Paper Roll as Fragrance Control Release System

The present invention relates to a paper roll, which besides its normal function, has additionally a function as fragrance control release system. Further, the present invention relates to a method for manufacturing said paper roll, as well as to a household product or consumer product, for instance a toilet paper roll, comprising said paper roll.

Air fresheners are consumer products that typically emit fragrance and are used in homes or commercial interiors such as restrooms, foyers, hallways, vestibules and other smaller indoor areas, as well as larger areas such as hotel lobbies, auto dealerships, medical facilities, public arenas and other large interior spaces. Different types of air fresheners are available on the market, e.g., liquids, gels, solids in the form of diffusers, reeds, plug-ins, fans, electrical units.

Of special importance is the suppression of unpleasant odours in bathrooms and toilets. Indeed, as a source of fragrances, specific air fresheners are made for bathrooms and toilets.

However, commercially available air fresheners, especially those that are made for deodorizing toilets and urinals, contain chemicals that provoke allergy and asthma symptoms or are toxic. Further, commercially available air fresheners introduce fragrance in an uncontrolled manner into the air of interior spaces as droplets with transition to vapor, creating frequently an unpleasant atmosphere for the person who enters the bathroom or toilet shortly after using the air freshener.

Therefore, there is a need for the development of other alternatives for releasing the fragrance, particularly in bathrooms and toilets.

One possible alternative are toilet paper rolls, wherein the inner side of toilet paper cardboard roll is impregnated by oil fragrances.

The disadvantage of these toilet rolls is that the fragrance is constantly released uncontrollably, which leads in most cases to an “overdose” or “saturation” of the fragrance in the atmosphere, which in many cases causes an unpleasant sensation for the toilet or bathroom user. Thus, as with common commercial air fresheners overly strong intense fragrance release is emitted, followed by decreased intensity. From an economic point of view, this alternative is also unsatisfactory, since a much larger quantity of fragrance is released than is necessary to create a pleasant atmosphere. An additional disadvantage is also, that the application of the oil fragrance to the corresponding cardboard ribbon generally via a nozzle causes the generation of a kind of “fragrance-cloud”, which does not arrive to the cardboard ribbon. This fact represents not only a high loss of material (oil fragrance), but also a remarkable hygienic problem in the manufactory. On the other hand, the use of oil fragrances for impregnating the cardboard tube is limited, since overdosage may cause of reduction of the cardboard tube material structural integrity.

The complex object of the present invention was to provide a paper roll, in particular a toilet paper roll which, besides its normal function in a toilet paper roll, has additionally a function as fragrance control release system solving the problems and disadvantages of the toilet paper rolls mentioned above.

A subject matter of the invention is a suspension consisting of

Surprisingly, it was found that a toilet paper roll containing a toilet paper roll impregnated with the suspension according to present invention, allows the controlled release of the encapsulated fragrance, so that a constant fragrance reactivation in the room (bathrooms and toilets) occurs. Thus, a long-lasting effect is achieved, that brings freshness, cleanliness and an enchanting aroma in the interior space.

Further, it was surprisingly found, that the suspension according to present invention shows not only a high storage stability, but also a high stability under the conditions used in the manufacturing-process of the paper roll.

Further, it was surprisingly found, that the combination of the specific components of the suspension according to present invention reduces remarkably the technical problems observed in the manufacture of paper rolls impregnated by oil fragrances, especially the reduction of the cardboard tube resistance, which may stop the manufacturing process or give a negative effect on toilet paper cardboard, since it may soften or interfere with the cardboard overall structural integrity or adhesive holding cardboard tube together.

Still further, it was surprisingly found, that the combination of the specific components of the suspension with the specific technical conditions of the method for the manufacturing the paper roll described in the present invention avoids the locking of the nozzle used for applying the suspension in the paper.

For the purposes of the present invention, all percentages are by weight unless specifically indicated otherwise.

