DESC:FIELD OF THE INVENTION
The present invention provides a slurry premix formulation comprising fragrance containing aminoplast capsule slurry in synergistic combination with bio-polymer/s and synthetic polymer (and/ or additive)/ adapted for storage stable free-flowable powder slurry premix with improved loading of fragrance that is stable at ambient conditions for 6 months to 1 yr, and particularly, provides a select process towards development of the same also optionally including cationic polymer for better deposition of said capsules on fabric. Particularly, a select process is also provided towards development of said free-flowing powder slurry premix of polymeric microcapsules containing liquid fragrances, and, having these delivered onto fabrics is through incorporation of said slurries in rinse off formats like detergent powders and laundry liquids. This invention demonstrates that powdered polymeric microcapsules containing fragrance can be loaded in higher amounts in said select slurry premix and yet achieve good stability and further also allows improved fragrance loading in detergent formulation through low slurry premix dosages and also exhibit good transfer efficiencies on fabrics even when rinse off formats such as detergent powder and fabric conditioners used in the washing process.

BACKGROUND ART
Fragrance is a consumer preferred attribute in a variety of fast moving consumer goods, and, therefore a key driver of the purchase intent. Fragrance cues and olfactory sensorial of the product category in question have a huge influence on the purchase intent of the consumer. The individual likeability of the fragrance profile, as well as, its intensity influences the overall purchase decision of the consumer, for instance, in the choice of personal application leave on products like creams and lotions. However, for product categories like personal wash bars, detergent powders and liquids for fabric wash the overall attributes which signify the likeability of the fragrance is based on olfactory assessments during various stages of the product consumption and usage cycle. Thus, for example, in the case of a personal wash bar, the fragrance at the point of purchase, whilst bathing, fragrance of the bloom emanating in the bathroom, as well as, retentivity of fragrance lingering on the skin post bath are assessed by the consumer to provide an objective judgement on their likeability. In slight contrast, in a laundry wash process involving fabric care products (such as detergent powders, liquid detergents, fabric softeners etc.), the olfactory experience during point of purchase, upon dissolution in water, upon soaking, rinsing and wringing of damp clothes, as well as, neat fragrances which tend to linger on the fabric or are delivered through the deposition of certain hard shell capsular systems containing encapsulated fragrance are important determinants of likeability with regards a specific fragrance. Examples of extended delivery of fragrances on fabrics when rinsed using a fabric care product with encapsulated fragrances are extremely rare in the art. This is because of the fact that free fragrance micellization is extensively favoured in such formats employing surfactants. Such micelles which entrap and solubilise fragrances get washed away in laundry liquor. Approximately 3-4% of free fragrances which survive micellization gets deposited into fabric after the wash; however, given their extremely low concentrations and deposition efficiencies do not contribute to any perceptible olfactive experience when the cloth is dried and folded. Encapsulation of fragrances in hard-shell polymeric capsules to achieve long lasting perception of fragrances via rinse off laundry applications is the most sought technology.
Methods of preparation, delivery and deposition of microcapsules aiming to serve the laundry applications are rich in literature. The capsules are reported to be stable in liquid form and suitable for the delivery through liquid rinse off products (e.g., liquid detergents, fabric conditioners). Only a few reports describe that either the microcapsules could be processed as solid powder or granular forms or could be incorporated into a solid product such as detergent cake or soap bar etc.
US 4,145,184 discloses granular and liquid laundry detergent compositions comprising fragranced microcapsules.
US 6,248,703 claims soap bar and detergent bar compositions comprising melamine capsules that contain essential oils.
WO 2007096790A1 describes a process for the preparation of powdered aminoplast, containing fragrances or other hydrophobic materials, by means of using de-tackifying colloids (such as modified starch; Capsule etc.) with emulsifying properties and spray-drying of the capsule containing slurries. WO 2007096790A1 further claims consumer products in the form of a water-free liquid detergent or fabric softener, a hair or body oil or gel, a hair or body spray based on cyclomethicone, a powder detergent or a fabric conditioning sheet.
WO 2004/016234 discloses spray-drying of aminoplast microcapsules in the presence of carboxymethylcellulose. However, inventors of WO 2007096790A1 reported that spray-dried powders were sticky and difficult to wash off from the spray-drier.
US 6,620,777 claims improved deposition of fragranced aminoplast microcapsules on fabric from liquid fabric softeners by adding cationic polymers. However, cationic polymers coated aminoplast capsules in powder form for improved delivery of fragrances onto fabric surfaces in the rise off formats is not reported in the literature.
