FR3017772A1 - MISCANTHUS ABSORBENT PARTICLES COATED BY AN OILY PSYLLIUM SUSPENSION - Google Patents

Abstract

Coated absorbent particles useful for the manufacture of animal litter, each coated absorbent particle comprising a Miscanthus core coated with a coating layer comprising an oily Psyllium suspension.

Description

FIELD OF THE INVENTION The present invention relates to coated absorbent particles adapted to the manufacture of animal bedding. More particularly, the coated absorbent particles comprise a Miscanthus core and a coating layer comprising an oil suspension of Psyllium. STATE OF THE ART For centuries, man has sought to improve the living comfort of domestic animals, that is to say, pets, such as cats, dogs, hamsters, rabbits, rabbits, cats and dogs. mice, rats, and birds and some farm animals, such as horses, pigs, poultry, rabbits, cows. It is to provide comfort to the animals that the litter was developed. The litter is a layer of absorbent material, deposited on the floor or in a receptacle provided for this purpose, serving primarily thermal insulation and helping to absorb the water contained in the animal waste. Today, several categories of litter are marketed. Publicly available litters are distinguished mainly by the nature of the basic materials that compose them, the basic materials may be of mineral or organic origin or include synthetic polymers. Base materials of organic origin include, in particular, plant material such as straw, sawdust and wood pellets. Mineral base materials include sand and clay soils, such as bentonite and attapulgite. Base materials including synthetic polymers include certain plastics. In addition, some litters may include mixtures of the above materials. In general, litter should preferably have certain properties such as the safety of the materials that compose it for humans and animals, a good capacity of absorption of the liquids contained in the animal dung, and if appropriate properties antimicrobial. Advantageously, cleaning the litter to get rid of faeces must be simple. There is growing research for the use of environmentally friendly and recyclable absorbent materials, so that the use of absorbent plant material as a base material for animal litter is now commonplace. Regarding the properties of litter to be easily removed after use, it is known in the state of the art so-called clumping litter. It is thus known clumping litters, whose constituent particles have the property of agglomerating with each other when they are in contact with the liquid contained in the animal waste. The particles thus agglomerated form compact masses that can be easily removed during the cleaning operation of the litter. It is also known non-clumping litters, which have satisfactory properties. Among the non-clumping litters, it may be mentioned, for example, litter based on a mixture of Miscanthus and straw, described by documents EP 1 792 536 and EP 1 969 924. Among the non-clumping litters, mention may be made, for example, of the litter described in document US 2012/0128620, based on zeolite, a composite absorbent material, which is mixed with a Psyllium powder which has a high binding power. However, Psyllium powder has the disadvantage of being toxic after inhalation, if it is used in large quantities. There is therefore a public need for the availability of alternative or improved bedding over known bedding.

SUMMARY OF THE INVENTION The present invention provides novel animal litter. Surprisingly and unexpectedly, the inventors have shown that the absorption properties of a particle of liquid-absorbing material, particularly aqueous liquids, could be increased when said particle was coated with an oily suspension comprising Psyllium. According to a first aspect, the present invention relates to coated absorbent particles useful for the manufacture of animal bedding, each coated absorbent particle comprising a Miscanthus core covered by a coating layer comprising an oil suspension of Psyllium. The applicant has shown that the oily suspension of Psyllium contained in the coating layer, by virtue of its hygroscopic properties, makes it possible to quickly absorb the aqueous liquids contained in the droppings with which it is in contact, and thus to accelerate or promote the absorption of water by the absorbent core of Miscanthus.

Another aspect of the present invention relates to a method for manufacturing coated absorbent particles comprising the following steps: a) mixing Miscanthus particles in a mixer at a speed of between 25 and 75 rpm, preferably 50 rpm at a temperature between 10 and 25 ° C, preferably at room temperature; b) adding to the Miscanthus particles undergoing step a) Psyllium and an oil, preferably a vegetable oil food, preferably a rapeseed oil; c) continue mixing for 1 to 10 minutes, preferably 4 minutes after adding said Psyllium and said oil; d) collecting the coated absorbent particles.

