HU218969B - Fabric softening composition - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention relates to a solubilized rinse conditioner comprising a fabric softening compound and a dual ionic surfactant material. More specifically, the present invention relates to a fabric softening composition comprising: i) a substantially water-insoluble fabric softener compound which may be a C2-C12 alkyl or alkenyl group containing at least one ester group attached to a quaternary ammonium major group, or an average of 20 or more; a quaternary ammonium compound containing a single chain of carbon black; and ii) a single solubilizing agent comprising an amphoteric surfactant and, optionally, a non-surfactant co-solubilizing agent, wherein the weight ratio of the solubilizing agent i) to the fabric softening compound i) is greater than 1: 6, and an aqueous dilution of the composition when i) and ii) the component concentration is reduced to 5% by weight, and at least 70% by weight of the fabric softener is in solution. ŕ

Description

The present invention relates to fabric softener compositions, in particular to fabric softener compositions having excellent stability, dosage and dispersion properties.

Fabric softener compositions containing rinse aid are well known products. These compositions contain a water-dispersible, water-insoluble fabric softener. In the case where the amount of active ingredient is up to 7% by weight, diluted formulations are used, and if this amount is 7-30% by weight, the formulation is considered to be concentrated. In tumble dryers, sheets coated with a plasticizer compound can also be used to soften textiles. Commercially available fabric softener compounds are generally layered structures characterized by specific Lp-La phase transition temperatures.

Conventional fabric softener compositions containing fabric softener have a softening effect by depositing the dispersed colloidal particles of the fabric softener on the fabric and transferring the fabric softener compound from the fabric softener sheets used in the tumble dryer directly to the fabric, as described in "Science" 2, Volume 37, Physical Properties of Cationic Surfactants 449-465. pages (Marcer Decker, Inc., 1991). Conventional liquid fabric softener compositions contain dispersed colloidal particles of a fabric softener compound. The fabric softener compositions may be a fabric softener compound dissolved in an organic solvent, or a powder or granular product.

Textile softener compositions contain dispersed colloidal particles of complex or unstable structure. Due to the instability, conventional fabric softener compositions have a number of problems. The main problems are: physical instability at high or low temperature storage; irreversible gelling at frost digging; difficult to meet requirements for formulations that are highly dispersible in the laundry, well deposited on the fabric, and dispensable from the dispenser drawer. The poorly dispersible fabric softener creates an uneven textile coating and sometimes causes stains. These problems are concentrated formulations and are exacerbated when perfume is added.

In the event of physical instability, the composition becomes so thick that the composition becomes inert and may even lead to irreversible gel formation. Gel formation may also occur in the dispenser drawer due to the increased temperature of the drawer due to the influx of hot water. Concentration is highly undesirable because it renders the formulation unusable. Physical instability may also occur by separating the preparation into two or more separate layers.

The consumer requires a concentrated product that is highly dispersible and dispensable, and can be stored well at high and low temperatures.

Numerous suggestions have been made in the art for solving problems associated with conventional fabric softener compositions containing dispersed colloidal particles.

U.S. Patent 4,789,491 describes the preparation of aqueous dispersions containing cationic plasticizers. The process is described to overcome the problems of viscosity of the product and poor dosing and dispersion as a result of storage.

A critically low pH adjustment is used to stabilize dispersions containing diester or monoester quaternary ammonium compounds having one or two methyl groups as described in EP 0 239 910.

A viscosity control agent or an agent to prevent gel formation may also be used to increase the physical stability of fabric softener compositions containing the fabric softener. For example, European Patent 13,780 discloses a viscosity control agent for certain concentrated formulations. Examples of such agents are C10-C18 fatty alcohols. EP-A-280 550 recently discloses biodegradable formulations containing quaternary ammonium compounds and fatty acids that use nonionic surfactants to enhance physical stability. European Patent 507,478 discloses a physically stable fabric softener composition comprising a water-insoluble, quaternary ammonium compound linked to a biodegradable ester group and a nonionic stabilizer.

