COMPOSITIONS FOR PROTECTION AND RELEASE OF ACTIVE MATERIALS

This application claims priority to U.S. Provisional Patent Application Serial No. 61/015,748 filed on December 21, 2007, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention is directed towards compositions that provide protection against aggressive-media and the use of such compositions in consumer products.

BACKGROUND OF THE INVENTION

Products containing fragrances as volatile active materials such as laundry and cleaning products are aesthetically appealing to the consumer as they impart a pleasant fragrance to cleaned surfaces and fabrics. However, the amount of fragrance carryover from stored product (particularly products that are in liquid form) through aqueous laundry baths and onto fabrics is often marginal. The detergent manufacturing industry, therefore, has long searched for an effective delivery system for use in laundry products to provide long-lasting, storage-stable, fragrance in product, as well as to provide fragrance to the laundered fabrics.

Consumer products that release active materials by, for example, diffusion, erosion, dissolution, or combustion, are well known. A disadvantage associated with such products is that some of the active material is lost to the environment or atmosphere during storage dissolution or chemical degradation. Furthermore, in the case of laundry products, active materials such as fragrance are released rapidly and uncontrollably to the wash liquor, whereupon large amounts may be lost to evaporation and dissolution rather than depositing onto fabric. Furthermore, many consumer products such as heavy duty liquid laundry detergents comprise an aggressive environment wherein active material such as fragrances may be degraded or altered. In typical encapsulation compositions, products can fail during aging in its aggressive environment or media due to loss of fragrance form the particle to the surrounding aqueous environment. The fragrance forms very stable micelles with the surfactant media and is thereby irretrievably lost from the encapsulate particle. During consumer use, encapsulate particles having lost its fragrance fail to provide any benefit over and above the effect of any fragrance

that is simply added directly to the surfactant media. In addition, once active materials such as fragrances leave the encapsulation particle and are solubilized by the surfactant media, those actives are free to chemically react with the media, chemically altering and/or destroying the actives. This limits the types of actives (e.g., fragrances) that can be used in an aggressive media (e.g., liquid laundry detergent).

Preventing degradation of active materials by aggressive media (i.e., media containing harsh chemicals) during storage, as well as the subsequent release of active materials during use involves very different and difficult technologies. Here, aggressive media includes but is not limited to aqueous solutions providing a relatively harsh environment such as low or high pH, neutral aqueous solutions containing appreciable surfactant levels (e.g., anionic, non-ionic, or cationic) that have a propensity to absorb oily actives into micelle structures, or solutions containing appreciable low-molecular weight organic solvents such as alcohols. Aggressive media can also include dry powder environments such as laundry detergent powders, which have a very high capacity to absorb any free volatile active such as water and fragrance oil. In these powders, the free active is absorbed by the powder during storage, thereby causing the particles to have a reduced effect or no effect. For liquid cleaning and conditioning products containing fragrances as active materials, protection is required that involves maintaining stability both during storage in aggressive media, and while in use in heat-elevated conditions of the wash and in the presence of harsh chemicals (such as bleach, enzymes, surfactants, etc.), while retaining the ability to deliver active materials in essentially their original state.

Encapsulation is the most common method for protection of sensitive ingredients in products. Laundry and other fabric care compositions that contain encapsulated ingredients are well known in the art.

Many encapsulating materials are known for use in household, detergent and shampoo products, such as fabric conditioners, heavy duty liquid detergents and hair or fabric cleaners. These include water soluble polymers for encapsulating fragrance oils for deodorant applications, and water insoluble polymeric carriers for encapsulating fragrances used in fabric conditioners. Microcapsules formed from gelatin, an anionic polymer, and a hardening agent are also known. Microcapsules having a tough coating material that effectively prohibits diffusion of the fragrance during the washing/drying process have been considered. It is also known to deliver fragrance by protecting the fragrance through its incorporation into particles containing

hydrogenated caster oil and a fatty quaternary ammonium salt. Fragrances have also been adsorbed onto various materials such as silica and clay. Fragrance may also be adsorbed onto porous carrier materials, which may be a polymeric material.

However, there still remains a need for protection of ingredients during storage in aggressive media, such as is found in heavy duty liquid detergent compositions, as well as protection of those ingredients during the majority of the cleaning process, followed by release of the entrapped ingredients as active materials late in the cleaning process and in the drying process.

