EP4634350A1

EP4634350A1 - Solid laundry composition

Info

Publication number: EP4634350A1
Application number: EP23821291.4A
Authority: EP
Inventors: Girish Muralidharan; Vishal Mohan UDMALE
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2022-12-14
Filing date: 2023-12-08
Publication date: 2025-10-22
Also published as: CN120344645A; WO2024126309A1

Abstract

A solid fabric conditioning composition comprising: fabric softening active, carbonaceous material and water soluble carrier.

Description

SOLID LAUNDRY COMPOSITION

Field of the Invention

The present invention relates to solid fabric conditioning compositions.

Background of the Invention

Solid fabric conditioners provide consumers with an easy-to-use concentrated fabric conditioner composition. These compositions have various benefits including that they can contain high levels of active ingredient and have very low water content, leading to easier storage and transportation.

Solid fabric conditioners come in different shapes and sizes, for example tablets, sheets, shaped articles, etc. The strength of the fabric conditioner is important to prevent brakeage prior to use.

Summary of the Invention

It has been found that the addition of carbonaceous materials to a solid fabric conditioner improves the strength of the solid composition.

Accordingly, is a first aspect of the present invention is provided a solid fabric conditioning composition comprising: a 5 to 80 wt.% Fabric softening active comprising quaternary ammonium compound; b Carbonaceous material; and c Water soluble carrier

Wherein the carbonaceous material has a 2D carbon lattice nanostructure.

The invention further relates to a method of preparing a solid fabric conditioning composition comprising the steps of; a Preparing a premix of a water-soluble carrier and water; b Adding fabric softening active, carbonaceous material and any remaining ingredients to the premix; c Casting the mixture on a surface or in a mold; and d Removing the water, preferably by evaporation.

Detailed Description of the Invention

These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

All ingredient inclusion levels are wt.% of the final solid fabric conditioner product.

Fabric softening active

The compositions described herein comprise a fabric softening active. The fabric softening active comprises quaternary ammonium compounds.

The quaternary ammonium compound (QAC) preferably comprises at least one chain derived from fatty acids, more preferably at least two chains derived from a fatty acid. Generally fatty acids are defined as aliphatic monocarboxylic acids having a chain of 4 to 28 carbons. Fatty acids may be derived from various sources such as tallow or plant sources. Preferably the fatty acid chains are derived from plants. Preferably the fatty acid chains of the QAC comprise from 10 to 50 wt. % of saturated C18 chains and from 5 to 40 wt. % of monounsaturated C18 chains by weight of total fatty acid chains. In a further preferred embodiment, the fatty acid chains of the QAC comprise from 20 to 40 wt. %, preferably from 25 to 35 wt. % of saturated C18 chains and from 10 to 35 wt. %, preferably from 15 to 30 wt. % of monounsaturated C18 chains, by weight of total fatty acid chains.

The preferred quaternary ammonium fabric softening actives for use in compositions described herein are so called "ester quats" or ester-linked quaternary ammonium compounds.

Particularly preferred materials are the ester-linked triethanolamine (TEA) quaternary ammonium compounds comprising a mixture of mono-, di- and tri-ester linked components. Typically, TEA-based fabric softening compounds comprise a mixture of mono, di- and tri ester forms of the compound where the di-ester linked component comprises no more than 70 wt.% of the fabric softening compound, preferably no more than 60 wt.% e.g., no more than 55%, or even no more that 45% of the fabric softening compound and at least 10 wt.% of the monoester linked component.

A first group of quaternary ammonium compounds (QACs) suitable for use in the compositions are represented by formula (I): wherein each R is independently selected from a C5 to C35 alkyl or alkenyl group; R¹ represents a C1 to C4 alkyl, C2 to C4 alkenyl or a C1 to C4 hydroxyalkyl group; T may be either O-CO. (i.e. an ester group bound to R via its carbon atom), or may alternatively be CO-O (i.e. an ester group bound to R via its oxygen atom); n is a number selected from 1 to 4; m is a number selected from 1, 2, or 3; and X- is an anionic counter-ion, such as a halide or alkyl sulphate, e.g. chloride or methylsulfate. Di-esters variants of formula I (i.e., m = 2) are preferred and typically have mono- and tri-ester analogues associated with them. Such materials are particularly suitable for use in the compositions described herein.

