Methods for manufacturing reinforcing components for tires and related tire manufacturing methods

Abstract

A method for manufacturing a reinforcing component for a tire, the method comprising: arranging at least one polymer elongated element (10); coating the at least one polymer elongated element (10) with an adhesive coating layer to form at least one viscous elongated element (11); providing an elastomeric compound comprising at least one elastomeric polymer, at least one reinforcing filler, and a component capable of promoting vulcanization; coating the at least one viscous elongated element (11) with the elastomeric compound, wherein coating the at least one polymer elongated element (10) comprises: positioning the polymer elongated element (10) between two electrodes (90a, 90b) placed in a chamber (100); introducing an activator gas and a precursor gas comprising an oxazoline precursor between the two electrodes (90a, 90b); generating a plasma gas comprising reactive fragments of the oxazoline precursor between the two electrodes; and depositing the reactive fragments on a free surface of the polymer elongated element (10) to form the adhesive coating layer.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a reinforcing component for a tire, and a related method for manufacturing a tire including such a reinforcing component. Background Technology

[0002] Tires used for wheels typically include a reinforcing component that comprises elongated elements (such as cords) and an elastomeric compound incorporating the elongated elements.

[0003] Typically, these reinforcing components can be, for example, one or more layers that constitute the tire carcass structure and / or belt structure, as well as protective layers (bead wraps) or reinforcing layers (bead wraps) for the tire sidewalls and bead structures.

[0004] Reinforcing components typically perform different functions, which can be structural, containment, and / or protective, and to ensure the integrity of these components, it is recommended to check that their elongated elements are firmly adhered to the elastomeric compound to avoid tearing and damage to the composite material.

[0005] Typically, depending on the tire's positioning and / or type and / or purpose, the material used to form the elongated element can be textiles or metal.

[0006] Specifically, the most commonly used textile materials can be naturally derived polymers such as rayon and lyocell, or alternatively synthetic materials such as aliphatic polyamides (nylon), polyesters, and aromatic polyamides (often referred to as aramids). These materials are selected based on the structural components into which the elongated element will be incorporated, the tire type (for two-wheeled or four-wheeled vehicles, for heavy-duty vehicles), and the required tire performance such as HP (high performance), UHP (ultra-high performance), racing, road, or off-road.

[0007] Polymer elongated elements, typically synthetic elements, can have a wide range of elastic responses to traction (from very small to very stiff, i.e., different elastic moduli) and high or relatively low or very low elongation, but they have low adhesion to elastomer compounds (due to poor chemical affinity), which leads to durability problems and / or reduced tire performance.

[0008] Therefore, in the tire manufacturing industry, it is known to use adhesive compositions, such as resorcinol-formaldehyde-latex (RFL) compositions, to facilitate adhesion between elongated elements and elastomeric compounds, and thus ensure the performance properties of the tire during its use.

[0009] Typically, an RFL-based adhesive composition is applied to the polymer elongated element by immersing it in an aqueous RFL solution, which is a rubber latex emulsion in an aqueous solution of resorcinol and formaldehyde (or a pre-condensed resin obtained by the reaction between resorcinol and formaldehyde).

[0010] The preparation of the RFL bath is carried out in two steps. First, an aqueous solution of resorcinol and formaldehyde is aged at room temperature for several hours. This mixture becomes alkaline by adding sodium hydroxide. During the aging process, resorcinol and formaldehyde undergo a certain degree of condensation. Subsequently, a latex-water mixture is added to the resorcinol and formaldehyde resin solution. The amount and ratio of latex-water can be varied to obtain the desired RFL aqueous solution. A typical RFL bath has a solids content of approximately 20% by weight and a pH of approximately 10. The structure of the crosslinked RFL appears to consist of a continuous resin phase and dispersed latex particles.

[0011] The polymer elongated elements thus treated can then be incorporated into an elastomer compound through calendering and extrusion processes for use in the subsequent assembly with other semi-finished products in the molding of green tires, which are then formed and subjected to molding and vulcanization.

[0012] Some materials, such as rayon and aliphatic polyamides, have achieved optimal adhesion properties to elastomeric compounds through a single immersion (impregnation, one-step process) in an RFL-based bath, while other materials, such as polyesters or aromatic polyamides, are more difficult to bond with elastomeric compounds and therefore benefit from specific physical or chemical activation pretreatments. For example, elongated polyester or aromatic polyamide elements undergo surface activation by pretreatment with a first activation bath (pre-impregnation, two-step process) or by pretreatment with ionizing rays, plasma, or solvents.

[0013] In particular, the pretreatment with the first activation bath achieves surface preactivation of the polymer elongated element by means of an epoxide or isocyanate or other suitable activator, which results in the formation of reactive groups on the surface of the polymer elongated element, which can promote better adhesion between the RFL system and the pretreated elongated element, and thus significantly improve the adhesion between the viscous polymer elongated element and the elastomer compound.

[0014] Furthermore, to further enhance the adhesion between elongated elements and elastomeric compounds, it is possible to introduce specific additives into the compounds that must cover the elongated elements. These adhesion promoters typically include methylene donors, such as hexamethylenetetramine, and methylene acceptors, such as resorcinol. Crosslinking of these additives during the vulcanization step allows for higher or lower adhesion, depending on the type of elastomeric compound, adhesion promoter, polymer material, and the type of treatment performed.

[0015] While RFL-based compositions have solved the adhesion problem between slender elements and elastomeric compounds in a very satisfactory manner, they have some drawbacks in industrial applications.

[0016] First, RFL-based compositions may be toxic to humans and the environment due to their reactive components, namely resorcinol and formaldehyde, which necessitates a significant reduction (or elimination) of their use at every stage of the tire manufacturing process.

[0017] Furthermore, the RFL composition is not particularly stable and requires a predetermined "aging" period, known as curing, to achieve sufficient stability for the end use of this application, which necessitates increasing the tire production cycle time.

[0018] Finally, the high solids content in the RFL composition leads to the gradual accumulation of deposits throughout various parts of the production line for the viscous, elongated components of tires. These deposits, if not properly removed, may represent a potential contamination risk.

[0019] In the past, several alternative adhesive compositions that are essentially free of resorcinol and formaldehyde have been studied and described in an attempt to overcome the aforementioned problems.

[0020] For example, documents WO2005 / 080481 and EP2426253 disclose compositions that are substantially free of resorcinol and formaldehyde for adhering polyester elongated elements to rubber, wherein the composition comprises at least one rubber latex, at least one epoxide, and a polyfunctionalized amine crosslinking agent in an aqueous dispersion.

