Method for producing fiber-reinforced tape

Abstract

The present invention relates to a method for producing a tape comprising a plurality of impregnated continuous multifilament strands and a polymer sheath closely surrounding the plurality of impregnated continuous multifilament strands, wherein each of the plurality of impregnated continuous multifilament strands extends in a longitudinal direction, wherein each of the plurality of impregnated continuous multifilament strands comprises at least one continuous glass multifilament strand, wherein the at least one continuous glass multifilament strand is impregnated with an impregnating agent, wherein the method comprises the steps of: a) unwinding the continuous glass multifilament strand from a package, b) applying the impregnating agent to the continuous glass multifilament strand to form the multifilament strand. c) placing the plurality of impregnated continuous multifilament strands in parallel alignment in the longitudinal direction, and d) applying a sheath of a thermoplastic polymer composition around the plurality of impregnated continuous multifilament strands of step c) to form the tape, wherein steps c) and d) are performed in a die having a guide member arranged to place the plurality of impregnated continuous multifilament strands in parallel alignment in the longitudinal direction, wherein downstream of the guide member the plurality of impregnated continuous multifilament strands pass through the melt of the thermoplastic polymer composition inside the die.

Description

[0001] The present invention relates to a method for producing a fiber-reinforced tape. The invention further relates to such a tape, a laminate or a woven fabric produced from the tape, an article comprising the tape or the laminate or woven fabric, and the use of the tape, laminate and woven fabric in applications such as automotive applications.

[0002] Introduced over half a century ago, fiber-reinforced plastics are composite materials with a wide variety of applications in industries such as the automotive industry. The term "composite" can apply to any combination of individual materials, such as a thermoplastic polymer (the matrix) in which fibers (reinforcing fillers) are dispersed. The reinforced plastics industry has used different forms of glass fibers to reinforce polymer matrices to produce a variety of products.

[0003] In the production of short glass fiber compositions or composites, short strands of predetermined length are mixed with a thermoplastic polymer in an extruder, during which the integrity of the glass fiber strands is destroyed and the glass fibers are dispersed throughout the molten thermoplastic polymer; in this process, the fiber length is reduced due to fiber breakage, typically to a value significantly less than 1 mm. Long glass fiber reinforced polymer compositions contain glass fibers having a length of at least 1 mm, typically at least 2 mm, and typically between 5 and 20 mm. Consequently, the glass fibers in molded articles made from long glass fiber reinforced polymer compositions generally have a greater length than in articles made from short glass fiber compositions, resulting in better mechanical properties. Consequently, long glass fiber reinforced polymer compositions are preferably used in applications requiring good mechanical properties.

[0004] However, the use of glass to reinforce thermoplastic polymers significantly increases the weight of the product because thermoplastic polymers generally have a lower density than glass. In order to be able to produce lightweight products that still have sufficient strength, long glass fiber reinforced tapes have been introduced to the market in recent years, allowing the production of lightweight products with sufficient strength due to the use of reinforced tapes.

[0005] A special type of tape is a unidirectional tape, which is a tape having fibers extending generally in a longitudinal direction. Such unidirectional tapes are often used to prepare articles having properties that vary in one or more directions or dimensions.

[0006] An example of a unidirectional glass fiber tape is known from WO 2016 / 142784 A1. WO 2016 / 142784 A1 discloses a fiber-reinforced composite comprising:

[0007] A matrix material comprising a thermoplastic material; and a nonwoven fibrous region comprising a plurality of continuous fibers dispersed in the matrix material;

[0008] wherein the width and length of the nonwoven fiber region are substantially equal to the width and length of the fiber reinforced composite, respectively;

[0009] wherein the nonwoven fiber region has an average relative fiber area coverage (RFAC) (%) of 65 to 90 and a coefficient of variation (COV) (%) of 3 to 20; and

[0010] Each of the plurality of continuous fibers is substantially aligned with a length of the fiber-reinforced composite.

[0011] Unidirectional composite fiber prepregs are described, for example, in WO 2011 / 163365 A2, and composite fiber profiles are described, for example, in WO 2011 / 156693 A2.

[0012] Reinforced composites from thermoplastic materials combine the rigidity provided by the reinforcement with the advantageous properties of thermoplastic materials, such as ease of moulding and stranding of the material above a certain temperature and solidification below this temperature.

[0013] There is a need in the art to provide unidirectional glass fiber tapes in an efficient manner.

[0014] An object of the present invention is to provide unidirectional glass fiber tapes in an efficient manner.