A second group of QACs suitable for use in the compositions described herein is represented by formula (II): CH.TR'¹ wherein each R¹ group is independently selected from C1 to C4 alkyl, hydroxyalkyl or C2 to C4 alkenyl groups; and wherein each R² group is independently selected from C8 to C28 alkyl or alkenyl groups; and wherein n, T, and X- are as defined above.

Preferred materials of this second group include 1,2 bis[tallowoyloxy]-3- trimethylammonium propane chloride, 1,2 bis[hardened tallowoyloxy]-3- trimethylammonium propane chloride, 1 ,2- bis[oleoyloxy]-3-trimethylammonium propane chloride, and 1,2 bis[stearoyloxy]-3- trimethylammonium propane chloride. Such materials are described in US 4, 137,180 (Lever Brothers). Preferably, these materials also comprise an amount of the corresponding monoester.

A third group of QACs suitable for use in the composition are represented by formula (III): wherein each R¹ group is independently selected from C1 to C4 alkyl, or C2 to C4 alkenyl groups; and wherein each R² group is independently selected from C8 to C28 alkyl or alkenyl groups; and n, T, and X- are as defined above. Preferred materials of this third group include bis(2-tallowoyloxyethyl)dimethyl ammonium chloride, partially hardened and hardened versions thereof.

A particular example of the fourth group of QACs is represented the by the formula (IV):

A fifth group of QACs suitable for use in the composition are represented by formula (V)

Ri and R2 are independently selected from C10 to C22 alkyl or alkenyl groups, preferably C14 to C20 alkyl or alkenyl groups. X- is as defined above.

The iodine value of the quaternary ammonium fabric conditioning material is preferably from 0 to 80, more preferably from 0 to 60, and most preferably from 0 to 45. The iodine value may be chosen as appropriate. Essentially saturated material having an iodine value of from 0 to 5, preferably from 0 to 1 may be used in the compositions described herein. Such materials are known as "hardened" quaternary ammonium compounds.

A further preferred range of iodine values is from 20 to 60, preferably 25 to 50, more preferably from 30 to 45. A material of this type is a "soft" triethanolamine quaternary ammonium compound, preferably triethanolamine di-alkylester methylsulfate. Such ester-linked triethanolamine quaternary ammonium compounds comprise unsaturated fatty chains.

If there is a mixture of quaternary ammonium materials present in the composition, the iodine value, referred to above, represents the mean iodine value of the parent fatty acyl compounds or fatty acids of all the quaternary ammonium materials present. Likewise, if there are any saturated quaternary ammonium materials present in the composition, the iodine value represents the mean iodine value of the parent acyl compounds of fatty acids of all of the quaternary ammonium materials present.

Iodine value as used in the context of the compositions described herein refers to, the fatty acid used to produce the QAC, the measurement of the degree of unsaturation present in a material by a method of nmr spectroscopy as described in Anal. Chem., 34, 1136 (1962) Johnson and Shoolery.

A further type of quaternary ammonium compound may be a non-ester quaternary ammonium material represented by formula (VI): wherein each R¹ group is independently selected from C1 to C4 alkyl, hydroxyalkyl or C2 to C4 alkenyl groups; R² group is independently selected from C8 to C28 alkyl or alkenyl groups, and X- is as defined above.

In a preferred embodiment the fabric softening active comprises a mixture of cationic quaternary ammonium compound having more than one long carbon chain in combination with a secondary surfactant selected from a single chain cationic surfactant and/or a non-ionic surfactant. Preferably the cationic quaternary ammonium compound having more than one long carbon chain and secondary surfactant are present in a ratio of 1 :10 to 10:1 , more preferably 1 :5 to 5:1. The combination of the cationic quaternary ammonium compound having more than one long carbon chain in combination with a secondary surfactant selected from a single chain cationic surfactant and/or a non-ionic surfactant provide a solid composition which can be diluted with water to form a stable liquid fabric softener and provides superior softening. Cationic quaternary ammonium compound having more than one long carbon chain are as described above.