US 5,137,646 discloses the process for the preparation and method of delivery of fragranced aminoplast particles which are stable in liquid compositions such as fabric softeners. However, this two-step manufacturing process involves firstly the solidification of fragrances with a meltable polymer, followed by grinding of the solidified fragrances and coating with the aminoplast resin.
It is well-known in the art that polymeric capsules are stable when present as aqueous slurries and, exhibit instabilities when dried to convert them to their powder form. This is because transportation and random movements during long-term storage ensure collision amongst various particles, because of which there are extensive capsule leakages. Although preparation of powdered aminoplast slurries reported in art. It is not reported how the powdered capsules can be applied in laundry rinse off formats both in solid mixes (det. powders) as well as in aqueous dispersion format (fabric conditioners). Furthermore, cationic modification of the powdered fragrance-containing capsules for effective adhesion on fabrics is not reported in art.
There is a need of development of simplified slurry premix formulation and method to produce powdered polymeric capsules, utilizing the readily available capsule slurries as the starting material, which is mechanically stable and free-flowable at ambient condition. Furthermore, the powdered capsules should be suitable for rise off laundry applications (e.g., det. powder, fabric conditioner). Additionally, cationic modification of powdered microcapsules is desirable for efficient adhesion onto fabrics during rinse off cleansing applications.
OBJECTIVES OF THE INVENTION
It is thus the primary objective of the present invention to provide for the development of a simple free-flowable powder capsule slurry premix comprising of polymeric hard shell liquid fragrant core capsules preferably aminoplast capsules that would effectively deliver fragrance onto fabrics using rinse off formats. For instance, the effective delivery of fragrance containing capsules onto fabrics when incorporated in either a detergent powder or a laundry liquid format (fabric softener) is at the heart of the invention.

It is still another objective of the present invention to provide for said slurry premix formulations that would be storage stable for at least 6 months to 1 year as free-flowable powder slurry premix free of any caking activity in spite of improved loading of aminoplast fragrance capsule is said slurry premix facilitating deposition when incorporated in detergent powder or laundry liquid formulations that would survive the wash off/rinse-off process, and, retain its ability to get lodged onto fabric surfaces, subsequent to the drying.
It is yet another object of the present invention to provide said slurry premix and select method of manufacture thereof which when provided in detergent/fabric care formulations in lower dosage would cause enhanced fragrance loading in detergent powder formulations to enable improvement over conventional formulations for the development of such formulation systems also allowing cationically coated capsules, and, a process for the preparation of the same. This provides for enhanced deposition efficiencies of capsules through the fabric care formulations (such as detergent powders, fabric softeners etc.) where the powdered capsules are well dispersed in the above-mentioned formulations and would be deposited onto the fabric during the rinse-off process.
SUMMARY OF THE INVENTION
It is thus the basic aspect of the present invention to provide for a slurry premix formulation comprising aminoplast capsule slurry in synergistic combination with bio-polymer/s and synthetic polymer (and/ or additive)/s in bio-polymer/s and synthetic polymer (and or additive)/s: slurry ratio range of 0.05:1 to 1:1 adapted for storage stable free-flowable powder slurry premix with improved loading of fragrance and yet stable at ambient conditions for 6 months to 1 yr.
Preferably said slurry premix formulation is provided wherein said slurry involving bio-polymer: synthetic polymer (and/or additive) ratio in the range of 1:0.07 to 1: 0.3 remains as a free flowable free of any caking activity.
According to another preferred aspect of the present invention there is provided a slurry premix formulation wherein said aminoplast capsules comprises polymeric hard shell and liquid core preferably liquid fragrance core and is capable of incorporation in slurry premix/ detergent powder devoid of caking problems or laundry liquid formulations and survives wash off/rinse-off process, and, retain its ability to get lodged onto fabric surfaces subsequent to drying of the same.
Preferably according to yet another preferred aspect of the present invention there is provided a slurry premix formulation wherein said aminoplast capsules are cationically modified by cationic polymer providing enhanced deposition efficiencies of capsules on fabric through fabric care formulations including detergent powders, fabric softeners with said capsules being well dispersed in said formulations for deposition onto fabric during rinse-off.
