GB2499628A

GB2499628A - Method of producing an aqueous fabric conditioning composition

Info

Publication number: GB2499628A
Application number: GB201203117A
Authority: GB
Inventors: Robert Eric Williams
Original assignee: Robert McBride Ltd
Current assignee: Robert McBride Ltd
Priority date: 2012-02-23
Filing date: 2012-02-23
Publication date: 2013-08-28
Also published as: GB201203117D0

Abstract

A method of producing an aqueous fabric conditioning composition comprises the steps of: 1) providing: a) an aqueous base formulation containing a quaternary ammonium fabric conditioning agent homogeneously distributed therein; b) an additive formulation which is a homogenous admixture of an amino functional silicone and a free oil perfume; and c) an encapsulated fragrance; and 2) admixing the aqueous base formulation, the additive formulation and the encapsulated fragrance to produce the fabric conditioning composition. Preferably the quaternary ammonium fabric conditioning agent is an ester quat [Stepanquat (RTM) GA90]. Preferably the amino functional silicone is Wacker (RTM) FC218 or FC203, or KF873 (Shin-Etsu Silicones). The fabric conditioner composition may additionally comprise a colourant, a stabilizer, and a viscosity modifier. By pre-mixing the amino functional silicone with the free oil perfume it is possible for step (2) of the method to be effected at ambient temperature and produce an aqueous fabric conditioning composition in which the encapsulated perfume is uniformly distributed without aggregation.

Description

1

A Method of Producing Aqueous Fabric Conditioning Compositions

The present invention relates to a method of producing an aqueous fabric conditioning liquid compositions intended for use particularly, but not necessarily exclusively, in domestic laundry operations. More specifically, the present invention provides an improved method for producing aqueous fabric conditioning liquid compositions which comprise a fabric conditioning quaternary ammonium salt, an amino silicone polymer and an encapsulated perfume, optionally together with other components.

Aqueous fabric conditioning compositions are liquid aqueous suspensions or emulsions that comprise a major amount of water, lesser amounts of fabric conditioning agents, and minor amounts of optional components such as fragrances (in the form of free perfume oils and/or encapsulated perfumes), dyes or other colouring agents, preservatives and stabilisers. Such fabric conditioning compositions are usually incorporated in the dispensing drawer of a domestic washing machine and dispensed into the final rinse cycle of the machine to impart an improved "skinfeel" to the laundered items.

Many different classes of fabric conditioning agents are used in commercially available liquid fabric conditioning compositions intended for the domestic laundry market, although the most extensively used class for this purpose is comprised of quaternary ammonium salts which are used to impart softness to laundered items. Historically, quaternary ammonium salts used as fabric softening agents were di-(long chain) alkyl, dimethyl quaternary ammonium compounds although in more recent years these have been extensively replaced by so-called "ester quats" in view of the improved biodegradability of the latter. All that said, there is a multitude of fabric conditioning, quaternary ammonium compounds known to the person skilled in the art.

An aqueous fabric conditioning liquid composition containing a quaternary ammonium salt as the sole fabric conditioning agent typically comprises about 14 -16% by weight of the quaternary ammonium salt (expressed as the salt as such) based on the weight of the fabric conditioning composition.

2

Recent years have seen the introduction of amino-functional silicone compounds as fabric conditioning agents for use in liquid aqueous fabric conditioner compositions. These are frequently used in conjunction with quaternary ammonium salts in aqueous liquid fabric conditioner compositions and allow a reduction in the 5 amount of the quaternary ammonium salt to about 10% or less, thus providing a saving in manufacturing costs.

As indicated above, aqueous liquid fabric conditioner compositions will frequently comprise a fragrance, e.g. in the form of a free oil perfume or an 10 encapsulated perfume or a combination of both free oil perfume and encapsulated perfume. Free oil perfumes are used to provide desirable "in-package" and "in-use" (dosing and during the wash) fragrance whereas encapsulated perfumes are used to provide long-term fragrance to the laundered textile fabrics.

15 Liquid fabric conditioning compositions which comprise, in addition to the major amount of water, at least (a) a quaternary ammonium compound, (b) an amino functional silicone and (iii) an encapsulated fragrance are known but present manufacturing difficulties when one of a range of products to be supplied by a particular manufacturer. More specifically, a particular manufacturer may wish/need to 20 offer a range of products which include (within the range) at least the following possibilities:

(i) a liquid fabric conditioning composition containing a quaternary ammonium compound and an encapsulated fragrance but not an amino

25 functional silicone; and

(ii) a liquid fabric conditioning composition comprising a quaternary ammonium compound, an amino functional silicone and an encapsulated perfume.

30 With regard to possibilities (i) and (ii) above, the manufacturer's individual customers may require different encapsulated fragrances. With particular regard to (ii), one customer may require the liquid fabric conditioning composition containing the quaternary ammonium compound and amino functional silicone to incorporate one particular encapsulated fragrance (e.g. recognised as its "house fragrance") whereas a 35 different customer may require a liquid fabric conditioning composition comprising a

3

quaternary ammonium compound and an amino functional silicone but with a different encapsulated fragrance (i.e. its own "house fragrance"). Similar considerations apply in relation to (i).

5 In order to cater for the above possibilities in the large scale batch process normally used for the production of liquid fabric conditioning compositions it is conventional practice to manufacture a "base formulation" which comprises water, the quaternary ammonium fabric condition agent(s), optionally together with preservatives and stabilisers. In fact, two or more such base formulations may be manufactured with 10 different concentrations of quaternary ammonium compound(s) and these base formulations are ultimately mixed together to provide a base formulation of the required concentration of quaternary ammonium compound(s) to meet a particular customer's requirements. Manufacture of the "base formulation(s)" will generally be affected at a temperature of about 40°C to allow for the quaternary ammonium compound(s) to be 15 homogenously distributed throughout the formulation. Subsequent to manufacture, the formulation(s) will be sent to storage until required. During storage, the temperature of the formulation(s) will fall to ambient temperature. The base formulation may subsequently be used for supplying liquid fabric conditioning compositions of the type (i) above (i.e. containing only the quaternary ammonium compound(s) as the fabric 20 conditioning agent(s)), in which case incorporation of encapsulated perfumes to meet a particular customer's requirement is relatively straightforward. However if a composition of the type (ii) is required (i.e. one including an amino functional silicone compound and an encapsulated perfume) then certain difficulties are encountered in that if the amino functional silicone is added to the base formulation at ambient 25 temperature the amino functional silicone is not fully incorporated into the base formulation and this results in aggregation of the encapsulated perfume. This is manifested as an unsightly sedimentation of the surface of the resulting liquid composition and/or at the base thereof and also impacts on the performance of the fabric conditioning composition. In order to prevent this aggregation occurring, it is 30 necessary to heat the base formulation to a temperature of 40-50°C and incorporate the amino functional silicone at this temperature. Whilst this heating step does prevent the aggregation, there is of course a significant energy cost associated with re-heating a large quantity of the base formulation to 40°-50°C.

4

It is therefore an object of the present invention to obviate or mitigate the abovementioned disadvantage.

According to the present invention there is provided a method of producing a 5 fabric conditioning composition which comprises the steps of:

(1) providing

(a) an aqueous base formulation containing a quaternary ammonium fabric conditioning agent homogenously distributed therein;

10 (b) an additive formulation which is a homogenous admixture of an amino functional silicone and a free oil perfume; and

(c) an encapsulated fragrance, and

(2) admixing the base formulation, the additive formulation and the 15 encapsulated fragrance to produce the fabric conditioning composition.

