Functional fragrance precursor

<u>TECHNICAL FIELD</u>

0001The present invention relates to a class of compounds, and especially a group of fragrance precursor compounds which are used for creating a fragrance effect, preferably on surfaces such as fibers, skin, hair and hard surfaces. More specifically, the invention relates to a group of fragrance precursor compounds that break down on the above outlined surfaces, and as a result of this release perfume. In preferred embodiments the invention relates to certain hemiacetal and acetal compounds. Since the perfume or fragrance is only released when the compounds of the invention are broken down, the compounds of the invention are capable of providing a long-lasting fragrance effect. That is, the compounds of the present invention provide for a sustained release of fragrances.

0002In a further aspect, the present invention relates to a process for preparing these precursor compounds. Fragrance precursor compounds consist of fragrance raw materials and functional compounds such as surfactants, polymers etc., which provide benefits such as surface protection, surface conditioning, and/or surface cleaning.

0003In addition, the present invention relates to compositions comprising the compounds of the invention, and to fragrance raw material delivery systems which provide extended fragrance benefits.

<u>BACKGROUND OF THE INVENTION</u>

0004In <patcit id="pcit0001" dnum="WO0072816A"><text>WO-00/72816</text></patcit>, fragrance delivery systems are described which comprise pro-fragrances or pro-accords selected from at least two of the following: (i) aldehyde and ketone releasing pro-fragrances, which pro-fragrances comprise <i>inter alia</i> and preferably oxazolidines; (ii) β-amino pro-fragrances; and (iii) orthoester pro-accords. The pro-fragrances described are capable of delivering fragrance raw material aldehydes and ketones to especially the human skin. More in detail, said international patent application is based on the finding that certain aldehyde fragrance raw materials, such as para-t-bucinal, cymal and lillial can be controllably released from particular heterocyclic pro-fragrances to especially the skin.

0005In laundry products, such as fabric softeners or detergents, generally perfume additives are present which make the said products more aesthetically pleasing to the consumers. The product should not only smell pleasantly and in that way add to the purchase perception, but also impart a pleasant and preferably long lasting fragrance to the fibers or fabrics treated therewith. One of the problems the person skilled in the art is confronted with is that the amount of perfume carryover is rather marginal; much fragrance is lost during washing and disappears down the drain. It would be very desirable to find ways of more effectively delivering perfume or fragrances to fibers, fabrics and textiles and to achieve the fragrance effect for a longer period of time.

0006Colgate-Palmolive application <patcit id="pcit0002" dnum="WO02057400A"><text>WO 02/057400</text></patcit> describes a water soluble crosslinked cationic polymer derived from the polymerisation of from 5 to 100 mole percent of a cationic vinyl addition monomer, from 0 to 95 mole percent of acrylamide, and from 70 to 300 ppm of a difunctional vinyl addition monomer cross-linking agent which enhances frangrance delivery from a fabric softening composition to the fabric to be softened.

0007In copending Colgate-Palmolive <patcit id="pcit0003" dnum="US9893117A"><text>U.S. Application Serial No. 9/893,117, filed June 27, 2001</text></patcit>, there is described a fabric care composition comprising a cationic softening compound; a non-confined fragrance oil; and at least one fabric or skin beneficiating ingredient such as a fragrance oil, contained within pressure sensitive microcapsules to provide enhanced delivery of such beneficiating ingredient to the fabric.

<u>OBJECTIVES OF THE PRESENT INVENTION</u>

0008The first objective of the present invention is to provide alternative fragrances precursors or pro-fragrances.

0009It is another objective to provide a more efficient delivery system of fragrance or perfume to surfaces.

0010It is a further objective to provide functional fragrance precursor compounds that impart long lasting fragrance benefits, especially to fiber containing materials, such as fabrics and laundry.

0011Moreover, it is an objective of the present invention to provide a controlled or sustained release system releasing fragrance for a longer period of time.

0012Yet a further objective is to provide consumer product compositions which are capable to provide sustained release of fragrance.

0013Other objectives will become apparent from reading the following description and are especially obtained for laundry products, personal care products, hard surface care products, oral products and so on.