[0015] This object is achieved by a method for producing a tape comprising a plurality of impregnated continuous multifilament strands and a polymer sheath closely surrounding the plurality of impregnated continuous multifilament strands,

[0016] wherein each of the plurality of impregnated multifilament strands extends in a longitudinal direction,

[0017] wherein each of the plurality of impregnated continuous multifilament strands comprises at least one continuous glass multifilament strand, wherein the at least one continuous glass multifilament strand is impregnated with the impregnant,

[0018] The method comprises the following steps:

[0019] a) unwinding a continuous glass multifilament strand from a package,

[0020] b) applying an impregnating agent to the continuous glass multifilament strand to form a plurality of impregnated continuous multifilament strands,

[0021] c) placing a plurality of impregnated continuous multifilament strands in parallel alignment in the machine direction, and

[0022] d) applying a sheath of a thermoplastic polymer composition around the plurality of impregnated continuous multifilament strands of step c) to form a tape,

[0023] wherein steps c) and d) are performed in a die having a guide member arranged to align the plurality of impregnated continuous multifilament strands in parallel in a longitudinal direction, wherein downstream of the guide member the plurality of impregnated continuous multifilament strands pass through a melt of the thermoplastic polymer composition inside the die.

[0024] According to the present invention, a sheath is applied around a group of parallel impregnated continuous multifilament strands.The method advantageously provides a tape by a simple process having a small number of steps.

[0025] In the plurality of impregnated continuous multifilament strands used in the method according to the present invention, the number of impregnated continuous multifilament strands is preferably at least 4, for example, the number of impregnated continuous multifilament strands in the plurality of impregnated continuous multifilament strands is between 4 and 40, preferably between 4 and 24.

[0026] Steps a)-b) are described in detail in WO 2009 / 080281 A1, which is hereby incorporated by reference.

[0027] Prior to applying the sheath in step d), the impregnated strands are preferably placed in parallel alignment in a plane in step c), wherein the distance between adjacent strands is preferably substantially the same and / or, for example, the distance between adjacent strands is 0.20 to 2.3 mm. "Substantially the same" means that the distance between adjacent strands does not differ by more than 8%. This is preferably done in a mold that is configured for parallel alignment of the strands and for applying the sheath.

[0028] Therefore, preferably, steps c) and d) are carried out in a die having guide members arranged to place the plurality of impregnated continuous multifilament strands in parallel alignment in the longitudinal direction, wherein downstream of the guide members the plurality of impregnated continuous multifilament strands pass through the melt of the thermoplastic polymer composition inside the die.

[0029] In some embodiments, the guide member is provided with a plurality of longitudinally aligned parallel elongated holes arranged in a single plane, each of which is configured to accommodate an impregnated continuous multifilament strand. In such embodiments, precise parallel alignment of the impregnated strands in the final tape is ensured, while also ensuring a good product appearance. Furthermore, strand breakage due to friction between the impregnated strands is avoided. Furthermore, the presence of the thermoplastic polymer composition between the impregnated continuous multifilament strands is ensured.

[0030] In other embodiments, the guide member is provided with an elongated hole having an oval cross section, wherein the elongated hole is arranged to accommodate a plurality of impregnated continuous multifilament strands in a plane. This has the advantage that such guide members are easy to manufacture.

[0031] According to the present invention, step c) ensures that the strands in the final tape are in the desired alignment prior to the sheathing step. However, it is possible that, prior to applying the impregnating agent, the plurality of continuous glass multifilament strands are aligned parallel to each other, for example, by means of a guide system upstream of the die used to apply the impregnating agent. Preferably, the plurality of continuous glass multifilament strands lie in a single plane, preferably with the distances between adjacent strands being substantially the same, for example, between 0.20 and 2.3 mm. "Substantially the same" means that the distances between adjacent strands differ by no more than 8%. This can help ensure that the strands are aligned parallel to each other during step c). It is also possible that, in the die used to apply the impregnating agent, the plurality of continuous glass multifilament strands are aligned parallel to each other, preferably with the plurality of continuous glass multifilament strands lying in a single plane, preferably with the distances between adjacent strands being substantially the same, for example, between 0.20 and 2.3 mm. "Substantially the same" means that the distances between adjacent strands differ by no more than 8%.

[0032] The strip obtained from step d) may be subjected to a step e) of applying pressure and optionally heat in order to adjust the thickness of the strip and to compact the strip.