For the purposes of the present invention, a “slurry” in the sense of the invention is nothing other than a particulate core-shell microcapsule suspension in water.

Preferably, the microcapsules (component (a)) are present in an amount from about 10% wt. to about 30% wt., relative to the weight of the suspension. More preferably, the microcapsules (component (a)) are present in an amount of about 12% wt., relative to the weight of the suspension.

Preferably, the at least one surfactant (component (b1)) is present in an amount from about 0.5% wt. to about 1.5% wt., relative to the weight of the suspension. More preferably, the at least one surfactant (component (b1)) is present in an amount of about 1% wt., relative to the weight of the suspension.

Preferably, the at least one fragrance oil (component (b2)) is present in an amount from about 60% wt. to about 70% wt., relative to the weight of the suspension. More preferably, the at least one fragrance oil (component (b2)) is present in an amount of about 64% wt., relative to the weight of the suspension.

Preferably, the at least one deflocculant agent (component (b3)) is present in an amount from about 0.02% wt. to about 0.08% wt., relative to the weight of the suspension. More preferably, the at least one deflocculant agent (component (b3)) is present in an amount of about 0.05% wt. relative to the weight of the suspension.

Preferably, water (component (b4) is present in an amount from about 5% wt. to 30% wt., relative to the weight of the suspension. More preferably, water (component (b4)) is present in an amount from about 10% wt. to 25% wt., relative to the weight of the suspension.

Accordingly, in a preferred embodiment, the suspension according to the invention consists of:

In a particularly preferred embodiment, the suspension according to the invention consists of:

According to the present invention, fragrance oils are enclosed in a microcapsule and released in a controlled manner. The aroma function is initiated according to a “release-on-demand” principle, i.e., the capsules burst on mechanical contact, releasing the fragrance contained within. As used herein, a “fragrance oil” comprises at least one or more odorous compounds. The term “fragrance oil” is well-known for one skilled in the art, and there is no need to further specification of these substances.

As used herein, a “core-shell microcapsule,” or more generically a “microcapsule” or “capsule,” is a substantially spherical structure having a well-defined core and a well-defined envelope or wall. The “core” is composed of any active material or material submitted to microencapsulation. The “wall” is the structure around the active material core being microencapsulated. In general, the wall of the microcapsule is made of a continuous, polymeric phase with an inner surface and outer surface. The inner surface is in contact with the microcapsule core. The outer surface is in contact with the environment in which the microcapsule resides. Ideally, the wall protects the core against deterioration by oxygen, moisture, light, and effect of other compounds or other factors (e.g. deterioration due to acidic or basic pH values); limits the losses of volatile core materials; and releases the core material under desired conditions. In this respect, the core-shell microcapsules of this invention provide controlled release of the active material.

As used herein, “controlled release” refers to retention of the active material in the core until a specified triggering condition—in case of the present invention friction—occurs.

Thus, according to the present invention, when the paper roll is not in use, for instance a toilet paper roll (i.e., when the toilet paper roll does not rotate on its support), the fragrances of the liquid suspension medium are released, creating a pleasant atmosphere in the room. However, each time the toilet paper is used, the cylinder-shaped toilet paper roll rotates on the roll holder, which supports it. Due to the friction, the capsules burst releasing the fragrance contained within. Consequently, each time that the toilet paper is used, a fragrance reactivation in the room (bathrooms and toilets) occurs.

The encapsulation of active ingredients, for instance of fragrances, is known in the prior art.

The two documents WO 2006 018694 A1 (FIRMENICH) and DE 102008051799 A1 (HENKEL) describe the suspension of perfumed microcapsules in aqueous solutions with mixtures of nonionic and cationic polymers.

WO 2013 026657 A1 (UNILEVER) describes active substance particles whose outer surface is composed of no-ionic polysaccharides, including hydroxypropyl guar, which is disclosed as a capsule wall component.

