WO2008061384A1

WO2008061384A1 - Preparation of an emulsion comprising lamellar liquid crystal (llc) particles containing fragrance

Info

Publication number: WO2008061384A1
Application number: PCT/CH2007/000574
Authority: WO
Inventors: Thomas Mcgee; Richard P. Sgaramella; Venkateswara Kumar Vedantam
Original assignee: Givaudan Sa
Priority date: 2006-11-20
Filing date: 2007-11-16
Publication date: 2008-05-29

Abstract

A process of preparing an emulsion comprising lamellar liquid crystal (LLC)-particles containing a fragrance by (a) blending the fragrance with emulsifiers capable of forming liquid-crystalline structures, at least one fatty alcohol co-emulsifier having at least 22 carbon atoms, an amphiphilic reinforcing material, and a wax with a needle penetration hardness of greater than 7 mm @25°C, the ratio of wax to amphiphilic reinforcing agent being from about 1:49 to about 1:2.; and (b) adding water slowly to the fragrance mixture thus formed and mixing under shear conditions for a sufficient time to obtain a stable emulsion and continuing to cool to room temperature whilst mixing. The resulting emulsions can be easily incorporated into surface conditioning products (e.g., shampoos and fabric conditioners), are resistant to manufacturing processing conditions and give a long-lasting fragrance delivery.

Description

IMPROVED PROCESS FOR A SUBSTRATE CONDITIONER

This invention relates to a formulation for and process of preparing a substrate conditioning system with a fragrance incorporated into a structured emulsion containing a liquid crystal phase and a free fragrance.

Liquid conditioning products for treating substrates, such as hair and fabric, contain actives for imparting softness and manageability. They also contain a fragrance, which remains on the substrate. This is one of the main consumer benefits sought from these products. However, fragrances frequently lose their activity in the product during storage and directly when they are used.

Several routes to possible enhancement of the fragrancing and longevity of the effect have been proposed. However, the disadvantage of these conventional, prior art delivery systems is that they only have a small loading potential, they suffer from instability and the release of fragrance on the treated substrate frequently cannot be controlled.

At first glance, encapsulation would appear to provide a possible answer, but the conventional encapsulation technologies do not provides a complete answer. A possibility is to utilize the so-called "mesophases", semi-solid regions that can form in lamellar liquid crystal structures of the type formed in some water/oil/surfactant blends (see, for example, Yang et al in JAOCS, 74, 809-816 (1997). The formation of these mesophases can be favoured by the inclusion of long chain linear alcohols as co-emulsifier, with the emulsifier being selected for its ability to form lamellar liquid crystal mesophase particles (LLC- particles). They have been used in the cosmetics and pharmaceutical industry to protect raw materials and to control their release when applied on skin (for example, US patents 6,066,328 and 6,660,278).

EP 0 466 237 teaches that stable emulsions containing LLC-particles can be made, based on non-ionic surfactants as emulsiiϊers. LLC-particles with improved stability are achieved by the addition of selected perfumery materials, obviating the need for emulsion stabilizers as taught in the prior art. Such LLC-particles containing fragrance can be used to deposit fragrance molecules on to treated substrates. These emulsions are suitable for incorporation into a variety of aqueous products such as shampoos, hair conditioners, fabric conditioners and shower gels.

However, it was found that the LLC-particles were not stable at higher temperatures, when incorporated into liquid products.

International Published Application WO 2004/064790 discloses how to improve the stability of LLC-particles containing fragrance when incorporated into aqueous products. The more stable LLC-particles comprise water, a fragrance material, a liquid crystal- forming material containing at least one fatty alcohol having at least 22 carbon atoms, and a reinforcing material. These LLC-particles are claimed to be useful in liquid substrate conditioners, such as hair and fabric conditioners. The liquid conditioners typically consist of a conditioning material, water and other materials. While the LLC-particles disclosed in WO 2004/064790 provide an improvement over the prior art, it has been found that they are very difficult to incorporate into liquid substrate conditioners. They require a long processing time and high shear mixing to incorporate into these products.

Moreover, it was also found that the stability of the LLC-particles containing fragrance, when incorporated in a liquid substrate conditioner, was poor in the presence of free fragrance. Free fragrance is a fragrance added to the liquid conditioner to fragrance the product, the solution on dilution and the treated damp substrate.

