Energy curable polyurethane emulsion for finishing leather or imitation leather

Abstract

Use of an energy curable polyurethane emulsion for finishing leather or imitation leather consisting of (A) at least 1%, preferably 1 - 20 % by weight of at least one polyol, (B) 0.05 - 4 % by weight of an ionomer, (C) 0.01 - 7 % by weight of at least one diisocyanate or polyisocyanate, (D) 0.01- 7 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups (E) 0.01 - 4 %, by weight of at least one neutralising agent, (L) 0.01 - 0.5 %, by weight of at least one catalyst, (M) 55 - 95 % by weight of water, (N) 0 - 30 % by weight of water-based polyurethane resins, (O) 0.5 - 25% by weight of at least one solvent, (Pl) 0 - 25 % by weight of additives. The ratio between the NCO / OH groups of the composition is comprised between 1 and 2.2, the neutralising agent is present in the composition in amounts between 0.8 and 1.3 equivalents with respect to moles of the ionomer, the polyol has a melting point greater than or equal to 40 °C measured according to the ISO 3146 standard.

Description

[0001] ENERGY CURABLE POLYURETHANE EMULSION FOR FINISHING LEATHER OR IMITATION LEATHER

[0002] DESCRIPTION

[0003] Field of the invention

[0004] The present invention relates to the technical field of chemical treatments of leather or imitation leather, and it particularly relates to a composition for preparing an energy curable polyurethane emulsion for finishing leather or imitation leather, as well as the emulsion and the method for preparing it.

[0005] Definitions

[0006] In the present document, the expression "leather goods" or "hide" or "leather" of similar expressions is used to indicate any layer, whether it be grain, crust or sub-crust, of the leather of an animal, in particular of a bovine, but also of sheep / goats, pigs, exotic, fur, wild animals or others, or nubuck, frosted leather, wet-blue leather, plant-based leather or wetwhite leather.

[0007] In the present document, the expression "imitation leather" is used to indicate a product of non-animal origin, whose external appearance is similar leather of animal origin.

[0008] In the present document, the expression "energy curable" and its derivatives is used to indicate a product which, when applied to the leather and it is exposed to UV irradiation by means of a UV lamp, UV LED, excimer lamp or low energy ionizing radiation by means of electron beam technology, cross-links forming a film on the treated medium.

[0009] In the present document, the expression "irradiation" and its derivatives is used to indicate irradiation with UV rays by means of UV lamp, UV LED, excimer lamp or low energy ionizing radiation by means of electron beam technology.

[0010] In the present document, the expression "percentage by weight (% by weight)" is used to indicate the percentage by weight of a component of interest in a mixture of interest, the percentage by weight being compared to the total weight of the components in said mixture of interest.

[0011] In the present document, the expressions "radical initiator" is used to indicate a chemical substance which, under certain conditions, undergoes a bond rupture (homolytic cleavage) forming free radicals that initiate cross-linking reactions of a composition having functional groups with double carbon-carbon bonds C=C that can be polymerised through radical polymerisation. In the present document, the expressions "thermolabile radical initiator" is used to indicate a radical initiator that initiates the radical polymerisation as temperature increases. Usually these species become effective at temperatures above 50°C. Each thermolabile radical initiator has its own specific triggering temperature.

[0012] In the present document, the expressions "redox radical initiator" is used to indicate a two-component radical initiator, wherein the two components undergo an oxidoreduction reaction which produces radical species capable of initiating radical polymerisation reactions.

[0013] In the present document, the expression "photoinitiator" is used to indicate a radical initiator that initiates radical polymerisation after irradiation with a UV lamp, UV LED or excimer lamp.

[0014] In the present document, the expression "sensibiliser" is used to indicate a compound that increases the effectiveness of the photoinitiator in producing radical species when subjected to irradiation.

[0015] In the present document, the expression "synergistic amine" is used to indicate a compound that increases the effectiveness of the photoinitiator in initiating the polymerisation / cross-linking of a composition when subjected to irradiation.

[0016] In the present document, the definition "ionomer" refers to a compound that allows the functionalisation of polymer chains with ionizable functional groups with the aim of making the polymer soluble, emulsifiable or dispersible in water.

[0017] In the present document, the expression "NCO / (OH+NHX)" refers to the molar ratio between the NCO groups and the sum of the amounts of -OH and -NHXgroups present at the beginning of the reaction in a composition of interest.

[0018] In the present document, the expressions "polyurethane resin" and "polyurethane" are used to indicate aqueous emulsions or dispersions whose main component consists of polyurethanes.

[0019] In the present document, the expression "double bond density" is used to indicate the amount of double bonds present per unit of dry mass of the sample. It is expressed in mmol / g.

[0020] State of the Art

[0021] It is known that the leather undergoes several processes that are typically riviera, retanning and finishing processes.

[0022] Among the various processes, finishing is intended to improve the aesthetic and / or product characteristics of the leather or imitation leather, such as the feel to touch, colour, evenness of the leather or imitation leather, concealing any superficial defects, increasing the resistance to chemical agents or water, resistance to continuous bending and resistance to abrasion.

[0023] In order to finish the leather, it is known to apply suitable primer and / or fixatives to the leather.

[0024] These products include specific products based on natural and / or synthetic binders, pigments, waxes, dyes, fillers, silicones, matting substances, solvents, plasticisers, penetrating agents, release agents, surfactants, oil and water-repellent agents, which require the addition of additional cross-linking agents at the time of application in order to improve physical and chemical performance.

[0025] The latter, after mixing with the basic product, allow the use thereof with a set times, demonstrating a reduced pot life, thus increasing the volume of processing waste.

[0026] Such additional cross-linking agents are for example polyaziridine, polyisocyanates, polyureas, epoxy resins which are known to be highly harmful to humans, toxic and environmentally hazardous, with a resulting negative impact on the management thereof.

[0027] Summary of the invention

[0028] An object of the present invention is to at least partly overcome the drawbacks illustrated above by providing an energy curable polyurethane emulsion, which does not require adding, and therefore handling, toxic substances for the application in the step for finishing the leather or imitation leather.

[0029] Another object of the present invention is to provide an energy curable polyurethane emulsion which, when applied to the leather or imitation leather, confers excellent flexibility to the latter.

[0030] A further object of the present invention is to provide an energy curable polyurethane emulsion with high pot life, simplifying the management of the product.

[0031] Another object of the present invention is to provide an energy curable polyurethane emulsion that reduces the amount of production waste.

[0032] Another object of the present invention is to provide an energy curable polyurethane emulsion applied to the leather or artificial leather which confers to the latter physical and / or mechanical and / or chemical characteristics comparable or superior to the products of the prior art.

[0033] Another object of the present invention is to provide an energy curable polyurethane emulsion which, when applied to the leather or imitation leather, confers excellent abrasion resistance.

[0034] Generally, the energy curable emulsion for finishing leather or imitation leather of the present invention may be prepared starting from a composition consisting of:

[0035] (A) at least 0.5 %, preferably 0.5 - 20 %, by weight of a polyol component;

[0036] (B) 0.05 - 2 % by weight of at least one ionomer;

[0037] (C) 0.01 - 7 % by weight of at least one diisocyanate or polyisocyanate;

[0038] (D) 0.01 - 4 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;

[0039] (E) 0.01 - 1.5 %, by weight of at least one first neutralising agent;

[0040] (L) 0.001 - 0.1% by weight of at least one catalyst;

[0041] (M) 55 - 95 % by weight of water;

[0042] (N) 0 - 30 % by weight of aqueous-based polyurethane resins;

[0043] (O) 0.5 - 25 % by weight of at least one solvent;

[0044] (Pl) 0 - 25 % by weight, preferably 0.1 - 25 % by weight, of additives.