Accordingly, there remains a need for compositions that can stabilize active materials that may be subject to degradative attack in aggressive media, and also selectively release such active materials in a controlled and reproducible manner, ensuring that the character of the active material, as initially added to the product, remains viable for end-use application.

SUMMARY OF THE INVENTION The present invention relates to compositions that aid actives in protection against aggressive-media. These compositions include at least one or more active materials and at least one or more encapsulating materials. At least one of the encapsulating materials has a water solubility of less than about O.lg per liter at 25 ⁰ C. The composition has a Thermal Gravimetric Analysis ('TGA') gradient (representing percent weight loss per ⁰ C) of less than about 0.1% for temperatures between about 16O ⁰ C and about 200 ⁰ C when the temperature is ramped at about 10°C/min from room temperature ('RT') to about 300 ⁰ C. The composition also has an onset temperature at which a majority of active material is abruptly released, the onset temperature being, for example, about 25O ⁰ C or greater. In one aspect the composition has a weight loss per ⁰ C of less than about 0.03% for temperatures between about 16O ⁰ C and about 200 ⁰ C when temperature is ramped at about 1O ⁰ C /min from RT to about 35O ⁰ C. In one aspect the composition onset temperature of abrupt release of the active is about 300 ⁰ C or greater.

In one embodiment the composition of this invention is in encapsulated form. This can include, for example, a microcapsule form having an inner core containing one or more actives surrounded by a shell of encapsulating material. The present invention also provides a method of delivering actives in aggressive media.

This involves encapsulating one or more actives with one or more encapsulating materials

- A -

forming an encapsulated delivery system. The adding the encapsulated delivery system can then be added to an aggressive media. In one respect, the encapsulated delivery system has a Thermal Gravimetric Analysis gradient representing percentage weight loss of active per ⁰ C of about 0.1% or less, an onset temperature for active release of about 25O ⁰ C or greater, and a water solubility of about Ig per liter or less at 25 ⁰ C. Examples of aggressive media include detergents and personal care compositions such as shampoos and bodywashes.

Compositions according to the present invention provide enhanced storage stability of active materials in products having aggressive -media. They also provide controlled release in- use for delivery of active materials as required. In one aspect, compositions according to the present invention assist in protecting actives or sensitive ingredients in cleaning compositions, such as heavy duty liquid compositions, fabric conditioners, shampoos, body washes, and absorptive powder detergents, while delivering the majority of the sensitive ingredients in their original state during the washing and drying stages.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph illustrating a curve obtained by Thermal Gravimetric Analysis. Figure 2 is a graph of curves obtained by Thermal Gravimetric Analysis of encapsulated delivery systems according to the Examples.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards encapsulating materials that are able to protect one or more active materials from aggressive media in which the active may be stored, thereby preserving the characteristics of the active and delivering it in substantially its original state to the substrate on which the consumer product is being used Thermal Gravimetric Analysis ('TGA') is an analytical technique that measures the weight loss or gain of a material as a function of temperature. TGA results are normally presented as curves on a graph of actual weight loss converted to percent weight loss on the y- axis versus temperature in ⁰ C or time on the x-axis (see Figure 1). A key TGA measurement is referred to as a ramp measurement. In this measurement, a composition is placed in an instrument that is programmed to increase the sample temperature at a desired rate while measuring weight loss.

For compositions according to the present invention, TGA may initially measure removal of residual water remaining in the capsule from processing. Excessive moisture content (e.g., greater than 80%) is preferably avoided for the purpose of this invention as it will render TGA results less precise with regards to the release of the active compound. Referring to Figure 1, this water content can be seen as an initial fast weight loss 1 in a TGA curve that is quickly dissipated at just above 100 ⁰ C (the gas transition temperature of water), as shown by the sudden change in slope of the weight loss curve 2.

During this ramp measurement, TGA curves according to the current invention show temperature regions where active material appears to evaporate in a slow, controlled manner. This is indicated by the slope of the weight loss curve between two selected temperature points (e.g., 3 and 4). In the examples below, the selected temperature points occur at about 16O ⁰ C and about 200 ⁰ C; however, this should not be interpreted as limiting the invention to this range.