Many fabric softeners in granular or powder form are also disclosed. Such typical agents described in European Patent Publication No. Alii 074 contain silica as a carrier for the plasticizer. The disadvantage of using carriers such as silica is that the product is compacted and does not ensure compatibility with other additives in the detergent powder.

European Patent No. 569,184 discloses a so-called pre-diluted granular composition that can be used when dispensed into a dispenser drawer.

WO 92/18593 discloses a granular fabric softener composition which, when added to water, forms an aqueous emulsion. This composition contains a nonionic fabric softener such as a sorbitan ester and a mono (lower alkyl) cationic surfactant.

WO 93/23510 discloses liquid and solid fabric softeners comprising a biodegradable diester quaternary ammonium fabric softener and a viscosity and / or dispersant. Specific processes for their preparation are also described. The viscosity and / or dispersant modifier may be a long chain alkyl cationic or a nonionic surfactant. The solid composition forms an emulsion or dispersion when added to water.

HU 218,969 Β

EP 728 178 discloses concentrated fabric softeners containing tegobetaine to combat perfume instability.

In order to overcome the problems associated with dispersed colloidal particles, proposals have previously been made for the production of fabric conditioning agents containing fabric softener compounds dissolved in organic solvents. Typical compositions of this type are those described in EP 681 604. However, upon contact with water, dispersed colloidal particles are still formed.

Further structural modification is another possibility for fabric conditioning solutions.

U.S. Pat. No. 3,892,669 discloses liquid homogeneous aqueous liquid fabric softener compositions which are limited to the use of solubilized tetraalkyl quaternary ammonium salts having two lower alkyl groups and two long alkyl groups and some methyl and ethyl branching in the longer chains. Solubilizers include arylsulfonates, diols, ethers, low molecular weight quaternary compounds, sulfobetaines, and nonionic surfactants. This specification discloses that nonionic surfactants and phosphooxides alone cannot be used as co-solubilizers.

In our work, we have developed new fabric softeners that overcome the previous disadvantageous properties. FIELD OF THE INVENTION The present invention relates to fabric softener compositions having excellent softening properties which exhibit excellent storage stability, good freeze-thaw properties at low and high temperatures, and excellent dosing and dispersibility in concentrated compositions even when the amount of fabric softener compound is greater than 30% by weight. . In addition, the compositions of the present invention retain their plasticizing properties.

Accordingly, the present invention relates to a fabric softener composition having the following composition:

(i) a substantially water-insoluble fabric softening compound, which may be a compound having two C12-C22 alkyl or alkenyl groups attached to at least one ester group via a quaternary ammonium main group, or a quaternary ammonium compound having an average of 20 or more carbon atoms; and ii) a solubilizer comprising an amphoteric surfactant and, optionally, a non-surfactant co-solubilizer, wherein the solubilizer of ii) has a weight ratio to fabric softener compound i) of greater than 1: 6; The concentration of components i) and ii) is reduced to 5% by weight and at least 70% by weight of the fabric softener compound is in solution.

Another object of the present invention is a fabric softener composition in the form of a so-called size-limiting molecular aggregate (hereinafter described in more detail).

Without wishing to be bound by theory, it is believed that the fabric conditioning agent of the present invention is not conventionally layered and, upon contact with water, is partially solubilized as a size-limiting molecular aggregate, such as micelles or solid solutions containing solids or liquids or mixtures thereof. When the composition is in the form of an aqueous medium, the composition is at least partially in the form of a size-self-limiting molecular aggregate. It is believed that the use of such novel fabric softener compositions will overcome the previous problems.