Another aspect of the present invention also relates to coated absorbent particles obtained by the process according to the invention. Another aspect of the invention relates to the use of coated absorbent particles in accordance with the invention for the manufacture of an animal litter. Another aspect of the invention relates to an animal litter comprising coated absorbent particles in accordance with the present invention. Another aspect of the invention relates to the use of coated absorbent particles in accordance with the present invention for the operation of dry toilets. DETAILED DESCRIPTION OF THE INVENTION Absorbent Particles The present invention relates to coated absorbent particles comprising a Miscanthus core coated with a coating layer comprising an oil suspension of Psyllium. Miscanthus is a perennial plant of the family Poaceae. Close in structure of sugar cane, this plant rich in cellulose and hemicellulose, has a high culture yield. In addition, it has significant absorbent properties. In the context of the present invention a "coated absorbent particle" is defined as a particle capable of absorbing a quantity of liquid at least equal to its own weight. The term "core" should be understood as referring to a compact grouping of grains or fine particles, which may be from a granulation step for example. The term "coating layer" refers to a film or film of material that covers all or part of the surface of the core. Psyllium is a soluble fiber, which becomes gelatinous and sticky on contact with water. It is nontoxic if ingested, provided that it is ingested with an appropriate amount of water. In the present invention Psyllium exerts an agglomerating effect and promotes the absorption of liquids by Miscanthus. The oil present in the coating layer acts as a binder for the maintenance of Psyllium particles on the surface of the absorbent particles. According to a preferred embodiment, the coated absorbent particles according to the present invention are characterized by a Miscanthus core representing between 80 and 97.5% by weight of the coated absorbent particle and a coating layer representing between 2.5% and 20% by weight of the coated absorbent particle. According to another preferred embodiment, the coated absorbent particles according to the present invention are characterized by a Miscanthus core representing between 80 and 95% by weight of the coated absorbent particle and a coating layer representing between 5% and 20% by weight of the coated absorbent particle.

According to a particularly preferred embodiment, the coated absorbent particles according to the present invention are characterized by a Miscanthus core representing between 92% by weight of the coated absorbent particle and a coating layer representing 8% by weight of the absorbent particle. coated, for which Psyllium represents 5% by weight of the coated absorbent particle and the oil represents 3% by weight of the coated absorbent particle. Core The Miscanthus constituting the core or core of the coated absorbent particles acts as a liquid absorbent. Advantageously, the Miscanthus core comprises between 51% and 100% Miscanthus by weight of the core, preferably between 75% and 100% by weight of the core.

According to a preferred embodiment, the Miscanthus core has a moisture content of less than 15%, preferably less than 12%, preferentially less than 10%. The skilled person is able to measure a moisture content in a solid state material according to any known technique. In the context of the present invention, the method is preferably used for measuring the moisture content in the oven, which comprises the following steps: a) providing a weight P1 of the material of interest; drying step at a temperature of 100 ° C for a time appropriate for the evaporation of all the water contained in said material, c) measuring the weight P2 of the material resulting from the drying step b), - d) it being understood that the difference P2-P1 is the quantity of water initially contained in the material of interest.

In a preferred embodiment, a time appropriate for the evaporation of all the water contained in said material is preferably between 5 minutes and 1 hour, more preferably between 15 minutes and 45 minutes. A Miscanthus adapted to the practice of the present invention may be selected from a group consisting of Miscanthus boninensis, Miscanthus capensis, Miscanthus floridulus, Miscanthus intermedius, Miscanthus japonicus' Giganteus', Miscanthus junceus, Miscanthus nepalense, Miscanthus oligonensis Miscanthus oligostachyus x ' Zwergelefant, Miscanthus oligostachyus 'Wetterfahne', Miscanthus olygostachyus, Miscanthus sacchariflorus, Miscanthus sinensis sp., Miscanthus tinctorius 'Nanus Variegatus', Miscanthus transmorissonensis, Miscanthus violaceus and Miscanthus 25 yakushimensis.