[0045] The % by weight of the components are calculated with respect to the total weight of the composition and the sum of the % by weight of the components is 100 %.

[0046] Advantageously, the application of the emulsion to the leather or imitation leather to be finished by spraying, using a roller machine, using a layer application machine, using a paper release machine, using a bycast system, using a strip transfer, by hand with buffering, by hand with a brush, or any other technique suitable for finishing the leather or imitation leather, both as a primer application and as a fixative.

[0047] Once applied, the emulsion can be dried, it can be possibly printed, and can be crosslinked using a suitable source of irradiation.

[0048] For example, the source of irradiation may be one or more UV lamps, preferably having a linear power between 80 and 120 Watts per linear centimetre. In this case, the emulsion may be in particular UV curable, as better explained below.

[0049] In a further example, the emulsion of the present invention may be cross-linked by irradiation with electron beam. In this case, the emulsion can be more generally energy curable, as better explained below.

[0050] The activation of the acrylic or methacrylic monomer with reactive groups towards the isocyanate (D) groups may be carried out only by exposing the leather or imitation leather on which the UV emulsion or electron beam is applied.

[0051] To this end, the composition mentioned above is without radical initiators of the thermolabile type and of the redox type.

[0052] There are different types of thermolabile radical initiators depending on their chemical nature, and they are classified according to the functional group that produces the radical, for example organic peroxides, hydroperoxides, diacyl peroxides, peroxesters, peracids, peroxodicarbonates, inorganic peroxides and azo compounds.

[0053] Examples of radical initiators of the thermolabile type are: di-tert-butyl peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, di-tert-butyl peroxyoxalate, di-tert-butyl hyponitrite, dicumyl peroxide, azo-bis-isobutyl nitrile, potassium peroxysulfate, ammonium peroxylsulfate, peroxynonanoic acid, dicyclohexyl peroxydicarbonate, rigonox M, Luperox 228, Interox BP, Interox MBP, Luperox 7M50.

[0054] Examples of redox-type radical initiators are the following pairs: hydrogen peroxide and iron (II), persulfate ion and iron (II), peracid and metal pairs, tertiary aromatic amine peroxide pairs.

[0055] On the other hand, the above composition may comprise a photoinitiator as an additive. In this case, the emulsion may be UV curable.

[0056] If present, the photoinitiator may be in an amount between 0.25 and 3 % by weight with respect to the weight of the weight of the composition, and it may be selected from: benzyl ketones, phosphine oxides, benzoin esters, dihydroxy acetophenones, amino alkyl phenones, benzo phenones, thioxanthones.

[0057] In case of energy curable emulsion intended to be activated by means of electron beam, the photoinitiator may or may not be present. However, in this case the photoinitiator may preferably not be present.

[0058] Suitably, once prepared, the emulsion may be stored in a containerthat does not allow light to filter, so that it can only be activated when applied to the skin and exposed to the source of UV rays or electron beam.

[0059] The polyol component consists of one or more polyols. The latter may preferably be selected from: polyethers such as PPG with molar mass comprised between 800 and 3200, PTMEG and bio-based version with molar mass between 800 and 3200, polys 1,3 propylene glycol 1000 e 2000 bio, organo-polysiloxane polyols; polyesters such as polymers produced by 1,4 BDO and NPG, 1,3 bio-based propanediol, ethylene glycols, 1,6 hexanediol and mixtures thereof for condensation with dicarboxylic acids, wherein the molar masses of the diols are comprised between 800 - 3200; polycaprolactone diol with molar mass between 900 - 2500; polycaprolactone triol with molar mass between 450 - 1200; polycaprolactone tetraol with molar mass ranging from 450 to 1200; polycarbonates and triols with molar mass comprised between 800 and 3500 or a mixture of two or more thereof.

[0060] Advantageously, at least 60% by weight and preferably 70% by weight of the polyol component may consist of one or more polyols having a melting point greater than or equal to 40 °C measured according to the ISO 3146 standard, that is liquids at room temperature.

[0061] Therefore, should the polyol component consist of a single polyol, the melting point of the polyol will be greater than or equal to 40 °C.

[0062] On the other hand, where the polyol component consists of more than one polyol, at least 60 % by weight and preferably 70 % by weight of the latter may consist of polyols having a melting point of 40 °C or higher.

[0063] In this manner, the emulsion will be stable in water and, once cross-linked, it will form a film on the leather or imitation leather with appropriate mechanical properties.

[0064] Advantageously, ionomers (B) may be one or more. For example, the composition may provide for a single ionomer, which may be DMPA.

[0065] Suitably, the at least one diisocyanate (C) may be selected from: aliphatic or cycloaliphatic diisocyanates and mixtures thereof, preferably I PDI, H12MDI, HDI.

[0066] Orthe at least one polyisocyanate (C) may be selected from: uretdiones, isocyanurates, allophanates, aliphatic or cycloaliphatic biurets.

[0067] Advantageously, the acrylic or methacrylic monomer having reactive groups towards the isocyanate groups (D) may be selected from: 2-HEA, 2-hydroxyethylmethacrylate, 2- hydroxypropyl acrylate, 3-hydroxypropylacrylate, neopentyl glycol monoacrylate, hexanediol monoacrylate, glycerol diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, 2-amino ethyl acrylate, 2-amino propyl acrylate, 3-amino propyl acrylate, 4-amino butyl acrylate, 6-hydroxy hexyl acrylate, 3-hydroxy-2-ethyl acrylate, 6-amino hexyl acrylate, dipropylene glycol monoacrylate, tri-propylene glycol monoacrylate, diethylene glycol monoacrylate, triethylene glycol monoacrylate, 2-thio ethyl acrylate, 2-amino ethyl acrylamide, 3-amino ethyl acrylamide, 2-hydroxyethyl acrylamide, 2-hydroxypropyl acrylamide, 3-hydroxypropyl acrylamide, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, a product of single addition between 2-HEA and IPDI or a mixture of two or more of the latter.

[0068] Suitably, the at least one first neutralising agent (E) may be selected from: triethylamine (TEA), DIPEA, methyl or ethyl or propyl morpholine or a mixture of two or more thereof.

[0069] Suitably, the catalyst (L) may be selected from salts and / or complexes of bismuth, tin, nickel, zinc.

[0070] Suitably, the solvent (O) may be selected from: ketones, ethers, alkyls and aromatics, preferably acetone and methyl ethyl ketone. The water (M) may be distilled or demineralized water.

[0071] If present, water-based polyurethane resins and additives may be present in the above composition respectively in a percentage by weight of 0.1 - 30 % and 0.1 - 25 %.

[0072] Preferably, the additives (Pl) if present may be selected from: a further at least one second neutralising agent selected from triethylamine (TEA), DIPEA, methyl or ethyl or propyl morpholine, triethanolamine, dimethyl amine ethanol, methyldiethanolamine or a mixture of two or more thereof, at least one photoinitiator, at least one polymerisation inhibitor, at least one chain extender, at least one sensibiliser, at least one co-initiator, at least one antifoam agent, at least one synergistic amine, at least one deaerating agent, silicas, drying agents and dispersants for silicas, dispersions of matting waxes, microbeads of resins or matting waxes, silicones for touch and dispersion, dispersion waxes, polyurethane and / or acrylic thickeners, at least one surfactant, reactive (meth)acrylic diluents that are water-soluble or dispersible in water or insoluble in water, pigments in paste form or a mixture of two or more thereof.