<u>SUMMARY OF THE INVENTION</u>

0014According to the present invention a class of chemical compounds, and especially a class of fragrance precursor compounds has been found, which form the basis of products and methods which meet at least a number of the above-identified objectives. More in particular, the present invention provides fragrance precursor compounds that are capable of breakdown under ambient conditions and that are the reaction product of a reaction between a hydroxyl compound, X-OH, and an aldehyde or a ketone. More in detail, the invention relates to a fragrance precursor compound comprising one or more of the compounds derived from the reaction of X-OH and an aldehyde or ketone, said fragrance precursor compounds being of the formula X-O-C(R)(R*)(OR**) wherein R is a C_6-24 alkyl group, a C_6-24 aralkyl group or a C_6-24 alkaryl group; R* is H or a C_6-24 alkyl group, a C_6-24 aralkyl group or a C_6-24 alkaryl group; R** is H or X; X-O representing a moiety derived from X-OH, and wherein X-OH is a compound selected from the group consisting of surfactants, fabric softeners, softener precursor ester amines, softener precursor amido amines, hair conditioners, skin conditions, saccharides and polymers. In preferred embodiments X-OH is of the following structure: <chemistry id="chem0001" num="0001"><img file="EP2353656A2_D0001.tif" /></chemistry> wherein R₁ and R₂ are each independently, H or: <ol id="ol0001" compact="compact" ol-style=""><li>(a) C₁-C₂₂ alkylenecarboxy moiety having the formula -(CH₂)_eR₃ wherein R₃ is -NHCOR₄; or -OCOR₄; or NR₅COR₄; and wherein R₄ and R₅ are each independently C₁-C₂₂ akyl or alkenyl; and e is an integer from 1 to 22; or</li><li>(b) C₁-C₂₂ linear or branched alkyl; or</li><li>(c) C₁-C₂₂ linear or branched alkenyl; or</li><li>(d) C₂-C₂₂ substituted or unsubstituted alkylenoxy; or</li><li>(e) C₃-C₂₂ substituted or unsubstituted alkylenoxy alkyl; or</li><li>(f) C₆-C₂₂ substituted or unsubstituted aryloxy; or</li><li>(g) C₇-C₂₂ substituted or unsubstituted alkylenearyl; or</li><li>(h) C₇-C₂₂ substituted or unsubstituted alkyleneoxyary;or</li><li>(i) C₇-C₂₂ oxyalkylenearyl; or</li><li>(j) an anionic unit having the formula:          <b>-(CH₂)_yR₆</b> wherein R₆ is -SO₃M, -OSO₃M, -PO₃M, -OPO₃M, Cl or mixtures thereof, wherein M is hydrogen, or one or more salt forming cations sufficient to satisfy charge balance, or mixtures thereof; y is an integer from 1 to about 22; or</li><li>(k) a mixture comprising at least two of (a) through (j); and</li></ol> q is an integer from 0 to about 22; m is an integer from 0 to about 22; Q is (CH₂)_m or (CH₂CHR₇O); R₇ is independently hydrogen, methyl, ethyl, propyl or benzyl; B is H or OH; and Y is CR₁ or N. <chemistry id="chem0002" num="0002"><img file="EP2353656A2_D0002.tif" /></chemistry> wherein R₁ and R₂, independently, represent C₁₂ to C₃₀ aliphatic hydrocarbon groups, R₃ represents (CH₂CH₂O)_pH, CH₃ or H; T represents NH; n is an integer from 1 to 5; m is an integer from 1 to 5 and p is an integer from 1 to 10. <chemistry id="chem0003" num="0003"><img file="EP2353656A2_D0003.tif" /></chemistry> wherein