Suitable single chain cationic surfactant preferably have the general formula:

(RI)₃ - N⁺ - R₂ X-

Wherein each Ri independently comprises 1 to 6 carbon atoms, selected from alky, alkenyl, aryl or combinations thereof. Each Ri may independently comprise hydroxy groups. Preferably at least two of the Ri groups correspond to a methyl group.

Wherein R₂ comprises at least 10 carbon atoms. The carbon atoms may be in the form of an alky, alkenyl, aryl or combinations thereof. Preferably the single chain cationic surfactant comprises at least 12 carbon atoms, preferably at least 14 and most preferably at least 16. R₂ may further comprise additional functional groups such as ester groups or hydroxy groups. X- is an anionic counter-ion, such as a halide or alkyl sulphate, e.g. chloride or methylsulfate Preferred cationic surfactants include Hydroxyethyl laurdimonium chloride, cetyltrimethylammonium chloride (CTAC), Behentrimonium chloride (BTAC), a Alkyl dimethyl hydroxyethyl ammonium chloride such as Praepagen HY ex Clariant GmbH.

The compositions described herein comprise more than 5 wt. % fabric softening active, more preferably more than 10 wt. % fabric softening active, most preferably more than 20 wt. % fabric softening active by weight of the composition. The fabric conditioners of the described herein comprise less than 80 wt. % fabric softening active, more preferably less than 70 wt. % fabric softening active, most preferably less than 65 wt. % fabric softening active by weight of the composition. The fabric conditioners comprise 5 to 80 wt. % fabric softening active, preferably 10 to 70 wt.% fabric softening active and more preferably 20 to 65 wt. % fabric softening active by weight of the composition.

Carbonaceous material

The compositions described herein comprise carbonaceous materials. The carbonaceous material leads to improved strength of the solid composition. Carbonaceous materials refer to materials having a 2D carbon lattice nanostructure. The 2D lattice may be flat for example graphene or may be shaped into a 3D shape such as carbon nanotubes. The carbonaceous material may be part of a larger structure, such as a composite material e.g. clay-carbonaceous material composite. Preferably the carbonaceous materials comprise a material selected from carbon nanotubes, graphene, activated carbon and combinations thereof. More preferably the carbonaceous materials comprise preferably graphene and/or derivatives thereof and most preferably graphene oxide.

Graphene is an allotrope, formed by a single layer carbon atoms arranged in hexagonal lattice structure. Graphene can be obtained in two manners. The first is by peeling layers from graphite until you achieve a graphene monolayer. The second is known as Chemical Vapor Deposition (CVD) and where large-scale uniformity can be obtained and controlled.

Preferably the graphene derivative suitable for the compositions described herein is graphene oxide. Graphene oxide can be manufactured through Hummer’s method. Graphene oxide is also commercially available and may be procured from suppliers such as Platonic Nanotech.

The compositions described herein preferably comprise 0.001 to 2 wt.% carbonaceous materials, more preferably 0.0025 to 1 wt.% carbonaceous materials, even more preferably 0.005 to 0.5 wt.% carbonaceous materials and most preferably 0.01 to 0.25 wt.% carbonaceous materials.

Water soluble carrier

The compositions described herein comprise water-soluble carrier. The water-soluble carrier provides solid structure to the solid fabric conditioner. The composition my comprise one carrier material or a combination of different carrier materials.