[0073] Advantageously, the chain extenders, if present, may be selected from: 1.4 butanediol, 1.6 hexanediol, aliphatic diols, linear or branched cycloaliphatic diols, ethylenediamine, hydrazine, hexamethylenediamine, cadaverine, putrescin, isophorone diamine, diethylenetriamine and other aliphatic or cycloaliphatic, glycerol monomethacrylate, trimethylolpropane di(meth)acrylate, pentaerythritol mono or di(meth)acrylate or a mixture of two or more thereof.

[0074] Suitably, the surfactants may be selected from non-ionic emulsifiers, such as polyethers of alcohols or fatty acids or fatty amines and polysorbates or anionics such as sulfuric esters, phosphoric esters and polyethers sulphates of fatty alcohols or o alkylbenzenes, levelling agents, drying agents such as polysiloxane, polyacrylic, polymeric macromolecular silicones, silicone surfactants, glycols and polyglycols or a mixture of two or more thereof.

[0075] If present, the polymerisation inhibitor may have the function of minimising accidental activations of the acrylic or methacrylic monomer having reactive groups towards the isocyanate groups (D) during the preparation, storage or application of the emulsion.

[0076] The emulsion may have different yields on the leather or imitation leather depending on the additives (Pl) selected in the above composition.

[0077] For example, in a first formulation with opaque yield on the leather or imitation leather, the composition may include 0.1 - 25% by weight of opaque water-based polyurethane resins (N) and the additives (Pl) may be: antifoam and de-aeration agents, silicas, drying agents and dispersants for silica, dispersions of matting waxes, microbeads of resins and matting waxes, silicones for touch and dispersion, surfactants, waxes in dispersion, polyurethane and / or acrylic thickeners, reactive (meth)acrylic diluents or dispersible in water or a mixture of two or more thereof.

[0078] In a second different formulation, with a glossy yield on the leather or imitation leather, the composition may be completely free of water-based polyurethane resins (N) and the additives may be: antifoam and de-aeration agents, silicones for touch and dispersion, polyurethane and / or acrylic thickeners, third surfactants, reactive (meth)acrylic diluents that are water-soluble or dispersible in water or a mixture of two or more thereof.

[0079] In a third different formulation, which can for example be used as a primer on the leather or imitation leather, the emulsion may be completely free of opaque water-based polyurethane resins (N) and the additives may be: antifoam and deaeration agents, silicones, polyurethane and / or acrylic thickeners, reactive (meth)acrylic diluents that are water-soluble or dispersible in water, loads and fillers, fourth surfactants, pigments in paste form or a mixture of two or more thereof.

[0080] With all three formulations described above, the finished leather or imitation leather may have the following physical and / or chemical and / or mechanical characteristics and tested after the leather or imitation leather has been properly dried and cross-linked by irradiation.

[0081] Therefore, the finished leather or imitation leather may have a dry bending resistance from 30000 to 250000 cycles, preferably from 40000 to 200000 cycles, even more preferably from 80000 to 150000 cycles according to the IUP 20 ISO 5402-1 standard.

[0082] In addition, the finished leather or imitation leather may have a dry degree of adhesion according to the IUF 470 ISO 11644 standard from 2 to 20 N, preferably from 3 to 15 N, even more preferably from 5 to 9 N.

[0083] Advantageously, in the case of the matt or glossy yield formulation, the finished leather or imitation leather may have a dry abrasion resistance according to the IUF 450 ISO 11640 standard between 200 and 3000 cycles, preferably between 300 and 2000 cycles, even more preferably between 500 and 1600 cycles.

[0084] Additionally or alternatively to the content outlined above regarding the dry abrasion resistance, the finished leather or imitation leather may have a wet abrasion resistance according to the IUF 450 ISO 11640 standard from 25 to 1500 cycles, preferably from 35 to 1200 cycles, even more preferably from 65 to 750 cycles. In this case, the finished leather or imitation leather may include a per se known top-coat product.

[0085] Preferably, in case of the primer formulation, the finished leather or imitation leather may have a dry abrasion resistance according to the IUF 450 ISO 11640 standard comprised between 200 and 3000 cycles, preferably between 800 and 2500 cycles and even more preferably between 1000 and 1800 cycles.

[0086] Additionally or alternatively, the finished leather or imitation leather may have a wet abrasion resistance according to the IUF 450 ISO 11640 standard comprised between 100 and 2000 cycles, preferably between 500 and 1500 cycles, even more preferably between 700 and 1200 cycles.

[0087] Suitably, the composition above at the start of the reaction may have a ratio between the NCO / (OH+NHX) groups comprised between 0.95 - 1.05, preferably equal to 1.

[0088] Advantageously, at least one first neutralising agent (E) may be present in the composition in amounts between 0.8 and 1.3 equivalents with respect to the moles of the ionomer (B).

[0089] Preferably, at least one first neutralising agent (E) may be present in the composition in amounts between 0.9 and 0.99, equivalents with respect to the moles of the ionomer (B).

[0090] Advantageously, the double bond density of the above composition may be less than 2, preferably less than 1.5 and even more preferably comprised between 0.05 and 1.45.

[0091] The double bond density (DDL) can be calculated using the known formula

[0092] 1000 wherein mk = mass of the k-th component in grams nk= number of double bonds per molecule of k-th component

[0093] MMk = molar mass of the k-th component in grams

[0094] Mass= total dry mass of the sample

[0095] The energy curable emulsion described above may have a high pot life and will not require the addition of toxic cross-linking agents for application in the step for finishing the leather or imitation leather.

[0096] Furthermore, once applied to the leather or imitation leather, it may confer to the latter physical and / or mechanical and / or chemical characteristics comparable or superior to products of the prior art.

[0097] In a first example, the composition for the preparation of the energy curable emulsion may consist of:

[0098] (A) 1.5 %, by weight of at least one polyol;

[0099] (B) 0.1 % by weight of an ionomer;

[0100] (C) 0.5 % by weight of at least one diisocyanate or polyisocyanate;

[0101] (D) 0.08 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;

[0102] (E) 0.08 %, by weight of at least one first neutralising agent;

[0103] (L) 0.001 %, by weight of at least one catalyst;

[0104] (M) 95 % by weight of water;

[0105] (N) 1 % by weight of water-based polyurethane resins;

[0106] (O) 0.5 % by weight of at least one solvent;

[0107] (Pl) 1.3 % by weight of additives.

[0108] In a second example, the composition for the preparation of the energy curable emulsion may consist of:

[0109] (A) 20 %, by weight of at least one polyol;

[0110] (B) 1.22 % by weight of an ionomer;

[0111] (C) 6.81 % by weight of at least one diisocyanate or polyisocyanate;

[0112] (D) 0.43 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;

[0113] (E) 0.76 %, by weight of at least one first neutralising agent;

[0114] (L) 0.01 %, by weight of at least one catalyst;

[0115] (M) 55 % by weight of water;

[0116] (N) 3.57 % by weight of water-based polyurethane resins;

[0117] (O) 6.69 % by weight of at least one solvent;

[0118] (Pl) 5.51 % by weight of additives.

[0119] In a third example, the composition for the preparation of the energy curable emulsion may consist of:

[0120] (A) 0.5 %, by weight of at least one polyol;

[0121] (B) 0.06 % by weight of an ionomer;

[0122] (C) 0.59 % by weight of at least one diisocyanate or polyisocyanate;

[0123] (D) 0.17 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;

[0124] (E) 0.05 %, by weight of at least one first neutralising agent;

[0125] (L) 0.001 %, by weight of at least one catalyst;

[0126] (M) 68.94 % by weight of water;

[0127] (N) 24.59 % by weight of water-based polyurethane resins;

[0128] (O) 0.7 % by weight of at least one solvent;

[0129] (Pl) 4.40 % by weight of additives.