R₁ is H or: <ul id="ul0001" list-style="none" compact="compact"><li>(a) C₁-C₂₂ alkylenecarboxy moiety having the formula: -(CH₂)_eR₃ wherein R₃ is NHCOR₄; or -OCOR₄; or NR₅COR₄; and wherein R₄ and R₅ are each independently C₁-C₂₂ akyl or alkenyl; and e is an integer from 1 to 22; or</li><li>(b) C₁-C₂₂ linear or branched alkyl; or</li><li>(c) C₁-C₂₂ linear or branched alkenyl; or</li><li>(d) C₂-C₂₂ substituted or unsubstituted alkylenoxy; or</li><li>(e) C₃-C₂₂ substituted or unsubstituted alkylenoxy alkyl; or</li><li>(f) C₆-C₂₂ substituted or unsubstituted aryloxy; or</li><li>(g) C₇-C₂₂ substituted or unsubstituted alkylenearyl; or</li><li>(h) C₇-C₂₂ substituted or unsubstituted alkyleneoxyaryl; or</li><li>(i) C₇-C₂₂ oxyalkylenearyl; or</li><li>(j) an anionic unit having the formula:          <b>-(CH₂)_yR₆</b> wherein R₆ is -SO₃M, -OSO₃M, -PO₃M, -OPO₃M, Cl or mixtures thereof, wherein M is hydrogen, or one or more salt forming cations sufficient to satisfy charge balance, or mixtures thereof; y is an integer from 1 to about 22; and</li><li>(k) a mixture comprising at least two of (a) through (j); and</li><li>q is an integer from 0 to about 22; m is an integer from 0 to about 22; Q is (CH₂)_m or (CH₂CHR₇O); R₇ is independently hydrogen, methyl, ethyl, propyl or benzyl; B is H or OH; and Y is O or S. <chemistry id="chem0004" num="0004"><img file="EP2353656A2_D0004.tif" /></chemistry> wherein R₁ and R₂ are each independently, H or: <ul id="ul0002" list-style="none" compact="compact"><li>(a) C₁-C₂₂ alkylenecarboxy moiety having the formula: -(CH₂)_eR₃ wherein R₃ is -NHCOR₄; or -OCOR₄; or NR₅COR₄; and wherein R₄ and R₅ are each independently C₁-C₂₂ akyl or alkenyl; and e is an integer from 1 to 22; or</li><li>(b) C₁-C₂₂ linear or branched alkyl; or</li><li>(c) C₁-C₂₂ linear or branched alkenyl; or</li><li>(d) C₂-C₂₂ substituted or unsubstituted alkylenoxy; or</li><li>(e) C₃-C₂₂ substituted or unsubstituted alkylenoxy alkyl; or</li><li>(f) C₆-C₂₂ substituted or unsubstituted aryloxy; or</li><li>(g) C₇-C₂₂ substituted or unsubstituted alkylenearyl; or</li><li>(h) C₇-C₂₂ substituted or unsubstituted alkyleneoxyaryl; or</li><li>(i) C₇-C₂₂ oxyalkylenearyl; or</li><li>(j) an anionic unit having the formula: <b>-(CH₂)_yR₆</b> wherein R₆ is -SO₃M, -OSO₃M, -PO₃M, -OPO₃M, Cl or mixtures thereof, wherein M is hydrogen, or one or more salt forming cations sufficient to satisfy charge balance, or mixtures thereof; R₆ may also be choloride; y is an integer from 1 to about 22; and</li><li>(k) a mixture comprising at least two of (a) through (j); and</li><li>q is an integer from 0 to about 22; m is an integer from 0 to about 22; Q is (CH₂)_m or (CH₂CHR₇O); R₇ is independently hydrogen, methyl, ethyl, propyl or benzyl; and mixtures thereof; B is H or OH; Y is C or N; R₈ is H or C₁-C₄ alkyl; Z^- is a counter anion, and preferably chloride,or methyl sulfate. <chemistry id="chem0005" num="0005"><img file="EP2353656A2_D0005.tif" /></chemistry></li></ul> wherein R₁ and R₂ are as defined in I; R' and R" are each independently OH or R₁ with the proviso that at least one of R' and R" is OH.</li></ul>