Suitable water soluble carrier materials may be selected from the group consisting of: synthetic polymers (e g, polyethylene glycol, ethylene oxide/propylene oxide block copolymers, polyvinyl alcohol, polyvinyl acetate, and derivatives thereof), proteins (e.g., gelatin, albumin, casein), saccharides (e.g. dextrose, fructose, galactose, glucose, isoglucose, sucrose), polysaccharides (e.g., starch, xanthan gum, cellulose, or derivatives thereof), vegetable soap (e.g. coconut soap beads or palm soap), ethoxylated non-ionic surfactants (having a formula RIO(R2O)XH, wherein Ri preferably comprises 12 to 20 carbon atoms, R2 is C2H4 or mixture of C2H4and C3H6 units and x = 8 to 120), urea and combinations thereof. Preferably synthetic polymers (e g, polyethylene glycol, ethylene oxide/propylene oxide block copolymers, polyvinyl alcohol, polyvinyl acetate, and derivatives thereof), proteins (e.g., gelatin, albumin, casein), polysaccharides (e.g., starch, xanthan gum, cellulose, or derivatives thereof), vegetable soap (e.g. coconut soap beads or palm soap), ethoxylated non-ionic surfactants (having a formula RIO(R2O)XH, wherein R1 preferably comprises 12 to 20 carbon atoms, R2 is C2H4 or mixture of C2H4and C3H6 units and x = 8 to 120) and combinations thereof.

Examples of suitable carrier materials include: water soluble organic alkali metal salt, water soluble inorganic alkaline earth metal salt, water soluble organic alkaline earth metal salt, water soluble carbohydrate, water soluble silicate, water soluble urea, starch, xanthan gum, dextrose, clay, water insoluble silicate, citric acid carboxymethyl cellulose, fatty acid, fatty alcohol, glyceryl diester of hydrogenated tallow, glycerol, polyvinyl alcohol, non-ionic surfactants sold under the trade name Lutensol ex. BASF and combinations thereof.

More preferably the water-soluble carrier is selected from polysaccharides, more preferably cellulose derivatives. Most preferably cellulose ether derivatives. Typically, cellulose ether derivatives are obtained by substituting one or more hydrogen atoms of hydroxyl groups in the anhydro-glucose units of cellulose with alkyl or substituted alkyl groups. Degree of substitution (DS) is one of the factors, that define the properties of cellulose ether derivatives, particularly, solubility in water. It is defined as the number of substituted hydroxyl groups for every glucose molecule ranging between zero and three. For example, cellulose ether derivatives with degree of substitution values between 1.2 to 2.4 are soluble in cold water. Examples of cellulose ether derivatives suitable for the compositions described herein includes methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), carboxymethyl cellulose (CMC) and sodium carboxymethyl cellulose (SCMC).

Preferably the cellulose ether derivative is selected form hydroxypropyl methyl cellulose, methyl cellulose, hydroxypropyl cellulose, and combinations thereof. Most preferred cellulose ether derivative is hydroxypropyl methyl cellulose.

The compositions described herein preferably comprise 2 to 80 wt.% water-soluble carrier materials, preferably 5 to 70 wt.%, more preferably 7.5 to 50 wt.% and most preferably 10 to 40 wt.% water-soluble carrier materials, by weight of the composition.

The water-soluble carrier preferably has a solubility at least 0.5% by weight in distilled water at 25 °C. Preferably a solubility at least 1.0 % by weight, more preferably at least 2 % by weight, and most preferably at least 3% by weight in distilled water at 25 °C. In other words, a solubility of at least 5 mg/ml of distilled water at 25°C, preferably at least 10 mg/ml of distilled water at 25°C, more preferably at least 20 mg/ml of distilled water at 25°C, most preferably 30 mg/ml of distilled water at 25°C.

Swellable disintegrant

The compositions described herein preferably comprise a swellable disintegrant. Swellable disintegrant herein refers to the components which swell in contact with water. The swellable disintegrant acts synergistically with the carbonaceous material to provide improved strength.

Preferably the swellable disintegrant has a Water Absorption Ratio (WAR) of greater than 1 , more preferably greater than 1.5. Water Absorption Ratio (WAR) is a measure as to how much water a material absorbs under controlled and defined conditions. Water absorption is expressed as the increase in weight percent of a specimen:

Increase in weight, % = [(wet weight - conditioned weight) / conditioned weight] x 100

The process described in ASTM D570 is suitable for measuring water absorption ratios. Specifically, the water absorption may be measured by:

Procuring a dry sample of the material to be tested

- Weighing the sample to be tested then, placing in a container of boiling distilled water for 120 minutes, ensuing it is entirely immersed.

Removing the specimen and removing excess water with filter paper.