The fabric softener compound and the solubilizing agent form, if appropriate, a transparent mixture. The following tests may be used to determine whether a composition falls within the scope of the present invention:

Study I

a) The fabric softener composition is diluted with water to a total concentration of 5% by weight of the fabric softener compound and all solubilizers, i.e., the nonionic surfactant and any non-surfactant co-solubilizer present. The diluted material was heated to 60-80 ° C, cooled to room temperature and stirred for 1 hour to equilibrate. From the first portion of the liquid to be examined, settle or filter off the undissolved solid; separation is carried out until a clear solution is obtained. (An ultracentrifuge or ultrafilter may also be used for this purpose.) The filtration may be carried out using filters of 1 µm, 0.45 µm and 0.2 µm, respectively.

b) The concentration of the fabric softener compound in the clear layer is determined by two-phase titration using a standard anionic surfactant (sodium dodecyl sulfate) titrator and dimethyl sulfide disulfin blue indicator and chloroform extraction solvent.

c) Repeat the titration with the second portion of the diluted but not separated fabric softener composition using the anionic surfactant.

d) Comparison of the results of measurements b) and c) should result in the composition tested in b) to contain at least 70 wt.%, preferably at least 80 wt.% of the textile softener compound content of the composition under c). This result means that the fabric softener compound is in solution.

II. test

a) The fabric softener composition is diluted as described in Test I.

b) Measure the viscosity of the diluted material using a shear rate of 110 s ¹ .

c) The diluted material is heated to 60 ° C and maintained at this temperature for 1 day.

d) The diluted material is cooled to 20 ° C and viscosity is again measured ^{using a} shear rate of 110 s.

e) Comparison of the results of the viscosity measurements in (b) and (c) shows that the difference is less than 5 mPa.s.

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Preferably, the fabric softener composition of the present invention also meets the requirements of the following test.

III. test

a) The fabric softener composition is diluted as described in Test I.

b) measuring the viscosity of the diluted material using a shear rate of 110 sec ^l.

c) The diluted material is frozen and thawed.

d) The viscosity is once again megméijük 110 sec ¹ shear rate.

e) Comparison of the results of the viscosity measurements in (b) and (c) shows that the difference is less than 10 mPa.s.

The fabric softener composition of the present invention may also be translucent. As used herein, the term "translucent" means that when a cell 1 cm deep is filled with a fabric softener composition, a "Courier 12" font can be read through the cell.

A further advantage of the invention is that the advantageous effect of the compositions of the invention over the prior art compositions is achieved in the presence of a similar concentration of a fabric softener compound.

A further advantage of the invention is that the stability of the product is not affected by the use of large amounts of perfume.

The fabric softening compound is described in more detail below.

Preferably, the fabric softener compound is a water-insoluble quaternary ammonium derivative containing a single alkyl or alkenyl chain having 20 or more carbon atoms, or more preferably, the fabric softener comprises a polar main group and two alkyl or alkenyl groups having an average of 12 carbon atoms. The latter compounds are, for example, quaternary ammonium derivatives containing two C 12 -C 22 alkyl or alkenyl groups attached to the quaternary ammonium main group via at least one ester group.

The fabric softener compound of the present invention preferably contains two long chain alkyl or alkenyl groups having an average chain length of 14 or more carbon atoms, more preferably 16 or more carbon atoms. Most preferably, at least 50% of the long chain alkyl or alkenyl groups contain 18 carbon atoms.

Preferably the long chain alkyl or alkenyl groups of the fabric softening compound of the present invention are primarily linear.

The fabric softener compounds used in the compositions of the present invention are excellent plasticizer molecules having a transition melting temperature - Lp-La - of greater than 25 ° C, preferably greater than 35 ° C, and most preferably greater than 45 ° C. Measurement of the Lp-La transition can be accomplished by DSC. The procedure is described in "Handbook of Lipid Bilayers" by D. Marsh, CRC Press, Boca Raton Florida, 1990, 137. pages 337 and 337.