0015In a second aspect, the present invention relates to a process for preparing the products of the invention, comprising reacting an aldehyde and or ketone and a compound X-OH. X-OH is defined as above.

0016In a third aspect, the present invention relates to an aqueous composition for fragrance delivery comprising one or more of the reaction products according to the invention. Preferably, said composition of comprises a fabric softener.

<u>BRIEF DESCRIPTION OF THE DRAWINGS</u>

0017In the drawings, <ul id="ul0003" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> shows the reaction between a difatty amido amine and a C₁₀ aldehyde;</li><li><figref idref="f0002">Figure 2</figref> shows the release of fragrance from fabric treated with fabric softener containing the fragrance precursor compounds of the present invention after 1 and after 5 days, for a C₈, C₉ and C₁₀ aldehydes by Solid Phase Micro Extraction GC/MS;</li><li><figref idref="f0003">Figure 3</figref> shows a GC/MS spectrum of pure C₁₀ aldehyde, and the compound released from cloth treated with a fragrance precursor compound based on C₁₀ aldehyde and Varisoft 510;</li><li><figref idref="f0004 f0005">Figures 4a-4d</figref> show the proton-NMR spectra and the ¹³C-NMR spectra of Varisoft 510 and Varisoft 510 reacted with C₁₀ aldehyde; and</li><li><figref idref="f0006 f0007 f0008">Figures 5a-5c</figref> show the Mass Spectrum of the reaction products of Varisoft 510 with C₁₀ aldehyde.</li></ul>

<u>DETAILED DESCRIPTION OF THE INVENTION</u>

0018As mentioned herein-above, the present invention relates to the reaction product of a reaction between X-OH and an aldehyde or a ketone. In the aldehyde or ketone starting compounds of this reaction, the C_6-24 alkyl moiety encompasses linear and branched alkyl groups which can have one or more unsaturations. Such groups can be substituted with substituents which do not adversely affect the fragrance activity of the aldehyde or ketones. Examples of such substituents encompass F, Cl and OH.

0019The C_6-24 alkaryl and aralkyl moiety can also be branched and contain substituents that do not adversely affect the fragrance properties.

0020In a more preferred embodiment, X-OH preferably is of the following structure: <chemistry id="chem0006" num="0006"><img file="EP2353656A2_D0006.tif" /></chemistry> wherein R₁ and R₂ are each independently, H or: <ol id="ol0002" compact="compact" ol-style=""><li>(a) C₁-C₂₂ alkylenecarboxy moiety having the formula -(CH₂)_eR₃ wherein R₃ is -NHCOR₄; or -OCOR₄; or -NR₅COR₄; and wherein R₄ and R₅ are each independently C₁-C₂₂ akyl or alkenyl; and e is an integer from 1 to 22; or</li><li>(b) C₁-C₂₂ linear or branched alkyl; or</li><li>(c) C₁-C₂₂ linear or branched alkenyl; or</li><li>(d) C₂-C₂₂ substituted or unsubstituted alkylenoxy; or</li><li>(e) C₃-C₂₂ substituted or unsubstituted alkylenoxy alkyl; or</li><li>(f) C₆-C₂₂ substituted or unsubstituted aryloxy; or</li><li>(g) C₇-C₂₂ substituted or unsubstituted alkylenearyl; or</li><li>(h) C₇-C₂₂ substituted or unsubstituted alkyleneoxyaryl; or</li><li>(i) C₇-C₂₂ oxyalkylenearyl; or</li><li>(j) an anionic unit having the formula: <b>-(CH₂)_yR₆</b> wherein R₆ is -SO₃M, -OSO₃M, -PO₃M, -OPO₃M, Cl or mixtures thereof, wherein M is hydrogen, or one or more salt forming cations sufficient to satisfy charge balance, or mixtures thereof; y is an integer from 1 to about 22; or</li><li>(k) a mixture comprising at least two of (a) through (j); and</li></ol> q is an integer from 0 to about 22; m is an integer from 0 to about 22; Q is (CH₂)_m or (CH₂CHR₇O); R₇ is independently hydrogen, methyl, ethyl, propyl or benzyl; B is H or OH; and Y is CR₁ or N.