[0033] Step e) is preferably carried out by the following steps:

[0034] e1) applying pressure to the strip while optionally heating the strip, and

[0035] e2) cooling and solidifying the product obtained in step e1), for example by means of cooling rollers, a water bath, a blower, a fan or a high-speed air knife,

[0036] Step e1) is preferably carried out by the following sequential steps:

[0037] e1a) maintaining the strip of step d) in its molten state, for example by subjecting the strip of step d) to elevated temperatures, for example by means of hot rollers, a flat belt, an oven or a belt press, and

[0038] e2a) applying pressure to the strip obtained from step d), for example by means of calendering rollers, in order to adjust the thickness of the strip and to compact the strip.

[0039] Step e1a) improves the impregnation of the thermoplastic polymer into the impregnated continuous multifilament strand, leading to improved tape properties.

[0040] Examples of units for performing step e1a) include hot rollers, flat belts, ovens, and belt presses. The advantage of using hot rollers for step e1a) is that it can be performed at high speeds. The advantage of using a flat belt or belt press is that the strip is in direct contact with the belt, allowing for good heat transfer, resulting in better impregnation. If step e1b) is performed at a lower temperature than step e1a), the impregnation of the impregnated continuous multifilament strand in the thermoplastic polymer can be improved. This step e) further produces a strip with improved properties, for example, a strip with good surface quality and / or improved mechanical properties. The solidified shape of the strip achieved after step e2 allows the strip to be further processed or manipulated. This can be performed using cooling rollers, which advantageously allow for relatively slow cooling to reduce shrinkage. Other possible cooling methods include a water bath, a blower, a fan, a high-speed air knife, and the like. These techniques can achieve rapid cooling, particularly a water bath.

[0041] The method may further comprise the step f) of cutting the tape obtained from step e) into desired lengths, which tape may be stacked or wound.

[0042] Preferably, the strip obtained from step d) is subjected to step e) without being cut.

[0043] In these embodiments, steps a)-d) and step e) of making the tape are performed in one manufacturing system. The method can be performed as a continuous process, i.e., as tape with improved properties is continuously formed through the method, a continuous glass multifilament strand is continuously unwound for use in the method.

[0044] Compared to methods where the strip obtained in step d) is cut into the desired length and then subjected to a step to improve its mechanical properties, a continuous process is easier to run because it does not require multiple separate steps. This results in lower manufacturing costs. In addition, strips produced using a continuous process exhibit less variability in properties such as tensile, flexural, and impact properties.

[0045] Preferably, the method of the present invention involves not cutting the ribbon until step d) is formed. Thus, preferably, the continuous glass multifilament strand unwound in step a) and the impregnated continuous multifilament strand formed in step b) are not cut during steps a) to d).

[0046] In other embodiments, the strip obtained from step d) may be cut into desired lengths. Thus, the method may further comprise the step g) of cutting the strip obtained from step d) into desired lengths.

[0047] In a manner similar to step e) above, the slit strip obtained from step g) may be subjected to heat and pressure to improve its mechanical properties. Thus, in some embodiments, the method further comprises a step h) of applying heat and pressure in a planar direction to the strip obtained from step g), preferably by the following sequential steps:

[0048] g1) heating the strip and applying pressure to the strip, and

[0049] g2) cooling and solidifying the product obtained from step g1), for example by means of cooling rollers, a water bath, a blower, a fan or a high-speed air knife, wherein g1) is preferably carried out by the following sequential steps:

[0050] g1a) melting the strip of step d) by, for example, passing through hot rolls, a flat belt, an oven or a belt press, and

[0051] g2a) applying pressure, for example by means of calender rollers, to the product obtained from step g1a).

[0052] In another aspect, the invention relates to a strip obtainable or obtainable by the method of the invention.

[0053] In another aspect, the present invention relates to a laminate having a plurality of tapes of the present invention. Within the framework of the present invention, 'laminate' means an arrangement of the tapes of the present invention in which at least two plies (layers) are present. For example, this laminate contains 2, 3, 4, 5, 6, 7, 8, 9, 10 or more plies, one of which is composed of the tapes of the present invention. For example, in a laminate, the plies can be placed so that their respective sheathed continuous multifilament strands are not parallel to each other. If their respective sheathed continuous multifilament strands are placed at approximately 90 ° angles relative to one another, this laminate is generally referred to as a cross-ply. The laminate of the present invention can, for example, be assembled or processed into a two-dimensional or three-dimensional structure, such as via winding and / or lamination techniques.

[0054] In another aspect, the present invention relates to a woven fabric made from a plurality of the tapes of the present invention.Any known method of weaving tapes into a woven fabric may be used.

[0055] In another aspect, the present invention relates to an article comprising the tape of the present invention, the consolidated laminate of the present invention, or the woven fabric of the present invention.