More preferably said slurry premix formulation is obtained of spray drying operations with inlet air temperature of from 145°C to 165°C and outlet air temperature of from 65 °C to 85 °C enabling improved fragrance loading through said aminoplast microcapsules taken in the range of 45-55 wt.% providing for slurry premix facilitating enhanced fragrance loading of 68-74 wt.% that is stable with the moisture content advantageously limited to 2.3-3 wt.%.
In said slurry premix formulation said bio-polymer/s includes modified bio-polymers of celluloses and starches including non-hygroscopic hydrolyzed low-molecular-weight carbohydrates tapioca dextrins with film forming ability, hydroxylpropyl methylcellulose, hydrogen octenylbutanedioate modified waxy maize starch carboxymethyl cellulose, partially hydrolyzed waxy maize starch, partially hydrolyzed maize starch as mixtures; and
wherein said synthetic polymers includes polyethylene glycol, polyvinyl alcohol; and
wherein said cationic polymer includes quaternary ammonium groups based polymers including polyacrylamidopropyltrimonium chloride, acrylamidopropyltrimonium chloride/acrylamide copolymer polydiallyldimethylammonium chloride, cationic polyethylenimine, polyquaternium such as polyquaternium-7, polyquaternium-28, polyquaternium-37; derived cationic polymers including polyquaternium-4, polyquaternium-10, Guar gum, 2-hydroxy-3-(trimethylammonio) propyl ether, chloride, hydrolyzed cationic corn starch, Crosslinked cationic tapioca starch, cationic hydrid corn starch; and
wherein the said additive includes powdered silica, alumina, zeolite, clay wherein said aminoplast capsules include melamine-formaldehyde capsules, with a particle size (d4,3) of 4-15 µm, having Zeta potential in the range of -20 mV to -50 mV.
In said slurry premix formulation wherein wt% of combined polymers in solid content of said premix slurries varies from 20% to 65%; and wherein total fragrance loading of slurry premix ranges from 5% to 85%.
Most advantageously said slurry premix formulation is provided as detergent/fabric care formulation in enabling higher loading of fragrance oil in powdered slurry premix in turn enables lower dosage of slurry premix in the range of 0.13 % to 0.56 % in rinse off detergent/fabric care formulations causing a reduction of 30-50% loading as compared to conventional detergent formulations to get the same fragrance effect.
According to another aspect of the present invention there is provided a simple method of manufacturing slurry premix formulation comprising the steps of
Providing aminoplast capsules;
Providing premix involving a select combination of bio-polymers including bio polymers, modified bio polymers and synthetic polymers (and/ or additive)/s in specific ratios;
Mixing said aminoplast capsules in said premix that were spray dried to obtain slurry premix formulation.
In said simple method of manufacturing slurry premix formulation said slurry premix were spray dried involving incoming air temperature of the chamber of 145°C–165°C and outgoing air temperature of 65°C–85 °C by involving a two fluid co-current nozzle of diameter 1.00 mm with auto de-blocking.

BRIEF DESCRIPTION OF FIGURES
Figure 1: illustrates average pre-rub and post-rub strengths of fragrance in powdered slurries premixes applied through detergent powder;
Figure 2: illustrates average pre-rub and post-rub strengths of fragrance in powdered slurries premixes and microcapsule slurries applied through fabric softener.
DETAILED DESCRIPTION OF THE INVENTION
As discussed hereinbefore, the present invention relates to slurry premix formulation comprising aminoplast capsule slurry in synergistic combination with bio-polymer/s and synthetic polymer (and/ or additive)/s, for incorporation in fabric cleaning rinse off formats such as detergent powder and fabric conditioners used in the washing process which enable the successful deposition of polymeric hard shell capsules containing liquid fragrances onto fabrics post-washing and drying though rinse off formats. The present invention concerns effective stabilisation of aminoplast caspules in slurry premix without any caking activity and delivery of the capsules onto fabric surfaces even when rinse off formats is employed for the purposes of fabric cleaning and care.
The effective transfer and lodging of polymeric microcapsules onto fabrics in a rinse off situation has been accomplished using rational principles of formulation design. The first step is the preparation of a free-flowable capsule containing powder, which, is then incorporated into a wash off formulation. A treated and improved capsule slurry premix is added to a laundry liquid with the objective of having capsules well dispersed in the medium, such that, these are effectively transferred to fabric post-wash. The deposition of capsules using flowable powders or aqueous slurries of fragrance-containing microcapsules in rinse off washing formats is impacted, primarily, due to stabilisation of micron-sized capsules in these formats, and, importantly due to the extremely poor transfer efficiency of these capsules onto the fabrics. The present invention ensures that capsules are adequately well protected in a stable free-flowable powder, further suitable for rinse off detergent formats in having capsule integrity in said slurry premix so that they get delivered onto fabrics even when rinse off product formats like detergent powders or laundry liquids are employed.