Although WO 2004/064790 discloses the use of waxes as optional materials it has now been surprisingly found that LLC-particles are only formed when the wax or mixture of waxes used has a needle penetration value of greater than 7 mm at 25 ⁰C as determined by ASTM-D 1321.

It has now been found that a particular formulation can considerably reduce, and even eliminate completely, the problems of the art. The invention therefore provides a process of preparing an emulsion comprising LLC-particles containing a fragrance by (a) blending the fragrance with emulsifiers capable of forming liquid-crystalline structures, at least one fatty alcohol co-emulsifier having at least 22 carbon atoms, an amphiphilic reinforcing material, and a wax with a needle penetration hardness of greater than 7 mm at 25°C, the ratio of wax to amphiphilic reinforcing agent being from about 1:49 to about 1:3, (b) adding water slowly to the fragrance mixture thus formed and mixing under shear conditions for a sufficient time to obtain a stable emulsion and continuing to cool to room temperature whilst mixing.

There is additionally provided a composition prepared by the method hereinabove described.

Although WO 2004/064790 discloses the use of waxes as optional materials, it has now been surprisingly found that the use of specific waxes or mixtures of waxes not described in that document gives unexpectedly large benefits.

The wax material for use in this invention is a wax or mixtures of waxes (the use of the term "wax" herein includes a mixture of waxes) with needle penetration hardness of less than 7 mm at 25°C, as measured by ASTM D 1321. In a particular embodiment, the wax exhibits a sharp principal melting point transition temperature, by which is meant that the temperature difference between the onset of melting and the principal melting point is 30 deg C maximum, as measured by a differential scanning calorimeter such as a Universal 2920 MDSC V2.6A ex TA Instruments. Any such wax may be used, and it may be of mineral, vegetable, animal or synthetic origin. Non limiting examples are beeswax, ester wax, paraffin wax, microcrystalline wax, and petrolatum wax. The preferred wax is either a straight chain or a branched chain alkane hydrocarbon of the general formula C_n H_2n+2, such as paraffin wax, which can be obtained commercially from Sasol Wax Americas Inc, Connecticut, USA, for example Sasol™ 2526, Sasol 2542, Sasol 2531 and Sasol 2556. Non-limiting examples of unsuitable waxes used alone are Carnauba wax, Silicone wax AMS C30, microcrystalline waxes, Candellia wax and Oricury wax .

Another particular embodiment is one in which the melting point of the wax or mixture of waxes is above 45 ⁰C.

The amphiphilic reinforcing materials of the present invention may be materials containing hydrophobic and hydrophilic moieties, the ratio of which moieties may vary according to the particular properties sought. Examples of suitable amphiphilic materials are surfactants, associative polymers such as graft and block copolymers, particularly poly (ethylene-b- ethylene oxide), poly (styrene-b-ethylene oxide), and alkyl-modified poly (dimethylsiloxane-g-ethylene oxide). Gelatin and pectin are further examples of biopolymers that can exhibit amphiphilic properties.

Particular amphiphilic materials are poly(ethylene-b-ethylene oxide) copolymers having an ethylene oxide level preferably lower than 80% and most preferably lower than 50%, and a molecular weight preferably lower than 2500 g/mol and most preferably lower than 1000 g/mol. Samples of such copolymers are available under the Trade Mark Performalene (ex Baker Hughes, Texas, USA).

Without restricting the scope of this disclosure in any way, it is believed that the preferred wax of this invention improves dispersability of the emulsions containing the LLC- particles by helping to incorporate the amphiphilic reinforcing materials into the organic film of the LLC-particles. As a consequence, there may be fewer hydrophobic interactions between the LLC-particles, resulting in improved dispersion and stability properties.

The liquid crystal-forming material of this invention may be selected from any of the range of components known in the art to be capable of forming a quasi-crystalline phase or ordered structures in systems containing oil and water. The liquid-crystal-forming material preferably contains an emulsifier that is able to form a lamellar phases with a high melting point.

hi particular, the liquid-crystal-forming material may contain a non-ionic emulsifier. Some non-limiting examples of these are ethoxylated fatty alcohols, polyethoxylated fatty alcohols, glycerol mono- fatty acid esters, fatty acid esters of polyethylene glycol, polyethoxylated sorbitan fatty acid esters, alkylglycosides, and alkylpolyolosides.