[0130] In a fourth example, the composition for the preparation of the energy curable emulsion may consist of:

[0131] (A) 5.93 %, by weight of at least one polyol;

[0132] (B) 0.45 % by weight of an ionomer;

[0133] (C) 4 % by weight of at least one diisocyanate or polyisocyanate;

[0134] (D) 1.21 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;

[0135] (E) 0.41 %, by weight of at least one first neutralising agent;

[0136] (L) 0.07 %, by weight of at least one catalyst;

[0137] (M) 55 % by weight of water; (N) 1.48 % by weight of water-based polyurethane resins;

[0138] (O) 8.87 % by weight of at least one solvent;

[0139] (Pl) 23.09 % by weight of additives.

[0140] To obtain the emulsion from the above composition, firstly, there may be prepared an intermediate compound by mixing in one or more reaction containers a portion of solvent (O), the polyol component (A), the ionomer (B), the diisocyanate or polyisocyanate (C), the acrylic or methacrylic monomer with reactive groups towards the isocyanate groups (D), the neutralising agent (E), the catalyst (L) and possibly one or more additives (Pl), reacting the whole.

[0141] The intermediate product thus obtained may then be poured into a second reaction container containing water (M), possibly a further portion of solvent (O) and possibly one or more additives (Pl).

[0142] At this point, the solvent (0) may be removed, for example by distillation or vacuum, and additional additives (Pl) and / or water-based polyurethane resins (N) may be added.

[0143] The solvent (O) may be removed fully or partially. By way of example, if present, in the emulsion the solvent (0) may be present at most at 3 % by weight. Preferably, the emulsion may be solvent-free.

[0144] The above-mentioned mixing may be carried out, in each individual ration container, for a period of time of 20 - 240 minutes, more preferably between 25 - 120 minutes.

[0145] Furthermore, the contents of each reactor may be heated for 0.5 - 3 hours, preferably 1 - 2 hours, at a temperature of 45 °C - 90 °C, more preferably between 50 °C - 75 °C, possibly by applying vacuum to remove the solvent.

[0146] The product obtained in each reactor may then be cold or hot filtered, for example on a 50 - 350 pm canvas, more preferably between 70 - 90 pm, on canvas with a finer weft, for example between 10 - 60 pm in the case of fixatives, and on canvas with a wider weft in the case of primer formulations, for example 200-250 pm.

[0147] Preferably, the composition may include chain extenders among the additives (Pl).

[0148] It is clear that the additives (Pl) may be added at any step of the method, without departing from the scope of protection of the attached claims.

[0149] The preparation of the first intermediate compound may be carried in a number of ways, which are known to the person skilled in the art, as indicated in the examples below. It should be observed that the regulatory references mentioned in the present document are those in force at the date of filing or priority of the present patent application.

[0150] The invention may be clearer in light of the following examples, which shall be deemed provided for exemplifying and non-limiting purpose with respect to the invention. In these examples, by way of example, the additives have been indicated with (F) and (P).

[0151] Examples

[0152] Below are some examples for preparing the emulsion from the composition described above. All emulsions shall be deemed UV curable.

[0153] 1. Preparing samples of UV curable emulsion

[0154] 1.1 Materials used for the preparation of samples according to the invention

[0155] (A) polyol component: Adicrol B 55 by Nord Composites, PTMEG 2000 by Gantrade, PTMEG 220 by Gantrade, BioPTMEG 2000 by Mitsubishi, Adicrol BIO SPD 56 by Nord Composites; PPG 2000 Gammachimica;

[0156] (B) ionomer: dimethyl propionic acid by Perstorp;

[0157] (C) diisocyanate: isophorone diisocyanate by Milano Colori;

[0158] (D) acrylic or methacrylic monomer having reactive groups towards the isocyanate groups: 2 - hydroxyethyl acrylate by Basf;

[0159] (E) neutralising agent: triethylamine by Gammachimica;

[0160] (F) additives to be added before solvent removal: Irganox 1135 (polymerisation inhibitor by BASF); glycerol mono methacrylate by Evonik, TPO-L di DKSH, DAROCUR® 1173 by Ciba (photoinitiators), Nymanox B 22 by Nymco; Tego foamex 825 by Evonik, DPM by Isello Vernici, ethylenediamine by Gammachimica, Ethylenediamine by Gammachimica, Miramer 2200 Minwo;

[0161] (L) catalyst: Borchi Kat 24 (Borchers);

[0162] (M) demineralised water;

[0163] (N) water-based polyurethane resins: Rolflex A 349 by Lamberti; Idrocap 993 PF by Icap-Sira; Alcopur 561 PG by Alcover;

[0164] (O) solvents such as: DMM by Dow, DPM by Isello Vernici, synthesis acetone by Merck;

[0165] (P) additives to be added after solvent removal: AMP 95 by Acef, TS 100 by Evonik; Dowsil 52 by Dow; Dowsil 5-7254 Dow; Modarez SW 452 by Synthron; Alcopur 561 PG di Alcover; Byk-3500 by Byk; G3 POTA by Jobachem; brown dye by Realcolor, Coripur AD 155 Corichem, Rheolate 278 TF Urai, Rolacril A349 Lamberti, CoriWax M / N2 by Corichem.

[0166] 1.2 Materials used for comparative samples:

[0167] Components:

[0168] (A) Polyol: PPG 2000;

[0169] (B) Ionomer: DMPA;

[0170] (C) Diisocyanate: I PDI;

[0171] (D) Acrylic or methacrylic monomer having reactive groups towards the isocyanate groups: 2-HEA;

[0172] (E) Neutralising agent: TEA;

[0173] (F) Additives to be added before solvent removal: Irganox 1135, TPO_L, Tego foamex 825, Ciba® DAROCUR®1173;

[0174] (L) catalyst: Borchi Kat 24 (Borchers);

[0175] (M) demineralised water;

[0176] (N) Neorad R1500 marketed by Covestro, Idrocap 993 PF, Alcopur 561 PG;

[0177] (O) Solvent: DMP, acetone;

[0178] (P) Additives to be added after solvent removal: Ciba® DAROCUR® 1173, Rheolate 278 TF, by Dowsil 52, Modarez SW 452 concentrate, AMP 95, TS 100, Rolflex A 349, Coriwax M / N2, Dowsil 5-7254, Byk-3500, G3 POTA, Coripur AD 155, brown pigment paste.

[0179] It should be noted that the types of components common to the samples referred to in paragraphs 1.1 and 1.2 refer to the same companies as those referred to in paragraph 1.1.

[0180] 1.2 Samples Al, A2, A3, obtained by means of a first method of obtaining the emulsion In a glass round-bottom flask, provided with stirrer, there were introduced, in a nitrogen atmosphere, 119.16 g of Adicrol B 55 (A) previously melted at 60°C, 8.12 g of dimethyl propionic acid (B), 40.73 g of isophorone diisocyanate (C) and 40 g of acetone (O). It is mixed slowly, heating to 50 °C and the nitrogen atmosphere is maintained throughout the reaction. There are introduced 0.4 g Borchi Kat 24 (L) and reaction is carried out for 0.5 hours. The reaction is exothermic and the temperature is maintained between 70°C and 75°C with suitable thermostating systems.

[0181] The NCO titre is checked using a method according to the ISO 14896 standard applied to a prepolymer, which must be 3.21 + / - 0.20 % on the dry residue.