As used herein, the term "substantially insoluble fabric softener compound" is used to describe a fabric softener compound having a solubility in deionized water at 20 ° C of less than 1 χ 10 ~ ³ % by weight, preferably less than 1 χ 10 ~ ⁴ % by weight, and more preferably less than 1 χ 10 ^-8 to 1 χ 10 ~ ⁶ % by weight.

The term "tallow ester" as used herein refers to an alkanoyloxy group derived from tallow fatty acid.

Preferred fabric softener compounds are quaternary ammonium compounds.

Particularly preferably, the fabric softening compound is a water-insoluble quaternary ammonium compound containing two C12-C18 alkyl or alkenyl groups attached to a molecule by at least one ester. More preferably, the quaternary ammonium compound contains two ester linking groups. A particularly preferred ester group-linked quaternary ammonium compound for use in the present invention is characterized by the general formula

R ¹ is independently C 1-4 alkyl, hydroxyalkyl or C 2-4 alkenyl; and

R ² is independently C 8 -C 28 alkyl or alkenyl;

OO ^{11 11}

T is -O-C- or -C-O-; and n is an integer from 1 to 5; and

A is a suitable anion such as a halide, acetate or lower alkyl sulfate ion.

Particularly preferred compounds of formula I are di (tallow ester) dimethylammonium chloride, available from Hoechst.

A further class of preferred quaternary ammonium compounds are compounds of formula II wherein

R ¹ is independently C 1-4 alkyl, hydroxyalkyl or C 2-4 alkenyl; and

R ² is independently C 8 -C 28 alkyl or alkenyl;

n is an integer from 1 to 5;

A is a suitable anion such as a halide, acetate or lower alkyl sulfate ion.

The quaternary ammonium compound is preferably a biodegradable compound from an environmental point of view.

Compounds of this type, for example 1,2-bis (hardened tallow ester) -3-trimethylammoniopropyl chloride, and processes for their preparation are described, for example, in U.S. Patent 4,137,180. These materials, as described in the above patent, preferably contain small amounts of the appropriate monoester, such as 1- (hardened tallow ester) -2-hydroxy-3-trimethylammoniopropyl chloride.

Amphoteric is a solubilizer

The solubilizer is an amphoteric surfactant characterized by its phase properties.

HU 218,969 Β

Suitable solubilizers include amphoteric surfactants which form the first liquid crystalline phase formed upon contact with water, as described by G. J. T. Tiddy et al., J. Chem. Soc. Faraday Trans. I., 79,975,1873 and G. J. T. Tiddy, "Modem Trends in Colloid Science in Chemistry and Biology", Ed. H-F. Eicke, 1985, Birkhauser Verlag Basel, can be normal cube (II) or normal cube biocontinous (VI), hexagonal (HI), nematic (Nel) or intermediate (Inti) phase. At less than 20% by weight, surfactants which form the La phase are not suitable.

As used herein, the term "amphoteric surfactant" is used to refer to materials having a hydrophilic and a hydrophobic moiety. The hydrophobic part consists of a hydrocarbon and the hydrophilic part consists of a positive and a negative group. Preferred amphoteric surfactants include amine oxides, betaines, including sulfobetaines and tegobetaines, phosphine oxides and sulfoxides.

Mixtures of solubilizers may also be used.

In the case of solid formulations, particularly in powder formulations, the solubilizing agent is desirably solid at room temperature to form fragments of the formulation.

It is particularly preferred that the solubilizer also contains a non-surfactant co-solubilizer. These include, for example, propylene glycol, urea, up to 6 carbonic acid amides, citric acid, and other polycarboxylic acids as described in European Patent 0 404 471, as well as glycerol, sorbitol and sucrose. Particularly preferred are polyethylene glycols having a molecular weight of 200-6000 and more preferably 1000-2000.

The weight ratio of co-solubilizer to amphoteric surfactant is preferably (2: 1) to (1:40) and weight ratio to nonionic surfactant is less than 1: 1, more preferably 1: 5.