The liquid crystal forming emulsifiers must have as co-emulsifier a fatty alcohol having 22 carbon atoms or more, such as 1-docosanol. They are used typically at levels of between 10 to 60% by weight of the liquid crystal-forming material. There are other, optional ingredients known to be useful in emulsions that may also be used in compositions of this invention in art-recognized quantities for their known purposes. These include, but are not limited to, antioxidants, odour-masking agents, insect repellents, dispersion aids, deposition aids and the like.

Conditioner materials may be selected from cationic, nonionic, amphoteric surfactants and their mixtures known in the art to impart softness and manageability properties. The most common type of conditioning material is essentially delivered via cationic actives. The level of cationic actives in a conditioner depends upon whether the product is dilute or concentrated. For example, the level of a cationic active in fabric conditioning dilute products ranges from about 1% (wt/wt) to about 7% (wt/wt) and in concentrated products from about 10% (wt/wt) to about 20% (wt/wt).

The cationic active in the conditioner may be, for example, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, chloride, dialkyl dimethyl ammonium chloride, dialkyl dimethyl ammonium methyl sulfate, di(hydrogenated tallow) dimethyl ammonium chloride, dihexadecyldiethylammonium chloride, distearyldimethylammonium chloride, dibehenyldimethylammonium chloride, di(coconut alkyl)dimethyl ammonium chloride, ditallowdimethyl ammonium chloride, dialkylyloxy dimethyl ammonium chloride, N,N-di(tallowyl-oxy-ethyl)-N N-dimethylammonium chloride, N N- (ditallowoxyl-oxy-ethyl)-N,N-dimethyl ammonium chloride, dialkyl imidazolium methyl sulfate, ester quats, amido silicones, and mixtures thereof.

The conditioner material of the present invention can include other optional adjuncts conventionally used in textile treatment compositions, for example, silicones, oils, colorants, preservatives, optical brighteners, opacifiers, surfactants, stabilizers, anti- shrinkage agents, anti-wrinkle agents, fabric crisping agents, anti-spotting agents, germicides, fungicides, anti-corrosion agents, anti-foam agents, enzymes such as cellulases, proteases, and the like, dye transfer inhibitors, chlorine scavengers, soil release agents, nonaqueous solvents, hydrotropes, antifoaming agents, anti-redeposit ion agents, anti-oxidants, ultra violet absorbers, heavy metal sequestrants, dye fixatives, anti-corrosion agents, drape imparting agents, and ironing aids. This list is not intended to be exhaustive. The free fragrance of the composition is composed of fragrance ingredients selected by those skilled in the art to provide a pleasant smell to the composition of the present invention and to fragrance pleasantly the solution and treated articles. The fragrance molecules may be selected from the extensive range of natural and synthetic molecules currently available, such as essential oil, alcohols, aldehydes and ketones, ether and acetals, ester and lactones, macrocycles and heterocycles, and/or in admixture with one or more ingredients.

It has unexpectedly been found that, if the wax is used in the defined ratio with the amphiphilic structuring agent, the emulsion containing fragrance-containing LLC-particles is much easier to incorporate into substrate conditioning products, greatly reducing processing time.

There is therefore also provides a process for preparing a substrate conditioning system comprising a conditioning material, containing a free fragrance and LLC-particles containing fragrance formed as hereinabove described, comprising the steps of:

(a) preparing a liquid substrate conditioning product: and

(b) mixing into the liquid substrate conditioning product prepared in step (a) the structured emulsion with LLC-particles.

The invention additionally provides a substrate-conditioning system preparable by the method hereinabove described.

A further particular embodiment is one in which a free fragrance is thoroughly mixed into the liquid substrate conditioner prior to the addition of the emulsion containing the LLC- particles containing fragrance.

The substrate conditioning system hereinabove described exhibits surprisingly enhanced stability of the fragrance-containing LLC-particles containing waxes at higher storage temperatures, even in the presence of free fragrance. Furthermore, it has been found that enhanced fragrance performance on the treated substrate is obtained when the mean size of the LLC-particles is around 7 micrometers or greater, as determined by cross polarized light microscopy.