- Weighing the sample immediately (wet weight) Drying the sample at 105°C for 20 minutes Reweighing the sample (conditioned weight)

The swellable disintegrant is preferably selected from sodium croscarmellose, sodium starch glycollate, crospovidone, C-TAG (co grinded treated agar) and C-TGG (co grinded treated guar gum), mucilage (for example from Isapgula or Fenugreek seed), Chitin, cross-linked cellulose (for example microcrystalline cellulose), sodium starch glycolate and mixtures thereof. More preferably the swellable disintegrant is selected from crosslinked cellulose (preferably microcrystalline cellulose), sodium starch glycolate and mixtures thereof. Even more preferrable the water swellable disintegrant is selected from crosslinked cellulose, and most preferably the water swellable disintegrant is selected from microcrystalline cellulose.

The composition may comprise from 1 to 30% by weight swellable disintegrant, more preferably from 2 to 20% by weight and most preferably from 3 to 15% by weight swellable disintegrant.

The composition described herein may further comprise a non-swellable disintegrant. Non- swellable disintegrant herein refer to those which have water absorption ratio (WAR) less than 1. Preferably the non-swellable disintegrate is selected from polyvinyl pyrrolidone, calcium silicate, starch, magnesium stearate and mixtures thereof.

Other ingredients

The compositions described herein may comprise additional ingredients common in the field of solid fabric conditioners, for example perfumes, perfume microcapsules, dyes, antifoams, insect repellents, shading or hueing dyes, preservatives (e.g. bactericides), pH buffering agents, perfume carriers, hydrotropes, anti-redeposition agents, soil-release agents, polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, anti-oxidants, colorants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents, sequestrants and ironing aids. The compositions described herein may contain pearlisers and/or opacifiers. Preferably the compositions comprise perfume, more preferably comprises 0.1 to 25 wt.% perfume, even more preferably 1 to 20 wt. % perfume and most preferably 2 to 15 wt.% perfume.

Water

The solid fabric conditioner described herein are preferably ‘free from water’ when manufactured, however they may absorb moisture on storage. Therefore, preferably the composition comprises 0 to 20 wt.% weight, more preferably 0 to 15 wt.% water, most preferably 0 to 12 wt.% water. Water content may be measured by thermogravimetry, like moisture balance.

Process of making and use of the compositions

The solid fabric conditioner composition described herein may be in any suitable form. A single dose of the composition may be a single article (e.g. a tablet or sheet), a part of a single article (i.e. a part of a sheet separated by tearing a section off a larger sheet), or may consist of multiple articles, (e.g. multiple particles of the composition). Preferably the solid composition is in the form of articles having a minimum linear dimension in any direction of more than 1 mm. The solid fabric conditioner composition does not include powders. Preferably the solid composition is in a form suitable for use as a single article for example a tablet or sheet. These may be referred to as a ‘unit dose’.

The solid fabric conditioner may be made by any suitable process. A preferred method comprises the steps of; a) Preparing a premix of a water-soluble carrier and water; b) Adding fabric softening active, carbonaceous material and any remaining ingredients to the premix; c) Casting the mixture on a surface or in a mold; and d) Removing the water, preferably by evaporation.

Step a) preferably comprises mixing and/or heating.

Step b) preferably comprises mixing fabric softening active, carbonaceous material and any remaining ingredients with water prior to addition to the pre-mix. In step c) if casting is used, preferably the thickness is controlled using an applicator. The mixture is preferably cast onto a Polytetrafluoroethylene (PTFE) surface, for example PTFE sheets, PTFE coated foils or PTFE coated fabrics.

Step d) preferably takes place at a temperature above room temperature (above 25°C), preferably at less than 100 °C, and more preferably less than 95 °C. Most preferably water is removed at a temperature of 70 to 90 °C. Preferably water is removed to reach a composition water content of 0 to 20 wt.%, more preferably a water content of 0 to 15 wt.%, more preferably 0 to 10 wt.%, even more preferably 0 to 5 wt. % and most preferably 0 to 2 wt.%.

More specifically a homogenized premix of water and water-soluble carrier is prepared with mixing. Subsequently, the swellable disintegrant, the carbonaceous material, fabric softening active and all remaining ingredients are mixed with water under high shear before being added to the premix. Thereon the premix is casted on a surface as a sheet or film with certain thickness.

Examples

Table 1: Example formulations

Quaternary ammonium compound¹ - TEA palm quaternary ammonium compound

Micro-crystalline cellulose² - KEVICEL PH 102 ex. Keval Exports The formulations where prepared by dispersing the hydroxypropyl methyl cellulose in hot water to make a 10% polymer solution. Separately the quaternary ammonium compound and perfume were mixed in the remaining water under high shear to make an emulsion. The remaining ingredients were added to the emulsion and mixed. The final mix was added to the polymer solution at room temperature and mixed well at high shear until a stable foam was formed. The foam was cast on a smooth, hard surface and dried at 80-90°C for 2 hours. The dried sheet was detached from the substrate on cooling.

Tensile strength was measured using a Zeus Ultimo tensile testing machine ex. Presto. The measurement was made according to ASTM D882. A 2.5cm X 5cm sample of the sheet as made above was fixed to the tensile testing machine and clamps connected to the load sensor. The sheet was pulled apart at a fixed speed of 300 mm/min. The tensile strength was measured at the breaking point of the sample.

Table 2: Results

Tensile strength was improved with the inclusion of a carbonaceous material. The improvement in tensile strength is greater when a carbonaceous material is present. This effect is further improved by the presence of a swellable disintegrant (microcrystalline cellulose).

Claims

1. A solid fabric conditioning composition comprising: a 5 to 80 wt.% Fabric softening active comprising quaternary ammonium compound; b Carbonaceous material; and c Water soluble carrier

Wherein the carbonaceous material has a 2D carbon lattice nanostructure.

2. A solid fabric conditioning composition according to claim 1, wherein the composition further comprises swellable disintegrant selected from: sodium croscarmellose, sodium starch glycollate, crospovidone, C-TAG (co grinded treated agar) and C-TGG (co grinded treated guar gum), mucilage (for example from Isapgula or Fenugreek seed), Chitin, cross-linked cellulose (for example microcrystalline cellulose), sodium starch glycolate and mixtures thereof.

3. A solid fabric conditioning composition according to claim 2, wherein the swellable disintegrant is selected from disintegrants having a Water Absorption Ratio (WAR) of greater than 1.

4. A solid fabric conditioning composition according to claims 2 or 3, wherein the composition comprises 1 to 30 wt.% swellable disintegrant.

5. A solid fabric conditioning composition according to any preceding claim, wherein the fabric softening active comprises a mixture of cationic quaternary ammonium compound having more than one long carbon chain in combination with a secondary surfactant selected from a single chain cationic surfactant and/or a non-ionic surfactant.

6. A solid fabric conditioning composition according to any preceding claim, wherein the carbonaceous material comprises a material selected from carbon nanotubes, graphene and derivatives thereof, activated carbon and combinations thereof.

7. A solid fabric conditioning composition according to any preceding claim, wherein the carbonaceous material comprises graphene and/or derivatives thereof. A solid fabric conditioning composition according to any preceding claim, wherein the composition comprises 0.001 to 2 wt.% carbonaceous materials. A solid fabric conditioning composition according to any preceding claim, wherein the water soluble carrier is selected from: synthetic polymers, proteins, saccharides, polysaccharides, vegetable soap, ethoxylated non-ionic surfactants, urea and combinations thereof. A solid fabric conditioning composition according to any preceding claim, wherein the water soluble carrier is selected from: cellulose derivatives and combinations thereof. A solid fabric conditioning composition according to any preceding claim, wherein the composition comprises 2 to 80 wt.% water-soluble carrier. A solid fabric conditioning composition according to any preceding claim, wherein the composition further comprises perfume. A method of preparing a solid fabric conditioning composition comprising the steps of; a Preparing a premix of water-soluble carrier and water; b Adding fabric softening active, carbonaceous material and any remaining ingredients to the premix; c Casting the mixture on a surface or in a mold; and d Removing the water, preferably by evaporation.