It is thus the finding of the present invention that a select system which when combined with aqueous slurries serves as a good vehicle for protecting the capsule integrity during the wash process and ensuring effective transfer and deposition of capsules onto fabric surfaces. A mixture of commercially available select modified bio-polymers /bio-polymers and synthetic polymers (modified celluloses procured from DuPontTM, modified starches procured from Ingredion, and synthetic polymers procured from Sigma-Aldrich) and/or additive at specified ratios was added to the diluted commercial slurries solutions to prepare a slurry premix. Free-flowable powdered slurries were obtained utilizing a select temperature based spray-drying operation particular to the ingredients involved for maintaining the integrity of the aminoplast capsules in the slurry. Additionally, cationic modification via. coating of a polycationic polymeric species during the preparation of the powdered capsules were reported here and this found to be beneficial in the retention of capsules in the rinse off laundry formats.
A premix can prepared by adding the required quantities of the two polymers in water and mixing those to prepare a diluted slurry. A few notable examples of bio-polymers /bio-polymers modified celluloses and starches are non-hygroscopic hydrolyzed low-molecular-weight carbohydrates namely tapioca dextrins with film forming ability (such as Crystal TexTM 626 and Crystal TexTM 644 sold by Ingredion), hydroxylpropyl methylcellulose, hydrogen octenylbutanedioate modified waxy maize starch (Hi-CapTM 100 sold by Ingredion), carboxymethylcellulose, partially hydrolyzed waxy maize starch (N-ZorbitTM 2144 DG sold by ingredion), partially hydrolyzed maize starch, specialty maize starch (AmazeTM by Ingredion), aluminum starch octenylsuccinate (Dry FloTM Plus by Ingredion), maltodextrin, etc.
Synthetic polyethylene glycols; (average molecular weights of 2500, 4000, 5000, 6000, 10000, 12500, etc) and partially hydrolyzed (80%, 88%) polyvinyl alcohols; (molecular weight range 9000-10000, 13000-26000, 31000-50000, 146000-186000, etc.) can be used with any of the above mentioned modified bio-polymers /bio-polymers.
Synthetic additives, uses here, include different grades of powdered silica, alumina, titania, zeolite.
Polymeric microcapsules used in the examples were melamine-formaldehyde microcapsules commercially produced in house with higher loading of fragrances up to 55%. Finally, the diluted premix was added with the microcapsule slurries to prepare a slurry premix.
The polycationic species of the present invention are synthetic polymers with several quaternary ammonium groups such as polyacrylamidopropyl trimonium chloride (N-DurhanceTM A-1000 by Ashland), acrylamidopropyltrimonium chloride/acrylamide copolymer (N-DurhanceTM AA-2000 by Ashland), polydiallyldimethylammonium chloride (MirapolTM 100S by Rhodia), polyquaternium such as polyquaternium-7, polyquaternium-28, polyquaternium-37, etc. Highly charged cationic polyethylenimine (LupasolTM FG by BASF) was also used in this invention.
Additionally, cationic polymers, used here, are derived from modified polymers such as cellulose, starch, guar, cassia, tapioca, Tara, etc. Examples of commercially available cationic polymers used are polyquaternium-4, polyquaternium-10, Guar gum, 2-hydroxy-3-(trimethylammonio) propyl ether, chloride (JaguarTM C17 by Solvay), hydrolyzed cationic corn starch (CaTOTM 75Q by Ingredion), cationic hydrolyzed tapioca starch (SPACTM by SPAC starch products), crosslinked cationic tapioca starch (MICROCATTM 310 by Ingredion), cationic hydrid corn starch (OptiPROTM 650 by Ingredion), etc.
Example 1: Preparation of Premix 1
100g N-ZorbitTM 2144 DG (Tapioca Maltodextrin) and 12g polyvinyl alcohol (Molecular weight range 9000-10000) were mixed in 500g water. Then to it, optionally 200g of 7.5% aqueous SPACTM (cationic hydrolyzed tapioca starch) was added. After thorough mixing for 15 minutes at 400 rpm using an overhead stirrer, Premix 1 was prepared.
Example 2: Preparation of Premix 2-5
Premix 2-5, were prepared in a similar manner as described in Example 1 and are summarized in Table 1.