The weight ratio of solubilizer (which includes the co-solvent used) to the fabric softener compound is greater than 1: 6, preferably greater than 1: 4, and more preferably 2: 3 or greater. The weight ratio of solubilizer to fabric softener is 4: 1 or less, more preferably less than 3: 2.

The amount of solubilizer / co-solubilizer is preferably greater than 5% by weight, preferably more than 10% by weight, of the total composition.

The amount of solubilizer / co-solubilizer may be more than 20% by weight or even more than 30% by weight of the total composition. Such a large amount is particularly advantageous when the fabric softener composition is solid.

PH of the preparation

The pH of the composition of the invention is preferably greater than 1.5 and more preferably less than 5.

Other additives

The composition may contain fatty acids, for example

C 8 -C 24 alkyl or alkenyl monocarboxylic acids or polymeric carboxylic acids. Saturated fatty acids are preferred, in particular hardened C16-C18 tallow fatty acids.

Preferably, the amount of fatty acid is greater than 0.1% by weight, more preferably greater than 0.2% by weight. Particularly preferred are concentrates containing from 0.5 to 20% by weight of fatty acids and more preferably from 1 to 10% by weight of fatty acids. The weight ratio of the fabric softener compound to fatty acids is from 10: 1 to 1:10.

The compositions of the invention may, if desired, contain a detergent builder and / or anionic surfactant. However, it is particularly preferred that the formulations are free of builders. Preferably, the compositions do not contain any substantially anionic surfactant.

The formulations are substantially free of nonionic hydrophobic organic substances such as hydrocarbons and fatty acid hydrocarbon esters.

The compositions may optionally contain one or more additional additives. Such materials include non-aqueous solvents, pH buffering agents, perfumes, perfume carriers, fluorescent agents, colorants, hydrotropes, antifoaming agents, anti-settling agents, polymeric or other thickening agents, enzymes, optical whitening agents, opacifying agents, shrinking agents, shrinking agents, shrinking agents, , fungicides, antioxidants, corrosion inhibitors, fabric improvers, antistatic agents, and ironing aids.

product Form

The product can be prepared in any product form. Particularly preferred are liquid and solid compositions and compositions suitable for coating sheets in the dryer. The solid compositions may be in the form of tablets, gels, pastes and, preferably, granules or powders.

The formulations may also be used in a tumble drier, but preferably in a washing machine, added to the dispenser drawer, optionally diluted prior to dosing.

Preparation of the preparation

It is a further object of the present invention to provide a fabric rinse conditioner as described above, comprising the steps of:

i) preferably combining the substantially water-insoluble fabric softener compound and the solubilizer with melting; and ii) adding the resulting mixture to conventional additives such as water.

Alternatively, the composition may be prepared by independently adding the water-insoluble textile softener and the solubilizer to the conventional additives.

Solid form preparations may be prepared by spray drying, freeze drying, milling, extraction, cryogenic milling or any other suitable process.

The following examples are intended to illustrate the invention in more detail and are not intended to limit the scope of the invention. In the examples,% values are by weight. For comparative examples, refer to5

HU 218 969 Β re and numerals are used to denote examples of the present invention.

Preparation of the Examples

The formulations shown in the following examples are prepared by one of the following procedures.

1. The fabric softener compound is melted together with the solubilizer and the dispersion thus obtained is added to the desired amount of hot water.

2. Add the fabric softener and the solubilizer to the spinning water one after the other.

For comparative formulations containing no solubilizing agent, the cationic material is dispersed in hot water (liquid formulations).

