MXPA06005290A - Polymeric compositions for sustained release of volatile materials - Google Patents

Abstract

A polymeric composition comprising a copolymer obtained from at least one monomer comprising an ether group and at least one monomer not comprising an ether group, a compatible plasticizer and a volatile material is able to provide sustained delivery of the volatile material over a long period of time. Additionally, if the volatile material is a composition formed by several components of different volatility, the compositions of the present invention is able to provide a uniform release of all components of the volatile material.

Description

POLYMERIC COMPOSITIONS FOR THE PROLONGED RELEASE OF VOLATILE MATERIALS FIELD OF THE INVENTION The present invention relates to plasticized polymeric compositions which can incorporate and release volatile materials in prolonged form (for example perfumes) based on copolymers obtained from at least one monomer comprising an ether group and at least one monomer which does not comprise a group ether. If the volatile material is in particular a composition formed by different components with varying volatility, the compositions of the present invention allow a uniform release of all the components of the volatile material over a prolonged period of time. In the case of perfumes, which are generally composed of many components of varying volatility, the present invention prevents the separation of the components based on their varying volatility, which allows a prolonged distribution of all the peculiarities of the perfume over a period of time. extensive. The compositions of the present invention can have a variety of applications where a prolonged distribution of the volatile materials in an environment is desired, such as devices for the action of products for the environment, deodorants, objects with fragrance, insecticides, etc.

BACKGROUND OF THE INVENTION Polymer compositions which have the ability to absorb and release volatile ingredients are well known in the industry, particularly as regards the distribution of perfume. The patent of Great Britain no. 1558960, by Nagae, describes a PVC film that emits perfume for use in umbrellas. U.S. Pat. no. 4618629, by T. Burnett & Co, Inc. describes polyurethane foams that emit fragrances that incorporate a resin that carries fragrances in the particulate form. The resin can be selected from a list of polymers (polyolefins, polyester, PVC and the like, polyamides, cellulose polymers). A common use of polymeric compositions for the distribution of perfume comprises, for example, devices for the action of products for the environment. These are generally in the form of aqueous gels which are usually obtained from cross-linked polysaccharide polymers (starches, alginates or CMC), such as those described in British Patent No. 2286531, by Kelco, and U.S. Pat. no. 3,969,280, from Johnson & Johnson. While these and other documents claim the supply of a prolonged distribution of volatile materials, they are still far from being fully satisfactory for a number of reasons. First, these polymeric compositions can usually incorporate and release a very limited amount of volatile material, in most cases, an amount that does not exceed 10% of the total weight of the compositions. Second, these polymeric compositions can not uniformly release the various components of the volatile material that have diverse volatility. For example, if a perfume that can have more than 10 different components is considered, the more volatile components will be released first, and after a certain time only the less volatile notes would be perceptible; therefore, the user would never perceive all the peculiarities of the perfume. Actually, the aforementioned polymeric compositions are commonly used to distribute simple perfumes, which generally comprise a single volatile substance, such as citronellol, because they simply do not have the ability to consistently deliver a more sophisticated perfume, as the industry increasingly requires. modern perfumer. Third, pure polymeric materials are difficult to transform and generally require high temperatures for molding. Therefore, whenever a volatile material is introduced into the fusion, a large quantity of said material is lost due to the high temperature. Firmenich has partially addressed the first and second problem in U.S. Pat. no. 4734278, which describes bodies formed from resins based on a polyether-amide block (for example Pebax ™) that provides a prolonged release of volatile actives (perfumes, deodorants, insecticides, etc.). The patent no. WO 9726020A1 describes an improvement achieved by Atochem, consisting of improved resins with fragrances made by Pebax ™, plus a complex perfume (ie, more than 5 components). Such resins can distribute a complex perfume with a reduced eparation of the volatile ingredients over time. The third problem has been partially solved by the use of plasticizers that, as is familiar to those with knowledge in the industry, allow the reduction of the processing temperature of polymer blends. This solution has been applied, for example, in U.S. Pat. no. 4,552,693 of Avon, in which transparent articles emitting fragrances obtained from compositions comprising a thermoplastic polyamide resin, a plasticizer / solvent system comprising a sulfonamide plasticizer and a fragrance are uncovered. The advantage of using a plasticizer in these compositions is the possibility of processing said compositions (molding, extrusion, film formation) at relatively low temperatures. However, prior art compositions are still not entirely satisfactory since they still have the tendency to release a larger amount of volatile ingredient at the first moment and to decrease the index over time. Also, although they have improved compared to the previous compositions, they still do not uniformly release the different components of the volatile material that has diverse volatility. Therefore, there remains the need to achieve a polymeric material that is capable of incorporating and releasing volatile materials in a prolonged form, which are composed of different ingredients of varying volatility over a prolonged period of time, without these ingredients separating during their release and also be able to process easily to form it in an article.