In a preferred embodiment, Miscanthus is selected from a group consisting of Miscanthus japonicus 'Giganteus' and Miscanthus sinensis sp. Most preferably, Miscanthus japonicus 'Giganteus' is used. According to an alternative embodiment, the Miscanthus core further comprises a second absorbent material, representing at most 49% by weight of the core. In the context of the present invention, the second absorbent material may be selected from a group comprising a mineral material and a plant material. Preferably, and for illustrative purposes, a mineral material adapted to enter the composition of the Miscanthus core may be chosen from a non-limiting group comprising slate, attapulgite, beidellite, bentonite, calcite, celadonite, dickite, dolomite, glauconite, gypsum, hectorite, illite, kaolinite, montmorillonite, nacrite, expanded perlite, phengite, pumice, sand, nontronite, saponite, sauconite, sepiolite, smectite, tobermite, vermiculite, zeolite and mixtures thereof.

By way of illustration, a plant material that is particularly suitable for the present invention may be chosen from a group comprising a wood, in particular chips or sawdust, for example softwoods, such as spruce, pine, fir, and hardwoods, such as oak, beech; a hemp; a cotton; a linen; a straw, especially a cereal straw, such as wheat, barley or oats; paper, including recycled paper; corn stalks, and their mixtures. Preferably, the second absorbent material is a straw, preferably a cereal straw. Advantageously, the second absorbent material has a size and / or shape identical or similar to that of Miscanthus grains forming the nucleus.25 Coating layer Psyllium is a soluble fiber, which becomes gelatinous and sticky on contact with the skin. 'water. In the context of the present invention, Psyllium has an agglomerating power promoting the absorption of liquids by the Miscanthus core.

In comparison with the absorbent particle composition described in the prior art, in particular in US 2012/0128620, for which zeolite absorbent particles are simply mixed with a Psyllium powder, the coated absorbent particles in accordance with the present invention comprise Psyllium which is present in a coating layer and not in mixture with the material constituting the core. In addition, while the composition according to document US 2012/0128620 comprises a quantity of Psyllium powder of less than 1% by weight, the inventors have shown that a coating in which Psyllium is contained in an oily suspension makes it possible to increase the amount of Psyllium beyond 2% by weight, without involving the safety of the animal or the person who is in contact with the absorbent particles. Indeed, although the ingestion of a Psyllium powder could be beneficial from an intestinal transit point of view, its inhalation can be problematic. The oil present in the coating layer acts as a binder for maintaining the Psyllium particles on the surface of the coated absorbent particles.

According to a preferred embodiment, the coating layer comprises a quantity of Psyllium varying from 2 to 15% by weight of the coated absorbent particle and an amount of oil ranging from 0.5 to 5% by weight of the absorbent particle. coated. Even more preferably, the coating layer comprises a quantity of Psyllium varying from 5 to 15% by weight of the coated absorbent particle.

Advantageously, an oil suitable for the present invention is a vegetable oil, preferably a food vegetable oil. Preferably, the edible vegetable oil is selected from a group comprising a sweet almond oil, peanut oil, argan oil, rapeseed oil, safflower oil, hemp oil, cotton oil, linseed oil, macadamia oil, maize oil, mustard, hazelnut, walnut, olive, palm, grape seed, sesame, soya, sunflower and their mixtures. In a preferred embodiment, the vegetable vegetable oil is advantageously chosen from a rapeseed oil, a palm oil, a peanut oil, a sunflower oil and their mixtures, preferably a rapeseed oil. According to a preferred embodiment, the oil is advantageously fluid and advantageously esterified. Indeed, the esterification of the oil allows the coating layer, and therefore the particle, to resist oxidation. The coating layer may further comprise one or more additive (s).

According to a preferred embodiment, the coating layer may further comprise an agent capable of neutralizing bad odors. For example, an agent capable of neutralizing bad odors may be chosen from a group comprising an antimicrobial agent, for example based on boron, a bactericide of the triclosan or farnesol type; a metal chelator (EDTA, DPTA); a bacterium of the genus Bacillus sp. (Bacillus amylfaciens, Bacillus cereus, Bacillus licheniformis, Bacillus pumilus, Bacillus spherious, Bacillus subes); a bacterium of the genus Bifidobacterium sp. (Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium lactis, Bifidobacterium longum, and Bifidobacterium pseudocatenulatum); a bacterium of the genus Lactobacillus sp. (Lactobacillus acidophilus, Lactobacillus alimentarius, Lactobacillus curvatus, Lactobacillus delbruckii, Lactobacillus jensenii, Lactobacillus lactis, Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus salviarius); an activated carbon; a cyclodextrin; an aluminum salt; a silver salt; a cadmium salt, such as, for example, cadmium acetate, cadmium borate, cadmium bromide, cadmium chlorate, cadmium chloride, cadmium formate, cadmium iodate, cadmium iodide, cadmium permanganate, cadmium nitrate, cadmium sulphate; a copper salt, such as copper chloride, copper gluconate; a zinc salt, such as, for example, zinc chloride, zinc gluconate, zinc lactate, zinc maleate, zinc salicylate, zinc sulphate, zinc ricinoleate; a silica. According to a preferred embodiment, the coating layer may further comprise a perfuming agent, such as an essential oil or a perfume.

According to a preferred embodiment, the additive may represent an amount of between 0 and 20% by weight of the coating layer, preferably between 1 and 15% by weight of the coating layer, preferably between 2 and 5 % by weight of the coating layer. The present invention relates to coated absorbent particles which advantageously have a particular particle size. By particle size is meant the determination of the size and the respective weight percentages of the different families of grains constituting the sample. Those skilled in the art know many methods for measuring this particle size, namely sieving, sedimentometry, centrifugation, laser diffraction and image analysis. In the context of the present invention the particle size is preferably measured by sieving. For example, it is possible to use a combination of sieves of standard dimensions, for example sieves whose mesh opening is between 0.08 mm and 20 mm, in particular sieves whose mesh opening is equal to 0.1. mm, 0.125 mm, 0.16 mm, 0.2 mm, 0.25 mm, 0.315 mm, 0.4 mm, 0.5 mm, 0.63 mm, 0.8 mm, 1 mm, 1.25 mm , 1.6 mm, 2 mm, 2.5 mm, 3.15 mm, 4 mm, 5 mm, 6.3 mm, 8 mm, 10 mm, 12.5 mm and 16 mm. Within the scope of the invention, three types of particles will be distinguished: - a) a Miscanthus granule, preferably obtained from a Miscanthus straw; b) a particle of Miscanthus, preferably resulting from a step of grinding a Miscanthus granule; - c) a coated absorbent particle, resulting from the coating of a Miscanthus particle by a coating layer comprising a mixture of Psyllium and an oil.

According to a preferred embodiment, a Miscanthus granulate has a diameter of between 1 and 10 mm, preferably a diameter of 6 mm and a length of between 5 and 40 mm, preferably a length of 30 mm. According to a preferred embodiment, a Miscanthus particle has a diameter of between 1 and 6 mm, preferably a diameter of between 3 and 3.5 mm and a length between 1 and 5 mm, preferably a length between 3 and 3.5 mm. According to a preferred embodiment, a coated absorbent particle according to the invention has a diameter of between 1 and 5 mm, preferably a diameter of between 1.5 and 3.5 mm and a length of between 1 and 5 mm, of preferably a length of between 1.5 and 3.5 mm. It should be noted that the Miscanthus particle, intended to form the Miscanthus core of the coated absorbent particle, can be broken in turn during the coating step, so that the Miscanthus core has a diameter and length substantially less than the diameter and length of the Miscanthus particle which is the starting material which undergoes the coating process. Absorbency In the context of the present invention, a coated absorbent particle according to the invention can absorb, in the presence of a liquid, a weight of liquid at least equal to its own dry weight, preferably at least 2 times its own dry weight, preferably at least 3 times its own dry weight, preferably at least 4 times its own dry weight.