0021The aldehydes useful in the present invention can be one or more of, but is not limited to the following group of aldehydes: <ul id="ul0004" list-style="none" compact="compact"><li>(a) Phenylacetaldehyde; or</li><li>(b) p-methyl phenylacetaldehyde; or</li><li>(c) p-isopropyl phenylacetaldehyde; or</li><li>(d) methylnonyl acetaldehyde; or</li><li>(e) phenylpropanal; or</li><li>(f) 3-(4-t-butylphenyl)-2-methyl propanal; or</li><li>(g) 3-(4-t-butylphenyl)-propanal; or</li><li>(h) 3-(4-methoxyphenyl)-2-methylpropanal; or</li><li>(i) 3-(4-isopropylphenyl)-2-methylpropanal; or</li><li>(j) 3-(3,4-methylenedioxyphenyl)-2-methylpropanal; or</li><li>(k) 3-(4-ethylpheny)-2,2dimethylpropanal; or</li><li>(l) phenylbutanal; or</li><li>(m) 3-methyl-5-phenylpentanal; or</li><li>(n) hexanal; or</li><li>(o) trans-2-hexenal; or</li><li>(p) cis-hex-3-enal; or</li><li>(q) heptanal; or</li><li>(r) cis-4-heptenal; or</li><li>(s) 2-ethyl-2-heptenal; or</li><li>(t) 2,6-dimethylpropanal; or</li><li>(u) 2,4-heptadienal; or</li><li>(v) octanal; or</li><li>(w) 2-octenal; or</li><li>(x) 3,7-dimethyloctanal; or</li><li>(y) 3,7-dimethyl-2,6-octadien-1-al; or</li><li>(z) 3,7-dimethyl-1,6-octadien-3-al; or</li><li>(aa) 3,7-dimethyl-6-octenal; or</li><li>(bb) 3,7-dimethyl-7-hydroxyoctan-1-al; or</li><li>(cc) nonanal; or</li><li>(dd) 6-nonenal; or</li><li>(ee) 2,4-nonadienal; or</li><li>(ff) 2,6-nonadienal; or</li><li>(gg) decanal; or</li><li>(hh) 2-methyl decanal; or</li><li>(ii) 4-decenal; or</li><li>(jj) 9-decenal; or</li><li>(kk) 2,4-decadienal; or</li><li>(ll) undecanal; or</li><li>(mm) 2-methyldecanal; or</li><li>(nn) 2-methylundecanal; or</li><li>(oo) 2,6,10-trimethyl-9-undecenal; or</li><li>(pp) undec-10-enyl aldehyde; or</li><li>(qq) undec-8-enanal; or</li><li>(rr) dodecanal; or</li><li>(ss) tridecanal; or</li><li>(tt) tetradecanal; or</li><li>(uu) anisaldehyde; or</li><li>(vv) bourgenonal; or</li><li>(ww) cinnamic aldehyde; or</li><li>(xx) α-amylcinnam-aldehyde; or</li><li>(yy) α-hexyl cinnamaldehyde; or</li><li>(zz) methoxy cinnamaldehyde; or</li><li>(aaa )citronellal; or</li><li>(bbb) hydroxy-citronellal; or</li><li>(ccc) isocyclocitral; or</li><li>(ddd) citronellyl oxyacet-aldehyde; or</li><li>(eee) cortexaldehyde; or</li><li>(fff) cumminic aldehyde; or</li><li>(ggg) cyclamem aldehyde; or</li><li>(hhh )florhydral; or</li><li>(iii) heliotropin; or</li><li>(jjj) hydrotropic aldehyde; or</li><li>(kkk) lilial; or</li><li>(lll) vanillin; or</li><li>(mmm)ethyl vanillin; or</li><li>(nnn) benzaldehyde; or</li><li>(ooo) p-methyl benzaldehyde; or</li><li>(ppp) 3,4-dimethoxybenzaldehyde; or</li><li>(qqq) 3-and 4-(4-hydroxy-4-methyl-pentyl)-3-cyclohexene-1-caroxaldehyde; or</li><li>(rrr) 2,4-dimethyl-3-cyclohexene-1-carboxaldehyde; or</li><li>(sss) 1-methyl-3-4-methylpentyl-3-cyclohexencarboxaldehyde; and</li><li>(ttt) p-methylphenoxyacetaldehyde</li></ul>

0022When an aldehyde is used the precursor of the invention is an acetal or hemiacetal.