Table 1
Example Polymer 1 Polymer 2 Water Aqueous polycationic dispersion
Premix 1 100g N-ZorbitTM 2144 DG (Tapioca Maltodextrin) 12g polyvinyl alcohol 500g cationic hydrolyzed tapioca starch (SPACTM)
Premix 2 75g Crystal TexTM 626 (specialty high stability dextrin refined from tapioca starch) 300g
Premix 3 75g Crystal TexTM 626 (specialty high stability dextrin refined from tapioca starch) 10g polyvinyl alcohol 400g 100g 5% N-DurhanceTM A-1000 (homopolymer of (3-Acrylamidopropyl) trimethyl ammonium chloride)
Premix 4 75g Crystal TexTM 626 (specialty high stability dextrin refined from tapioca starch) 10g polyvinyl alcohol 400g
Premix 5 75g Crystal TexTM 626 (specialty high stability dextrin refined from tapioca starch) 5g powdered silica (silicon dioxide) 370g water 100g 5% N-DurhanceTM A-1000
(homopolymer of (3-Acrylamidopropyl) trimethyl ammonium chloride)

Importantly, the bio-polymer: synthetic polymer (and/or additive) ratio in the range of 1:0.07 to 1: 0.3 enables a free flowable free of any caking activity of the slurries premix below.
Example 3: Preparation of Slurries Premix 1-5
1 kg of polymeric slurries with specified fragrance and loading of fragrance was used to mix with each of the premixes (premix 1 to 5). Polymeric melamine-formaldehyde shell liquid fragrance core microcapsule slurries with a fragrance loading of 40% to 55% were available commercially from Keva Fragrances Ltd., India. Details are summarized in Table 2. Polymeric slurries with a particle size (d4,3) of 4-15 µm were having Zeta potential in the range of -20 mV to -50 mV.
Table 2
Example Premix used Commercial Code of Fragrance used in polymeric microcapsule slurries Olfactive notes of fragrance Loading of fragrance in slurries (in % of weight)
Slurries premix 1 Premix 1 NP 0578 Aldehydic, Floral, Marine, Vanillic, Ambery, Gourmand 40.5
Slurries premix 2 Premix 2 C 4985 Citrus, Floral, Green, Powdery, Woody, Musky 45
Slurries premix 3 Premix 3 C 4985 Citrus, Floral, Green, Powdery, Woody, Musky 45
Slurries premix 4 Premix 4 C 4985 Citrus, Floral, Green, Powdery, Woody, Musky 45
Slurries premix 5 Premix 5 C 4985 Citrus, Floral, Green, Powdery, Woody, Musky 45

Example 4: Spray-drying of Slurries Premix 1-5
Slurries premix 1-5 were spray-dried using a JISL “Spray Mate” laboratory spray Dryer. The incoming air temperature of the chamber was 145°C–155°C and the outgoing air temperature was 75°C–85 °C during the spray-drying operation. A two fluid co-current nozzle of diameter 1.00 mm with auto de-blocking was used to spray-dry the samples. Details of the results of spray drying are summarized in Table 3.

Table 3
Sample Details Yield of obtained powder (in % of weight) Amount of fragrance encapsulated in powder (in % of weight) Moisture-Content of the powder (in % of weight)
Slurries premix 1 83 68.25 2.86
Slurries premix 2 78 74.65 3.80
Slurries premix 3 85 73.62 2.72
Slurries premix 4 81 70.84 2.37
Slurries premix 5 83 72.45 2.07

It was thus found from the above table that while slurries premix 2 based on a single polymer is bad in moisture content that is not stable, slurry premix 4 in the absence of preferred cationic polymer is also within the desired range.
The above slurries premix obtained of spray drying operations with inlet air temperature of from 145°C to 165°C and outlet air temperature of from 65 °C to 85 °C thus enables improved fragrance loading through said aminoplast microcapsules taken in the range of 45-55 wt. % providing for slurry premix facilitating enhanced fragrance loading in the range of 68-74 wt.% that is stable with the moisture content advantageously limited to 2.3-3 wt.%, as is reflected in Example 7 below.
Analysis of the powdered polymeric microcapsules slurries
Zeta potential measurements
Zeta potential analysis of the diluted samples of polymeric microcapsules in water (5% by weight) were performed using a Malvern Zeta Sizer.