[0182] Into the reactor there are introduced 0.80 g Irganox 1135 (F), 6.54g 2-hydroxyethyl acrylate (D), 4.50 g glycerol mono methacrylate (F) and 0.80 g Borchi Kat 24 (L), and reaction is carried out at 70-75°C for 1.5 hours. The NCO titre is checked, which shall be 0 and 0.1 % on the dry residue so that the NCO / (OH+NHX) ratio is equal to 1. Were this not to be the case, there is added a further catalyst portion and the reaction continued for another 0.5 hours. Heating is interrupted until a temperature of 60 to 65°C is reached, 6.54g of triethylamine (E) are introduced into the reactor followed by 5.52 gTPO-L (F) and 5.51 g Ciba® DAROCUR® 1173 (F), there follows stirring for at least 10 minutes, taking care not to expose the reactor to direct light sources.

[0183] A second beaker reactor is then prepared providing it with a rod stirrer with a sawtooth impeller and introducing 580 g of demineralized water (M) and 0.22 g of Tego foamex 825 (F) thereinto and then stirred vigorously for 10 minutes.

[0184] As a result, in order to obtain the emulsion it will be sufficient to slowly introduce flush the contents of the first reactor into the second reactor within 15 minutes, while stirring very vigorously. Continue stirring vigorously for 30 minutes.

[0185] The contents of the second reactor opened for 2 hours shall be heated to 62 °C to remove the solvent and shall be filtered cold or hot on an 80 pm canvas.

[0186] Depending on the type of additives (P) selected and added to complete the mixing step, the following formulations are obtained:

[0187] Sample Al, opaque type formulation: the mixing step is completed by adding, in a different reactor, 98 g of the previously obtained dispersion and 27.1 g of demineralized water (M). Then, there are sequentially and slowly added, while stirring quite vigorously 2 g of DPM (O), 0.1 g of AMP 95 12 (P), 2.5 g TS 100 (P), 0.5 g Rolflex A 349 (P), 3 g of Coriwax M / N2 (P), 2 g of Dowsil 52 (P), 0.3 g Modarez SW 452 concentrated (P), 2.5 g of Rheolate 278 TF (P), 12 g of Idrocap 993 PF (N). The whole is mixed until homogeneity and stirred for another 30 minutes, then filter under pressure or gravity on a 25 pm canvas.

[0188] Sample A2, glossy type formulation: the mixing step is completed by adding, in a different reactor, 39.5 g of the previously obtained dispersion and 450 g of demineralized water (M). Then, there are sequentially and slowly added while stirring vigorously 0.7 g of G3 POT A Jobachem (P), 3.0 g of Dowsil 5-7254 (P), 0.3 g of BYK 3500 (P), 0,2 g of Modarez SW 452 concentrated (P), 8.0 g Alcopur 561 PG (N), 1.5 g of Rheolate 278 TF (P). The whole is mixed until homogeneity and stirred for another 30 minutes, then filter under pressure or gravity on a 20 pm canvas.

[0189] Sample A3, primer formulation: the mixing step is completed by adding, in a different reactor, 85 g of the dispersion obtained above, 12.8 g of brown pigment paste (P), 0.9 g of Ciba® DAROCUR® 1173 (N) and 1 g of Coripur AD 155 thickener (P). It is stirred for 15 min. It is filtered on a 250 pm canvas.

[0190] 1.3 Samples Bl, B2, B3, obtained by means of a second method for obtaining the emulsion

[0191] In a round-bottomed balloon glass reactor, provided with a rod stirrer, there are introduced, in a nitrogen atmosphere, 173.45 g of PTMEG 2000 (A) previously melted at 60°C, 10.60 g of dimethyl propionic acid (B), 59.80 g of isophorone diisocyanate (C), 52 g of acetone (O).

[0192] It is mixed slowly, heating to 50 °C and the nitrogen atmosphere is maintained throughout the reaction.

[0193] Into the reactor there are introduced 0.25 g of Nymanox B 22 (F), 3.71 g of 2- hydroxyethyl acrylate (D) and 2.57 g of glycerol monomethacrylate (F). There are introduced 0.4 g Borchi Kat 24 (L) and reaction is carried out for 1.5 hours. The reaction is exothermic and the temperature is maintained between 70 and 75°C with suitable thermostating systems.

[0194] Therefore, the NCO titre is checked, which shall be 1 ,40±0,2% on the dry residue so that the NCO / (OH+NHX) ratio is greater than 1 . Were this not to be the case, there is added another catalyst portion (F) and the reaction continued for another 30 minutes. Heating is stopped until 60-65°C are reached. 6.64 g of triethylamine (E) are then introduced into the reactor followed by 7.73 g TPO-L (F).

[0195] Mixing is carried out for 10 minutes, taking care not to expose the reactor to sources of direct heat.

[0196] In order to obtain the emulsion, a second beaker reactor is then prepared providing it with a rod stirrer with a saw-tooth impeller and introducing 385 g of demineralized water (M), 0.45 g of Tego foamex 825 (F) and 7.35 g of Ciba® DAROCUR® 1173 (F) thereinto, and then stirred vigorously for 10 minutes.

[0197] The contents of the first reactor are introduced slowly flush into the second reactor within 15 minutes, while stirring very vigorously.

[0198] 4.03 g of ethylenediamine (F) diluted in 20 g of water (M) are pipetted, ensuring that the pH of the dispersion or emulsion does not exceed 9.5. Continue stirring vigorously for 30 minutes. The contents of the second reactor opened for 2 hours shall be heated to 62 °C to remove the solvent. Cold or hot filtering is carried out on an 80 pm canvas. The NCO content is then checked and it must be between 0 and 0.1 % on the dry residue so that the NCO / (OH+NHX) ratio is equal to 1.

[0199] Depending on the type of additives (P) selected and added to complete the mixing step, the following formulations are obtained:

[0200] Sample Bl, opaque type formulation: The mixing step is completed by adding, in a different reactor, 230 g of the above polyurethane dispersion and 30.2 g of water (M). The following are added sequentially, slowly, while stirring vigorously: 2 g di DMP (O), 0.1 g di AMP 95 (P), 2.3 g of TS100 (P), 0.5 g of Rolacril A 349 (P), 2.0 g of Dowsil 52 (P), 0.2 g of Modarez SW 452 concentrated (P), 10.5 g of Idrocap 993 PF (N), 3.0 g of Coriwax M / N2 (P), 2.5 g of Rheolate 278 TF (P). The whole is mixed until homogeneity and stirred for another 30 minutes, then filter under pressure or gravity on a 50 pm canvas.

[0201] Sample B2 glossy type formulation: the mixing step is completed by adding, in a different reactor, 46 g of the dispersion obtained above and 40.7 g of water (M). The following are added sequentially while stirring vigorously: 3 g of Dowsil 5-7254 (P), 8 g of Alcopur 561 PG (N), 0.3 g of Byk-3500 (P), 1 g of Rheolate 278 TF (P), 0.7 g of G3 POTA (P), 0,3 g of Modarez sw 452 concentrated (P). The stirring is maintained until complete uniformity and it is extended for another 30 min. It is filtered by gravity or pressure on a 20 pm canvas.

[0202] Sample B3, primer formulation: the mixing step is completed by adding, in a different reactor, 85 g of the dispersion obtained above, 12.8 g of brown pigment paste (P), 0.9 g of Ciba® DAROCUR® 1173 (N) and 1 g of Coripur AD 155 thickener (P). It is stirred for 15 min. It is filtered on a 250 pm canvas.