[0021] Document EP1818443A1 discloses a reinforcing cord for rubber reinforcement, comprising reinforcing fibers coated with a coating layer. The coating layer comprises acrylonitrile rubber and a compound containing oxazoline groups as its main components. A method for manufacturing the reinforcing cord comprises: i) applying an aqueous solution comprising acrylonitrile latex and a compound containing oxazoline groups to the reinforcing fibers, and ii) drying the applied aqueous solution to form a coating layer on the surface of the reinforcing fibers.

[0022] Document US4460029A discloses a latex prepared by polymerizing a polymerizable oxazoline (such as 2-isopropenyl-2-oxazoline) and at least one other monomer (such as a mixture of styrene and butadiene). The latex thus prepared is used to promote the adhesion of polymeric elastomers, particularly tire rubber, and matrices, particularly reinforcing cords of tires.

[0023] Document US20150151578A1 discloses a method for treating textile reinforcing elements, comprising: exposing the reinforcing elements to a plasma gas generated by a plasma torch at room temperature and a gas containing at least one oxidizing component.

[0024] Even with the existence of alternative systems such as those mentioned above, the RFL system remains the most widely used and effective adhesive composition for elongated elements in the tire industry to date, and to the applicant’s knowledge, there appears to be no alternative system that achieves effective industrial applicability with adhesive properties comparable to the RFL system. Summary of the Invention

[0025] Therefore, in the tire industry, there is a particular need to at least partially replace the use of RFL-based compositions in order to reduce (if not eliminate) the use of toxic and / or contaminating components in all tire manufacturing steps, and to simplify the adhesion process of elongated elements while providing optimal adhesion performance between elongated elements and elastomer compounds.

[0026] The applicant faces the challenge of producing more eco-friendly tires, particularly those that are substantially free of resorcinol and formaldehyde in the adhesive coating of polymer elongated elements and / or in the elastomer compounds, in order to reduce the environmental impact of tire and its reinforcing components production, allow transportation under the most normal conditions possible (e.g., without the need for refrigeration, inertization with special gases, or storage in the dark) and / or limit (if not eliminateable) the accumulation of solid residues in the factory.

[0027] Furthermore, the applicant faces the challenge of manufacturing tires that include reinforcing components, characterized in that, even under harsh operating conditions, the adhesion between the elastomeric compound and the elongated elements is at least comparable, if not improved, to the adhesion imparted by the RFL-based composition, and is durable over time, thus ensuring tire reliability. This adhesion contributes to the structural integrity of the tire.

[0028] According to the applicant, one or more of the aforementioned problems are solved by a method for manufacturing a reinforcing component for a tire and a related method for manufacturing a tire including such a reinforcing component, wherein the reinforcing component comprises a viscous elongated element obtained by exposing a polymer elongated element to a plasma gas generated from a precursor gas containing an oxazoline precursor.

[0029] According to one aspect, the present invention relates to a method for manufacturing a reinforcing component for a tire, the method comprising:

[0030] - Arrange at least one elongated polymer element;

[0031] - Coat the at least one polymer elongated element with an adhesive coating layer to form at least one viscous elongated element;

[0032] - Provides an elastomeric compound comprising at least one elastomeric polymer, at least one reinforcing filler, and a component capable of promoting vulcanization;

[0033] - (at least partially) the at least one viscous elongated element is coated with the elastomeric compound.

[0034] Preferably, coating the at least one polymer elongated element comprises:

[0035] - Position the elongated polymer element between two electrodes placed in the chamber;

[0036] - Introduce an activator gas and a precursor gas containing an oxazoline precursor between the two electrodes;

[0037] - A plasma gas containing a reactive fragment of the oxazoline precursor is generated between the two electrodes;

[0038] - The reactive fragments are deposited on the free surface of the polymer elongated element to form the adhesive coating layer.

[0039] According to one aspect, the present invention relates to a tire manufacturing method, comprising:

[0040] - A manufacturing method according to any embodiment of the foregoing aspects of the present invention produces at least one reinforcing component of a raw tire, wherein the reinforcing component is selected from the group consisting of: reinforcing structures (bead wrapping and / or bead wrapping), carcass ply and belt ply;

[0041] - To form a raw tire including at least one reinforcing component;

[0042] - To subject raw tires to molding and vulcanization to obtain finished tires, wherein during the molding and vulcanization, the at least one viscous elongated element and the elastomeric compound are compressed and heated to adhere the at least one viscous elongated element to the elastomeric compound.

[0043] For the purposes of this invention:

[0044] - The terms "elastomer polymer", "elastomer material", "rubber" or "elastomer" refer to natural or synthetic materials that, when vulcanized at room temperature, can be repeatedly stretched to at least twice their original length and return substantially immediately and forcefully to approximately their original length after the tension is removed (as defined in the standard terminology of ASTM D1566-11, a specification related to rubber).

[0045] The term "elastomer compound" refers to a compound obtained by mixing and possibly heating at least one elastomeric polymer with at least one of the additives commonly used in the preparation of compounds for tires.

[0046] The term "slender element" refers to an element whose dimension (length) is much larger than its other dimensions (cross-section). Slender elements are also called cords or reinforcing cords, or more simply, cords.

[0047] - The term "free surface" for an elongated element refers to the surface of the elongated element that is able to adhere to the elastomeric compound coating when the elongated element comes into contact with the elastomeric compound.

[0048] The term "oxazoline precursor" refers to any molecule containing an oxazoline ring (a five-membered ring containing one oxygen atom, one nitrogen atom, and three carbon atoms).

[0049] The applicant has experimentally discovered that the adhesive coating obtained by depositing reactive fragments of an oxazoline precursor, when coupled with an elastomeric compound, provides adhesive properties sufficient to ensure good adhesion between the adhesive elongated element and the elastomeric compound, without using substances harmful to health and / or the environment. The adhesive properties of the adhesive elongated element coated according to the invention were compared with those of an adhesive elongated element coated with a known RFL-based composition by means of a tear test performed after adhesion between the adhesive elongated element and the elastomeric compound (which will be explained better below). These tests yielded satisfactory results regarding the force required to break the adhesion between the adhesive elongated element and the elastomeric compound, and the amount of elastomeric compound remaining on the adhesive elongated element at the end of the tear test, which is a qualitative indicator of the adhesive strength and effectiveness between the adhesive elongated element and the elastomeric compound.

[0050] The applicant also discovered through experiments that, compared to known impregnation techniques, using plasma gas allows the adhesive coating to be distributed more uniformly on the free surface of the polymer elongated element. According to the applicant, the uniform distribution of the adhesive coating helps increase the reliability of adhesion between the viscous elongated element and the elastomeric compound over time, and increases tire durability and performance reliability. Without being bound by any theory, the applicant believes that when the tire is in use and thus undergoes deformation, the uniform distribution of the adhesive coating allows for better stress distribution along the entire development direction of the viscous elongated element. This stress distribution reduces the probability of generating overstress points along the development of the viscous elongated element, thus reducing the probability of the viscous elongated element becoming brittle and / or fatigue-induced.

[0051] Furthermore, according to the applicant, the use of plasma gas allows for the production of adhesive coatings with well-controlled thicknesses, typically smaller than those achievable using known impregnation methods.

[0052] In fact, according to the applicant's theory, and not limited to any theory, especially in the case of flexural deformation of composite materials (i.e., viscous elongated elements coupled with an elastomer compound), excessive thickness of the adhesive coating will cause stress to begin at the interface between the viscous elongated element and the elastomer compound. Over time, this stress will lead to damage and / or cracking of the adhesive coating, and consequently, loss of adhesion between the viscous elongated element and the elastomer compound, and consequently, a reduction in the performance properties of the tire itself. In particular, the flexural deformation that composite materials typically experience during their use will generate compressive stress on one face of the viscous elongated element and tensile stress on the opposite face of the viscous elongated element (depending on the direction of the torque that determines the flexural deformation), with its strength increasing as it moves radially away from the neutral axis of the viscous elongated element, i.e., ideally along an imaginary line passing through the longitudinal axis of the viscous elongated element.

[0053] Therefore, the applicant experimentally evaluated the thickness of the adhesive coating obtained by plasma gas coating using a surface photometer, verifying how, in addition to accurately controlling the thickness of the obtained adhesive coating, it is possible to obtain a low thickness value for the adhesive coating relative to the thickness of coatings obtained by known impregnation methods. These low thickness values ​​allow for limiting the intensity of the aforementioned compressive and tensile stresses acting on the adhesive coating, reducing the likelihood of separation and / or breakage at the interface between the viscous elongated element and the elastomeric compound.

[0054] In one or more of the foregoing aspects, the present invention may have one or more of the following preferred features.

[0055] Preferably, the oxazoline precursor comprises 2-oxazoline, more preferably selected from the group consisting of 2-isopropenyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-ethyl-2-oxazoline, and 4,4-dimethyl-2-oxazoline, and even more preferably 2-isopropenyl-2-oxazoline. In this way, a highly reactive chemical compound is used, thereby making it possible to form a large number of reactive fragments. This is possible, for example, in the case of 2-isopropenyl-2-oxazoline, because many functional groups are present in the oxazoline ring, and an isopropenyl group is present at the 2-position of the oxazoline ring. The presence of reactive functional groups and heteroatoms in the selected molecule leads to the formation of many reactive fragments that tend to deposit on the free surface of the polymer elongated element. For example, the breaking of the bond between the oxygen atom at position 1 and the carbon atom at position 5 of the oxazoline ring leads to the formation of an isocyanate ion, and the breaking of the carbon-carbon bond between the isopropenyl group and the oxazoline ring promotes the formation of the isopropenyl ion. According to the applicant, both isocyanate ions and isopropenyl ions are capable of forming covalent bonds with the polymer material of the elongated element and the elastomeric polymer of the elastomeric compound, forming a bridge that allows effective adhesion between the viscous elongated element and the elastomeric compound.

[0056] In an alternative embodiment, the oxazoline precursor includes one or more of 3-oxazoline, 4-oxazoline, and isoxazoline. In this way, a compound with good reactivity is used.

[0057] The polymer elongated element may include a single polymer yarn, or preferably multiple polymer yarns, more preferably two or more and / or four or fewer polymer yarns.

[0058] For the purposes of this invention, the term "yarn" refers to a continuous filamentary structural unit that may consist of an aggregate of multiple (e.g., hundreds or thousands) textile filaments (i.e., multifilament yarns) or alternatively, a single textile thread (e.g., a hot-extruded thread, such as nylon thread).

[0059] For the purposes of this invention, the term "diameter" refers to the diameter of a polymer elongated element or yarn (both multifilament and monofilament) as measured according to the Bisfa method (Test methods for para-aramidic yarns, 2002 edition). In the case of a yarn composed of an aggregate of multiple textile filaments, "diameter" means the diameter of the ideal circumference of all the filaments defining the yarn.

[0060] For the purposes of this invention, the term "linear density" (or "count") for elongated elements or yarns (both multifilament and single yarn) refers to the weight per unit length of the elongated element or yarn. Count can be measured in decibels (grams per 10 km length). For the measurement of linear density, reference is made to the test established according to BISFA (International Bureau for the Standardization of Fibers Artificial), using flat yarns without twist during the test or twisting steps.

[0061] Preferably, the linear density of each polymer yarn is greater than or equal to 300 dtex, more preferably greater than or equal to 500 dtex, even more preferably greater than or equal to 700 dtex, and / or less than or equal to 5000 dtex, more preferably less than or equal to 4200 dtex, even more preferably less than or equal to 3600 dtex. In this way, suitable structural properties can be provided for slender polymer components.

[0062] Typically, the total linear density of a polymer elongated element is given by the sum of the linear densities of each polymer yarn that makes up the polymer elongated element.

[0063] Preferably, each polymer yarn is made of a material selected from the group consisting of: aliphatic polyamide fibers (e.g., nylon 6, nylon 6.6, nylon 4.6, nylon 4.10, nylon 10.10, nylon 11, nylon 12, nylon 6.10, nylon 6.12), polyester fibers (e.g., polybutylene terephthalate, polyethylene terephthalate, polyethylene isophthalate), polyaryletherketone fibers (e.g., polyetheretherketone), cellulose (e.g., rayon, lyocell), aromatic polyamides (e.g., aramid), or mixtures thereof.

[0064] Preferably, each polymer yarn is made of polyester, more preferably of polyethylene terephthalate (PET) and / or polyethylene naphthalate (PEN).

[0065] In one embodiment, the polymer yarns are made of the same material (e.g., all yarns are made of polyester). This simplifies the production of polymer elongated elements.

[0066] In an alternative embodiment, the polymer yarn is made of different materials (e.g., at least one yarn is made of polyester and at least one other yarn is made of aramid). In this way, it is possible to combine the properties of yarns made of different materials.

[0067] Preferably, each polymer yarn is twisted (i.e., helically twisted) on itself. In this way, the free surface of individual polymer yarns can be increased compared to the case where the polymer yarns are used in a stretched configuration.

[0068] Typically, the polymer elongated element comprises two to four polymer yarns (e.g., each multifilament), each yarn being twisted on itself, and all yarns being twisted together to form the elongated element.

[0069] Preferably, the activator gas is selected from rare gases and / or mixtures of rare gases, more preferably including argon (Ar), or composed of argon.

[0070] Preferably, the activator gas is introduced between the two electrodes at a volumetric flow rate of greater than or equal to 1.5 mL / min, more preferably greater than or equal to 1.8 mL / min, and / or less than or equal to 3.5 mL / min, more preferably less than or equal to 3.2 mL / min.

[0071] Preferably, the precursor gas is introduced between the two electrodes at a mass flow rate greater than or equal to 2.0 SCCM, more preferably greater than or equal to 2.3 SCCM, even more preferably greater than or equal to 2.6 SCCM, and / or less than or equal to 5 SCCM, more preferably less than or equal to 4.5 SCCM, even more preferably less than or equal to 4.0 SCCM. The mass flow rate of the gas containing the oxazoline precursor is expressed in standard cubic centimeters per minute (SCCM), which is the mass of gas passing through a volume of 1 cubic centimeter per minute under standard temperature and pressure conditions, i.e., at a temperature and atmospheric pressure equal to 273.15 K.

[0072] Preferably, the working chamber includes a decompression system, more preferably a rotary pump and / or a turbomolecular pump.

[0073] In one embodiment, before introducing the activator gas and the precursor gas between the two electrodes, the internal pressure of the chamber is reduced to less than or equal to 100 Pa, more preferably less than or equal to 1 Pa, and even more preferably less than or equal to 0.1 Pa. In this way, it is possible to limit the risk of contamination of the polymer elongated elements and / or the gases used. Indeed, such contamination (e.g., dust and / or oxidation on the surface of the polymer elongated elements due to contact with air and / or moisture) can cause the free surface of the polymer elongated elements to be obscured, and / or reduce the reactivity of the reactive fragments of the oxazoline precursor, resulting in reduced effectiveness of the coating process.

[0074] In an alternative embodiment, the internal pressure of the chamber is maintained at a value substantially equal to atmospheric pressure. In this way, the coating process is simplified and its cost is reduced.

[0075] Preferably, the plasma gas is cold plasma. "Cold plasma" means plasma with a total temperature (excluding electrons, which typically have a temperature of about 20,000 K) between room temperature and about 1,000 K. In this way, the coating process is simplified because mechanical and / or structural components capable of withstanding very high temperatures are not required.

[0076] Preferably, the plasma gas is generated by capacitive coupling between two electrodes.

[0077] Preferably, generating the plasma gas includes applying an alternating voltage (e.g., radio frequency) to the two electrodes, and more preferably, it includes applying an alternating voltage pulse.

[0078] In this way, plasma gas is simply generated.

[0079] Preferably, the duration of each AC voltage pulse is greater than or equal to 1 millisecond, more preferably greater than or equal to 2 milliseconds, and / or less than or equal to 10 milliseconds, more preferably less than or equal to 7.5 milliseconds.

[0080] Preferably, the AC voltage pulse is applied at a frequency greater than or equal to 60 Hz, more preferably greater than or equal to 75 Hz, and / or less than or equal to 170 Hz, more preferably less than or equal to 150 Hz.

[0081] Preferably, generating the plasma gas includes supplying a pulse to at least one of the two electrodes (90a, 90b) having a supply power of greater than or equal to 100W, more preferably greater than or equal to 150W, and / or less than or equal to 250W, more preferably less than or equal to 220W.

[0082] Preferably, the power supply is constant.

[0083] According to the applicant, plasma gas is generated by applying an AC voltage pulse having a duration and frequency within the aforementioned range and a supply power included within the corresponding aforementioned range, allowing the coating of elongated polymer elements to provide suitable adhesive properties for the formed adhesive coating. In fact, according to the applicant, as the duration and frequency increase and the supply power increases within the corresponding aforementioned range, there is an increase in the fragmentation of the oxazoline precursor, resulting in the formation of a greater number of reactive fragments that deposit on the free surface of the elongated polymer elements, allowing the adhesive coating to possess the desired adhesive properties.

[0084] According to the applicant, pulse duration and frequency, as well as the supplied power, being below the corresponding aforementioned ranges, under certain conditions can lead to insufficient fragmentation of the oxazoline precursor, resulting in insufficient formation of reactive fragments that can be deposited on the free surface of the polymer elongated element. Under certain conditions, pulse duration and frequency, as well as the supplied power, being above the corresponding aforementioned ranges can lead to excessive fragmentation of the oxazoline precursor, resulting in excessive formation of reactive fragments and thus excessive thickening of the adhesive coating.

[0085] Preferably, the polymer elongated element is pretreated before the activator gas and the precursor gas are introduced between the two electrodes, wherein the pretreatment of the polymer elongated element includes:

[0086] - Introduce a pretreatment gas between the two electrodes;

[0087] - A pretreated plasma is generated between the two electrodes.

[0088] In this way, when reactive groups (e.g., free radicals) are formed in the material on the free surface of the polymer elongated element, it is possible to facilitate the subsequent deposition of reactive fragments of the oxazoline precursor on the free surface of the polymer elongated element. The formation of these reactive groups helps to increase the hydrophilicity of the free surface of the polymer elongated element, and thus increases the subsequent deposition and adhesion of the reactive fragments. Furthermore, according to the applicant, this pretreatment of the polymer elongated element prior to coating it helps to improve the uniform distribution of the adhesive coating on the polymer elongated element.

[0089] Preferably, the pretreatment gas is selected from rare gases and / or mixtures of rare gases, more preferably including argon (Ar), or composed of argon.

[0090] Preferably, the pretreatment gas is introduced at a volumetric flow rate greater than or equal to 1.5 mL / min, more preferably greater than or equal to 1.8 mL / min, and / or less than or equal to 3.5 mL / min, more preferably less than or equal to 3.2 mL / min.

[0091] Preferably, the pretreatment plasma is cold plasma.

[0092] Preferably, the pretreated plasma is generated by capacitive coupling between two electrodes.

[0093] Preferably, generating the pretreated plasma involves applying an alternating current (AC) voltage (e.g., radio frequency) to the two electrodes, more preferably by continuously applying the AC voltage.

[0094] Preferably, the AC voltage is applied for a duration of 20 seconds or more, more preferably 30 seconds or more, and / or less than or equal to 150 seconds, more preferably less than or equal to 120 seconds.

[0095] Preferably, generating the pretreated plasma includes supplying an AC voltage with a power of greater than or equal to 20W, more preferably greater than or equal to 30W, and / or less than or equal to 180W, more preferably less than or equal to 150W to at least one of the two electrodes.

[0096] Preferably, the power supply is constant.

[0097] As is known in the art, the term “phr” as used below means the number of weight parts of a particular component of the elastomeric compound per 100 parts by weight of the elastomeric polymer.

[0098] For the purposes of this invention, the description of a component or component system as "substantially free of resorcinol" and / or "substantially free of free formaldehyde" means that the component or component system has no resorcinol and / or formaldehyde content, or at most has a resorcinol and / or formaldehyde content of less than 0.5 phr, preferably less than 0.2 phr, more preferably less than 0.1 phr.

[0099] Preferably, the elastomer compound is substantially free of resorcinol.

[0100] Preferably, the at least one viscous elongated element is substantially free of resorcinol.

[0101] Preferably, the at least one viscous elongated element is substantially free of free formaldehyde.

[0102] In this way, the health risks to operators and / or the environmental pollution risks associated with the use of resorcinol and formaldehyde are minimized or completely eliminated.

[0103] Preferably, the elastomer polymer is selected from diene elastomer polymers and monoene elastomer polymers or mixtures thereof.

[0104] Preferably, the elastomer polymer is: cis-1,4-polyisoprene (natural or synthetic rubber, preferably natural rubber), 3,4-polyisoprene, poly1,3-butadiene (especially high-vinyl poly1,3-butadiene with a 1,2-polymer unit content of about 15% to about 85% by weight), polychloroprene, optionally halogenated isoprene / isobutene copolymer, 1,3-butadiene / acrylonitrile copolymer, 1,3-butadiene / styrene copolymer, 1,3-butadiene / isoprene copolymer, isoprene / styrene copolymer, isoprene / 1,3-butadiene / styrene terpolymer; or mixtures thereof.

[0105] Preferably, the monoolefin elastomer polymer is: a copolymer of ethylene with at least one α-olefin having 3 to 12 carbon atoms, and optionally a copolymer with a diene having 4 to 12 carbon atoms; polyisobutylene, isobutylene copolymer, and at least one diene. Particularly preferred are: ethylene / propylene copolymer (EPR); ethylene / propylene / diene terpolymer (EPDM); polyisobutylene; butyl rubber; halogenated butyl rubber; or mixtures thereof.

[0106] Preferably, the reinforcing filler is selected from: carbon black, silicon dioxide, alumina, aluminosilicate, calcium carbonate, kaolin, or a mixture thereof.

[0107] Preferably, the component capable of promoting vulcanization includes a vulcanizing agent selected from, for example, sulfur, sulfur-containing molecules (sulfur donors), or mixtures thereof.

[0108] Preferably, the component capable of promoting vulcanization includes an accelerator selected from, for example, dithiocarbamates, guanidines, thioureas, thiazoles, sulfenamides, thiurams, amines, xanthates, or mixtures thereof.

[0109] Preferably, the elastomeric compound includes a methylene receptor compound.

[0110] Preferably, the methylene acceptor compound includes phenolic resin, more preferably phenolic varnish.

[0111] Alternatively, the methylene acceptor compound is selected from: mixtures of o-cresol, p-cresol, and m-cresol; and polyhydroxyphenols, such as pyrogallol and fluorine-glucinol.

[0112] Preferably, the elastomeric compound includes a methylene donor compound.

[0113] Preferably, the methylene donor compound is selected from: hexamethylenetetramine (HMT); hexamethoxymethyl melamine (HMMM); paraformaldehyde; trioxane; 2-methyl-2-nitro-1-propanal; substituted melamine resins, such as N-substituted oxymethyl melamine resins; glycourea compounds, such as tetramethoxymethylglycourea; urea-formaldehyde resins, such as butylated urea-formaldehyde resins; or mixtures thereof, more preferably hexamethylenetetramine (HMT) or hexamethoxymethyl melamine (HMMM). Attached Figure Description

[0114] Figure 1 An apparatus is schematically shown that, according to the invention, polymer elongated elements can be coated to obtain viscous elongated elements for reinforcing components;

[0115] Figures 2a to 2bAn optical micrograph of the elongated polymer element at the end of the corresponding coating process is shown;

[0116] Figures 3a to 3b The diagram schematically illustrates two production steps for preparing a sample by adhering an elastomer compound to a viscous, elongated element.

[0117] Figures 4a to 4b An optical microscope image of the corresponding polymer elongated element after a tear test is shown. Detailed Implementation

[0118] Referring to the accompanying drawings, the features and advantages of the present invention will be further illustrated by the following detailed description of some embodiments, which are presented as non-limiting examples of the invention.

[0119] refer to Figure 1 The apparatus 99 is schematically shown and is exemplary for carrying out the coating process of the polymer elongated element 10.

[0120] The device 99 includes an exemplary steel chamber 100, inside which two electrodes 90a and 90b are placed.

[0121] Two reels 80 are present in the chamber 100, at least one of which is electrically powered (actuator not shown) for unwinding and winding the polymer elongated element 10. In use, the polymer elongated element 10 is, for example, from... Figure 1 Unwind on the left spool to position it between the two electrodes 90°, and after coating... Figure 1 The scroll on the right side has been rewound.

[0122] For example, the airtight chamber 100 includes a pressure reduction system, which for example includes a rotary pump 20 and a turbomolecular pump 21.

[0123] The two pumps 20 and 21 are connected by corresponding conduits (in) Figure 1 (Shown schematically in dashed lines) is the suction valve 30 obtained on the main body of the chamber 100.

[0124] Exemplarily, the device 99 also includes two separate hermetically sealed containers 50 and 51, for an activator gas and a precursor gas, respectively, the precursor gas containing an oxazoline precursor. These containers 50 and 51 are connected to the working chamber 100 by corresponding conduits, which in turn connect to corresponding micrometer valves 60 and 61. Micrometer valves 60 and 61 are then connected to an upper electrode 90a of the working chamber, which has a perforated plate facing a lower electrode 90b to allow gas to escape into the space defined by the two electrodes. Preferably, the device 99 includes another container for a pretreatment gas, which is associated with a corresponding micrometer valve connected to one or more electrodes. This other container (and associated valve) may (not shown) differ from containers 50 and 51, such that the pretreatment gas may be different from the activator gas, or the other container may be consistent with container 50 (in which case, the activator gas and the pretreatment gas are consistent).

[0125] In an alternative embodiment (not shown), there is a single sealed container containing a mixture of activator gas and precursor gas.

[0126] Device 99 is exemplarily powered by a 13.56 MHz radio frequency power supply system (not shown) connected to the upper electrode 90a via an emi-automatic adaptation network (not shown). For example, the radio frequency power supply is amplitude modulated by a square wave that generates AC voltage pulses.

[0127] In an alternative embodiment (not shown), the power supply system is connected to the lower electrode 90b, or alternatively to both electrodes 90a, 90b.

[0128] In an alternative embodiment, not shown, the device is powered by a pulse and / or microwave source.

[0129] In use, after a portion of the elongated element is placed between the two electrodes 90a and 90b, one end of the polymer elongated element 10 is unwound from the left spool 80 and hooked onto the right spool 80.

[0130] Subsequently, the internal pressure at Studio 100 decreased.

[0131] Subsequently, a pretreatment is provided, exemplarily, on the polymer elongated element 10, while the polymer elongated element 10 slides continuously or gradually between the two electrodes.

[0132] Preprocessing includes:

[0133] - Introduce pretreatment gas (preferably supplied by tank 50) between the two electrodes;

[0134] - Power is supplied to the upper electrode 90a for generating pretreated plasma.

[0135] For example, the pretreatment plasma is generated by a radio frequency AC voltage (e.g., 13.56 MHz) continuously applied between two electrodes 90a and 90b.

[0136] After pretreatment, activator gas and precursor gas containing oxazoline precursor are introduced between the two electrodes 90a and 90b.

[0137] During the introduction of gas, the upper electrode 90a is powered to generate plasma gas containing reactive fragments of the oxazoline precursor, and the reactive fragments are deposited on the free surface of the polymer elongated element 10 while the polymer elongated element 10 slides continuously or gradually between the two electrodes to form an adhesive coating layer of the polymer elongated element 10 and obtain a viscous elongated element 11.

[0138] For example, plasma gas is generated by means of an AC voltage pulse (radio frequency, e.g., 13.56 MHz) applied between two electrodes 90a and 90b.

[0139] For example, only the upper electrode 90a is powered.

[0140] In an alternative embodiment, plasma gas may be generated by an alternating voltage applied in a non-pulsed mode.

[0141] The applicant has conducted some tests on samples of the viscous elongated elements formed according to the present invention, and the results are compared with the test results of comparative samples of viscous elongated elements formed by known impregnation methods.

[0142] The applicant also prepared additional samples of elongated polymer elements (tens of centimeters in length) coupled to an elastomeric compound without any coating and subjected them to tear tests, as explained below. These uncoated samples are referred to in the following text as “reference examples.”

[0143] All of the above samples were prepared starting from elongated polymer elements with the following properties:

[0144] - A single monofilament yarn that is not twisted on itself;

[0145] Material: PET

[0146] - Diameter: 0.3 mm;

[0147] - Linear density: 800 deciter.

[0148] Comparison Example 1

[0149] The aforementioned polymer elongated element has undergone a coating process involving a first pretreatment step of immersion in a solution containing epoxide and isocyanate, and a subsequent bonding step of immersion in an RFL-based aqueous solution.

[0150] The solution of epoxide and isocyanate is prepared by mixing solid components in an aqueous solution at a weight percentage of about 4%, wherein 1% by weight is composed of epoxide and 3% by weight isocyanate.

[0151] The following describes the preparation of RFL-based aqueous solutions:

[0152] Step 1: Preparation of precondensation resin

[0153]

[0154] Resorcinol was dissolved in water to obtain an aqueous solution, to which formaldehyde and sodium hydroxide were added. Sodium hydroxide was used as a condensation catalyst to form methanol groups on the resorcinol (called methyl phenolic resins) to prepare an intermediate solution. The intermediate solution was then mixed at room temperature for 6 hours to prepare a pre-condensed resin.

[0155] Step 2: Preparation of RFL-based aqueous solutions starting from precondensation resin

[0156]

[0157] First, the latex is dissolved in water to obtain a latex aqueous solution. Then, the pre-condensed resin prepared in step 1 and an additional amount of formaldehyde are added to this latex aqueous solution, while maintaining gentle stirring to prepare a final mixture. Formaldehyde is added so that the wet weight ratio of formaldehyde to resorcinol in the final mixture is 2:1. The final mixture is then allowed to mature for approximately 24 hours to facilitate complete reaction of the methanol groups and increase the viscosity of the RFL-based aqueous solution.

[0158] Then, the elongated polymer elements are first immersed in a solution containing epoxide and isocyanate for 1–5 seconds, and then immersed in an RFL-based aqueous solution for 1–5 seconds. The coated samples are then subjected to a drying and stabilization process by exposure to a temperature of approximately 225°C for approximately 120 seconds.

[0159] Comparison Example 2

[0160] The applicant conducted preliminary plasma deposition tests, similar to those described in Example 1 below according to the invention, using furfuryl methacrylate having the following formula instead of the oxazoline precursor.

[0161]

[0162] However, the desired adhesion results were not obtained.

[0163] Example 1 (according to the present invention)

[0164] A portion of the aforementioned approximately 2-meter-long polymer elongated element is wound around the support frame to keep some portions of the yarn exposed, which undergo the coating process according to the invention by exposure to pretreatment and coating gases.