Core-shell capsules with a capsule wall of polycarboxylic acids are known from WO 2014/064255 A2 (GIVAUDAN). Described is stabilization of the capsules during storage in a medium at a specified pH.

For the purposes of the present invention, capsules are preferred, in which the wall is formed of a polymer such as a urea-formaldehyde polymer, a melamine-formaldehyde polymer, a phenolic-formaldehyde polymer, a urea-glutaraldehyde polymer, a melamine-glutaraldehyde polymer, a phenolic-glutaraldehyde polymer, polyurea, polyurethane, polyacrylate, polyamide, polyester, an epoxy cross-linked polymer, a polyfunctional carbodiimide cross-linked polymer, silica, a silica-derived material, polysiloxanes, polyimide, polyvinyl alcohol, polyanhydride, polyolefin, polysulfone, polysaccharide, protein, polylactide (PLA), polyglycolide (PGA), polyorthoester, polyphosphazene, silicone, lipid, modified cellulose, gums, polystyrene, and combinations of these materials. Other suitable polymeric materials are ethylene maleic anhydride copolymer, styrene maleic anhydride copolymer, ethylene vinyl acetate copolymer, and lactide glycolide copolymer. Biopolymers and modified biopolymers are derived from alginate, chitosan, collagen, dextran, maltodextrins and starch can also be used as the encapsulating materials. Additionally, microcapsules can be made via the simple or complex coacervation of maltodextrins. Preferred encapsulating wall polymers include those formed from isocyanates, acrylates, acrylamide, acrylate-co-acrylamide, hydrogel monomers, sol-gel precursors, maltodextrins, melamine-formaldehyde or urea-formaldehyde condensates, as well as similar types of aminoplasts. Said capsules are particularly preferred. Thus, it was observed that the use of said capsules is especially advantageous, since these capsules shows a notable stability under the manufacturing conditions of the paper roll.

The description of preparation of said capsules can be found in: U.S. Pat. No. 6,586,107 B2, US 2019/0134592 A1, US 2015/0210965 A1, US 2019/0358603 A1, US 2018/0049957 A1, US 2019/0062676 A1, US 2020/0129385 A1, U.S. Pat. No. 9,631,165 B2, WO 2020/233773 A1, US 2020/0216782 A1, US 2011/0118161 A1, US 2021/0127719 A1, US 2021/0238510 A1, WO 2019/179597 A1, WO 2021/073775 A1, US 2020/0253857 A1 and EP 3 512 626 B1.

Particularly preferred are the use of formaldehyde-free capsules, for example the capsules disclosed in EP 3 512 626 B1.

In a preferred embodiment, the microcapsules (component (a)) according to the present invention are free of formaldehyde.

As already mentioned, the core material of the microcapsules comprises at least one fragrance oil. The selection of the fragrance oils to be encapsulated is not critical per se and is determined exclusively by the desired application. The only limiting factor is that these must either be present as oil or be sufficiently oil-soluble, i.e. lipophilic, to dissolve in an oil phase, and the fragrance must not have components that affect the core-shell microcapsule wall chemistry.

Suitable fragrances are well-known for one skilled in the art, and there is no need to further specification of these substances. However, suitable fragrances are described for example in US 2021/0269739 A1, WO 2015/023961 A1, US 2014/0287008 A1, US 2018/0049957 A1 and WO18050248 A1.

Preferably, the at least surfactant (component (b1)) comprises a non-ionic surfactant. Further the surfactants may be low and high HLB (hydrophilic-lipophilic) or mixtures thereof.

Preferably, the surfactant (component (b1)) is selected from the group consisting of polysorbates and Ethoxylated hydrogenated castor oil esters (commercially available for example under the tradenames Chremophor®, ALPICARE®, EUMULGIN®, polyoxyl 35) or mixtures thereof. Preferably said polysorbates are selected from the group consisting of polyethylene glycol sorbitan monolaurate (Tween™ 20; Croda Americas, Inc), polyoxyethylene sorbitan monooleate (Tween™ 80; Croda Americas, Inc) or mixtures thereof

In a preferred embodiment, the surfactant (component (b1)) is selected from the group consisting polysorbate, particularly preferred from the group consisting of polyethylene glycol sorbitan monolaurate (Tween 20), polyoxyethylenesorbitan monooleate (Tween 80) or mixtures thereof.