The weight loss curve between these points can also be referred to as plateaus. According to the present invention, these temperature regions are analyzed from which compositions are prepared having low weight loss per ⁰ C between these points 3 and 4. The lower the slope or flatter the plateau region, the better an active is encapsulated and protected from evaporation. Finally, TGA curves may show a well-defined "onset temperature" or "knee" 5 in the temperature range wherein disruptive volatilization and evaporation occur.

The present invention relates to compositions for providing protection against aggressive - media. Such compositions include at least an active material and at least an encapsulating material. In one embodiment, the encapsulating material has a water solubility of less than about 0.1 g per liter at 25 ⁰ C and a TGA gradient, representing percentage weight loss per ⁰ C of less than 0.1% 8 for temperatures between about 16O ⁰ C and about 200 ⁰ C when temperature is ramped at about 1O ⁰ C /min from RT to about 300 ⁰ C. The composition can also have an onset temperature at which the majority of active material is released, wherein in one embodiment the onset temperature is about 25O ⁰ C or greater 9. In another aspect, compositions according to the present invention have a weight loss per ⁰ C of less than about 0.03% for temperatures between about 16O ⁰ C and about 200 ⁰ C when temperature is ramped at 1O ⁰ C /min from RT to about 35O ⁰ C. The compositions may also have an onset temperature of release of the active that is about 300 ⁰ C or greater. In even another aspect, compositions according to the present invention

have a weight loss per ⁰ C of less than about 0.02% for temperatures between about 16O ⁰ C and about 200°C 10 when temperature is ramped at 10°C /min from RT to about 35O ⁰ C and the composition onset temperature of abrupt release of the active is about 300 ⁰ C or greater 11.

In one embodiment compositions according to the present invention are in encapsulated form. In this regard, compositions according to the present invention can be in microcapsule form, wherein the microcapsule includes an inner core containing at least one active surrounded by a shell of encapsulating material(s). Encapsulating materials having specifically defined water solubility, TGA gradients, and TGA onsets provide needed storage and use properties in aggressive media. Those skilled in the art realize that the TGA loss gradient and onset temperature are a complex function of several material properties of the active and encapsulating materials. As the TGA monitors the loss in weight as a function of time and temperature under dry air or nitrogen environments, it follows that the TGA loss gradient and onset temperature represent the behavior of these particles in this dry environment. Temperature-dependent material properties that affect TGA loss gradient and onset temperature include diffusion constant and solubility of the active material in encapsulation material, size of the encapsulation particle, wall thickness of the encapsulation material, vapor pressure of the active material, and known particle size distribution. Using the Fick equation for diffusion as well as finite element analysis techniques and the known vapor pressure of the volatile actives, it may be possible to model some of the behavior of encapsulation particles as seen in TGA tests under dry air conditions.

One feature of the present invention is that by using a dry TGA technique, encapsulation compositions can be described which succeed in protecting an active such as fragrance from aggressive storage media, thereby preserving the characteristics of the active and delivering it in its substantially original state onto a substrate of a consumer product, even through processes having aggressive media such as surfactants, agitation-induced shear, and heat. An example of such processes includes the laundry process.

For actives such as fragrances, encapsulating material useful in the present invention should prevent at least part of the fragrance from diffusing out of the composition during long storage periods. Moreover, the encapsulating material should aid in preserving the original "character" of fragrances having particularly volatile top-notes, while protecting the fragrance

from other ingredients in the formulation. Compositions according to the present invention may comprise more than one encapsulating material.

Water solubility of the encapsulating material may be determined using a Quantitative Structural Activity Relationship (QSAR) program. This program uses molecular structure to estimate physical-chemical properties such as molecular weight, vapor pressure, solubility, bio- concentration factor, hydrolysis half-life, Henry's coefficient, partitioning data, and other parameters (based on Lyman, W., Reehl, W., and Rosenblatt, D., HANDBOOK OF CHEMICAL PROPERTY ESTIMATION METHODS, Chpt. 2, "Solubility in Water", McGraw Hill Book Co., New York (1982) , which is incorporated by reference in its entirety herein). The QSAR database used to calculate the water solubility assessment is maintained by the Institute for Process Analysis, Montana State University, Bozeman, Montana, USA, and is accessed through Tymnet Data Systems and Numerica Online Systems (Numericom 1994) The Online Interface for Numerica Users Technical Data Base Services, Inc. (TDS, 135 West 50th Street, New York, N.Y. 10020) , which is incorporated by reference in its entirety herein. Water solubility of the encapsulating material may vary according to factors such as crystallinity, hydrophilicity, capacity for hydrogen bonding and molecular weight. Consequently, molecular weight and concentration of the encapsulating material can be adjusted to modify its water solubility. In one aspect the encapsulating material has a low degree of crystallization, a low degree of hydrogen bonding and high solubility in organic solvents. For high molecular weight polymers, the water solubility can be so low that it cannot be easily measured, so calculations of small and medium molecular weight analogues give an indication of solubility.