[0203] 1.4 Samples Cl, C2, C3, obtained by means of a third method for obtaining the emulsion

[0204] 60 g acetone (O), 5.52 g DMPA (B) and 19.28 g IPDI (C) are introduced into a glass round-bottom flask provided with a rod stirrer. It is heated to 55°C and there are introduced 0.2 g of Borchi Kat 24 (L). It is allowed to react until a clear reaction environment is obtained and the temperature is maintained at around 70 °C. 18.78 g of PTMEG 220 (A) are then introduced followed by 0.20 g of Borchi Kat 24 (L). Reaction is carried out for 1 hour at 70 - 75°C.19.28 g of IPDI (C) are introduced and reaction is carried out for 30 minutes. 7.17 g of 2- hydroxyethylacrylate (D), are introduced. Reaction is carried out for 1 hour. Cooling is carried out and the product is not isolated. The NCO content, which shall be comprised between 0 and 0.1 % is titrated. Were this not to be the case, the reaction shall be continued by adding a third aliquot of Borchi Kat 24 (L). Cooling is carried out and the product is not isolated.

[0205] In a different glass round-bottom flask, provided with a stirrer rod, there are introduced 55.64 g of BioPTMEG 2000 previously melted at 60 °C (A), the whole product obtained according to the previous paragraph and 12.13 g of isophorone diisocyanate (B). Heating is carried out slowly to 50°C and 0.4 g of Borchi Kat 24 (L) are added, allowing it to react for 1 hour. The reaction is exothermic and the temperature is maintained between 70 - 75°C with suitable thermostating systems. 7.21 g of 2-hydroxyethyl acrylate (D) are added followed by 0.4 g of Borchi Kat 24 (L), reaction is carried out for 2 hours.

[0206] The whole product obtained as prepared in the previous reactor are added, followed by 3.95 g of TEA (E) and 3.50 g of Ciba® DAROCUR® 1173 (F), mixing is carried out for 20 minutes. To obtain the emulsion, an additional beaker reactor is prepared providing it with a rod stirrer and introducing 3000 g of demineralized water (M) and 0.20 g of Tego foamex 825 (F) thereinto. Stirring is carried out vigorously for 10 minutes. The contents of the first reactor are introduced slowly flush within 15 minutes, while stirring very vigorously. Stirring continues for 30 minutes. The stirring is reduced and heated to 62 °C to remove the solvent. Cold or hot filtering is carried out by gravity or under pressure on an 80 pm canvas.

[0207] Depending on the type of additives (P) selected and added until the mixing step is completed, the formulations of Sample Cl and Sample C3 are obtained as outlined above with reference to samples Al and B3 respectively.

[0208] Sample C2 glossy type formulation: the mixing step is completed by adding, in a different reactor, 46 g of the dispersion obtained above and 40.7 g of water (M). The following are added sequentially while stirring vigorously: 3 g of Dowsil 5-7254 (P), 30 g of Alcopur 561 PG (N), 0.3 g of Byk-3500 (P), 1 g of Rheolate 278 TF (P), 0.7 g of G3 POTA (P), 0,3 g of Modarez sw 452 concentrated (P). The stirring is maintained until complete uniformity and it is extended for another 30 min. It is filtered by gravity or pressure on a 20 pm canvas.

[0209] 1.5 Samples DI, D2, D3, obtained by means of the third method for obtaining the emulsion

[0210] 150 g of acetone (O), 7.89 g of DMPA (B) and 26.73 g of IPDI (C) are introduced into a glass round-bottom flask provided with a rod stirrer. It is heated to 55°C and there are introduced 0.2 g of Borchi Kat 24 (L). It is allowed to react until a clear reaction environment is obtained and the temperature is maintained at around 70 °C. 24.79 g of PTMEG 220 (A) are then introduced followed by 0.20 g of Borchi Kat 24 (L). Reaction is carried out for 1.5 hours at 70 - 75°C. The NCO content, which shall be comprised between 0 and 0.1% is titrated. Were this not to be the case, the reaction shall be continued by adding a third aliquot of Borchi Kat 24 (L). Cooling is carried out and the product is not isolated.

[0211] In a different reactor provided with a rod stirrer, there are introduced 78.26 g of Adicrol BIO SPD 56 (A) previously melted at 60°C, the product obtained according to the preceding paragraph and 42.67 g of isophorone diisocyanate (C), temperature is maintained at around 70°C and reaction is carried out for 30 min. There are introduced 21.06 g of 2- hydroxyethyl acrylate (D) and it is allowed to react for 30 min. The NCO contents which shall be comprised between 0 and 0.1% are titrated and were this not to be the case, the reaction is continued addition a third aliquot of Borchi Kat 24 (L). Heating is interrupted until a temperature of 60 to 65°C is reached. 7.12 g of triethylamine (E) are introduced into the reactor followed by 5.52 g Ciba® DAROCUR® 1173 (F), there follows stirring for at least 10 minutes, taking care not to expose the reactor to direct light sources.

[0212] To obtain the emulsion, a second beaker reactor is prepared providing it with a rod stirrer and introducing 950 g of demineralized water (M) and 0.45 g of Tego foamex 825 (F) thereinto. Stirring is carried out vigorously for 10 minutes. The contents of the first reactor are introduced slowly flush within 15 minutes, while stirring very vigorously. Stirring continues for 30 minutes. The stirring is reduced and heated to 62 °C to remove the solvent. Cold or hot filtering is carried out by gravity or under pressure on an 80 pm canvas.

[0213] Depending on the type of additives (P) and water-based polyurethane or acrylic resins (N) selected and added until the mixing step is completed, the formulations of Sample DI, Sample D2 and Sample D3 are obtained as outlined above with reference to samples Al, B2, B3.

[0214] 1.6 Comparative samples El, E2, E3: samples with polyol only with a melting point below 40°C

[0215] In a glass round-bottom flask, provided with stirrer, there were introduced, in a nitrogen atmosphere, 92.80 g of PPG 2000 (A), 6.64 g of dimethyl propionic acid (B), 44.61 g of isophorone diisocyanate (C) and 20 g of acetone (O). It is mixed slowly, heating to 50 °C and the nitrogen atmosphere is maintained throughout the reaction.

[0216] There are introduced 0.4 g Borchi Kat 24 (L) and reaction is carried out for 0.5 hours. The reaction is exothermic and the temperature is maintained between 70°C and 75°C with suitable thermostating systems.

[0217] The NCO titre is checked using a method according to the ISO 14896 standard applied to a prepolymer, which must be 5.38 + / - 0.20 % on the dry residue.

[0218] Into the reactor there are introduced 0.80 g of Irganox 1135 (F), 4.55 g of 2- hydroxyethyl acrylate (D) and 0.80 g of Borchi Kat 24 (L), reaction is carried out at 70-75°C for 1.5 hours. The NCO titre is checked which should be 4.40± 0.20 % on the dry residue. Were this not to be the case, there is added a further catalyst portion and the reaction continued for another 0.5 hours. The heating is interrupted until 60-65°C are reached. 2.33 of TEA (E), 2 g of TPO-L (F)are introduced and stirring is carried out for another 10 min.

[0219] A second beaker reactor is then prepared providing it with a rod stirrer with a sawtooth impeller and introducing 213 g of demineralized water (M) and 0.22 g of Tego foamex 825 (F), 5.51g of Ci ba® DAROCUR® 1173 (F), 1.54 g of Miramer 2200 thereinto and then stirred vigorously for 10 minutes. As a result, in order to obtain the emulsion it will be sufficient to slowly introduce flush the contents of the first reactor into the second reactor within 15 minutes, while stirring very vigorously. 3.15 g of hydrazine (F) are added slowly and stirring continues very vigorously for 30 minutes.