[0165] Parameters for pretreatment of plasma:

[0166] Internal pressure in the studio: 0.001 Pascals;

[0167] Pretreatment gas: Argon;

[0168] Pretreatment gas volumetric flow rate: 2.3 ml / min;

[0169] Pretreatment plasma type: cold plasma

[0170] AC voltage application time: 120 seconds;

[0171] Upper electrode power supply: 100W

[0172] Parameters of the plasma-coated gas:

[0173] Internal pressure in the studio: 0.001 Pascals;

[0174] Activating gas: Argon;

[0175] Oxazoline precursor: 2-isopropenyl-2-oxazoline;

[0176] Activator gas volumetric flow rate: 2.3 mL / min;

[0177] Mass flow rate of precursor gas: 3.3 SCCM

[0178] Plasma gas type: cold plasma

[0179] Duration of AC voltage pulse: 5 milliseconds

[0180] AC voltage pulse frequency: 100 Hz

[0181] Total pulse application time: approximately 20 minutes;

[0182] Upper electrode power supply: 175W

[0183] The chemical structure of the selected oxazoline precursor is schematically shown in the figure below:

[0184]

[0185] The applicant performed optical microscopy tests on the manufactured samples to assess the uniformity of the adhesive coating distribution on the free surface of the polymer elongated element at the end of the coating process. Microscopic testing of the sample according to Example 1 allowed for assessment of the distribution of reactive fragments of the oxazoline precursor on the free surface of the polymer elongated element and verified that these produced a very uniform adhesive coating on substantially the entire free surface of the polymer elongated element, while optical microscopy tests of the sample according to Comparative Example 1 showed lower distribution uniformity. Figure 2a and Figure 2b Images obtained by optical microscopy on the sample according to Example 1 and the sample according to Comparative Example 1 are shown exemplarily.

[0186] Subsequently, the samples manufactured according to Example 1, Comparative Example 1, and Reference Example are coupled to the elastomer compound.

[0187] First, based on Example 1 (in Figure 3a (represented by reference numeral 11a in the attached drawing), according to comparative example 1 (in Figure 3a (as indicated by reference numeral 11b in the accompanying drawings) and according to the reference example (in Figure 3a A set of three samples of each of the elements (represented by reference numeral 11c in the attached drawing) are placed in mold 200 (e.g., as shown in Figure 11c). Figure 3a It is stably fixed to the mold 200 within the mold (illustrated in the middle) and within the suitable grooves 201 present at both ends of the mold 200.

[0188] At this time, the elastomeric compound sheet 20 ( Figure 3b The mold 200 has been placed to cover the surface of the mold 200 between the groove groups 201.

[0189] Properties of elastomeric compounds

[0190] Ingredients Quantity (phr) Diene polymer 1: Poly-1,3-butadiene (BR) 30 Diene polymer 2: cis-1,4-polyisoprene (IR) 70 Reinforcing filler: CB 60 Vulcanizing agent: S 4 Accelerator: N-tert-butyl-2-benzothiazole sulfenamide 6 Methylene receptor (phenolic varnish) 2 Methylene donor: Hexamethoxymethyl-melamine (HMMM) 1

[0191] Once placed on mold 200, the elastomeric compound sheet 20 is covered by Mylar sheet 21, and mold 200 is placed inside a press (not shown).

[0192] At this point, the press is shut down, and the elastomer compound is vulcanized to allow the sample to adhere to the elastomer compound.

[0193] Vulcanization parameters:

[0194] - Pressure: 30 bar;

[0195] -Temperature: 150℃;

[0196] - Vulcanization time: 30 minutes.

[0197] At the end of the vulcanization process, mold 200 is removed from the press, and for each of the three sets of samples, three samples coated with the elastomer compound are cut out, each 300 mm in length. Each sample is then allowed to acclimatize at room temperature for approximately 20 hours at a relative humidity of approximately 65%.

[0198] At the end of the conditioning period, the obtained samples were subjected to a tear test to evaluate two parameters:

[0199] - The maximum pull-out force between the elastomeric compound and the viscous, slender element;

[0200] - At the end of the tear test, the amount of residual elastomeric compound on the surface of the viscous elongated element is expressed as the coverage of the viscous elongated element surface. The coverage is assessed by optical microscopy according to the grades specified in Table 1.

[0201] grade Coverage 5 100％ 4 Up to 75% 3 At most 50% 2 up to 25% 1 0％

[0202] Grade 5, the highest, indicates excellent adhesion between the elastomeric compound and the sticky elongated element, which remains completely covered with compound residue after tearing. Conversely, Grade 1 indicates poor adhesion and complete removal of the elastomeric compound from the surface of the sticky elongated element after tearing.

[0203] Table 2 shows the results of the tear test, where the values ​​of average force, minimum force, and maximum force are expressed in Newtons, and the assessment of coverage is expressed according to the scale shown in Table 1:

[0204]

[0205]

[0206] As can be seen from Table 2, the maximum force value obtained according to Example 1 for breaking the adhesion between the elastomeric compound and the viscous elongated element is approximately 80% of the value obtained according to Comparative Example 1 for breaking the adhesion between the elastomeric compound and the viscous elongated element. These values ​​are considered sufficient to result in good adhesion quality between the viscous elongated element and the elastomeric compound. The advantage is that the viscous elongated element obtained according to Example 1 is non-toxic to operators and / or the environment, has greater stability, and significantly limits contamination of the viscous elongated element production line.

[0207] Furthermore, it may be noted from Table 2 that:

[0208] - The difference between the maximum and minimum force values ​​in Example 1 is lower than the corresponding difference in Comparative Example 1, and

[0209] - Compared to the average force values ​​measured in Comparative Example 1, the average force values ​​measured in Example 1 appear to be more concentrated within the range defined by the corresponding maximum and minimum force values.

[0210] These results demonstrate that, compared to the conventional RFL process, the adhesive coating layer on the entire free surface of the polymer elongated element coated according to the invention exhibits better uniformity of distribution.

[0211] Regarding the assessment of coverage, it was observed that on the viscous elongated element obtained according to Example 1, a larger percentage of the surface was covered by elastomeric compound residue at the end of the tear test compared to the viscous elongated element obtained according to Comparative Example 1. Figure 4a and Figure 4b Images obtained by optical microscopy on the sample according to Example 1 and the sample according to Comparative Example 1, respectively, after a tear test are shown.

[0212] The tear test described above was performed on samples prepared from polymer elongated elements comprising single monofilament yarns, to test the adhesion between the viscous elongated elements and the elastomeric compound under greater adhesion critical conditions, since the free surface of the polymer elongated elements is minimized for the same linear density.

[0213] However, the present invention can be applied to any polymer elongated element 10, such as the polymer elongated elements described in the same applicant's WO2014091429A1 or WO2020026178A1.

[0214] In tire manufacturing, for example according to known techniques, the viscous elongated element 11 is coupled to an elastomer compound to manufacture a reinforcing component for a tire.