Measurement of loading of fragrance
Actual loading of fragrance in polymeric microcapsules slurries and powdered microcapsules slurries were measuring by the solvent extraction method. The samples were extracted by hot solvent (soxhlet extraction) and the extracted fragrances were analyzed by Agilent GCMS to quantify the loading of fragrances in the samples.
Stability tests
The powdered capsules in were subjected to two hours of mechanical shaking at 1200 rpm to simulate a transportation test. Then the same was analysed by TGA. No change in the TGA profiles was noticed before and after the mechanical shaking, inferring the stability of the capsules in the powder form. A similar study is not reported in the prior art of powdered capsules.
The capsule in were further subjected to two weeks stability test following a standard ICH protocol (45 °C and 70% Relative Humidity). Then the same was analysed by TGA. No noticeable change in the TGA profiles was noted before and after the stability test, indicating the mechanical robustness of the powdered polymeric capsules. This test is also not mentioned in the prior art.
Examples 5: Evaluation for powdered microcapsule slurries in Detergent powder
We have evaluated laundry wash off formulations, incorporating the powdered polymeric capsules slurries premix 3 and 4 of example 4 into detergent powder. A prototype detergent powder base without fragrance was prepared using the ingredients mentioned in Table 4.
Table 4
Ingredient % of weight in the formulation
Combination of anionic and nonionic based actives: linear alkyl benzene sulphonic acid, sodium lauryl ether sulphate, alpha olefin sulphonate, sodium lauryl sulphate, 23
Sodium tripolyphosphate 2
Sodium carbonate 24.5
Calcium carbonate 3
Mixer of sodium chloride and corn starch 20
Sodium sulphate 22
Fluorescher/polymer blend 1
Sodium hypochlorite 1
Colored sodium lauryl sulphate needles/speckles 1
Moisture 1.5
Other minor ingredients 1
Total 100

Procedure: Powdered slurries premix 3 was mixed into the above detergent powder formulation at a dosage of 0.31g spray-dried powdered polymeric slurries per 100g of detergent powder. Similarly, powdered slurries premix 4 was mixed into the above detergent powder formulation at a dosage of 0.30g spray-dried powdered polymeric slurries per 100g of detergent powder. 6g of detergent powders with slurries premix 3 and slurries premix 4 were dispersed separately in 1 liter of water each bucket. Then clothes were soaked for 20 minutes in the two buckets. The soaked clothes in the previous step were washed twice with 1 liter of water for each washing cycle. Next, the clothes were dried under ambient conditions. Dried fabrics then were evaluated by a panel of trained evolutionists for pre-rubbing and post-rubbing experiences for profile and strength of the deposited fragrance through the powdered polymeric slurries on the fabrics. The pre-rubbing and post-rubbing strength scores were analyzed and presented in Figure 1 in powdered slurries premixes applied through detergent powder. It is seen from Figure 1 that addition of cationic polymers (in premix 3) help in better adhesion of powdered microcapsule slurries is evident from the above analysis. No significant difference in profile was noticed in the samples; hence, profile results were not shown here.
Examples 6: Evaluation for powdered microcapsule slurries in Fabric Softener
We further demonstrated laundry rinse off formulation, incorporating the powdered polymeric capsules slurries premix 3 and 4 of Example 4 separately into the fabric softener (FS) base. A fabric softener composition with pure polymeric slurries with equivalent loading of microencapsulated fragrance was also prepared for comparison. First, a fabric softener base without fragrance was prepared using the ingredients mentioned in Table 5.
Table 5
Ingredient/ Trade Name % of weight
Water 90.15
FlosoftTM 222 (of SNF) 0.20
ArquadTM 2HT-75 (of Nouryon) 9.3
KathonTM CG (of Dow) 0.20
Citric acid 0.15
Total 100

Procedure: Water and ArquadTM 2HT-75 were heated in separate vessels up to 70-80 °C and the temperature was maintained. FlosoftTM 222 was added in water slowly with continuous stirring. Arquad 2HT (75%) was added in water slowly with stirring to allow it to disperse and to make a homogenous dispersion. KathonTM CG was added at 35 to 40 °C under continuous stirring. Citric acid was added at the end to adjust the below pH 5. The fabric softener base was then ready for use. 1.25 g of powdered polymeric slurries obtained from slurries premix 3 and premix 4 were mixed with 2.75g of water separately to prepare two thick pastes. 1g of each of the pastes of previous step were added separately to 99g of the fabric softener base each and stirred to prepare two homogeneous mixtures.