[0220] The contents of the second reactor opened for 1 hour shall be heated to 62 °C to remove the solvent and shall be filtered cold or hot on an 80 pm canvas.

[0221] Depending on the type of additives (P) and water-based polyurethane or acrylic resins (N) selected and added until the mixing step is completed, the formulations of Sample El, Sample E2 and Sample E3 are obtained as outlined above with reference to samples Al, B2, B3.

[0222] Films prepared according to the methods for performing the chemical-physical tests below are too sticky to conduct such tests.

[0223] 1.7 Comparison sample F: commercial resin formulation for wood to obtain a glossy fixative

[0224] In a beaker reactor there are mixed under strong stirring, one at a time and in the following order, 50 g of Neorad R1500 Covestro, 1.5 g of Ciba® DAROCUR® 1173 (P), 47.0 g of demineralised water (M), 3.0 g of Rheolate 278 TF (P), 0.85 g of Dowsil 52 (P). Stirring is carried out for 30 min and filtering is carried out on a 50 pm canvas. The product is applied as fixative.

[0225] 2. Finished leather and imitation leather characteristics analysis for samples in glossy and opaque formulations

[0226] Each of the samples mentioned above in formulations of the glossy and opaque type were applied on bovine leather in crust wet-blue (Aljeather, A2_leather; BIJeather, B2_leather; Cljeather, C2_leather; DIJeather, D2_leather, Eljeather, E2_leather, FJeather) and imitation leather in a fabric coated with polyurethane (AIJmitation leather, A2_imitation leather; BIJmitation leather, B2_imitation leather; CIJmitation leather, C2_imitation leather; DIJmitation leather, D2_imitation leather, EIJmitation leather, E2 imitation leather, F imitation leather) as fixative by means of spray technique. Then, they were dried in an oven at 85°C and cross-linked under a UV ribbon lamp provided with two lamps of type Hg and Hg+GA for a dwell time of 12 seconds.

[0227] The leather or imitation leather had been previously treated with a primer according to the prior art applied by spraying and dried in the oven at 85 °C.

[0228] For the samples mentioned above, there were measured parameters such as:

[0229] - dry bending resistance according to the IUP 20 ISO 5402-1 standard;

[0230] - dry abrasion resistance according to the IUF 450 ISO 11640 standard;

[0231] - wet abrasion resistance according to the IUF 450 ISO 11640 standard;

[0232] - dry adhesion according to the IUF 470 ISO 11644 standard.

[0233] The results are reported in Table 1 below: in the light of the above, it is clearthat all samples according to the invention are within the stated ranges with regard to the properties described above. For comparison samples El, E2, E3 testing could not be carried out given that the substrate, once treated with these samples, was too sticky to handle the specimens. Comparison sample F, on the other hand, showed insufficient resistance to bending and poor dry adhesion.

[0234] 3. Finished leather and imitation leather characteristics analysis for samples in the primer formulations

[0235] Each of the above samples in primer formulations were applied to bovine leather (A3_leather; B3_leather; C3_leather; D3_leather, E3_leather) and imitation leather of polyurethane type (A3_imitation leather; B3_imitation leather; C3_imitation leather; D3_imitation leather, E3_imitation leather) by spraying. They were then dried in a ventilated oven at 85° C. The leather or imitation leather was then fixated with a classic finishing system.

[0236] For the samples mentioned above, there were measured parameters such as:

[0237] - flexural strength according to the IUP 20 ISO 5402-1 standard;

[0238] - dry abrasion resistance according to the IUF 450 ISO 11640 standard;

[0239] - wet abrasion resistance according to the IUF 450 ISO 11640 standard;

[0240] - dry adhesion according to the IUF 470 ISO 11644 standard.

[0241] The results are reported in Table 2 below: in the light of the above, it is clearthat all samples according to the invention are within the stated ranges with regard to the properties described above. For comparison sample E3 testing could not be carried out given that the substrate, once treated with this sample, was too sticky to handle the specimens.

Claims

CLAIMS1. A composition for the preparation of an energy curable polyurethane emulsion for finishing leather or imitation leather, the composition consisting of:(A) at least 0.5 %, preferably 0.5 - 20 %, by weight of a polyol component;(B) 0.05 - 2 % by weight of at least one ionomer;(C) 0.01 - 7 % by weight of at least one diisocyanate or polyisocyanate;(D) 0.01 - 4 % by weight of at least one acrylic or methacrylic monomer having reactive groups towards the isocyanate groups;(E) 0.01 - 1.5 %, by weight of at least one first neutralising agent;(L) 0.001 - 0.1 % by weight of at least one catalyst;(M) 55 - 95 % by weight of water;(N) 0 - 30 % by weight of aqueous-based polyurethane resins;(O) 0.5 - 22% by weight of at least one solvent;(Pl) 0 - 25 % by weight of one or more additives; wherein the % by weight of the components are calculated with respect to the total weight of the composition; wherein the sum of the % by weight of the components is 100%; wherein at least 60% by weight of said polyol component consists of one or more polyols having a melting point greater than or equal to 40 °C measured in accordance with ISO 3146; wherein the composition is without radical initiators of the thermolabile type and / or of the redox type.

2. Composition according to claim 1, wherein said one or more polyols (A) are selected from the group consisting of: polyethers such as PPG with molar mass between 800 - 3200, PTMEG and bio-based version with molar mass between 800 - 3200, poly 1,3 propylene glycols and bio-based version with molar mass comprised between 800 and 3200, organo- polysiloxane polyols; polyesters such as polymers produced by 1,4 BDO and NPG, 1,3 biobased propanediol, ethylene glycols, 1,6 hexanediol and mixtures thereof for condensation with dicarboxylic acids, wherein the molar masses of the diols are comprised between 800 - 3200; polycaprolactone diol with molar mass between 800- 3200; polycaprolactone triol with molar mass between 500 - 1000; polycaprolactone tetraol with molar mass ranging from 450 to 1200; polycarbonates and triols with molar mass comprised between 800 and 3500; or amixture of two or more thereof.

3. Composition according to claim 1 or 2, wherein said at least one ionomer (B) is DMPA.

4. Composition according to claim 1, 2 or 3, where said at least one diisocyanate (C) is selected from aliphatic or cycloaliphatic diisocyanates and / or mixtures thereof, preferably IPDI, H12MDI, HDI.

5. Composition according to claim 1, 2 or 3, wherein said at least one polyisocyanate (C) is selected from the group consisting of: uretdiones, isocyanurates, allophanates, aliphatic or cycloaliphatic biurets.

6. Composition according to any one of the preceding claims, wherein said acrylic or methacrylic monomer having reactive groups towards the isocyanate groups (D) is selected from the group consisting of: 2-HEA, 2-hydroxyethylmethacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropylacrylate, neopentyl glycol monoacrylate, hexanediol monoacrylate, glycerol diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, 2-amino ethyl acrylate, 2-amino propyl acrylate, 3-amino propyl acrylate, 4-amino butyl acrylate, 6-hydroxy hexyl acrylate, 3-hydroxy-2-ethyl acrylate, 6-amino hexyl acrylate, dipropylene glycol monoacrylate, tri-propylene glycol monoacrylate, diethylene glycol monoacrylate, triethylene glycol monoacrylate, 2-thio ethyl acrylate, 2-amino ethyl acrylamide, 3-amino ethyl acrylamide, 2- hydroxyethyl acrylamide, 2-hydroxypropyl acrylamide, 3-hydroxypropyl acrylamide, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, a product of single addition between 2-HEA and IPDI or a mixture of two or more of the latter.