The method of the invention provides for the ready production of a fabric conditioning composition which comprises a quaternary ammonium fabric conditioning agent, an amino functional silicone, free oil perfume and an encapsulated fragrance 20 from a base formulation comprising water and a quaternary ammonium fabric conditioning agent homogenously distributed therein. More specifically, we have surprisingly found that by pre-mixing the amino functional silicone with the free oil perfume it is then possible for step (2) of the method to be effected at ambient temperature and produce an aqueous fabric conditioning composition in which the 25 encapsulated perfume is uniformly distributed without aggregation. Effectively, the free oil perfume provides a "solubilising system" for the amino functional silicone. It will be appreciated that the fact that step (2) of the method may be effected at ambient temperature is a significant development over the prior art since it avoids the need (and attendant costs) for heating relatively large quantities of a previously prepared base 30 formulation which has been stored (until required for use) from ambient temperature to 40-50°C.

5

Aqueous fabric conditioning compositions produced in accordance with the invention will comprise, in addition to water, at least the following components:

(i) the quaternary ammonium fabric conditioning agent;

(ii) the amino functional silicone fabric conditioning agent;

(iii) the free oil perfume; and

(iv) the encapsulated perfume.

It should be appreciated that any one of component types (i)-(iv) may be 10 comprised of one or more different components. Thus, for example, there may be more than one quaternary ammonium fabric conditioning agent in the composition. Similarly for the amino functional silicone fabric conditioning agent, the free oil perfume, and the encapsulated perfume. There may be additional types of fabric conditioning agents present, e.g. polyol fabric conditioning agents and other silicone fabric conditioning 15 agents. It will be further appreciated that the fabric conditioning composition may incorporate further components as conventionally included in fabric conditioning compositions. Without limitation, these include preservatives, colorants, stabilisers, and viscosity modifiers.

20 A typical aqueous fabric conditioning composition produced in accordance with the invention will comprise:

Components % bv weight

25 Quaternary ammonium fabric condition agent(s) 2-20

Amino functional silicone(s) 0.1 -10 Other fabric conditioning agent(s), eg polyols

(for example glycerol) 0.1 -5

Free oil perfume(s) 0.01-3.5

30 Encapsulated fragrance(s) 0.1-4

Preservative(s) 0.0001-0.1

Colourant(s) 0.0001-0.2

Stabiliser(s) 0.01-0.2

Viscosity modifier(s), eg calcium chloride 0.1-3

35 Other component(s) 0.05-0.5

6

Water to 100

In the above table, the amounts refer to the amount of the actual component that is present in the aqueous fabric conditioner composition. As one skilled in the art 5 will appreciate, many of the components that may be incorporated in compositions produced in accordance with the invention are supplied (by the manufacturer of those components) as emulsions and the manufacturer will provide data that includes percentages of active ingredients. Thus, for the avoidance of any doubt, the above amounts relate to the amounts of components per se and not the amount of emulsion 10 or other "diluted" form in which the component is supplied.

Quaternary Ammonium Fabric Conditioning Agent

Aqueous fabric softening compositions produced in accordance with the 15 invention will include at least one such agent in a preferred total amount from 2 to 20% by weight of the total composition, these percentages being based on the weight of the quaternary ammonium compound(s) perse.

Exemplary quaternary ammonium compounds include alkylated quaternary 20 ammonium compounds, ring or cyclic quaternary ammonium compounds, aromatic quaternary ammonium compounds, diquaternary ammonium compounds, alkoxylated quaternary ammonium compounds, amidoamine quaternary ammonium compounds, ester quaternary ammonium compounds, and mixtures thereof. Suitable quaternary ammonium compounds are available from (without limitation) Stepan Company and 25 Kao Chemicals and include examples such as Stepanquat GA90 and Kaosoft AG80.

The quaternary ammonium compounds can include any counter ion that allows the component to be used in a manner that imparts fabric-softening properties according to the invention. Exemplary counter ions include chloride, methyl sulfate, 30 ethyl sulfate, and sulfate. For example, a potential formulation route for fabric conditioners is for "transparent" liquids, based on Stearyl Trimethyl Ammonium Methosulphate.