Those skilled in the art will create a fragrance accord for the LLC-particle that has high impact and partitions well into the organic film of the LLC-particle. A further advantage is that substrate conditioning systems prepared by the abovementioned process do not require any high shear and/or high temperature agitation to mix in the structured emulsion containing LLC-particles into the substrate conditioning product; such agitation may lead to disruption of the structure of the LLC-particles and the processing time is greatly reduced. Moreover, the systems thus produced have higher thermal and mechanical stability.

Because of the stability of the LLC-particles of this invention to both processing and storage, they allow the fragrance formulator unusual latitude in developing creative fragrances hitherto not possible in such particles. As a result, novel accords of high impact can be realised. The choice of fragrance materials that compose the fragrance within the LLC-particle may be selected by those skilled in the art, using the ordinary skill of the art, to maximize performance and stability.

The invention is now further described with reference to the following examples, which are illustrative only and are not intended to be in any way limiting.

Example 1.

The waxes shown in Table 1.1 were incorporated into the LLC-particles: Table 1.1 Range of Waxes

(1) Sasol™ 2526 is a paraffin wax consisting mostly of straight chain hydrocarbons ex Sasol Wax Americas Inc, Connecticut, and USA.

(2) Carnauba wax is a natural wax from the leaves of the carnauba palm, containing mainly esters of fatty acids (80-85%), fatty alcohols (10-15%), acids (3-6%) and hydrocarbons (1-

3%) with a melting point of 78-85°C, obtained from Smart Wax, California, USA.

(3) Silicone AMS C30 wax™ is an alkyl methyl polysiloxane with about 90% of the molecule being C37 alkyl chains grafted on an approximately 10%) silicone backbone ex Dow Corning USA. (4) Beeswax is a wax recovered from honeycombs and composed mainly of palmitate, palmitoleate, hydroxypalmitate and oleate esters of long-chain (30-32 carbons) aliphatic alcohols, with a melting point of circa 62 °, obtained from Alberta Beeswax, Canada.

(5) Lanolin Wax is the grease obtained from wool and consists of around 50% wax esters and around 30% Sterol esters with a melting point of around 4OC.

A series of fragrance emulsions (%w/w) were prepared according to the following method.

All ingredients, except water, were mixed with fragrance oil at 90 ⁰C in a closed vessel until all the ingredients were dissolved to form a homogeneous oil mixture. The water was heated to 90 ⁰C. It was then added slowly to the abovementioned oil mixture under moderate shear mixing using a propeller mixer operating at 2300 rpm. Thereafter, the fragrance emulsions were allowed to cool to room temperature.

The microparticle emulsions made were according to the formulations in Tables 1.2 and 1.3: Table 1.2. Control Emulsion According to WO 2004/064790

(1) Fragrance BA is a Givaudan fragrance having a fruity note.

(2) Performalene™ 400 is a linear ethylene homopolymer ex Baker Hughes, Texas, USA.

(3) Docosano ilTM is C22 linear alcohol ex Cognis, Ohio, USA.

(4) Span TM 60 is sorbitan monostearate ex Uniquema, Delaware, USA.

(5) Tween ,TM 60 is polyoxyethylene sorbitan mono-stearate ex Uniquema, Delaware, USA.

Table 1.3 Emulsions incorporating wax

The emulsions were examined for LLC -particle formation, size and density with an Olympus™ BX 51 polarizing microscope ex Scientific Inc, New York USA: The results are shown in Table 1.4:

Table 1.4. Microparticle Formation

VH = Very High, H = High, M = Moderate, L = Low

Only those formulations containing a wax with a high needle penetration value form microparticles.

To assess the dispersability of the emulsions containing the LLC-particles we added 1.5 grams of the emulsion to 100 grams of dilute blue liquid fabric softener at room temperature and mixed with an overhead mixer with a 2 inch diameter propeller at 900 RPM. The results of the dispersability study are shown in Table 1.5. Table 1.5. Dispersability of the emulsions

All the wax containing LLC-particle emulsions dispersed readily within 5 minutes. The control was not dispersed within 40 minutes of mixing and white particles were still visible.