7. Composition according to any one of the preceding claims, wherein said at least one first neutralising agent (E) is selected from the group consisting of: triethylamine (TEA), DIPEA, methyl or ethyl or propyl morpholine or a mixture of two or more thereof.

8. Composition according to any one of the preceding claims, wherein said catalyst (L) is selected from salts and / or complexes of bismuth, tin, nickel and / or zinc.

9. Composition according to any one of the preceding claims, wherein said one or more additives (Pl) are present in a percentage by weight of 0.1 - 25% with respect to the total weight of the composition, said one or more additives (Pl) being preferably selected from the group consisting of: a further at least one second neutralising agent selected from triethylamine (TEA), DIPEA, methyl or ethyl or propyl morpholine, triethanolamine, dimethyl amine ethanol, methyldiethanolamine or a mixture of two or more thereof, at least onephotoinitiator, at least one polymerisation inhibitor, at least one chain extender, at least one sensibiliser, at least one co-initiator, at least one antifoam agent, at least one synergistic amine, at least one deaerating agent, silicas, drying agents and dispersants for silicas, dispersions of matting waxes, microbeads of resins or matting waxes, silicones for touch and dispersion, dispersion waxes, polyurethane and / or acrylic thickeners, at least one surfactant, reactive (meth)acrylic diluents that are water-soluble or dispersible in water or insoluble in water, pigments in paste form or a mixture of two or more thereof.

10. Composition according to the preceding claim, wherein said one or more additives (Pl) include or consist of at least one chain extender preferably selected from the group consisting of: 1.4 butanediol, 1.6 hexanediol, aliphatic diols, linear or branched cycloaliphatic diols, ethylenediamine, hydrazine, hexamethylenediamine, cadaverine, putrescin, isophorone diamine, diethylenetriamine and otheraliphatic orcycloaliphatic, glycerol monomethacrylate, trimethylolpropane di(meth)acrylate, penta erythritol mono, di(meth)acrylate or a mixture of two or more thereof.

11. Composition according to claim 9 or 10, wherein said one or more said additives (Pl) include or consist of at least one surfactant preferably selected from the group consisting of: non-ionic emulsifiers, such as polyethers of alcohols or fatty acids or fatty amines and polysorbates or anionics such as sulfuric esters, phosphoric esters and polyethers sulphates of fatty alcohols or o alkylbenzenes, levelling agents, drying agents such as polysiloxane, polyacrylic, polymeric macromolecular silicones, silicone surfactants, glycols and polyglycols or a mixture of two or more thereof.

12. Composition according to claim 9 to 11, wherein said water-based polyurethane resins (N) include or consist of 0.1 - 25 % by weight of the total weight of the composition of opaque water-based polyurethane resins, wherein said one or more additives (Pl) are selected from the group consisting of: said antifoam and de-aeration agents, said silicas, said wetting agents or dispersants for silicas, said dispersions of matting waxes, said microbeads of resins or matting waxes, said silicones for touch and dispersion, said dispersion waxes, said polyurethane and / or acrylic thickeners, said surfactants, said reactive (meth)acrylic diluents, that are water-soluble or dispersible in water or a mixture of two or more thereof.

13. Composition according to any one of the preceding claims, wherein the composition is of the UV curable type, said one or more additives (Pl), including or consisting of 0.25 - 3 % by weight of the total weight of the composition of at least one photoinitiatorpreferably selected from the group consisting of: benzyl ketones, phosphine oxides, benzoin esters, dihydroxy acetophenones, amino alkyl phenones, benzo phenones, thioxanthones.

14. Composition according to any one of the preceding claims, where the ratio between the NCO / (OH+NHX) is comprised between 0.95 - 1.05, and it is preferably equal to 1.

15. Composition according to any one of the preceding claims, wherein at least one first neutralising agent (E) is present in the composition in amounts between 0.8 - 1.3 equivalents with respect to the moles of the ionomer (B), preferably 0.9 - 0.99 equivalents with respect to the moles of the ionomer (B).

16. Composition according to any one of the preceding claims, wherein the density of the double bonds of the composition is less than 2, preferably less than 1.5 and even more preferably comprised between 0.05 and 1.45.

17. A method for the preparation of an energy curable polyurethane emulsion for finishing leather or imitation leather starting from the composition according to one or more of the preceding claims, comprising the steps of: preparation of a first intermediate compound which includes or consists of said components (A), (B), (C), (D), (E), (L), at least one portion of said component (O) and, possibly, at least one portion of said one or more additives (Pl); mixing said first intermediate compound with said component (M), possibly a further portion of said component (O) and, where possibly, at least one portion of said one or more additives (Pl); possible addition of at least one portion of said one or more additives (Pl) and / or said component (N).

18. Method according to the preceding claim, wherein said step for preparing said first intermediate compound is carried out by reacting in a first reactor said components (A), (B), (C), (D), (L), said at least one portion of the component (O) and, possibly, at least one portion of said one or more additives (Pl) and subsequently adding said component (E).

19. Method according to claim 17 or 18, wherein said mixing step of said first intermediate compound with said component (M) and possibly with a further portion of said component (0) is carried out by pouring the contents of said first reactor into a second reactor containing the component (M) and possible further portion of the component (O).

20. Method according to claim 17, 18 or 19, further comprising a step of total or partial removal of said component (O).

21. Method according to the preceding claim, wherein said step of removal of the component (0) is carried out by distillation.

22. An energy curable polyurethane emulsion for finishing leather or imitation leather which can be obtained by means of method according to one or more of claims 17 to 21.

23. The use of the energy curable polyurethane emulsion according to the preceding claim for finishing the leather or imitation leather.

24. Use according to the preceding claim, wherein the finished leather or imitation leather has a dry abrasion resistance according to the IUF 450 ISO 11640 standard between 200 and 35 cycles, preferably between 300 and 2000 cycles, even more preferably between 500 and 1600 cycles and / or wet abrasion resistance according to the IUF 450 ISO 11640 standard from 25 to 1500 cycles, preferably between 3000 and 1200 cycles, even more preferably between 65 and 750 cycles.

25. Use according to claim 23, wherein the finished leather or imitation leather has a dry abrasion resistance according to the IUF 450 ISO 11640 standard comprised between 2000 and 500 cycles, preferably between 800 and 2500 cycles and even more preferably between 1000 and 1800 cycles and / or a wet abrasion resistance according to the IUF 450 ISO 11640 standard comprised between 100 and 200 cycles, preferably between 3000 and 1500 cycles, even more preferably between 700 and 1200 cycles.

26. Use according to any one of claims 23 to 25, wherein the finished leather or imitation leather has a dry bending resistance from 30000 to 250000 cycles, preferably from 40000 to 200000 cycles, even more preferably from 80000 to 150000 cycles according to the IUP 20 ISO 5402-1 standard.

27. Use according to any one of claims 23 to 26, wherein the finished leather or imitation leather has a degree of dry adhesion according to the IUF 470 ISO 11644 standard from 2 to 20 N, preferably from 3 to 15 N, preferably from 5 to 9 N.

28. Use according to any one of claims 23 to 27 , wherein the emulsion is applied to the leather or imitation leather and subsequently the latter is exposed to a source of UV rays or electron beam irradiation.

29. Use according to the preceding claim, wherein the emulsion is applied to the leather or imitation leather by spraying, using a roller machine, using layer application machine, using paper release machine, using bycast system, using strip transfer, by hand with buffering, by hand with brush.

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