The abbreviations used in the examples are:

HT TMAPC = 1,2-bis (hardened tallow ester) -3-trimethylammoniopropyl chloride DEQA = di (tallow ester ethyl) dimethylammonium chloride

Plasticizing assessment

One gram of water softener compound (0.1 g, 2 ml of a 15% w / w dispersion of active detergent) is added to 1 liter of water at a temperature of 10 ° C in 1 liter of room temperature water containing 10% French sodium alkyl benzene sulphonate (ABS). ABS is used to facilitate the transfer of the anionic detergent from the main wash. Place 3 pieces of fluffy towels (8 χ 8 cm, total weight g) in the tergotometer. The materials were treated at 65 rpm for 5 minutes, centrifuged to remove excess liquid, and dried overnight.

The softness of the fabric is determined by a four-member panel of experts. The test is confirmed by a signed protocol signed by the members. Each member evaluates 4 sets of textiles to be tested. Each set of fabrics to be tested consists of fabrics belonging to a system to be tested. Committee members use an 8-point scale for comparison. The degree of softness is determined by the "variance analysis" method. Lower values indicate a better softening effect.

Example Component (crowd%) First Second Third HTTMAPC 1.2 1.2 0.9 CIO sulfobetaine 0.30 - - C14 sulfobetaine - 0.3 0.6 Water 8.5 8.5 8.5

The formulations are well dispersible and can be administered.

4-7. Examples A and B are comparative examples

By one of the methods described above, compositions containing the fabric softening compound and the solubilizer can be prepared according to the following table. This table also summarizes the results of the softening effects of the formulations.

HTTMAPC: * L5351 (wt%) Lágyságérték THE 5: 0 2.5 4th 4: 1 2.75 5th 3: 2 3.0 6th 2: 3 3.25 7th 1: 4 5.5 B 0: 5 7.25

* Fatty acid amidoalkyl betaine, manufactured by Th Goldschmidt

4-7. The compositions disclosed in Examples 1 to 4 show good plasticizing activity and good stability. Preparation A is prepared as described in section III above. undergoes a freeze / thaw test.

1-3. Examples 8-14. Examples A and C to F are comparative examples

The following compositions are prepared as described above. 45 are summarized in the following table.

8th 9th 10th 11th 12th 13th 14th C D E F HTTMAPC 9 7.5 9 7.5 DEQA 7.5 9 7.5 ♦ ArosurfTA-100 9 7.5 9 7.5 DDAO 6 7.5 7.5 6 7.5 Tegobetaine L5351 6 7.5 6 7.5 6 7.5 Perfume 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 Water 84.1 84.0 84.1 84.1 84.1 84.1 84.1 84.1 84.1 84.1 84.1

DDAO = N, N-dimethyl dodecylamine N-oxide, Flucka product L5351, Th Goldschmidt product * distearyl dimethyl ammonium chloride product, Shercx product

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7-14. The storage stability of the compositions of Examples was determined that the formulations under different conditions (which will appear hereinafter referred to as F / O) including freeze / thaw conditions is maintained, and a Carri-med rheometer at 110 sec ¹ shear 5 rósebesség their viscosity. The results are summarized in the following table.

Each of the comparative formulations and their components each exhibit poor stability.

8th 9th 10th 11th 12th 13th 14th Initial return- viscosity of [MPa.s] 19.7 12.9 12.8 13.5 7.8 12.9 12.5 2 weeks (F / O) 25.4 24.8 12.3 12.5 18.6 13.2 12.9 4 ° C 27.2 25.3 12.5 12.8 12.5 14.0 12.9 22 ° C 28.7 30.4 15.1 13.4 16.5 14.0 13.6 37 ° C 15.1 10.2 46.9 29.5 54.9 14.1 13.9 4 weeks (F / O) 21.5 22.5 12.5 12.7 26.5 13.6 12.9 4 ° C 26.0 24.1 12.6 12.8 37.5 14.1 13.2 22 ° C 23.4 26.2 15.0 14.1 65.6 13.0 12.7 37 ° C 13.0 7.3 18.73 19.4 90.9 14.2 14.1 10 weeks (F / O) 16.3 15.1 12.6 12.7 46.2 13.5 12.8 4 ° C 16.1 27 12.4 12.3 15.1 14.2 13.2 22 ° C 24.9 18.7 16.0 14.1 41.7 15.1 12.9 37 ° C 71.8 61.6 21.5 16.1 531.2 16.1 14.5

Each of the compositions of the present invention exhibits acceptable storage stability and does not separate within the freeze / thaw range.