In a particular preferred embodiment, the surfactant (component (b1)) is polyoxyethylene sorbitan monooleate (Tween™ 80).

As mentioned above the liquid medium of the suspension contains also at least one fragrance oil (component (b2)). This/these fragrance oil/s may be the same or different as the fragrance oil of the core material in the microcapsules; therefore, the above explanations apply also to component (b2) of the liquid medium of the suspension.

As mentioned above the liquid medium of the suspension contains also at least one deflocculant agent (component (b3). Deflocculants are substances used for preventing the formation of agglomerates. These substances are well-known for one skilled in the art.

In a preferred embodiment, the at least one deflocculant agent (component (b3)) is selected from the group consisting of humic acids and derivatives, alkaline lignosulfonates, tannin compounds, polyacrylates and acrylic derivatives, acrylate copolymers, cationic acrylamide copolymers polycarbonates, sodium citrate, polysaccharides, sodium and potassium carbonates, sodium and potassium hydroxides, sodium silicates, phosphates and polyphosphates, sodium and ammonium oxalates and mixtures thereof.

In a preferred embodiment, the at least one deflocculant agent (component (b3)) is selected from the group consisting of polyacrylates and acrylic derivatives, acrylate copolymers, cationic acrylamide copolymers polycarbonates, polysaccharides, tannins, silicates and mixtures thereof.

In a particular preferred embodiment, the at least one deflocculant agent (component (b3)) is selected from the group consisting of polyacrylamide cationically modified, acrylate copolymers, cationic acrylamide copolymers polycarbonates, polysaccharides, and mixtures thereof.

In an especially preferred embodiment, the at least one deflocculant agent (component (b3)) is selected polyacrylamide cationically modified (Rheovis CSP @ 2.5%/W; BASF SE 67056 Ludwigshafen, Germany). This compound was particularly efficient avoiding the formation of agglomerates, which could lock the nozzle used for applying the suspension in the paper cardboard.

In a particular preferred embodiment, the suspension according to the present invention is free of formaldehyde.

For the purposes of the present invention the further auxiliaries and/or additives may be selected from the group consisting of antidandruff agents, irritation-preventing agents, irritation-inhibiting agents, antioxidants, astringents, antiseptic agents, anti-statics, binders, buffers, carrier materials, chelating agents, cell stimulants, cleansing agents, care agents, softeners, emulsifiers, enzymes, fibres, film-forming agents, fixatives, foam-forming agents, foam stabilizers, substances for preventing foaming, foam boosters, gelling agents, gel-forming agents, hair care agents, hair-setting agents, hair-straightening agents, moisture-donating agents, moisturizing substances, moisture-retaining substances, bleaching agents, strengthening agents, optically brightening agents, gloss agents, polymers, powders, proteins, re-oiling agents, silicones, hair promotion agents, cooling agents, skin-cooling agents, warming agents, skin-warming agents, stabilizers, UV-absorbing agents, UV filters, detergents, thickeners, vitamins, oils, waxes, fats, phospholipids, saturated fatty acids, mono- or polyunsaturated fatty acids, monoohydroxy acids, polyhydroxyfatty acids, liquefiers, dyestuffs, color-protecting agents, pigments, odoriferous substances, polyols, surfactants, electrolytes, organic solvents and silicone derivatives.

The present invention concerns further to a method for manufacturing the suspension disclosed above comprising or consisting of the following steps:

Accordingly, the method for manufacturing the suspension according to the present invention offers two alternatives, each comprising or consisting of the following steps: