PROCEDURE FOR PREPARING A POLYURETHANE-BASED MATERIAL INTENDED FOR THE MANUFACTURE OF SYNTHETIC LEATHER PRODUCTS

Description

DESCRIPTION of the patent for industrial invention from the title: PROCEDUREPREPARATION OF DIUNMATERIAL AND BASIS POLYURETHANOTE DESTINATED TO THE ROYAL ZZA ZA IONEDYPRODE TT IIN FOR SYNTHETIC LL by CHEMICAL INDUSTRY NEAS RRA . R . L . of Italian nationality concede : VIAMICHELANELOCHIPA , 115 8 0 1 22 NAPLES ( THE ) 10 Vendors : FIOREF ready , PALMERIR open * * * IF TT HEAR LL TECHNICAL The present invention relates to a procedure for the preparation of a laminated material based on 15 polyurethane intended for the manufacture of products in synthetic leather. Such products find application, ad for example, in the sector of appetizers and furnishings, of footwear and automotive. STATE OF THE ART As is known, in the leather goods sector, leather natural is increasingly being replaced by materials synthetic. Such materials generally comprise a base textile, cotton or polyester, on which a layer of plastic material. 25 To date, 11 most used plastic materials It is polyvinyl chloride (PVC), which has a characteristic characteristic to be printable and to be plasticized in a large extension to the desired degree of flexibility. In addition to having a significantly lower cost, 1 synthetic materials allow for a greater range of subsequent processes compared to natural leather. For 1 reasons above, synthetic leather is increasingly used also for luxury products, such as for example bags, wallets or other leather goods, 10 marketed under prestigious fashion brands. Synthetic materials used as a substitute for leather must necessarily satisfy certain requirements quality, even more so if the products they are intended for they are luxury products. 15 In particular, the quality requirements must be intended both from an aesthetic point of view and from a viewofmaterialstrength. In fact, who buys for the production of a famous brand, with costs this bears , it is not arranged cc and tt are not defective tt aesthetics is unsuoprecocedeterior chin . In recent years, thermoplastic polyurethane (TPU) ha partly replaced PVC as the material for the making of fake leather. In fact, TPU has the advantage of presenting appearance 25 handoils , one high resistance and one , in particular with respect to bending strength and at the abstraction, this content Furthermore, TPU has the advantage of being machined ed extruded in the absence of solvents, with the imp ortant benefits in environmental terms that this entails. Generally , 11 TPU once standardized weight, is homogenized and coupled with a on pp textile. This coupling occurs through a silicone cylinder, under pressure, 10 couples the textile support with the extruded TPU layer. The material thus obtained is cooled and, then onwards, under all the points finishing. The finishing process involves the covering 15 of the TPU layer with a coating layer capable of to give the material greater lightfastness, a high resistance to hydrolysis and a high resistance to push-ups and scratches. As a finishing coating layer it can be 20 used a polyurethane or polyurethane varnish- polycarbonate applied in aqueous dispersion. The finishing procedure may also include a embossing treatment which consists in engraving the product surface for the creation of various designs. 25 The finishing procedure described above although generally used, however it presents a series of production problems. 1In fact, if the protective coating is not applied correctly, or the embossing phase presents some errors, it will be It is necessary to discard the entire material produced. Sometimes, furthermore, it may happen that the defect is created during the manufacturing phase finishing is not immediately detected and that, therefore, the material is sold and then discarded at the time of the production of the finished product. In this case, 1lo 10 discard would constitute an uncomfortable problem commercial as it relates to an already existing material marketed. An even worse scenario is that in in which the material with the finishing defect is shared used for the production of products, 1 such as, a 15 times mm and ss on the market, constitute a risk of image for 11 brands they are associated with. The inventors of the present invention have realizing a procedure, whose technical characteristics are such as to overcome the problems represented by art note and described above. DESCRIPTION OF THE INVENTION The object of the present invention is a process for the creation of a leather goods material based on polyurethane, whose essential technical characteristics are 25 reported in independent claim 1 and whose secondary and auxiliary technical features are reported in dependent claims 2 - 8. In essence, the inventors of this invention he has not created a solution that provides for the layer polyurethane is coupled, on opposite sides and in contemporary, to a finishing release paper and to a support layer. A further object of the present invention is a group for the production of a leather goods material 10 polyurethane base, technical characteristics essential are reported in the independent claim 9, and whose secondary and auxiliary technical characteristics are reported in dependent claims 10 and 11. BRIEF DESCRIPTION OF THE SIGNS 15 For a better understanding of this invention, below are some examples of realization for illustrative and non-limiting purposes with 1"with the help of the attached figures, in which: - figure 1 illustrates, in an extremely schematic, a plant for 11 paper treatment release; and - figure 2 illustrates, in an extremely schematic, a rolling mill. FORMA DIA TTU PREFERRED ACTION OF THE INVENTION 25 In figure 1 it is indicated as a whole with 1 release paper processing plant, illustrated in an extremely chematic form with a rare exemption to blocks. Plant 1 comprises a loading station 2 of the cartarelease , unstation and accumulation 3 , unstation unsmearing 4 , unstationanddraining hour 5 unstation of harvest 6. In particular , in the station accumulate 3 lacquer release is run through a series of rollers for 10 ensure the correct voltage , while installing smearing 4 the release paper is contacted with a grooved roller, usually to pyramidal trunk incision, which yields to the paper the amount of material of polymer finish between 10 - 50 g / m? of bucket. 15 The applicator roller pud rotate in the same direction as advancement of the paper, as is preferred, in the sense or pp osto . Polymer finishing material is generally a polyurethane polymer or) polyurethane-polycarbonate aliphatic in aqueous dispersion, which already contains all the finishing elements of the final composite, or rather colour coating, 1' possible opacifying filler, 11 adhesion promoter of any subsequent printing of the article, 1st UV stabilizer for color fastness, etc. 25 The release paper then passes into the drying station 5 which includes a solvent (water) evaporation oven to be collected on another roller after cooling in collection station 6. This way it is realized the finishing release paper. With this technology it is possible to spread up to very high weights using the appropriate incision of the roller. In figure 2 it is indicated as a whole with 11 a plant for the lamination of a polymeric multilayer 10 TPU base, illustrated in an extremely schematic form with a block representation. The plant 11 comprises a loading station 12, a station of extrusion 1 3 , a station of lamination / coupling 14, an accumulation station 15 and 15 a collection station 16. In extrusion station 13 the polymer polyurethane is used at a temperature between 170 and 220°C using a flat head extruder of width equal to that of the finishing release paper at most. Immediately downstream of extrusion station 13, the extruded polyurethane polymer enters the station lamination / coupling 14, where it is coupled by parts opposite with the finishing release paper made in plant 1 and with a support layer. The multilayer 25 formed is rolled by 1 ' actioncylinders lamination, which have a temperature between 50°C and 20°C. In particular, the polyurethane polymer once that comes out of the flat head is immediately coupled with the finishing release paper and with the support by the action of the two rolling cylinders. The coupling between the finishing release paper and the polyurethane polymer layer occurs by bringing this last one in direct contact with the material of polymer finish coated on the release paper itself. 10 The rolling cylinders are adjustable so as to vary the mutual distance. In this way it is possible modify the degree of penetration of the polymer film and the quantity of polymer per cm? to be coupled with the paper and the fibrous support. 15 The rolling speed is dictated by the quantity of polymer to be deposited on the rolling cylinders in relation to the quantity of polymer extruded from the die and to the cooling capacity. The combination of the data of flow rate, speed and temperature determine the quality of the transfer of the finishing from paper to extruded TPU. process of the invention preferably uses a rolling speed between 2 and 10 m (line D) / minute . The operating pressure applied by the cylinders of 25 lamination to the polyurethane polymer layer is another important parameter, because it determines the homogeneity of the polymer on the entire surface of the cylinders and the degree of penetration into the fibrous support. The operating pressure is between 10 and 100 bar. Still in the lamination / coupling station 14 the consolidation of the coupling of the layer takes place polyurethane polymer with finishing release paper and with the support layer by passing through a plurality of parallel and cooled cylinders 10 temperature between 15 and 30°C operating simply how do they know each other , conunp P path of the corrugated sheet between the different rollers. In the process of the proposed invention there are no further finishing stages needed because this is already 15 included in the finish release card included in the polymer multilayer. Once again , multilayer polymers oppose in the station with mule 1 5 , it had to be stopped through a series of rollers, to then be collected in the 20 stationary with lta 1 6 , probably informs the coil Multistratopolymers , on the contrary , undergo a peeling of the paper , note the description in detail for simplicity. Following the peeling phase, the following was obtained: 25 polyurethane-based leather goods material. Below are two embodiments of the production of a leather goods material based on polyurethane according to the procedure of this document invention. EXAMPLE 1 Laminate with final composition: and TPU = 6 0 % and Polyester / cotton based fibrous support (65 / 35%) = 35 and PU based finishing = 5% 10 Total thickness = 1.1 mm Total weight = 580 g / m? The TPU extruded in this embodiment is a Polyester based TPU with the following main features characteristics: 15 Specific gravity = 1.18 g / cm? Hardness = 70 Shore A Abrasion loss = 30 mm? Tensile strength = 42 N / mm? Tear strength = 70 N / mm? 20 V icat = 6 0 ° C The fibrous support in this embodiment is a cotton / polyester blend fabric with the following main features: Composition: Cotton / polyester yarn = 3.5 / 6.5% 25 Armor: Drill (carded diagonal weave) oo Weight: 200 g / m? The finishing layer in this form of construction and a polyurethane water-based paint aliphatic polyether-based with the following principal characteristics characteristics: Elastic modulus = 10 MPa Tensile strength = 42 MPa Elongation at break = 440% Softening point = 220 ° C 10 The laminate of this example presented the following performance features: Strength > 6 00 N / 5 cm (ISO 1421) Elongation < 10% (ISO 1421) Tear strength > 40 N (ISO 4674-1) 15 A brasionease cc o > 1 0 2 4 00 C cycles (ISO 20344) Moisture brasion > 5 1 2 00 C icli (ISO 20344) Flexural strength > 300000 cycles (ISO 4818-13) Lightfastness > 7 (ISO 105 BO02) EXAMPLE 2 20 Laminate with final composition: and TPU = 60% and TPU-based fibrous support = 36% and PC-PU base finish = 4% Total thickness = 1.1 mm 25 Total weight = 600 g / m? The extruded TPU in this embodiment is a TPU polyester base with the following main characteristics: Specific weight = 1.18 g / cm? Hardness = 70 Shore A Abrasion loss = 30 mm? Tensile strength = 42 N / mm? Tear strength = 70 N / mm? V icat = 6 0 ° C 10 The fibrous support in this embodiment is a TPU TNT with the following main characteristics: Composition: Melt blown TPU 100 Weight: 230 g / m? Resistance to traction = 135 N / bcm 15 Elongation at break = 320 The finishing layer in this form of construction and a polyurethane water-based paint aliphatic polycarbonate based with the following main features characteristics: 20 Elastic modulus = 6 MPa Resistance to traction = 4 3 MP a Elongation at break 400% Softening point = 170-220 °C 25 The laminate in this example presented the following oo oo performance features: Breaking load > 350 N / 5cm (ISO 1421) Elongation at break < 100 % (ISO 1421) Tear resistance > 4 0 N (ISO 4674-1) Brasionase cc > 1 0 2 4 00 Cycles ( ISO 2 0 3 44) Abrasionwet > 5 1 2 00 Cycles ( ISO 2 0 3 44) Bending resistance > 3 00000 cycles (ISO 4 8 1 8 - 1 3 ) Resistance to light > 7 ( ISO 105 BO 0 O 2 ) The materials in examples 1 and 2 above are were made by depositing in the spreading operation a quantity of finishing material respectively equal to 29 g / m2 and 24 g / m2 dry; a temperature of 25 °C 15 and 35 °C in contact operation; a temperature of 25 °C in the consolidation operation; and a pressure of 40 bar exerted by the cylinders between which the semi-finished product passes polymer multilayer in contact operation. 20 L or support layer made of TPU is less rigid, very flexible and more resistant to breakage for elongation. The plywood made in this way has the particularity of being able to be crushed, re-extruded and reused in the same production process, or in 25 alternative can be transformed according to the others TPU transformation technologies to produce other articles. This embodiment meets the dictates of the circular economy, according to which the first characteristic that an article made of plastic must have be recyclable in nature, and can be produced at starting from recycled polymer. D in orma the finishing of the laminate takes place in a continuous process, using a multi-layer system, through a 10 rotogravure coating directly on the film surface polyurethane. Prepare the finishing on the paper in advance transferring it onto the polyurethane film presents significant advantages both in terms of process and quality of the 15 finished product. In fact, spread on paper instead of polyurethane means greater precision and versatility thanks to to the rigidity of the paper support. On white paper possible errors in the coating, acausadiunmal 20 roller operation, are clearly visible immediately with waste reduction as only the paper and not the finished product. Furthermore, with 11 ©process object of this in ve nz i one the surface quality of the finishing is 25 superior as it constitutes a mirror of the finish of the paper and not of the coating roller finish, as in traditional processes. Furthermore, through the most appropriate choice of the type of paper you can impose surface qualities on the paint which cannot be done in direct rotogravure, such as for example an embossing effect without having to make a further phase out of line. Finally, from the point of view of the global process, having paper up to the last stage of the process allows 10 to be able to choose the polyurethane polymer, up to to get to the softer types without incurring danger defends nomenclature of sticking between the coils if the process of maturation has not been fully completed, or if the cooling of the laminate did not occur properly 15 o tt imale .