7

Preferred quaternary ammonium fabric conditioning agents for use in accordance with the invention are "ester quats", i.e. ester quaternary compounds, which are typically of the general formula:

R1

R2 N+—R3 X-

(1)

R4

10 in which:

R1 is CH3 or C2H5 R2 is (CH2)2OH

15

R3is (CH2)2COOR1 R4 is (CH2)2COOR1 20 In which R1 is a C14-C18 alkyl group (preferably C16-C1B). X" is a counter ion.

Amino Functional Silicone Fabric Conditioning Agent

25

This will generally be present in the final liquid fabric conditioning composition in an amount of 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight.

30

The use of amino functional silicones in fabric conditioners provides an overall formulation cost saving because the addition of silicone results in both the opportunity significantly to reduce levels of quaternary ammonium compound whilst maintaining

8

softening performance and the ability to >ewet" certain substrates (eg towels) to improve their absorption of water and subsequently aid drying of the human body (eg following bathing/showering).

5 The amino functional silicones as used in the present invention may be siloxane polymers in which at least some of the silicon atoms (which may be terminal silicon atoms and/or silicon atoms intermediate the terminal positions) are bonded to amino groups via linkers. The amino groups are preferably secondary or tertiary amino groups. The groups bonded to the nitrogen atoms are preferably optionally substituted 10 alkyl groups each having up to twenty carbon atoms. The linker may be substituted or unsubstituted alkylene or polyoxyalkylene groups with from 2 to 15 atoms in the linker chain (i.e. 2 to 15 atoms between the siloxane chain and the amino group).

Examples of amino functional silicones are disclosed, for example, in WO 15 2012/003192, US 2005/233938, WO 2006/005068, US 4 818 242, US 2008/307586 and WO 2011/002825.

Suitable amino functional silicones are available from, amongst others, Evonik Industries and Wacker Chemicals and include Evonik AS356 and Wacker FC 218 20 which is an amino functional silicone with polyether groups.

Free Oil Perfume

The free oil perfume is initially incorporated in the additive formulation and (as 25 indicated) serves to provide a solubilising system for the amino functional silicone.

The amount of free oil perfume (i.e. a non-encapsulated perfume oil) included in fabric conditioning compositions produced in accordance with the invention will generally be in the range of 0.01% to 3.5%. That said, the total amount of free oil 30 perfume incorporated in the fabric conditioning composition produced in accordance with the invention will generally be governed by the weight ratio of the amount of the amino functional silicone compound to the amount of the free oil perfume in the additive formulation (see also below), so the amounts of these two components are interrelated and thus dependent on each other.

35

9

The free oil perfume may be a blend of such perfumes and can be prepared using numerous odiferous ingredients of natural or synthetic origin. The range of the natural raw ingredients and that of the synthetics can include examples from virtually all classes of fragrant substances as shown in the following illustrative compilation: natural 5 products, such as basil oil, citrus fruit oils ( such as mandarin oil, bergamot oil, etc.), palmarosa oil, patchouli oil, wormwood oil, alcohols, such as geraniol, linalool, phenylethyl alcohol, aldehydes, such as hydroxycitronellal, Lilial (p-tert-butyl-alpha-methyldihydrocinnamaldehyde), ketones, such as allylionone, methylionine, esters, such as benzyl salicylate, citronellyl acetate, hexenyl isobutyrate, various components

10 often used in perfumery, such as musk ketone, indole and methyl-eugonol.. Likewise, any conventional fragrant acetal or ketal known in the art may be added to the present composition as an optional component of the perfume. Such conventional fragrant acetals and ketals include the well known methyl and ethyl acetals, as well as acetals or ketals based on benzaldehyde, that comprise phenylethyl groups.

15

Examples of free oil perfume that may be used for the purposes of the present invention are commercially available from IFF, Givaudan, Firmenich.

Encapsulated Fragrance

20

Encapsulated fragrances comprise, as their name suggests, capsules which contain a fragrance, preferably a free oil perfume.