SUMMARY OF THE INVENTION The present invention relates to a polymer composition comprising: a) A copolymer obtained from at least one monomer comprising an ether group and at least one monomer that does not comprise an ether group, b) a compatible plasticizer, c) a volatile material DETAILED DESCRIPTION OF THE INVENTION Surprisingly, it has been found that a composition comprising a) a copolymer obtained from at least one monomer containing an ether group and at least one monomer not comprising an ether group; b) a compatible plasticizer, and c) a volatile material, has the ability to release said volatile material over an extended period more extensively, ie with a more constant rate of release and over a longer period of time when compared with solutions from the previous industry. Another surprising benefit provided by the polymeric compositions of the present invention is that when said volatile material is composed of several components of varying volatility, the compositions of the present invention allow a more uniform release of all the components of the volatile material over a period of time. more extensive, which prevents the separation of the components based on such diverse volatility. This can be seen, for example, in Example 6 below. Another very important benefit provided by the polymeric compositions of the present invention is the possibility of introducing a wider range of volatile materials. The prior industry solutions describe polymer compositions based on specific polymers such as polyether-polyamide block copolymers or pure polyamide polymers. As a consequence, the choice of volatile material was limited to those ingredients that were soluble or compatible with a specific polymer. Surprisingly it has been found that the polymer compositions according to the present invention, comprising a copolymer obtained from at least one monomer containing an ether group and at least one monomer not containing an ether group as well as a compatible plasticizer, can incorporating and effectively distributing a much greater amount of volatile materials in a range of greater polarity than the same pure copolymer. Unlike the previous industry, the compositions of the present invention are much more flexible in terms of the compositions of volatile materials that can be distributed, since the one who formulates them can choose the copolymer among all the copolymers obtained from at least one monomer which comprises an ether group and at least one monomer which does not comprise an ether group; additionally, the plasticizer can be selected from a wide variety of suitable materials of varying polarity and behavior. Also, an amount of additives can be introduced into the formulation, as explained in detail below. Such flexibility of formulation of the plasticized polymer matrix (copolymer, plasticizer, optionally other polymers or additives) allows the adjustment of the characteristics of the polarity with extreme precision. This makes it possible to maximize the compatibility with any volatile material that could be introduced into the plasticized polymer matrix, whereby a polymeric composition according to the present invention is obtained. Without intending to be limited by theory, it is believed that it is necessary that there be some polarity correspondence between the plasticized polymer matrix and the volatile material to provide a good incorporation and a prolonged distribution of the volatile material. Therefore, the copolymer and the compatible plasticizer of the polymer compositions of the present invention can be selected such that there is virtually correspondence between the polarity of the plasticized polymer matrix and the polarity of the volatile material, where the polarities can be evaluated. according to one of the methods known in the industry. All copolymers obtained from at least one monomer comprising an ether group and at least one monomer not comprising an ether group are suitable for the present invention. The term "monomer comprising an ether group" includes all those monomers wherein at least one oxygen atom is attached to two different carbon atoms, none of which is connected to another oxygen atom, including those where the atom Oxygen is included in an acyclic epoxide structure such as for example ethylene oxide, propylene oxide, tetramethylene oxide and the like. The term "monomer comprising an ether group" also includes those molecules, oligomers or polymers that contain an ether group within the molecule and can be further polymerized. In most cases said copolymers comprise a polyether group and a non-polyether group. Such copolymers can be both block copolymers and copolymers which are not; Also suitable for the present invention are copolymers formed by grafting polyether groups into polymeric structures, copolymers wherein the polyether group is comprised of a side chain or crosslinking and copolymers wherein the ether monomers are randomly copolymerized with monomers . Among the preferred copolymers obtained from at least one monomer comprising an ether group and at least one monomer not comprising an ether group suitable for the present invention are, for example, polyether amide copolymers, polyether ester copolymers, polyether urethanes , polyether ester sulfonate copolymers, polyether ester copolymers, copolymers formed by the polymerization of polyether acrylates with other acrylic monomers / oligomers, etc. When a polyether group is present, the preferred polyether groups are those with monomers containing more than 2 carbon atoms; more preferred are those with monomers containing more than 3 carbon atoms. The most preferred polyether containing groups are polypropylene glycol, and even more preferred are those containing polytetramethylene glycol. The monomer comprising an ether group in the copolymers suitable for the present invention represents at least 5% of the total weight of the copolymer, preferably at least 10%, more preferably at least 15%. Preferred copolymers for the present invention are polyether-amide block copolymers (for example Pebax ™), polyether-ester-amide block copolymers, polyether-polyester block copolymers (for example Hytrel ™), polyurethane copolymers containing polyether blocks (for example Tinne ™) or mixtures thereof. Among the various copolymers of this type, those having a polyether-p-group referred to above are preferred. Therefore, the most preferred copolymers are those in which the polyether group is a polypropylene glycol or a polytetramethylene glycol. The second essential component in the polymeric matrix of the polymeric compositions of the present invention is a plasticizer compatible with the copolymer obtained from at least one monomer comprising an ether group and at least one monomer that does not comprise an ether group. Plasticizers suitable for use in the polymer compositions according to the present invention include citric acid esters, low molecular weight polyesters, polyethers, liquid pitch esters, aromatic sulfonamides, phthalates, benzoates, sucrose esters, polyfunctional alcohol derivatives ( where polyfunctional means that they have 2 or more hydroxyl groups), adipates, tartrates, sebacates, esters of phosphoric acid, acids and diacids, fatty alcohols and diols, epoxidized vegetable oils, etc. and mixtures of these. As mentioned earlier, one can use the p olarity of compatible test subjects (measured according to any method with which those with knowledge in the industry are familiar, for example the water partition coefficient). / octanol) to adjust the polarity of the polymeric matrix in order to provide a greater correspondence with the polarity of the volatile material. The third essential component of the present invention is a volatile material that is incorporated and then extended by the compositions of the present invention. The volatile materials that can be used in the present invention are for example flavors, deodorants, insecticides, pheromones, flavors, repellents and, more advantageously, perfumes. The benefits provided by the present invention are particularly important when the volatile material is a perfume. Perfumes are usually composed of many components of varying volatility. The present invention, in order to avoid separation of the components on the basis of their varying volatility, allows the prolonged distribution of the entire perfume bouquet over a prolonged period of time. In a preferred embodiment of the present invention the volatile material is a perfume that is preferably composed of a plurality of components, more preferably more than 5 components. As used herein, the term "perfume" means any odoriferous material. In general, these materials are characterized by a vapor pressure lower than atmospheric pressure at room temperature. The perfumes used herein will most often be liquid at room temperature, but may also be solid, such as the various camphor perfumes known in the industry. There is a large amount of chemicals for perfumery uses, including materials such as aldehydes, ketones, esters, alcohols, terpenes and the like. Oils and natural exudates of vegetable and animal origin that comprise complex mixtures of various chemical components are known for their use as perfume; said materials may be used herein. The perfumes herein may have a relatively simple composition or may comprise highly sophisticated and complex mixtures of natural and synthetic chemical components selected to provide any desired aroma. Typical perfumes which can be used in the present invention comprise, for example, wood / earth bases containing exotic materials such as sandalwood oil, civet, patchouli oil and the like. Other suitable perfumes may be light floral fragrances, for example rose extract, violet extract and the like. The perfumes can be formulated to impart desirable fruit odors, for example lime, lemon, orange and the like. In summary, any chemically compatible material that emanates a non-degradable or d atable from a non-toxic or non-toxic substance can be used in the present invention. The perfume materials are described in greater depth in S.