0023The ketones useful in the present invention can be one or more of, but is not limited to the group of following ketones: <ul id="ul0005" list-style="none" compact="compact"><li>(a) alpha-damascone; or</li><li>(b) beta-damascone; or</li><li>(c) delta-damascone; or</li><li>(d) beta-damascenone; or</li><li>(e) muscone; or</li><li>(f) 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone; or</li><li>(g) cashmeran; or</li><li>(h) cis-jasmone; or</li><li>(i) dihydrojasmone; or</li><li>(j) alpha-ionone; or</li><li>(k) beta-ionone; or</li><li>(l) dihydro-beta-ionone; or</li><li>(m) gamma-methyl ionone; or</li><li>(n) alpha-iso-methyl ionone; or</li><li>(o) 4-(3,4-methylenedioxyphenyl)butan-2-one; or</li><li>(p) 4-(4-ydroxyphenyl)butan-2-one; or</li><li>(q) methyl beta-naphthyl ketone; or</li><li>(r) methyl cedryl ketone; or</li><li>(s) 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (tonalid); or</li><li>(t) 1-carvone; or</li><li>(u) 5-cyclohexadecen-1-one; or</li><li>(v) acetophenone; or</li><li>(w) decatone; or</li><li>(x) 2-[2-(4-methyl-3-cyclohexenyl-1-yl)propyl]cyclopentan-2-one; or</li><li>(y) 2-sec-butylcyclohexanone; or</li><li>(z) beta-dihydro ionone; or</li><li>(aa) allyl ionone; or</li><li>(bb) alpha-irone; or</li><li>(cc) alpha-cetone; or</li><li>(dd) alpha-irisone; or</li><li>(ee) acetanisole; or</li><li>(ff) geranyl acetone; or</li><li>(gg) 1-(2-methl-5-isopropyl-2-cyclohexenyl)-1-propanone; or</li><li>(hh) acetyl diisoamylene; or</li><li>(ii) methyl cyclocitrone; or</li><li>(jj) 4-t-pentyl cyclohexanone; or</li><li>(kk) p-t-butylcclohexanone; or</li><li>(ll) o-t-butylcyclohexanone; or</li><li>(mm) ethyl amyl ketone; or</li><li>(nn) ethyl pentyl ketone; or</li><li>(oo) menthone; or</li><li>(pp) methyl-7,3-dihydro-2H-1,5-benzodioxepine-3-one; or</li><li>(qq) fenchone; or</li><li>(rr) methyl naphthyl ketone; or</li><li>(ss) propyl naphthy ketone; and</li><li>(tt) methyl hydroxynaphthyl ketone</li></ul>

0024The fragrance precursor compounds of the invention were found to act as source for long lasting fragrance benefits, especially when applied to on surfaces such as fibers, skin, hair and hard surfaces, especially to fabrics and laundry. More specifically, the invention relates to fragrance precursor compounds that break down on surfaces such as fibers, skin, hair and hard surfaces, especially to fabrics and laundry, and as a result of this, release perfume.

0025Since the perfume or fragrance is only released when the compounds of the invention are broken down, the compounds of the invention are capable of providing a long-lasting fragrance effect. That is, the compounds of the present invention provide for a sustained release of fragrances.

0026In accordance with the present invention there is a balance between the degree of breakdown of the fragrance precursor compounds to form the fragrance and the intensity of the fragrance. The intensity of the fragrance is substantially based on the fragrance formed.

0027To guarantee also the release of fragrance after a few days, such as after 5 and preferably after 7 days, the fragrance must be released by a controlled breakdown of the fragrance precursor compounds of the invention. That is, the equilibrium between the fragrance precursor compounds and the components including the fragrance must preferably be such that sufficient fragrance is released during a number of days. This equilibrium depends on the type of aldehyde and or ketone and the nature of compound X-OH.

0028In another embodiment of the present invention, the fragrance precursor compound of the invention is derived from a compound X-OH, selected from the group consisting of polyalkylene glycol, polyalkylene glycol ester and polysaccharide. Preferably, the polyalkylene glycol or the ester thereof are based on polyethylene glycol, polypropylene glycol and poly(ethylene/propylene) glycol.

0029The fragrance precursor compounds of the present invention are especially aimed to be incorporated in compositions to treat surfaces such as fibers, skin, hair and hard surfaces, especially to fabrics and laundry. From that perspective, it would be highly desirable to have available compounds which not only are compatible with compositions used to treat such materials, but additionally would have properties useful in such compositions. In this respect, in specifically preferred embodiments, the present invention relates to fragrance precursor compounds of the type described herein-above, wherein X-OH is a surfactant described herein-above as I. The preferred structure is of the formula (R₁-(CH₂)_z)_x-N-(CH₂)_y-OH, wherein R₁, independently, is selected from the group consisting of a fatty amido amine moiety of the formula AlkC(O)NH-, a moiety having the formula AlkC(O)O, a moiety having the formula Alk-O-, wherein Alk is a linear or branched C₂-C₂₄ alkyl or alkylene group, optionally substituted with one or more hydroxyl groups, nitro groups, amine groups, and/or halogen atoms, or represents a CHOH-R group. z and y, independently, are integers having a value between 0 and 10, preferably between 0 and 5, more preferably between 1 and 3; x represents 2 or 3.