[0215] Examples of tire reinforcement components manufactured using the present invention may be carcass ply, belt ply (cross or zero angle), and / or reinforcement structures (bead wrapping and / or bead wrapping). The configuration, location, and function of such reinforcement components are described, for example, in the same applicant's patent WO2014091429A1.

[0216] Once a raw tire is formed or molded, it undergoes molding and vulcanization to obtain the finished tire. During this step, the elastomeric compound of the aforementioned reinforcing components is also vulcanized, resulting in adhesion between the viscous elongated element and the elastomeric compound.

Claims

1. A manufacturing method for a tire reinforcement component, the manufacturing method comprising: arranging at least one polymeric elongated element (10); coating the at least one polymeric elongated element (10) with an adhesive coating layer to form at least one adhesive elongated element (11); providing an elastomeric compound comprising at least one elastomeric polymer, at least one reinforcing filler and components capable of contributing to vulcanization; coating the at least one adhesive elongated element (11) with the elastomeric compound, wherein coating the at least one polymeric elongated element (10) comprises: positioning the polymeric elongated element (10) between two electrodes (90a, 90b) placed in a working chamber (100); introducing between the two electrodes (90a, 90b) an activator gas and a precursor gas comprising an oxazoline precursor; generating between the two electrodes a plasma gas comprising a reactive fragment of the oxazoline precursor; depositing the reactive fragment on a free surface of the polymeric elongated element (10) for forming the adhesive coating layer.

2. The manufacturing method according to claim 1, wherein, the oxazoline precursor comprises a molecule selected from the group of 2-oxazoline, 3-oxazoline, 4-oxazoline and isoxazoline.

3. The manufacturing method according to claim 1, wherein, the oxazoline precursor comprises 2-oxazoline selected from the group of 2-isopropenyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-ethyl-2-oxazoline and 4,4 dimethyl-2-oxazoline.

4. The production method according to any one of claims 1 to 3, wherein the plasma gas is a cold plasma, wherein generating the plasma gas comprises applying an alternating voltage pulse to the two electrodes (90a, 90b), wherein the alternating voltage pulse has a duration greater than or equal to 1 ms and / or less than or equal to 10 ms, wherein the alternating voltage pulse is applied at a frequency greater than or equal to 60 Hz and / or less than or equal to 170 Hz, wherein generating the plasma gas comprises supplying at least one of the two electrodes (90a, 90b) with a supply power greater than or equal to 100 W and / or less than or equal to 250 W, and wherein the supply power is constant.

5. The production method according to any one of claims 1 to 3, wherein the activator gas is selected from the group of a noble gas and / or a noble gas mixture, wherein introducing the activator gas between the two electrodes (90a, 90b) is carried out with a volume flow of the activator gas greater than or equal to 1.5 ml / min and / or less than or equal to 3.5 ml / min, and wherein introducing the precursor gas between the two electrodes (90a, 90b) is carried out with a mass flow greater than or equal to 2.0 SCCM and / or less than or equal to 5 SCCM, and wherein, before introducing the activator gas and the precursor gas between the two electrodes (90a, 90b), the internal pressure of the working chamber is reduced to a pressure value less than or equal to 100 Pascal.

6. The manufacturing method according to any one of claims 1-3, comprising pre-treating the polymeric elongated element (10) before introducing the activating agent gas and the precursor gas between the two electrodes, wherein, the pre-treatment of the polymeric elongated element (10) comprises: introducing a pre-treatment gas between the two electrodes (90a, 90b); generating a pre-treatment plasma between the two electrodes (90a, 90b), wherein said pre-treatment gas is selected from the group of noble gases and / or mixtures of noble gases, wherein said pre-treatment gas is introduced with a volumetric flow greater than or equal to 1.5 ml / min and / or lower than or equal to 3.5 ml / min, wherein said pre-treatment plasma is a cold plasma, wherein generating said pre-treatment plasma comprises continuously applying an alternating voltage to said two electrodes (90a, 90b) for a time interval greater than or equal to 20 seconds and / or lower than or equal to 150 seconds, and wherein generating said pre-treatment plasma comprises supplying an alternating voltage to at least one of said two electrodes (90a, 90b) with a constant supply power greater than or equal to 20 W and / or lower than or equal to 180 W.

7. The production method according to any one of claims 1 to 3, wherein The polymeric elongated element (10) comprises from 2 to 4 polymeric yarns, each polymeric yarn being twisted on itself, all polymeric yarns being twisted together to form the polymeric elongated element (10), wherein each polymeric yarn has a linear density greater than or equal to 300 dtex and / or lower than or equal to 5000 dtex, wherein each polymeric yarn is made of a material selected from the group of aliphatic polyamide fibers, polyester fibers, polyaryletherketone fibers, cellulose, aromatic polyamides or mixtures thereof, and wherein said polymeric yarns are made of the same material or different materials.

8. The production method according to any one of claims 1 to 3, wherein The elastomeric compound is free of resorcinol, wherein said at least one adhesive elongated element (11) is free of resorcinol, and wherein said at least one adhesive elongated element (11) is free of free formaldehyde.

9. The production method according to any one of claims 1 to 3, wherein The at least one elastomeric polymer is selected from a diene-based elastomeric polymer, a mono-olefin-based elastomeric polymer or mixtures thereof, wherein the at least one reinforcing filler is selected from: carbon black, silica, alumina, aluminosilicates, calcium carbonate, kaolin or mixtures thereof, wherein the components capable of contributing to vulcanization comprise a vulcanizing agent and an accelerator, wherein the elastomeric compound comprises a methylene acceptor compound comprising a phenol-formaldehyde resin, wherein the elastomeric compound comprises a methylene donor compound selected from hexamethylenetetramine (HMT) or hexamethoxymethyl melamine (HMMM).

10. A manufacturing method of a tyre, the manufacturing method comprising: producing at least one reinforcing component of a green tyre according to the manufacturing method of any one of the preceding claims, wherein said reinforcing component is selected from the group of: a reinforcing structure, a carcass layer and a belt; moulding a green tyre comprising said at least one reinforcing component; subjecting said green tyre to moulding and vulcanization to obtain a finished tyre, wherein, during said moulding and vulcanization, said at least one adhesive elongated element (11) and said elastomeric compound are compressed and heated one with the other to adhere said at least one adhesive elongated element (11) to said elastomeric compound.

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