Example 2.

The microparticle emulsions made were according to Tables 2.1 using the methodology in Example 1: Table 2.1 Emulsion Formulations.

The samples thus prepared were examined under a polarizing microscope. The results are shown in Table 2.2.:

Table 2.2. Microparticle Formation

The dispersability was determined as given in Example 1. The results are shown in Table 2.3:

Table 2.3.

Formulations M6 which contained 0.5% Sasol 2526 wax and zero Performalene 400 and the control did not disperse readily, white emulsion particles were clearly visible even after forty minutes of stirring. The remainder of the LLC-particle emulsions dispersed in less than 5 minutes of stirring. The combination of paraffin wax and the amphiphilic reinforcing component Performalene 400 in a ratio between 1:49 — 1 :2 is better than the Performalene 400 or the paraffin wax alone in enabling emulsion of the microparticles to disperse easily in the fabric conditioner.

Example 3. Microparticle emulsions Ml and the control, prepared as per example 1, were incorporated into a commercial dilute liquid conditioner base as per Table 3.1. The total fragrance in each product is the same.

Table 3.1. Fabric Conditioner formulation

The base was heated to 40 ⁰C. The LLC-particle emulsion was added into the base and mixed on a lab paddle mixer for 60 minutes to ensure complete dispersion of the LLC- emulsion into the conditioner base.

The products were allowed to stand for 24 hours and then towels were laundered in the procedure shown below. The products were put in storage at 45 ⁰C for 5 weeks and new towels were laundered as per the procedure below.

Laundry procedure

1. 20 (50 gram) cotton terry towels were washed using Purex fragrance-free detergent in a washing machine set on low load.

2. The wash/spin cycles were allowed to complete.

3. Prior to the final rinse cycle, the machine was stopped and the towels removed. 4. The machine was allowed to fill with water. 100 grams of the respective fabric softener was added and mixed in thoroughly.

5. The wet towels were replaced and the machine was allowed to agitate for 30 seconds. The machine was stopped and the towels allowed to soak for 5 minutes.

6. The machine was restarted and allowed to complete the rinse cycle.

7. After the final spin cycle the towels were removed and line dried.

A sensory panel of 5 people ranked the towels in order of fragrance intensity:

Fresh samples:

M l-O Control-C> Free fragrance-C 5 weeks stored at 45 ⁰C Ml -C> Control-C > Free Fragrance-C

The inclusion of Sasol 2526 wax apparently improved performance and also contributed to increased temperature stability.

Example 4.

Microparticle emulsions Ml and M5 prepared in example 1 were incorporated, respectively, into a commercial dilute liquid conditioner base as per Table 3.1.

Table 4.1. Fabric Conditioner formulation

Fabric conditioner products were formulated as shown in Table 4.1. Towels were washed as per example 3 and evaluated by a panel of 5 experts.

The results were:

Fresh samples:

M 5-C > Ml-C > Free fragrance-C 5 weeks stored at 45 ⁰C

Ml-C > M5-C = Control

The lanolin wax gave good results initially but after high temperature storage the performance advantage was lost. The lanolin wax (melting point 40 ⁰C) high temperature stability was inferior to the higher melting point Sasol 2526 wax ( melting point 56 ⁰C.)

Example 5.

The waxes shown in Table 5.1 were evaluated.

Table 5.1. Microcrystalline waxes

(1) Sasol Wax M7370 and M7381 are microcrystalline waxes which contain a higher percentage of isoparaffinic hydrocarbons and naphthenic hydrocarbons and finer crystals than macrocrystalline paraffin wax.

The following emulsions in Table 5.2 were prepared using the method given in example 1. Table 5.2 Emulsions with Microcrystalline waxes.

The quality of the particles and their dispersion efficacy is shown in Table 5.3:

Table 5.3. Quality of microparticles

A Universal 2920 MDSC V2.6A ex TA Instruments system using a heating rate of 5°C per minute was used to characterize the melting characteristics of the waxes. The results are shown in Table 5.2

5.4 Differential Scanning Calorimeter

Good LLC-particles are made when the transition melting is sharp. The difference in the temperature of the onset of melting and the melting point of the waxes should be less than 3O ⁰C.