In the context of the present invention, a coated absorbent particle according to the invention can absorb, in the presence of a liquid, a volume of liquid at least equal to its own dry volume, preferably at least twice its volume. its own volume to dry, preferably at least equal to 3 times its own volume to dry, preferably at least equal to 4 times its own dry volume. Process Miscanthus straw can be prepared from plants that are ready to be harvested (dry straw) or purchased commercially, for example in the form of granules 1 to 10 mm in diameter, preferably 6 mm in diameter, for a 10 to 10 mm diameter. length between 5 and 40 mm, preferably for a length of 30 mm. After harvesting dry Miscanthus straws on the legs, the straws can be crushed coarsely in a knife mill bowl to obtain, for example, Miscanthus particles with a size between 40 and 100 mm. In a second step, a second grinding, for example in a hammer mill, with a grid of 15 mm, can be performed to obtain particles of a size between 1 and 15 mm. The Miscanthus particles thus ground can then be compacted in a suitable press to obtain granules, for example with a diameter of 6 mm, for a length of between 20 and 40 mm, preferably for a length of 30 mm. At this stage, Miscanthus granules are obtained which are particularly suitable for the manufacture of an absorbent particle according to the present invention. Miscanthus granules can be introduced into a rotary cylinder with a steel cylinder, in order to break the granulate without making powder, and to obtain Miscanthus particles. In the context of the invention is defined by the term "powder" the product 25 obtained by grinding, pounding or spraying a solid material, so as to obtain particles smaller than 0.1 mm. At this stage of the process, the Miscanthus particles, intended to be coated, have a diameter of between 1 and 6 mm, preferably a diameter of between 3 and 3.5 and a length of between 1 and 5 mm, preferably length between 3 and 3.5 mm. The Miscanthus particles thus obtained after sieving are then mixed at slow speed. A slow speed suitable for a process according to the present invention may be between 10 and 100 revolutions / minute (rpm), preferably between 25 and 75 rpm, preferably 50 rpm. The addition of Psyllium powder and an oil is done during mixing. The mixture is produced at a temperature of between 10 and 25 ° C., preferably at room temperature. Indeed, the inventors have observed that below 10 ° C the oil is likely to freeze, and that above 25 ° C the oil is likely to be impaired with respect to these physical properties. chemical. The addition of an additive, as defined above, is feasible at any stage of the process, preferably during the coating step, that is to say at the same time as the adding Psyllium and an oil. According to a particular embodiment, the addition of Psyllium and an oil is carried out sequentially or simultaneously. According to a first preferred embodiment, the addition of Psyllium and an oil is carried out sequentially, preferably the oil being added first and Psyllium second. According to a second preferred embodiment, the addition of Psyllium and an oil is carried out simultaneously, preferably in the form of an oily suspension of pre-mixed Psyllium. According to a preferred embodiment, the coated absorbent particles in accordance with the invention can be transferred to an automatic bagging machine. The bag used for storage is advantageously opaque.

The invention thus relates to the use of coated absorbent particles according to the present invention for the manufacture of animal litter.

The invention also relates to an animal litter comprising coated absorbent particles in accordance with the present invention. According to a preferred embodiment, the litter according to the invention is suitable for domestic animals. Pets are meant to include pets, as well as farm animals. Pets are advantageously selected from a group consisting of cats, dogs, guinea pigs, ferrets, hamsters, rabbits, mice, rats, and birds. The farm animals are advantageously chosen from a group comprising horses, pigs, poultry, rabbits and cows. The person skilled in the art is capable of adapting the quantity of absorbent particles to be used and the frequency of renewal of the absorbent particles as a function of the size and / or the mass and / or the animal species envisaged and / or the receptacle. adapted to receive the absorbent particles, if necessary.

For example, for a small animal, such as a guinea pig, hamster, bird, etc., the amount of coated absorbent particles to be used may vary from about 100 grams to 500 grams. For a medium-sized animal, such as a rabbit, cat, dog, etc., the amount of coated absorbent particles to be used may vary from about 500 g to 5 kg. For a large animal, such as a horse, a cow, etc., the amount of coated absorbent particles to be used may vary from about 5 kg to 50 kg. For example, the frequency of complete renewal of the litter can vary between 2 days and 2 weeks, preferably between 3 days and 1 week. In another aspect, the invention also relates to the use of coated absorbent particles according to the present invention, in the implementation of dry toilets. In the context of the present invention, expressions such as "dry toilets", "composting toilets", "controlled organic litter toilets" or "separation toilets" are considered equivalent and can be used interchangeably. It is well known that dry toilets have the property of being able to operate without water. The droppings are collected in a container provided for this purpose and coated absorbent particles in accordance with the present invention can be added to promote the composting of excrement. The detailed description of the operation of dry toilets is not the subject of the present invention, but the use of the coated absorbent particles according to the invention for the operation of dry toilets does not pose any particular difficulty to the skilled person , who has the technical knowledge to adapt existing dry toilet systems to that use. EXAMPLES Example 1 Composition of a litter according to the invention An example of litter according to the invention comprises 92% Miscanthus by weight of the absorbent particle (Miscanthus japonicus' Giganteus), 5% of Psyllium powder by weight of the absorbent particle coated (AEI, Soufflet group) and 3% of a rapeseed oil by weight of the coated absorbent particle (Sofiprotéol).

EXAMPLE 2 Method of manufacturing a litter according to the invention Preliminary steps for the preparation of Miscanthus granules: a) harvest of Miscanthus after complete maturity, during the period March-April, b) natural drying of harvested Miscanthus (measurement of the humidity), to obtain straw; c) grinding of the straws to obtain fibers ranging in size from 0.1 to 15 mm, d) granulation of the ground straws to obtain granules having an average diameter of 6 mm and an average length of 30 mm .

The coated absorbent particles according to Examples 1 and 2 are obtained by the following process: a) Preparation of Miscanthus particles having a size varying from 1 to 5 mm, by reduction of 100 kg of crushed straw granules obtained by the method described herein. above, and b) coating the Miscanthus particles prepared in step a) with 8.64 kg of a suspension of Psyllium powder (62.5% by weight of the coating suspension) in oil rapeseed (37.5% by weight of the coating suspension).

Claims (14)

REVENDICATIONS1. Coated absorbent particles useful for the manufacture of animal litter, each coated absorbent particle comprising a Miscanthus core coated with a coating layer comprising an oily Psyllium suspension. 2. Particles according to claim 1, said coated absorbent particles have a diameter of between 1 and 5 mm, preferably a diameter of between 1.5 and 3.5 mm and a length between 1 and 5 mm, preferably a length of between 1.5 and 3.5 mm. 3. Particles according to one of claims 1 to 2, wherein the Miscanthus core is between 80 and 97.5% by weight of the coated absorbent particle and the coating layer is between 2.5% and 20% by weight. weight of the coated absorbent particle. 4. Particles according to one of claims 1 to 3, the Miscanthus core comprises between 51% and 100% Miscanthus by weight of the core, preferably between 75% and 100% by weight of the core. 5. Particles according to one of claims 1 to 4, wherein the coating layer comprises an amount of Psyllium varying from 2 to 15% by weight of the coated absorbent particle and an amount of oil ranging from 0.5 to 5 % by weight of the coated absorbent particle. 20 6. Particles according to one of claims 1 to 5, for which the oil is selected from a group comprising a rapeseed oil, a palm oil, a peanut oil, a sunflower oil and mixtures thereof, preferably a Colza oil. A method of manufacturing coated absorbent particles comprising the steps of: a) mixing Miscanthus particles in a mixer at a rate of between 25 and 75 rpm, preferably 50 rpm, at a temperature between 10 and 25 ° C, preferably at room temperature, b) adding to the Miscanthus particles undergoing step a) Psyllium and an oil, preferably a vegetable oil food, preferably a rapeseed oil; c) continue mixing for 1 to 10 minutes, preferably 4 minutes after adding said Psyllium and said oil; d) collecting the coated absorbent particles. 8. The method of claim 7, wherein the addition of Psyllium and an oil is carried out sequentially or simultaneously. 9. Method according to one of claims 7 and 8, wherein the addition of Psyllium and oil is carried out sequentially, preferably the oil being added first and Psyllium second. 10. Method according to one of claims 7 to 9, the Miscanthus particles have a present a diameter of between 1 and 6 mm, preferably a diameter of between 3 and 3.5 mm and a length between 1 and 5 mm, preferably a length of between 3 and 3.5 mm. 11. Absorbent coated particles obtained by the process according to one of claims 7 to 10. 12. Use of coated absorbent particles according to one of claims 1 to 6 or claim 11 for the production of animal litter. 13. Animal litter comprising coated absorbent particles according to one of claims 1 to 6 or claim 11. 14. Use of coated absorbent particles according to one of claims 1 to 6 or claim 11 for the operation of dry toilets.