Arctander, Perfume Flavors and Chemicals, Vols. I and II. Aurthor, Montclair, N.J. and the Merck Index (Manual Merck), 8a. Edition, Merck & Co., Inc. Rahway, N.J. Preferably, the volatile material of the present invention is introduced into the polymer composition in a form that does not prevent the chemicals constituting said volatile material from dissolving chemically in the plasticized polymer matrix. Particularly, volatile and encapsulated materials and products which comprise volatile species covalently bound to a nonvolatile one (eg, aroma precursors) are not recommended and are preferably excluded for use herein as volatile materials. in accordance with the present invention. Without intending to be limited by theory, it is believed that the advantageous properties of the polymeric compositions of the present invention can be seen when the volatile material is solubilized in the plasticized polymer matrix, since the release of the volatile material is related to the interaction in the polymeric matrix. the molecular level between the volatile material and said plasticized polymer matrix. Therefore, systems such as encapsulation, which prevent the volatile material from mixing at the molecular level with the polymer matrix, are not preferred for use as volatile materials in the present invention and, preferably, should be excluded. Preferably, the polymer composition of the present invention comprises from 5% to 75%, more preferably from 10% to 50% by weight of the polymer composition of the copolymer obtained from at least one monomer comprising an ether group and at least a monomer that does not comprise an ether group; from 5% to 60%, preferably from 10% to 40% by weight of the polymeric composition of the plasticizer or mixture of suitable plasticizers, and more than 10%, preferably more than 20%, more preferably more than 30% of a material volatile; the volatile material is preferably composed of a maximum percentage of up to 90% by weight of the polymer composition. The polymeric compositions of the present invention may further comprise additional optional components to further improve the processability of the compositions and also the mechanical characteristics as well as other characteristics such as tackiness, resistance to aging by light, oxygen and heat, appearance visual, etc., of the objects formed from such polymer compositions. Such optional components include other copolymers that can be included in the formulations to improve their properties, for example increasing adhesion or compatibility with the substrates. For this purpose, the preferred optional copolymers are those consisting of both polar and non-polar groups, for example copolymers of ethylene and at least one vinyl or acrylic monomer, copolymers of styrene and at least one vinyl or acrylic monomer, copolymers of polyvinyl alcohol, polyamides, poly (vinylpyrrolidone) copolymers, polyacrylates, polyvinyl ether copolymers), ionomers, polyesteramide copolymers, etc. The polymeric compositions of the present invention are preferably thermoplastic polymer compositions. These may be manufactured by any known process for the manufacture of thermoplastic polymer compositions and will generally comprise the steps of melting the polymer and then mixing the plasticizer and the volatile material to form a homogeneous mass which is then cooled to obtain the polymer composition in accordance with the present invention. Among other preferred thermoplastic compositions are those which have a low melting temperature and viscosity and, therefore, can be processed by hot melt. In these systems, the loss of volatile material is minimized with mixing. Other optional components that can preferably be used when the polymer composition according to the present invention is a thermoplastic composition and preferably have a rheology of the hot melt are the tackifying resins, such as pitch derivatives, aliphatic resins, aromatic resins or mixed aliphatic-aromatic resins. The composition can then also be formulated for the purpose of achieving the characteristics of a hot-melt adhesive, in addition to the ability to release volatile materials. Moreover, optional ingredients such as other polymers or copolymers, fillers, crosslinking agents, pigments, dyes, anti-oxidants and other stabilizers, etc. can also be added. to provide the desired properties to the composition. The polymeric compositions of the present invention can also be prepared using a polymer solution, either as an intermediate or final step. Those with knowledge in the industry are very familiar with preparations of this type and generally comprise the steps of dissolving the selected polymer, plasticizer and volatile material in an effective solvent, as well as proceeding to heating to prepare a solution or a gel , if necessary. The solvent can then be removed by evaporation. Alternatively, the polymer compositions of the present invention may be prepared in the form of an aqueous emulsion or dispersion. Those with knowledge in the industry are familiar with the techniques for obtaining aqueous emulsions or dispersions of polymers. For example, selected polymer, plasticizer and volatile material can be mixed as a thermoplastic material. The resulting melt can be dispersed in water, preferably at a temperature above its melting temperature by mixing. Surfactant and / or stabilization systems may be used with which those of known skill in the industry are familiar with the object of stabilizing the resulting emulsion or dispersion. Alternatively, a preformed aqueous polymer dispersion or emulsion can be mixed with the selected plasticizer and volatile material. This can be done by adding the ingredients directly to the polymer dispersion or emulsion or by forming an aqueous dispersion of the perfume and the plasticizer to mix it with the polymer dispersion or emulsion. Both methods result in the formation of an aqueous dispersion of a polymeric composition in accordance with the present invention. The polymer compositions according to the present invention can have various applications when it is desired to release the volatile material. They can be used, for example, in devices for the action of products for the environment (air fresheners, automotive fragrances, baskets for toilets, etc.), perfume distribution in empty spaces in containers such as bottles, boxes, bags, etc., cleaning / drying systems (dryers, automatic dishwashers, dry cleaning systems, etc.), laundry detergents, clothes conditioners, home care products, personal care products (deodorants, antiperspirants, shampoos) , conditioners, cosmetics, skin moisturizers, makeup, etc.), fine fragrances, perfumed coatings, films, laminas, hygiene items (feminine care protectors, pantiliners, diapers, shoe insoles, etc.), perfumed inks, perfumed three-dimensional objects, distribution of disinfectants, distribution of insecticides, distribution of insect repellents, distribution flavor, etc.

Examples Example 1 24.5 parts of Pebax ™ 2533, a polyether amide copolymer distributed by Atofina (France), 12.5 parts of Foralyn ™ 5020F, a tar ester plasticizer distributed by Eastman Chemical and 0.5 parts of Irganox ™ B225, an antioxidant were added. distributed by Ciba Geigy (Switzerland), in a double-arm mixer, and heated to a temperature of approximately 10-20 ° C above the melting temperature of the polymer (approximately 160 ° C for the Pebax ™ 2533 product) . The ingredients were mixed until a homogeneous mass was obtained. The temperature was then reduced to a point where the mixture was still melted, generally at about 10-20 ° C above the melting temperature of the mixture (approximately 120 ° C in the present case). 12.5 parts of Foralyn 5020F were mixed with 25 parts of gamma-methyl-ionone, a perfume material distributed by International Flavors & Fragrances, and this mixture was added to the plasticized polymer mixture. The ingredients were mixed until a homogeneous mixture was obtained, and the resulting material was removed from the mixer, formed as a perfumed block, which was allowed to cool to room temperature. In the examples below, the same preparation procedure was followed, and in all cases 50% of the total amount of plasticizer is mixed particularly with the polymer and other additives in a first step; then the remaining 50% of the total amount of plasticizer is mixed with the volatile material (for example the perfume) in a second step, and the two mixtures are combined in a third step.

Example 2 Following the procedure outlined in Example 1, the following plasticized polymer composition was prepared: Benzyl acetate is a perfume material distributed by Sigma Aldrich.

Example 3 Following the procedure outlined in Example 1, the following plasticized polymer composition was prepared: Estañe ™ 58280 is a polyether urethane distributed by Noveon. Dipropylene glycol benzoate is a benzoate plasticizer distributed by Velsicol under the tradename Benzoflex ™ 988. Cis-3-Hexenil salicylate is a perfume material distributed by International Flavors & Fragrances.

Example 4 Following the procedure outlined in Example 1, the following plasticized polymer composition was prepared: Spring Fresh is a blend of perfumes marketed by Givaudan (France).

Example 5 15 parts of benzyl acetate were mixed with 15 parts of acetyl tributyl citrate, a citrate plasticizer distributed by Jungbunzlauer (Switzerland) under the tradename Citrofol ™ Bll. This liquid was then added to 70 parts of deionized water and then subjected to high shear mixing using an Ultra Turrax T50 Basic mixer, distributed by Ika Werke (Germany). An opaque white dispersion (30% solids) was obtained. This was then added to 100 parts of Rolflex ™ C89, an aqueous dispersion with 30% solids of a polyether urethane distributed by Cesalpinia (Italy). The mixture was allowed to stir for 24 hours, which resulted in a plasticized polymer dispersion with the following compositions in% by weight.

Example 6 Six polymeric compositions comprising a pure perfume material (ie, a single perfume comprising only one volatile component) were prepared. Formulations B, D and F were prepared in accordance with the present invention following the method delineated in Example 1. Formulations A, C and E were based on prior industry technology (pure polymer without plasticizer); the polymer was heated to about 160 ° C, and the perfume was gradually added until a homogeneous mixture was obtained; then the mixture was allowed to cool to room temperature. The raw material of pure perfume used was D-limonene, distributed by Sigma Aldrich, cis-3-Hexenil acetate, distributed by Givaudan, and metildihidrojasmonato, distributed by Firmenich. Table 2 shows the physical data of three pure perfume materials: D-limonene and cis-3-hexenyl acetate have relatively low boiling points as perfume materials, and in the industry they are recognized as being ingredients of more volatile perfume; methyldihydrojasmonate has a higher boiling point, and in industry it is recognized as a less volatile ingredient. The weight loss over time of the different formulations was measured according to the thermogravimetric analysis (TGA, for its acronym in English). The ingredient used was a TGA Q500 from TA-Waters. A constant flow of nitrogen was applied over the crucible (without equilibrium). The following conditions were used: • Cycle time: 360 minutes • Temperature: 37 ° C • Crucible: alumina, 4.55 mm diameter, 3.9 mm height The weight loss was measured after 360 minutes for each sample. This is taken as the evaporation of the perfume, this being the only volatile material present in the formulation. The results are illustrated in Table 1.

Table 1 Thermogravimetric results show how a polymer composition according to the present invention provides a slower and, therefore, more durable release of a volatile perfume ingredient in comparison as the same pure polymer. The example also shows how the release of a lower volatility perfume ingredient is not reduced when it is incorporated into compositions according to the present invention. Therefore, the difference in the release rate of a volatile and a non-volatile perfume ingredient is much less when the perfume is incorporated into the polymer compositions according to the present invention. It is now clear to those with knowledge in the industry that this fact leads to a better and more prolonged distribution of the peculiarities of perfume when complex perfumes are considered, composed of many different volatility ingredients.

Table 2

Claims (3)

1. A polymeric composition characterized in that it comprises: a) A copolymer obtained from at least one monomer comprising an ether group and at least one monomer that does not comprise an ether group, b) a compatible plasticizer, and c) a volatile material.

2. A polymer composition according to claim 1, further characterized in that the copolymer comprises a polyether group and a non-polyether group.

3. A polymer composition according to claim 2, further characterized in that the copolymer is a block copolymer and comprises at least one polyether block and at least one non-polyether block. 4 A polymer composition according to claim 2 or 3, further characterized in that the group or the polyether block included in the copolymer is a polytetramethylene glycol group or block. 5. A polymer composition according to any of the preceding claims, further characterized in that the copolymer is from 5% to 75%, preferably from 10% to 50% by weight of the polymer composition, the compatible plasticizer is from 5% to 60%. %, preferably from 10% to 40% by weight of the polymer composition, and the volatile material is more than 10%, preferably more than 20%, more preferably more than 30% of the total weight of the composition. 6. A polymeric composition according to claim 5, further characterized in that the volatile material is less than 90% of the total weight of the composition. 7. A polymeric composition according to any of the preceding claims, further characterized in that the volatile material is a perfume. 8. A polymer composition according to claim 7, further characterized in that the perfume comprises an aldehyde, a ketone, an alcohol, a terpene or an ester. 9. A polymer composition according to any of the preceding claims, further characterized in that the monomer comprising an ether group represents at least 5%, preferably at least 10%, more preferably at least 15% of the total weight of the copolymer. 10. A polymer composition according to any of the preceding claims, further characterized in that the copolymer is selected from polyether amide copolymers, ester polyether copolymers, polyether urethanes, polyether ester sulfonate copolymers, polyether ester amide copolymers, copolymers formed by the polymerization of polyether acrylates with other acrylic monomers / oligomers. 11. A polymeric composition according to any of the preceding claims, further characterized in that the compatible plasticizers are selected from the group comprising citric acid esters, low molecular weight polyesters, polyethers, liquid pitch esters, aromatic sulfonamides, phthalates, benzoates. , esters of sucrose, derivatives of polyfunctional alcohols, adipates, tartrates, sebacates, esters of phosphoric acid, acids and diacids, fatty alcohols and diols, epoxidized vegetable oils, etc. and mixtures of these.