The capsules generally have a particle size of 10-300 |um , preferably 20-200

25 |jm, and even more preferably 40-120 nm. The shell material of the capsule may comprise a material selected from cross-linked melamine formaldehyde, cross-linked urea formaldehyde and mixtures thereof. The shell encloses a fragrance, for preference a free oil perfume which may either be the same as, or different in nature to, the free oil perfume present in the additive composition.

30

The amount of capsules incorporated in liquid fabric conditioning compositions produced in accordance with the invention will generally be in the range of 0.2 to 2% by weight.

10

Examples of encapsulated perfume systems commercially available from IFF, Givaudan, Firmenich and include, but are not limited to, the CapLock, Mechacaps and NewtonCaps systems respectively.

5 Other Fabric Conditioning Agents

These are optional and may be incorporated to provide the liquid fabric conditioning composition produced in accordance with the invention with properties as provided by such additional agents.

10

The additional fabric conditioning agent may, for example, be a general type of fabric softening component referred to as a polyol. Suitable polyols capable of imparting some fabric softening effects include diols and triols with three or more carbon atoms in the backbone, eg propane-1,2,3-triol (i.e. glycerine) and lanolin.

15

Suitable polyols are available from but are not limited to Spectrum Chemical Manufacturing Corporation, USA

If a polyol is present in the fabric conditioning liquid produced in accordance

20 with the invention then it will typically be present in an amount of 0.1-5 % by weight, more preferably 0.2-4% by weight.

Other Components

25

Additional components that may be included in liquid fabric conditioning compositions produced in accordance with the invention include preservatives, colorants, stabilisers, and viscosity modifiers, all of which will generally be present in the final liquid fabric conditioning composition in amounts as indicated in the above 30 table. These components are conventional and are well known to the person skilled in the art.

35

11

Preparation of Base Formulation

The base formulation is an admixture (using conventional mixing apparatus) of the quaternary ammonium fabric conditioning agent(s) with water until a homogenous 5 mixture is obtained. Typically this procedure involves introducing all of the water (usually at a temperature of around 40 - 50°C) into a mixing vessel provided with a stirrer. The quaternary ammonium fabric conditioning agents (e.g. stored at a temperature of around 50°C are then added to the mixing vessel with stirring which is continued until the mixture is homogenised.

10

Generally the total amount of quaternary ammonium fabric conditioning agents used in preparation of the base formulation will be such as to provide 2 to 25%, more preferably 2 to 20%, and even more preferably 4 to 16% by weight of the overall weight of the base formulation..

15

To provide maximum flexibility in the manufacturing process, two base formulations may be prepared and stored, each base formulation containing different total amounts of quaternary ammonium compound. Thus, for example, one base formulation may comprise 4% by weight of the quaternary ammonium compounds and

20 the other base formulation may comprise 16% by weight of the quaternary ammonium compound. The two base formulations can be mixed at different ratios to provide a final base formulation containing between 4 and 16% of the quaternary ammonium compounds. This final base formulation may then be used for the purpose of producing fabric conditioning liquid using the process of the present invention.

25

If polyol fabric conditioning agents are also required in the final liquid fabric conditioning composition, then these may also be incorporated in appropriate amounts in the base formulation (s)

30 The base formulation thus produced may then be cooled and sent for storage for future use.

35

12

Preparation of Additive Formulation

The additive formulation will comprise the amino functional silicone(s) together with a free oil perfume.

5

The or each amino functional silicone used will generally be supplied as an aqueous emulsion and may be used in that form for preparation of the additive formulation.

10 The additive formulation may be prepared by admixture of the amino functional silicone fabric conditioning agent(s) with the free perfume oil using conventional mixing apparatus, e.g a low shear rotary stirrer with multi-blade paddles.

Generally the ratio of the total amount of amino functional silicone fabric 15 conditioning agent(s) to the free oil perfume will be in the range (5-20): 1, more preferably 8-12:1, even more preferably about 10:1.

