.
• the non-dissolved single region composition is taken from the water, dried with tissue paper and the weight of the remaining single region is determined.
• the amount of dissolved single region is calculated by subtracting the weight of the remaining single region from the starting single region.
• the solubility of the single regions is expressed as amount of single region dissolved in 5 minutes. The higher the number, the better.
• the strength of single regions from which the tablets may be composed is measured by a compressing technique using the MTS Synergy 1000 electro-mechanical testing machine.
• the ingredients of a single region are formed into a form-stable block with a size of about 5x5x5 cm.
• a small cylinder is cut out of this block using a cork drill; diameter and length of the cylinder are 13 mm and 13 mm, respectively.
• This cylinder is compressed with a 500 N load-cell.
• the so-called 'force at failure' (in N) is measured, being the maximum in the force-compression curve.
• Detergent tablets comprising two non-compressed regions with different compositions were prepared.
• the composition and physical parameters of the tablets are given in Table 1.
• Table 1 Composition of a detergent tablet according to the invention.
• the weight of the first region was 40 gram, and the weight of the second region was 10 gram, resulting into a detergent tablet of 50 g.
• the preparation method of region 1 involved the following steps. LAS-acid was added to dipropyleneglycol while stirring, and after a homogeneous mixture had been obtained, Tween 40 was added, followed by part of the caustic solution. Fatty acid flakes were added and the temperature was raised to 75°C. The rest of the caustic solution was added to fully neutralise the fatty acid to soap. The nonionic was added and the temperature was raised to 85°C, followed by pH adjustment to about 11 using caustic solution. Zeolite powder was added as the last ingredient, and the mix was stirred until homogeneous.
• Region 2 was prepared by the following process. Nonionic was added to dipropyleneglycol while stirring at 40 0 C. After increase to a temperature of 55°C, PEG 4000 was added. When a homogeneous solution was obtained, the other ingredients were added while mixing, until the mixture was homogeneous.
• a detergent tablet was manufactured by casting 10g of the mix of region 2 (at 55°C) in a mould, waiting for its surface to cool down and solidify, and followed by casting 4Og of the mix of region 1 (at 85°C) on top of the other layer. After cooling to room temperature and hardening a detergent tablet was obtained, consisting of two non- compressed regions.
• first region compositions were produced, and tested on dissolution rate and strength.
• Table 2 Compositions and physical properties of first regions with various concentrations of zeolite A24

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  • 2008-07-08 WO PCT/EP2008/058851 patent/WO2009021784A1/en active Application Filing
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