Encapsulating materials suitable for use in this invention include thermoplastic resins such as aromatic vinyl compounds (e.g., polystyrene) and copolymers thereof (e.g., polystyrene - acrylonitriles and acrylonitrile-butadiene-styrene polymers); aminoplast polymers such as melamine formaldehyde and urea formaldehyde; amides such as acrylamide and methacrylamide; polyamide-imides; polyimides; aliphatic dienes such as polybutadienes; polymers prepared from (meth)acrylds such as (meth)acrylic acid, crotonic acid, fumaric acid and itaconic acid, salt or esters thereof; polyolefins such as low density polyethylene, medium density polyethylene, high density polyethylene, atactic(amorphous)polypropylene, isotactic(crystalline) polypropylene, ethylene -propylene copolymer, propylene -butylene

copolymer; polyvinyls prepared from halogen substituted vinyl compounds such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluorides; polyacrylonitriles; polyethylene -terephthalates; polybutylene-terephthlates; polyacetals; cellulose esters; polyurethanes; polyacrylates; vinyl carboxylic esters such as vinyl acetate; and polyaryl ethers. Active materials that may be incorporated into the composition will depend upon the ultimate use of the final product. Examples of such active materials include fragrances, pharmaceuticals, nutraceuticals (e.g., vitamins, nutritional supplements), personal care ingredients (e.g., sunscreens, mineral oil), dyes, biocides, pigments, pesticides, insect repellents, etc. In one respect, the active material is a volatile active material such as a fragrance. In another respect, the active material may contain a mixture of both volatile and non-volatile actives. Should the active material have no appreciable volatility at temperatures of about 16O ⁰ C to about 200 ⁰ C then model encapsulates containing volatile test materials can be created and tested.

Benefits provided by the present invention are particularly relevant when the active material is a fragrance. Fragrances are typically composed of many components of different volatility. The present invention allows for sustained delivery of a full fragrance bouquet over a long time.

In another aspect, the present invention provides compositions having a controlled release profile, for example, detergent products, wherein the active material (e.g., fragrance) is characterized by a latency period such that a significant payload of fragrance survives the wash, rinse and drying process resulting in continued release after completion of the laundry process. Maximum concentration of fragrance in the wash/rinse liquor, drying and post laundry stages may be measured by carrying out headspace analysis according to any of the techniques known in the art. With respect to laundry detergents where active materials are typically at least fragrance materials, the composition controls release properties in such a way that 40% or more of the fragrance materials are retained in the composition during product storage at 4O ⁰ C for at least eight weeks, preferably for at least 12 weeks. In another aspect, 75% or more of the fragrance materials are retained in the composition during product storage at 4O ⁰ C for at least eight weeks. In even another aspect, 95% or more of the fragrance materials are retained in the composition during product storage at 4O ⁰ C for at least eight weeks.

Generally, compositions according to the present invention may comprise from about 5% to about 70% of fragrance. In another aspect, these compositions may comprise from about 5% to about 50% of fragrance. The exact amount of fragrance used in the particles will vary greatly depending on the strength of the particular fragrance used and the desired odor effect. Compositions according to the present invention may comprise fragrances that are typically not delivered to a surface, for example, fragrance delivery to fabric through the laundry process. For example, fragrance materials that would ordinarily be described as too volatile, unstable, or soluble in particular products, may, by virtue of this invention, be used in such products because the fragrance is isolated from the product by the encapsulating material. Fragrance materials that are not substantive to fabrics in the laundry process can also be used in the present invention since the composition delivers the fragrance to the fabric surface where it is released. Thus, use of the present invention to protect and deliver a fragrance to a surface broadens the class of fragrance materials that can be utilized.

A benefit provided by the composition of the present invention is the possibility to introduce a wide range of volatile active materials.