Example 6.

The properties of Sasol Waxes 2526, 2542 and 2526, are shown in Table 6.1

Table 6.1 Properties of Macrocrystalline Paraffin Waxes

.

(1) Sasol Wax 2542 and 2556 are macrocrystalline paraffin waxes with small amount of branched chain hydrocarbons

The fragrance emulsions shown in Table 6.2 were prepared. Table 6.2: Emulsion of Paraffin Waxes

The particle size, density and dispersability were determined as per Example 1. The results are shown in Table 6.3.

Table 6.3. Emulsion Properties.

All the Sasol macrocrystalline paraffin waxes formed good microparticles that disperse well. The low level of branching has not affected the dispersion of the emulsion into the softener.

Example 7.

Microparticle emulsions M20 and M21 prepared in Example 6 were incorporated, respectively, into a commercial dilute liquid conditioner base as per Table 7.1.

Table 7.1. Fabric Conditioner formulation

Fabric conditioner products were formulated as in Example 3. Towels were washed as per example 3 and evaluated by a panel of 5 experts.

The results were: Fresh samples:

M 20-C > Free fragrance-C

M21-C > Free fragrance-C 2 weeks stored at 45 ⁰C M20-C > Free fragrance-C

M21-O Free fragrance- C

Example 8

The following emulsions in Table 8.1 were prepared according to the method given in Example 1.

Table 8.1 Emulsions with different fragrance levels.

The emulsion properties are shown in Table 8.2. Table 8.2. Emulsion Properties.

Formulations M22-M21 all made LLC-particles and the emulsions dispersed easily in the conditioner base. Example 9. The following emulsions in Table 9.1 were prepared according to the method given in Example 1.

Table 9.1 Emulsions with Woody Fragrance

(1) Fragrance AF is a Givaudan fragrance with a woody note.

A standard unperfumed dilute fabric conditioner composition was prepared by dissolving 6% dihydrogenated tallow ethyl hydroxyethylmonium ethosulfate (Rewoquat™. WE 18, ex Degussa) and 0.5% C9-11 Pareth-8 (Neodol™ 91 8E, ex Shell) in deionised water at 65. degree. ⁰C followed by cooling down to room temperature under stirring at 2000 rpm.

The base was heated to 40⁰C. The structured emulsion was added into the base and mixed on a lab paddle mixer for 60 minutes to ensure complete dispersion of the structured emulsion into base. The free fragrance was added once the softener base and structured emulsion mixture is uniform.

The products were allowed to stand for 24 hours and then towels were laundered as per the procedure in Example 3. The products were put in storage at 40⁰C and towels were laundered.

A sensory panel of 5 people rated the towels on intensity, and the following results were obtained:

Fresh Conditioner M28 = M29> free fragrance

Conditioner stored one week at 40 ⁰C M28 > M29 > free fragrance.

With the woody fragrance the LLC -particles made with Sasol Wax 2526 were more stable at elevated storage temperature.

Example 10.

Two samples (M30 and M31) of the emulsion shown in Table 10.1 were prepared as per

Example 1.

Table 10.1 Emulsion formulation

(1) TAT is an experimental fragrance with the following formulation:

The particle size and the density of the LLC -particle determined as in Example 1 were different as shown in Table 10.2:

Table 10.2 Emulsion properties

The respective emulsions containing the LLC -particles were incorporated into a commercial concentrated liquid conditioner base.

Commercial Fabric Conditioner Base 97.8 Emulsion with LLC-particles 1.5 Givaudan Fragrance TAT 0.7

The base was heated to 40 ⁰C. The structured emulsion was added into the base and mixed on a lab paddle mixer for 10 minutes to ensure complete dispersion of the structured emulsion into base.

A control was prepared with an equal amount of free TAT fragrance.

The products were allowed to stand for 24 hours and then towels were washed and treated as per Example 3. The products were put in storage at 40 ⁰C and towels were washed an treated.

A sensory panel of 5 people ranked the towels in order of fragrance intensity:

Fresh samples: M 31> M 30 > free fragrance Stored Sample M31 > M30 > Control Improved performance is achieved when the mean particles size is around 7.0 microns or greater, preferable greater than around 10.0 microns

Example 11.