Generally this mixing operation is effected at ambient temperature. 20 Preparation of Fabric Conditioner Composition

This step of the method is effected by admixing the base formulation, the additive formulation (both prepared as described above) and the encapsulated fragrance. In a preferred embodiment of the invention, the additive formulation and the 25 base formulation are initially mixed together until a homogenous blend is obtained, subsequent to which the encapsulated fragrance is added with continued mixing until the encapsulated fragrance has been uniformly distributed throughout the composition. Other components for the composition (e.g. colourant, stabilisers and viscosity modifiers) can be added at any stage, e.g. admixed with the base formulation prior to 30 addition of the additive formulation. It is however preferred that such components are added after the base formulation, additive formulation and encapsulated fragrance have been homogeneously blended together.

The relative amounts of the base formulation, the additive formulation, and 35 encapsulated fragrance to be used for this step of the process can of course readily be

13

determined from a knowledge of the compositions of (i) the base formulation, (ii) the composition of the additive formulation, and (iii) the desired liquid fabric conditioner composition.

5 Mixing of the base formulation, the additive formulation and encapsulated fragrance may be effected using conventional stirring apparatus (e.g. the same as that used for production of the base formulation).

The base formulation, the additive formulation and the encapsulated fragrance 10 may all be at ambient temperature when introduced into the mixing process.

This mixing operation results in the production of the final liquid fabric conditioning composition in which the amino functional silicone and the encapsulated fragrances are both homogenously incorporated throughout the liquid fabric conditioner 15 composition. The resulting composition is storage stable and the fact that it can be produced by using ambient temperature for this step of the production operation is, of course, a considerable advantage.

The invention will now be illustrated with reference to the following non-limiting 20 Examples.

Example 1 (Invention)

25 This Example describes production of an aqueous fabric softening composition using a method in accordance with the invention. The method involved for four steps, namely:

(1) production of a base formulation containing 16% by weight (expressed as active material) of an "ester quat",

30

(2) production of a base formulation containing 4% by weight (expressed as active material) of an "ester quat",

35

(3) production of an additive formulation, and

14

(4) production of fabric conditioning composition.

Step 1 - Production of 16% Base Formulation

5

A base formulation containing 16% by weight of quaternary ammonium compound (an "ester quat") was prepared from:

Component Percent by Weight

10 Water 82.19

Stepanquat GA90 17.77

Preservative 0.04

To prepare this base formulation, the water was heated to 50°C and added to a 15 mixing tank equipped with a low shear stirrer. The stirrer was started and the Stepanquat GA90, which had been pre-heated to 50°C was added to the mixing tank and stirring continued until the mixture was homogenised.

The preservative was then added and stirring continued to produce a

20 homogenous mixture.

The resulting base formulation was then allowed to cool to ambient temperature.

25 Step 2 - Production of 5% Base Formulation

Using the procedure described in Step 1, a base formulation containing 4% by weight of quaternary ammonium compound ("ester quat") expressed as active

was prepared from:

30

Component

Water

Stepanquat GA90

Preservative

Percent by Weight

95.82

4.44

0.04

35

15

Step 3 - Production of Additive Formulation

An additive formulation was prepared from:

5 Component Percent bv Weight

Wacker FC218 (Amino Silicone) 95.24 Silky Green19 (ex Givaudan) 4.76 (Free Oil Perfume)

10 To prepare the additive formulation, the Wacker FC218 was added to a premix tank fitted with a low shear stirrer. The free oil perfume was then added with mixing until a homogenous blend was obtained.

Step 4 - Preparation of Fabric Conditioner Composition

15

The final composition was prepared from:

Component Percent bv Weight

16% Base Formulation 47.83

20 4% Base Formulation 47.83

Glycerine (optional) 1.00

Calcium Carbonate 0.50 (Optional Viscosity Modifier)

Colourant(s) 0.0001

25 1Additive Formulation 0.84

Camille Cap (ex Givaudan) 2.00 (Encapsulated Fragrance)

provides 0.80% by weight wacker FC218 and 0.04% by weight free oil perfume for the final composition.