Compositions according to this invention may be manufactured according to techniques known generally in the art. These techniques include spray-on coatings (employing, for example, pan coaters or fluid bed coaters); spray drying; various coacervation-based techniques, in-situ polymerization, and interfacial polymerization. A particularly convenient and simple process is spray drying.

To provide capsules, the active material, with or without delivery material, may be coated by any conventional coating technique such as fluid-bed coating, spray drying; various coacervation-based techniques, in-situ polymerization, and interfacial polymerization.. It is understood that any other process known in the art may be used to encapsulate the active materials useful for the invention.

The skilled person will appreciate that the process of forming the composition of the present invention may be performed on an industrial scale using a batch process or alternatively a continuous process.

The active material may be contained in, and/or on, a delivery material and then coated with the encapsulating material. Preferably, the delivery material is inert to the fragrance, relatively odorless, able to allow for diffusion of the fragrance, and melt without decomposition.

Without limitation, examples of useful delivery materials include polyethylenes, polyamides, polystyrenes, polyisoprenes, polycarbonates, polyesters, polyacrylates, vinyl polymers and polyurethanes and mixtures thereof that meet the above-described criteria (e.g., they are water-insoluble, have a molecular weight between about 100 and about 30,000, have a melting point between about 37 ⁰ C and about 19O ⁰ C and a hardness value between about 0.1 and about 15).

It may be desirable to utilize a mixture of different delivery materials in the composition of the present invention, for example, a blend of a polymeric material and a minor amount of a wax material. Examples of useful wax materials include materials sold under the trade names BOLER 1014, STARWAX 100 and VICTORY, all available from the Boler Petroleum Company. Such a blend allows for better deposition properties because the particles formed therefrom have a stickier surface. A great number of combinations of materials are possible and are intended to be covered by this invention so long as the final blend of delivery materials meets the criteria outlined above. The choice of delivery material to be used in compositions of the present invention will depend to some degree on the particular active material to be used. Some active materials will require a greater amount of protection than others and the delivery material to be used therewith can be chosen accordingly.

As used herein, the expression "aggressive -media" includes, by way of example, consumer articles of the soap, deodorant or detergent type.

As used herein the term "fragrance" means any odoriferous material. In general, such materials are characterized by a vapor pressure less than the atmospheric pressure at room temperatures. The fragrances employed herein will most often be liquid at room temperatures, but also can be solid such as the various camphoraceous fragrances known in the art. A wide variety of chemicals are known for fragrance uses, including materials such as aldehydes, ketones, esters, alcohols, terpenes and the like. Naturally occurring plant and animal oils and exudates comprising complex mixtures of various chemical components are known for use as fragrances, and such materials can be used herein. The fragrances herein can be relatively simple in their composition or can comprise highly sophisticated, complex mixtures of natural and synthetic chemical components, all chosen to provide any desired odor.

Fragrance materials are described more fully in S. Arctander, FRAGRANCE FLAVORS AND CHEMICALS, VOIS. I and II, Author, Montclair, N.J., and the MERCK INDEX, 8th Edition, Merck & Co., Inc. Rahway, NJ, which is incorporated by reference in its entirety herein.

In general, any chemically compatible material which emanates a pleasant or otherwise desirable odor can be used as a fragrance in the present invention.

Fragrances that are normally solid can also be employed in the present invention. These may be admixed with a liquefying agent such as a solvent prior to incorporation into the particles, or may be simply melted and incorporated, as long as the fragrance does not sublime or decompose upon heating. The invention also encompasses the use of materials which act as malodor counteractants. These materials may not themselves have a discernible odor but can conceal or reduce any unpleasant odors. Examples of suitable malodor counteractants are disclosed in U.S. Patent No. 3,102,101 , which is incorporated by reference in its entirety herein.

Compositions according to the present invention may have application in consumer products and processes wherever the release of active materials is desired. For example, they can be used in cleaning and/or drying systems (e.g., tumble dryers, dishwashers, dry cleaning systems etc.), laundry detergents, fabric conditioners, home care products, disinfectants delivery, insecticides delivery, insect repellents delivery, clothes deodorants applied by washing machine applications (e.g., detergents, powders, liquids, whiteners or fabric softeners), household cleansers such as disinfectants and toilet bowl cleaners, odour control products, agricultural and pet care products, and products for use in large scale closed air systems. Preferably, the consumer product is a cleaning composition such as a heavy duty liquid detergent.