The emulsions in Table 11.1 were formed according to the methodology outlined in Example 1.

Table 11.1 Emulsion formulation

(1) Polawax ,,TM is a fatty alcohol ethoxylated fatty ester blend ex Croda Inc. New Jersey US

(2) Lanette 22 is behenyl alcohol, ex Cognis Corp.Cincinnatti, USA.

The following conditioner containing the fragrance AF in the LLC-particles and a free AF fragrance was prepared by three processes shown below: w/w

Commercial Concentrated Fabric Softener Base 97.8

Emulsion with M32 LLC-particles 1.5 Givaudan Fragrance AF 0.7

Process 1.

The base was heated to 40 ⁰C. The structured emulsion was added into the base and mixed on a laboratory paddle mixer for about 40 minutes for complete dispersion of the structured emulsion into base. The free fragrance was added once the softener base and structured emulsion mixture was uniform.

Process 2.

The base was heated to 40 °and free fragrance was added. The mixture is stirred for 10 minutes. The structured emulsion was then added to the base and mixed on a laboratory paddle mixer for 40 minutes to ensure complete dispersion of the structured emulsion into base.

Process 3.

The structured emulsion and free perfume were mixed together until homogeneous and then added to the conditioner base at 40°C and stirred for 40 minutes to ensure the dispersion of the structured emulsion into base was complete.

The products were allowed to stand for 24 hours and then towels were washed and treated as per Example 3. The products are put in storage at 40 ⁰C and towels were washed and treated

A sensory panel of 5 people scored the towels for intensity:

Fresh Conditioner: Process 2 > Process 1 > Process 3

Conditioner stored one week at 40 ⁰C: Process 2 » Process 1 > Process 3.

After one month at 40 ⁰C storage of the products, one towel from each process was placed in a glass jar attached to an extraction pump that can draw the headspace in the jar through a Tenax™ filter. Samples were equilibrated for 2 hours then a 4-liter headspace sample was taken. Headspace samples were analyzed by thermal desorption (ATD 400) of the fragrance materials from Tenax™ into a GC/MS for analysis. The results are shown below: Nanograms per liter

Process 1 547

Process 2 1606 Process 3 782

The analytical data confirming that the process in which the free fragrance was intimately mixed into the conditioner base prior to addition of the LLC-particles provides a greatly superior performance.

Claims

Claims:

1. A process of preparing an emulsion comprising LLC-particles containing a fragrance by (a) blending the fragrance with emulsifiers capable of forming liquid-crystalline structures, at least one fatty alcohol co-emulsifier having at least 22 carbon atoms, an amphiphilic reinforcing material, and a wax with a needle penetration hardness of greater than 7 mm @25°C, the ratio of wax to amphiphilic reinforcing agent being from about 1 : 49 to about 1:2; (b) adding water slowly to the fragrance mixture thus formed and mixing under shear conditions for a sufficient time to obtain a stable emulsion and continuing to cool to room temperature whilst mixing.

2. A process according to claim 1, in which the wax exhibits a sharp principal melting point transition temperature, as defined by a temperature difference between the onset of melting and the principal melting point of 30 deg C maximum, as measured by a differential scanning calorimeter.

3. A process according to claim 1, in which the melting point of the wax is above 45°C.

4. A process according to claim 1, in which the amphiphilic material is a poly(ethylene- b-ethylene oxide) copolymer having an ethylene oxide level lower than 80% and a molecular weight of lower than 2500 g/mol.

5. A process according to claim 1, in which the ratio of wax to amphiphilic structuring agent is from about 1 :49 to about 1 :2.

6. An emulsion comprising perfume-containing LLC-particles prepared by a process according to claim 1.

7. An emulsion according to claim 6, in which the mean size of the LLC-particles is at least about 7 micrometers.

8. A process of preparing a substrate conditioning system comprising a conditioning material and fragrance-containing LLC-particles, comprising the steps of:

(a) preparing a liquid substrate conditioning product: and

(b) mixing into the liquid substrate conditioning product an emulsion of fragrance- containing LLC-particles according to claim 6.

9. A process according to example 8, in which free fragrance is mixed into the liquid substrate conditioning product prior to the addition of the LLC-particles.