0030These fragrance precursor compounds are for instance based on fatty or di fatty amido amines, which in themselves have fabric softening properties. Examples of such fatty amido amines are for instance the fabric softeners sold under the trade name Varisoft, such as Varisoft 510 (<i>ex</i> Goldschmidt, Germany) as mentioned in <patcit id="pcit0004" dnum="US5501806A"><text>US-A-5,501,806</text></patcit>. As will follow from the examples herein-below the reaction product between a di fatty amido amine (Varisoft 510) and C_8-12 aldehydes give pro-fragrances that give continuous release of the aldehydes until after more than 1 week.

0031The fragrance precursor compounds of the invention can be obtained by reacting an aldehyde and or ketone fragrance and a compound X-OH; X-OH is selected from the group consisting of surfactants, fabric softeners, softener precursor ester amines or amido amines, hair and skin conditioners and polymers. This forms a further aspect of the present invention.

0032In fact, the formation of a acetal, hemiacetal, and or a ketal involves a compound comprising at least one nucleophilic free -OH group and an aldehyde and or ketone. This reaction is known <i>per se.</i> Preferably, this reaction is carried out in an aqueous solution in the presence of an acid or a catalyst.

0033In <figref idref="f0001">figure 1</figref>, the reaction between an amido amine and a C₁₀ aldehyde is shown as an example. An example of the amido amine starting compound is Varisoft 510. The products obtained from this reaction can very suitably be incorporated in a product formula such as a rinse cycle fabric softener, and from said formula be delivered to a surface to give a long lasting fragrance.

0034Dependent on the number of free hydroxyl groups, one or more aldehyde and or ketone molecules can be coupled to the XOH molecule. This makes that the capacity of fragrance to be released can be controlled to some degree.

0035In yet a further aspect, the present invention relates to an aqueous composition for fragrance delivery comprising one or more fragrance precursor compounds according to the invention. Preferable said aqueous composition is a fabric softener composition and especially a rinse cycle fabric softener composition.

0036Good results are obtained when incorporating between 0.001-10 wt.% of fragrance precursor of the invention, drawn to the total weight of the composition, in the aqueous composition. Preferably between 0.01 and 35 wt.% and more preferably between 2 and 15 wt.% of any fabric softening active ingredient is present. A preferred cationic softener is an esterquat softener having the following structural formula: <chemistry id="chem0007" num="0007"><img file="EP2353656A2_D0007.tif" /></chemistry> wherein R4 represents an aliphatic hydrocarbon group having from 8 to 22 carbon atoms, R2 and R3 represent (CH₂)_s-R₅ where R₅ represents an alkoxy carbonyl group containing from 8 to 22 carbon atoms, benzyl, phenyl, (C1-C4)-alkyl substituted phenyl, OH or H; q, s, and t, each independently, represent an integer from 1 to 3; and X^- is a softener compatible anion.

0037A fragrance precursor compound delivery system is also provided, which comprises: <ol id="ol0003" compact="compact" ol-style=""><li>(a) at least about 0.001% by weight, of a fragrance precursor conjugate, comprising: <ol id="ol0004" compact="compact" ol-style=""><li>(i) a fragrance precursor compound as described herein capable of releasing a fragrance raw material; or</li><li>(ii) a fragrance raw material; and</li></ol></li><li>(b) the balance carriers and adjunct ingredients.</li></ol>

0038A laundry detergent is also provided, which comprises: <ol id="ol0005" ol-style=""><li>(a) at least about 0.001% by weight, of a fragrance precursor conjugate, comprising: <ol id="ol0006" compact="compact" ol-style=""><li>(i) a fragrance precursor compound as described herein capable of releasing a fragrance raw material; or</li><li>(ii) a fragrance raw material; and</li></ol></li><li>(b) effective amount of a detersive surfactant; and</li><li>(c) the balance carriers and adjunct ingredients.</li></ol>