The amount of composition employed in a consumer product according to the present invention depends upon the nature of that consumer product (e.g., household products and laundry products, such as detergents or fabric softeners) and its intended use. In general, consumer products can comprise from about 0.4 wt. % to about 30 wt. % of compositions of this invention; preferably about 0.1 to about 5 wt. %; most preferably about 0.3 to about 3 wt. %.

The invention will now be described in further detail by way of the following examples.

EXAMPLES

Comparative Example 1 -

This is an example of a composition comprising a matrix encapsulation particle that does not successfully satisfy the compositional requirements of this invention. The composition was made according to the following process -

60% wax (Polyethylene 2000 available from Baker-Petrolite, Corp, Sand Springs, Texas) was melted and mixed with a typical liquid laundry detergent fragrance composition obtained from Quest International. The composition was blended with 65% polyethylene wax, 5% of a fatty alcohol (Incrosoft 100 from Croda Corp.), and 30% fragrance. The mixture was then melted and sprayed through a 1 mm diameter nozzle with air atomization. The air pressure was adjusted to 16 psi to give a final particle with a median size of 60 micrometers. The sample was then placed in a TA instruments 2960 Thermal Gravimetric Analyzer and a TGA ramp from room temperature to 300°C was made at a ramp speed of 10 °C/min. (See Figure 2, Example 1.) Weight loss per ⁰ C was 0.17 % for temperatures between 16O ⁰ C and 200°C 6. There was no observable knee or onset temperature for sudden weight loss, indicating that the composition readily and continually released as the temperature is increased. Further, there was no fast loss of weight indicating release of water at low temperatures, which was expected as no water was used in formulation of this composition.

Comparative Example 2 -

This is an example of a composition comprising a microcapsule particle that does not successfully satisfy the requirements of this invention. The composition was made according to the following process - 7.0 g Urea, 1.25 g Resorcinol and 0.3 g NH4C1 was dissolved in 100 ml H ₂ O in a 600ml glass beaker at room temperature. 150 g of 10wt% EMA Z-400 (from Zeeland Chemicals) was mixed into the aqueous solution. 3 drops of n-Octanol was added to the aqueous solution. 80 ml of a typical liquid laundry detergent fragrance composition (obtained from Quest International) was then added to the aqueous solution and emulsified using an Indco Type B dispersion blade (diameter = 2") on high speed for 5 minutes (target emulsion particle size at 20-40 μm). Particle size of the emulsion was measured by a Beckmann Coulter LS 13 320 Laser Diffraction Particle

Size Analyzer immediately after the emulsion step. After emulsification, the dispersion speed was reduced to half of the original setting. 17 ml of a 37 % formaldehyde solution was then added to the emulsion. 10% H2SO4 was added as needed to lower the pH to 2.25. The temperature was raised to 55 ⁰ C and the beaker covered with foil to reduce evaporation of water. Mixing was continued for 3 hours. At the end of the reaction, the slurry was allowed to return to room temperature naturally. The sample was then placed in a TA instruments 2960 Thermal Gravimetric Analyzer (TGA) and a TGA ramp from room temperature to 300°C was made at a ramp speed of 10°C/min. (See Figure 2, Example 2.)

From the Figure it can be seen that there is a fast initial weight loss of 75% which transitions at around 141 ⁰ C 8, indicating evaporation of free water used in formation of the encapsulate. It can also be seen that the weight loss per ⁰ C is 0.19 % for temperatures between 16O ⁰ C and 200°C 7. There was no observable knee or onset temperature for sudden weight loss at any temperature above 200°C, indicating that the active in the composition is readily and continually released as the temperature is increased above the water evaporation transition temperature 8. From the Figure it is seen that there is no observable knee or onset temperature for sudden weight loss at any temperature above 25O ⁰ C.