30

All of the above components were at ambient temperature.

To produce the final composition, the 16% base formulation was added to a mixing tank provided with a low shear stirrer and stirring was commenced. The 4%

16

base formulation was then added followed by the glycerine, calcium carbonate, colourants, additive formulation and encapsulated fragrance.

Stirring was continued until the composition was homogenised.

5

In the resulting fabric softening composition, all components were homogenously distributed throughout the composition. In particular, the encapsulated fragrance was uniformly distributed without aggregation.

10 The Example therefore demonstrates the benefits of the invention for producing a fabric softening composition containing an encapsulated fragrance by employing pre-mixing of the amino silicone and free oil perfume.

Example 2 /Comparative)

15

A fabric softening composition was prepared by employing Steps 1 and 2 as described in Example 1 in conjunction with a modification of Step 4 (Step 3 being omitted). The modification of Step 4 involved separate additions of the Wacker FC 218 and free oil perfume (in amounts of 0.80% and 0.04% by weight respectively) to the

20 mixing tank.

In the resultant product, the encapsulated perfume formed aggregates and was not homogenously distributed as in the case of the product of Example 1.

25 Example 3 (Invention)

The following components have been used successfully in place of the corresponding component used in Example 1.

30 Amino Silicone

KF873 (ex Shin-Etsu Silicones, Akron OH) and Wacker FC203.

35

17

Free Oil Perfume

Black Jack187 (ex IFF) and Sunny Lagoon 38 (ex Givaudan). Encapsulated Fragrance Florida Pops (ex IFF).

18

Claims

CLAIMS:

1. A method of producing an aqueous fabric conditioning composition which comprises the steps of:

5

(1) providing

(b) an additive formulation which is a homogenous admixture of an amino 10 functional silicone and a free oil perfume; and

(c) an encapsulated fragrance, and

(2) admixing the base formulation, the additive formulation and the encapsulated fragrance to produce the fabric conditioning composition.

15

2. A method as claimed in claim 1, in the additive formulation, the ratio of the total amount of amino functional silicone fabric conditioning agent(s) to the total amount of free oil perfume is (5-20): 1.

20

3. A method as claimed in claim 2, in the additive formulation, the ratio of the total amount of amino functional silicone fabric conditioning agent(s) to the total amount of free oil perfume is (8-12): 1.

4. A method as claimed in any one of claims 1 to 2 wherein the weight ratio of the 25 additive formulation to the base formulation in step (2) is 1:100 to 5:100

5. A method as claimed in any one of claims 1 to 4 wherein the quaternary ammonium fabric conditioning agent in the aqueous base formulation is an ester quaternary compound.

30

6. A method as claimed in claim 5 wherein the ester quaternary ammonium compound is of the general formula

R1

R2 N+ R3

R4

5 in which:

R1 is CH3 or C2H5 R2 is (CH2)2OH

10

R3 is (CH2)2COOR1 R4 is (CH2)2COOR1 15 In which R1 is a C14-C18 alkyl group (preferably C16-C18).

X" is a counter ion.

7. A method as claimed in any one of claims 1 to 6 wherein the aqueous base 20 formulation comprises a total of 2-25% by weight, based on the total weight of the formulation, of quaternary ammonium fabric conditioning agent(s).

19

(1)

8. A method as claimed in any one of claims 1 to 7 wherein the ratio of the total 25 amount of amino functional silicone and the free oil perfume in the additive formulation is in the range (5-20): 1.

30

9. A method as claimed in claim 8 wherein the ratio of the total amount of amino functional silicone and the free oil perfume in the additive formulation is in the range (8-12): 1.

20

10. A method as claimed in claim 9 wherein the ratio of the total amount of amino functional silicone and the free oil perfume in the additive formulation is about 10:1.

11. A method as claimed in any one of claims 1 to 10 wherein step (2) is effected at ambient temperature.