The formulations were subjected to Assay I as described above and screened for separation using a 1, 0.45 and 0.2 pore filter, respectively. The residual cationic material was determined by standard titration. The results are summarized in the following table.

Example using nonionic material % Cationic material remaining after 0.2 µm filtration 8th 85 9th 90 10th 97.1 11th 94.9

Example using nonionic material % Cationic material remaining after 0.2 µm filtration 12th 86.3 13th 84.6 14th 94.1 C 50 D 56 E 16 F too viscous for filtration

The formulations are prepared as described in Table II above. and III. subject to investigation. The viscosity measurement is carried out with a Carrimed rheometer at 110 sec ¹ shear rate. The results are summarized in the following table.

would Initial viscosity (mPas) II. test (24 hours, 60 ° C / mPa · s) III. test (freeze / read / mPas) 8th 3.2 3.4 3.8 9th 6.8 4.1 2.7 10th 2.7 1.9 2.8 11th 2.6 2.0 1.8 12th 2.0 4.2 3.5 13th 2.6 2.5 2.1 14th 1.8 1.7 2.3 C 7.4 come apart D come apart come apart E 57 95 F 111 come apart

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The plasticizing effect of the formulations is determined. The test is carried out with a 5% solution of a 3: 2 weight ratio fabric softener and solubilizer. The results are summarized in the following table.

Sample Lágyságérték 5% HEQ5 0 3.0 10 2.75 13 3.75

PATENT CLAIMS

Claims (10)

PATENT CLAIMS 1. A fabric softener composition having the following composition: (i) a substantially water-insoluble fabric softening compound, which may be a compound having two C12-C22 alkyl or alkenyl groups attached to at least one ester group via at least one ester group or a quaternary ammonium compound having an average of 20 or more carbon atoms; and ii) a solubilizer comprising an amphoteric surfactant and optionally a non-surfactant co-solubilizer, characterized in that the solubilizer of ii) has a weight ratio to fabric softener of i) greater than 1: 6, and when diluted, when the concentration of components (i) and (ii) is reduced to 5% by weight, at least 70% by weight of the fabric softener compound is in solution. The fabric softener of claim 1, wherein the quaternary ammonium compound is a substantially water-insoluble fabric softener comprising two C12-C22 alkyl or alkenyl groups attached to at least one ester group through a quaternary ammonium main group. The fabric softener composition according to claim 1 or 2, characterized in that the solubilizer comprises an amphoteric surfactant and a non-surfactant co-solubilizer. 4. A fabric softener composition according to any one of claims 1 to 4, wherein the weight ratio of solubilizer to fabric softener is from 2: 3 to 4: 1. 5. A fabric softener composition according to any one of claims 1 to 6, wherein the fabric softener compound has a solubility in deionized water at 22 ° C of less than 1 x 10 ³ % by weight. 6. A fabric softener composition according to any one of claims 1 to 5, characterized in that the plasticizer compound is selected from the group consisting of 1,2-bis (hardened tallow ester) -3- (trimethylammonio) propyl chloride and di (tallow ester ethyleneoxy) dimethylammonium chloride. 7. A fabric softener composition according to any one of claims 1 to 5, wherein the solubilizer is present in an amount of more than 10% by weight of the composition. 8. A fabric softener composition according to any one of claims 1 to 5, characterized in that it is in the form of a size-limiting molecular aggregate. 9. A fabric softener composition according to any one of claims 1 to 3, characterized in that it is in liquid form. 10. A fabric softener composition according to any one of claims 1 to 5, characterized in that it is in the form of a powder or granules.