0039The fabric softener or fabric softening dryer sheet is also provided, which comprises: <ul id="ul0006" list-style="none"><li>a) at least about 0.001% by weight, of a fragrance precursor conjugate, comprising: <ol id="ol0007" compact="compact" ol-style=""><li>(i) a fragrance precursor compound as described herein capable of releasing a fragrance raw material; or</li><li>(ii) a fragrance raw material; and</li></ol></li><li>(b) effective amount of a fabric softening compound; and</li><li>(c) the balance carriers and adjunct ingredients.</li></ul>

0040The perfume or fine fragrance is also provided, which comprises: <ul id="ul0007" list-style="none"><li>a) at least about 0.001% by weight, of a fragrance precursor conjugate, comprising: <ol id="ol0008" compact="compact" ol-style=""><li>(i) a fragrance precursor compound as described herein capable of releasing a fragrance raw material; or</li><li>(ii) a fragrance raw material; and</li></ol></li><li>(c) at least about 0.01% to about 99% by weight, of an admixture of fragrance raw materials; and</li><li>(d) the balance carriers and adjunct ingredients.</li></ul>

0041A personal care product, or oral care product or hard surface care product is also provided, which comprises: <ol id="ol0009" ol-style=""><li>(a) from about 0.001% by weight, of a fragrance precursor conjugate, comprising: <ol id="ol0010" compact="compact" ol-style=""><li>(i) a fragrance precursor compound as described herein capable of releasing a fragrance raw material; or</li><li>(ii) a fragrance raw material; and</li></ol></li><li>(b) from about 0.1 % by weight, of a surfactant, or emollient or abrasive or antibacterial agent suitable for use in personal care or oral care or hard surface care products; and</li><li>(c) the balance carriers and adjunct ingredients.</li></ol>

0042The balance carriers and adjunct ingredients are typically selected from: <ul id="ul0008" list-style="none" compact="compact"><li>builders, optical brighteners, bleaches, bleach boosters, bleach catalysts, bleach activators, soil release polymers, dye fluorescers, fabric conditioners, hydrolyzable surfactants, transfer agents, dispersents, enzymes, suds suppressers, dyes, perfumes, colorants, filler salts, hydrotropes, hotoactivators,preservatives, anti-oxidants, chelants, stabilizers, anti-shrinkage agents, anti-wrinkle agents, germicides, fungicides, anti corrosion agents, and mixtures thereof.</li></ul>

0043The invention will be described in more detail in the following examples, which do not limit the invention, but merely illustrate the invention. Unless otherwise indicated, all percentages are by weight drawn to the weight of the final composition.

<u>Example 1</u>

0044Fragrance precursors can be formed by preferable but not limited to combining Varisoft 510 (3.0g) with decyl aldehyde (1.8ml), water (0.2ml) and <i>p</i>-toluenesulfonic acid monohydrate (20mg). The reaction was then heated in a 60°C. oil bath with stirring overnight open to the air. The reaction was then cooled to room temperature and solidified upon standing. In <figref idref="f0004 f0005">figure 4</figref>, the proton- and ¹³C-NMR spectra are given of Varisoft 510 and of Varisoft 510 reacted with C₁₀ aldehyde. <figref idref="f0006 f0007 f0008">Figure 5</figref> shows the mass spectrum of the reaction products.

0045Fragrance precursors can also be formed by preferable but not limited to the above reaction without the addition of water.

<u>Example 2</u>

0046Fabric softener compositions are prepared comprising 5 wt.% esterquat having the following structural formula: <chemistry id="chem0008" num="0008"><img file="EP2353656A2_D0008.tif" /></chemistry> wherein R4 represents an aliphatic hydrocarbon group having from 8 to 22 carbon atoms, R2 and R3 represent (CH₂)_s-R₅ where R₅ represents an alkoxy carbonyl group containing from 8 to 22 carbon atoms, benzyl, phenyl, (C1-C4)-alkyl substituted phenyl, OH or H; q, s, and t, each independently, represent an interger from 1 to 3; and X^- is a softener compatible anion. 1 wt.% of the amido amine fragrance precursor compounds prepared; and 94 wt.% water. Fabric was treated with the fabric softener composition prepared, and the release of fragrance was measured after 1 day and after 5 days by solid phase micro extraction (SPME) coupled with GC/MS. For C₁₀ aldehydes the amount of fragrance released on day 1 and on day 5 is about the same. Showing the desired sustained release of fragrance from the fabric surface.