Example 3 -

A composition according to the present invention was made by the following process - 7.0 g Urea, 1.25 g Resorcinol and 0.3 g NH ₄ Cl were dissolved in 100 ml H ₂ O in a 600ml glass beaker at room temperature. 150 g of 10wt% EMA Z-400 (from Zeeland Chemicals) was added to the aqueous solution. 3 drops of n-Octanol was added to the aqueous solution. 80 ml of a typical liquid laundry detergent fragrance composition (obtained from Quest International) was added to the aqueous solution, and the solution emulsified using an Indco Type B dispersion blade (diameter = 2") on high speed for 5 minutes (target emulsion particle size at 20-40 μm). Particle size of the emulsion was measured by a Beckmann Coulter LS 13 320 Laser Diffraction Particle Size Analyzer immediately after emulsification. After emulsification, the dispersion speed was reduced to half of the original setting. 17 ml 37% formaldehyde solution was added to the emulsion. If needed, sufficient 10% H2SO4 was added to lower the pH to 2.25. The temperature was raised to 55 ⁰ C and the beaker covered with foil to reduce evaporation of water. Mixing continued for 3 hours, and the temperature was then raised to 8O ⁰ C and with mixing

continuing for an additional 2 hours. At the end of the reaction, the slurry was allowed to return to room temperature naturally. The sample was then placed in a TA instruments 2960 Thermal Gravimetric Analyzer (TGA) and a TGA ramp from room temperature to 300°C was made at a ramp speed of 10°C/min. (See Figure 2, Example 3.) From the Figure it is seen that there is a fast initial weight loss of 80% which transitions at around 14O ⁰ C 9, indicating evaporation of free water used in formation of the encapsulate composition. Also, it can be seen that weight loss per ⁰ C is 0.023 % for temperatures between 16O ⁰ C and 200°C 10, and that there is an observable knee or onset temperature at 255 ⁰ C 11. This indicates that the active material in the composition is more rigorously contained than in Example 2 and a release of active, or "onset", is only initiated at temperatures higher than 25O ⁰ C 11.

Example 4 -

A composition was made according to the process taught in U.S. Patent No. 4,100,103. 100 ml of a typical liquid laundry detergent fragrance composition (obtained from Quest International) was encapsulated. Particle size of the final encapsulation particle was measured by a Beckmann Coulter LS 13 320 Laser Diffraction Particle Size Analyzer. The sample was then placed in a TA instruments 2960 Thermal Gravimetric Analyzer (TGA) and a TGA ramp from room temperature to 300 ⁰ C was made at a ramp speed of 1O ⁰ C / min. (See Figure 2, Example 4.)

From the Figure it is seen that there is a fast initial weight loss of 40% which transitions at around 105 ⁰ C 12, indicating evaporation of free water used in formation of the encapsulate. It is also seen that weight loss per ⁰ C is 0.007% for temperatures between 16O ⁰ C and 200 ⁰ C. An observable knee or onset temperature is seen at 36O ⁰ C 14, indicating that the active material is more rigorously contained than in Example 3 and a sudden release of active, or "onset", is only initiated at this higher temperature 14.

Example 5 -

Samples of material from Examples 1, 2, 3, and 4 were placed in Tide Free liquid laundry detergent, manufactured by the Proctor and Gamble Company. Typically, samples would be

aged at 4O ⁰ C for a period of time ranging from 1 day to 3 months. In this example, multiple laundry detergent test samples were aged at 40 ⁰ C for 7 days and for 1 month

The samples were then taken and the encapsulation particles were filtered out of solution using a 4" Buchner funnel and filter paper. The particle samples were rinsed well with water and allowed to dry in the Buchner funnel for 30 minutes following the final rinse. The samples were then analyzed using an Agilent 6890N Gas Chromatograph (GC) system.

Control samples were tested in each case. 0.1 g of each sample was weighed into a separate extraction vial. 10 ml of methanol was added, capped, and then heated to 6O ⁰ C for 30 minutes. After the sample was cooled and centrifuged, a clear methanol solution with dissolved remaining fragrance active was separated. This solution was finally injected into the GC system.

By comparing the amount of fragrance present before and after particle aging, the protection provided by the encapsulation process could be measured. This is referred to as the fragrance retention of sample after aging in the table below. In the table below, each particle was aged in Tide Free liquid detergent for 7 days and for 1 month at 40 ⁰ C. The examples and test measurements demonstrate the effectiveness of Example 3 and 4 made according to the claims of this invention for protecting the fragrance in an aggressive media aging test.

Although the present invention has been described and illustrated in detail, it is to be understood that the same is by way of illustration and example only, and is not to be taken as a limitation. The spirit and scope of the present invention are to be limited only by the terms of any claims presented hereafter.