Similarly, equivalent amount of native microcapsule slurries (to maintain the equivalent loading of microencapsulated fragrance in the final fabric softener) was added to FS base with stirring to prepare fabric softener with microcapsule slurries. The above fabric softeners with slurries premix 3, slurries premix 4, and polymeric microcapsule slurries were applied separately at a dosage of 5g per liter in water and fabrics were soaked for 20 minutes. Then excess water was rinsed off from the fabrics and fabrics were dried at ambient conditions. Dried fabrics were then evaluated by a panel of trained evolutionists for pre-rubbing and post-rubbing experiences for profile and strength of the deposited fragrance through the powdered polymeric slurries on the fabrics. The pre-rubbing and post-rubbing strength scores were analyzed and presented in Figure 2 in powdered slurries premixes and microcapsule slurries applied through fabric softener.
It is seen from Figure 2 that addition of cationic polymers (in slurries premix 3) help in better adhesion of powdered microcapsule slurries is evident from the above analysis. Slurries premix 4 is also good in terms of stability and deposition with regard to the conventional microcapsules slurries plotted in right hand side of Figure 2. No significant difference in profile was noticed in the samples; hence, profile results were not shown here.
Example 7: Evaluation of stability of slurries premixes at ambient condition after six months
30 g of premix slurries 2, 4, & 5 were stored in 100 mL screw capped PET bottles under ambient condition (25 °C & 75% relative humidity) for six months-1 yr. Then the physical appearance and moisture content were checked in the three samples.
Sample Details Relative humidity (% w/w) Physical appearance
After preparation After 6 months to 1 yr time After preparation After 6 months to 1 yr time
Slurries premix 2 3.80 7.05 Free-flowable powder Small grains formed
Slurries premix 4 2.37 2.89 Free-flowable powder Almost free-flowable powder
Slurries premix 5 2.07 2.43 Free-flowable powder Free-flowable powder

All the slurries premixes were free-flowable after spray-drying. However, slurries premix 2 without Polymer 2 formed small grains after storage and Slurries premixes 4 (with Polymer 2 but without cationic polymer) and 5 with a synthetic polymer (polyvinyl alcohol) or additive (silica) were found to be free-flowable after storing six months at ambient condition and also attracted less moisture.
The slurries premix in accordance with the invention 4, 5 enhances the stability as evidenced from moisture content data and physical appearances (free-flowable powder with no caking activity) of the samples.
The present advancement is intended to eliminate water from aminoplast slurries and stabilize the same in solid form. If we consider same dosage of fragrance loading, then to load 0.45g of fragrance it requires approximately 1.00g of conventional slurries and only about 0.58g of powdered slurry premix of the present invention. Therefore, a 42% lowering of dosage is achieved compared to the conventional state of the art knowledge.
To load a lower dosage of 0.1% fragrance 0.13% of slurry premix is required. Similarly, to load 0.4% fragrance only 0.56% of slurry premix is required.
The incoming and outgoing air temperatures were made selective and only then best slurry premix powder could be obtained.
The process of the present invention is made selective wherein incoming air temperature is taken at (145°C–165°C): Lowering the temperature resulted granules along with powder and increasing the temperature resulted loss of fragrances due to breakage of aminoplast capsules (instable slurry premix).
Outgoing air temperature (65°C–85°C) was also made selective wherein: Lowering the temperature resulted slurry premix with higher moisture content and above 85°C, coloration (off-white to light) brown developed.
It is thus the finding of the present advancement that a slurry premix formulation of aminoplast capsules could be achieved by providing aminoplast capsule slurry in synergistic combination with bio-polymer/s and synthetic polymer (and/ or additive)/s in select ratios by following a select process that allows improved fragrance loading through said aminoplast microcapsules in the range of 45-55 wt.% in slurry premix, said slurry premix thus having enhanced fragrance loading in the range of 68-74 wt.% that is stable with the moisture content advantageously limited to 2.3-3 wt.%. Such higher loading of fragrance oil in powdered slurry premix in turn enables lower dosage of slurry premix in the range of 0.13 % to 0.56 % in rinse off detergent/fabric care formulations causing a reduction of 30-50% loading of the slurry premix in detergent formulation as compared to conventional detergent formulations, to get the same fragrance effect.