Claims

1. Process for producing a synthetic leather material; said process being characterised by the fact that it comprises - a release paper treatment step, in which a polymer finishing layer is deposited on a surface of a release paper, producing a finishing release paper, - a lamination step, in which a layer of extruded polyurethane polymer is coupled under pressure and on opposite sides to a support layer and to said finishing release paper to obtain a multi-layer polymer semi-finished product; said finishing release paper being coupled to said polyurethane polymer layer on the side of said polymer finishing layer;and - a peeling phase, in which the release paper of said finishing release paper is removed from the multilayer polymeric semi-finished product, while the polymer finishing layer of said finishing release paper remains fixed to the polyurethane polymer layer.; 2. A process according to claim 1, characterized in that said release paper treatment step comprises in sequence (i) a coating operation, in which a finishing polymer solution is applied to a surface of said release paper by the action of a roller, and (ii) a drying operation, in which the finishing polymer is dried from the solvent in which it was dispersed.

3. Process according to claim 2, characterised in that in said coating operation a quantity of finishing polymer ranging between 10 and 50 g / m2 of dry material is deposited.

4. Process according to one of the preceding claims, characterised in that said finishing layer is made with an aliphatic polyurethane-polycarbonate polymer.

5. Process according to one of the preceding claims, characterised in that said coupling step comprises (i) a contact operation carried out at a temperature between 50 and 20°C, in which said support layer and said finishing release paper adhere on opposite sides to said polyurethane polymer layer, and (ii) a consolidation operation carried out at a temperature between 15 and 30°C, in which said support layer and said polymer finishing layer are stably fixed to said polyurethane polymer layer.

6. Process according to claim 5, characterized in that said contact operation occurs by passing the multilayer polymer semi-finished product between cylinders operating at a pressure between 10 and 100 bar, while said consolidation operation occurs by passing the multilayer polymer semi-finished product between cylinders operating as a drag and not under pressure between them, with the laminate following a wave-like path between the different cylinders.

7. Process according to one of the preceding claims, characterised in that said support layer is made of cotton or polymeric material.

8. Process according to claim 7, characterized in that said polymeric material is TPU.

9. Group for the production of a polyurethane-based leather goods material; said group being characterised by the fact that it comprises a first plant (1) for the production of finishing release paper and a second plant (11) for the lamination of a polyurethane-based polymeric multilayer; said first plant (1) comprising a loading station (2) for the release paper, a coating station (4) and a drying station (5); in said coating station (4) the release paper being placed in contact with a grooved roller which transfers the quantity of polymeric finishing material to the paper; said second plant (11) comprising a loading station (12), a polyurethane polymer extrusion station (13) and a lamination / coupling station (14);in said extrusion station (13) the polyurethane polymer is extruded by means of a flat-head extruder with a maximum width equal to that of the finishing release paper made with said first plant (1); said lamination / coupling station (14) creates a polymeric multilayer by coupling said polyurethane polymer from opposite sides with the finishing release paper made in said first plant (1) and with a support layer.; 10. Group according to claim 9, characterised in that said rolling / coupling station (14) comprises a plurality of drive rollers at a temperature between 10 and 50oC.

11. Group according to claim 10, characterized in that said plurality of drive rollers comprises a first group of rollers operating at a temperature between 20 and 500C and capable of exerting a pressure between 10 and 100 bar to achieve the coupling of said polyurethane polymer with the finishing release paper and with said support layer; and a second group of drive rollers operating at a temperature between 15 and 30OC.