,CLAIMS:We Claim:

1. A slurry premix formulation comprising aminoplast capsule slurry in synergistic combination with bio-polymer/s and synthetic polymer (and/ or additive)/s in bio-polymer/s and synthetic polymer (and or additive)/s: slurry ratio range of 0.05:1 to 1:1 adapted for storage stable free-flowable powder slurry premix with improved loading of fragrance and yet stable at ambient conditions for 6 months to 1 yr.
2. A slurry premix formulation as claimed in claim 1 wherein said slurry involving bio-polymer: synthetic polymer (and/or additive) ratio in the range of 1:0.07 to 1: 0.3 remains as a free flowable free of any caking activity.
3. A slurry premix formulation as claimed in claims 1-2 wherein said aminoplast capsules comprises polymeric hard shell and liquid core preferably liquid fragrance core and is capable of incorporation in detergent powder devoid of caking problems or laundry liquid formulations and survives wash off/rinse-off process, and, retain its ability to get lodged onto fabric surfaces subsequent to drying of the same.
4. A slurry premix formulation as claimed in claims 1-3 wherein said aminoplast capsules are cationically modified by cationic polymer providing enhanced deposition efficiencies of capsules on fabric through fabric care formulations including detergent powders, fabric softeners with said capsules being well dispersed in said formulations for deposition onto fabric during rinse-off.
5. A slurry premix formulation as claimed in claims 1-4 obtained of spray drying operations with inlet air temperature of from 145°C to 165°C and outlet air temperature of from 65 °C to 85 °C enabling improved fragrance loading through said aminoplast microcapsules taken in the range of 45-55 wt.% in slurry premix facilitating further enhanced fragrance loading in said slurries premix in the range of 68-74 wt.% with the moisture content advantageously limited to 2.3-3 wt.% that is again stable in detergent powder formulations.
6. A slurry premix formulation as claimed in claims 1-5 wherein said bio-polymer/s includes modified bio-polymers of celluloses and starches including non-hygroscopic hydrolyzed low-molecular-weight carbohydrates tapioca dextrins with film forming ability, hydroxylpropyl methylcellulose, hydrogen octenylbutanedioate modified waxy maize starch carboxymethyl cellulose, partially hydrolyzed waxy maize starch, partially hydrolyzed maize starch as mixtures; and
wherein said synthetic polymers includes polyethylene glycol, polyvinyl alcohol; and
wherein said cationic polymer includes quaternary ammonium groups based polymers including polyacrylamidopropyltrimonium chloride, acrylamidopropyltrimonium chloride/acrylamide copolymer polydiallyldimethylammonium chloride, cationic polyethylenimine, polyquaternium such as polyquaternium-7, polyquaternium-28, polyquaternium-37; derived cationic polymers including polyquaternium-4, polyquaternium-10, Guar gum, 2-hydroxy-3-(trimethylammonio) propyl ether, chloride, hydrolyzed cationic corn starch, Crosslinked cationic tapioca starch, cationic hydrid corn starch; and
wherein the said additive includes powdered silica, alumina, zeolite, clay wherein said aminoplast capsules include melamine-formaldehyde capsules, with a particle size (d4,3) of 4-15 µm, having Zeta potential in the range of -20 mV to -50 mV.
7. A slurry premix formulation as claimed in claims 1-6 wherein wt% of combined polymers in solid content of said premix slurries varies from 20% to 65%; and wherein total fragrance loading of slurry premix ranges from 5% to 85%.
8. A slurry premix formulation as claimed in claims 1-7 as detergent/fabric care formulation in enabling higher loading of fragrance oil in powdered slurry premix in turn enables lower dosage of slurry premix in the range of 0.13 % to 0.56 % in rinse off detergent/fabric care formulations causing a reduction of 30-50% loading as compared to conventional detergent formulations to get the same fragrance effect.
9. A simple method of manufacturing slurry premix formulation as claimed in claims 1-8 comprising the steps of
Providing aminoplast capsules;
Providing premix involving a select combination of bio-polymers including bio polymers, modified bio polymers and synthetic polymers (and/ or additive)/s in specific ratios;
Mixing said aminoplast capsules in said premix that were spray dried to obtain slurry premix formulation.
10. A simple method of manufacturing slurry premix formulation as claimed in claim 9 wherein said slurry premix were spray dried involving incoming air temperature of the chamber of 145°C–165°C and outgoing air temperature of 65°C–85 °C by involving a two fluid co-current nozzle of diameter 1.00 mm with auto de-blocking.

Dated this the 28th day of August, 2020 Anjan Sen
Of Anjan Sen and Associates
(Applicants Agent)
IN/PA-199