[0056] The tapes, laminates, woven fabrics or articles of the present invention may be used, for example, in automotive applications.

[0057] It has been found that the impact energy per unit thickness of the tape according to the invention containing wax is higher than that of the tape without wax (impregnant) in its composition. In addition, the E modulus (also known as Young's modulus or stiffness) can also be increased by the tape according to the invention.

[0058] Thus, the impact energy per unit thickness measured according to the method described herein is higher for tapes according to the present invention compared to tapes from a plurality of sheathed continuous multifilament strands having a core that has not been impregnated with an impregnant.

[0059] In the context of the present invention, the term "ribbon" refers to an object that is extremely thin relative to its length and width. That is, the ribbon has a high aspect ratio. Typically, the width of the ribbon is 1-1500 times, for example, 2-100 times, its thickness. The length of the ribbon can vary. The ribbon can have a rectangular cross-section, but can also have a shaped cross-section (corrugated, ribbed, etc.).

[0060] Typically, the strip obtained from step d) has a thickness of 0.1 to 10 mm, such as 0.8 to 4 mm, and / or a width of 1 to 4000 mm, such as 10 to 400 mm, such as 3 to 50 mm.

[0061] Typically, the strip obtained from step e) or step g) has a thickness of 0.1 to 10 mm, such as 0.5 to 3 mm, and / or a width of 1 to 4000 mm, such as 10 to 400 mm, such as 3 to 50 mm.

[0062] In the context of the present invention, 'extending in the longitudinal direction' means oriented in the direction of the major axis of the impregnated continuous multifilament strand.

[0063] An impregnated continuous multifilament strand is prepared from a continuous glass multifilament strand and an impregnating agent.

[0064] As used herein, the term "closely surrounding" should be understood to mean that the polymer sheath substantially completely contacts the plurality of impregnated continuous multifilament strands. In other words, the sheath is applied to the plurality of impregnated continuous multifilament strands in such a manner that there is no intentional gap between the inner surface of the sheath and the impregnated continuous multifilament strands.

[0065] Glass fiber is typically supplied as multiple, continuous, very long filaments in the form of strands, rovings, or yarns. A filament is a single fiber of the reinforcing material. A strand is a bundle of multiple filaments. A yarn is a collection of strands, such as strands twisted together. A roving refers to a collection of strands wound into a package.

[0066] For purposes of this invention, a glass multifilament strand is defined as a plurality of bundled glass filaments.

[0067] Glass multifilament strands and their preparation are known in the art.

[0068] The filament density of the continuous glass multifilament strand can vary within wide limits. For example, the continuous glass multifilament strand can have at least 500, e.g., at least 1,000, and / or at most 10,000, e.g., at most 5,000, grams per 1,000 meters of glass filaments. Preferably, the weight of each glass filament is from 500 to 10,000 grams per 1,000 meters of glass filaments.

[0069] The thickness of the glass filaments is preferably 5 to 50 μm, more preferably 10 to 30 μm, even more preferably 15 to 25 μm. Typically the glass filaments are circular in cross section, meaning that the thickness as defined above will refer to the diameter. The glass filaments are generally circular in cross section.

[0070] The length of the glass filaments is generally not limited, as it is substantially equal to the length of the sheathed continuous multifilament strand. However, for practical reasons of handling the tape, it may be necessary to cut the sheathed continuous multifilament strand into shorter strands. For example, the length of the sheathed continuous multifilament strand is at least 1 m, e.g., at least 10 m, e.g., at least 50 m, e.g., at least 100 m, e.g., at least 250 m, e.g., at least 500 m, and / or, e.g., at most 25 km, e.g., at most 10 km.

[0071] Preferably, the continuous glass multifilament strand in the tape of the present invention comprises up to 2 wt%, preferably 0.10 to 1 wt%, of sizing agent based on the continuous glass multifilament strand. The amount of sizing agent can be determined using ISO 1887:2014.

[0072] The sizing composition is typically applied to the glass filaments before the glass filaments are bundled into continuous glass multifilament strands.

[0073] Suitable examples of sizing compositions include solvent-based compositions, such as organic materials dissolved in aqueous solution or dispersed in water and melt-based or radiation-curable compositions.Preferably, the sizing composition is an aqueous sizing composition.

[0074] As described in the art, for example in documents EP 1 460 166 A1 , EP 0 206 189 A1 or US Pat. No. 4,338,233 , the aqueous sizing composition may comprise a film former, a coupling agent and other additional components.

[0075] The film-forming agent is generally present in an effective amount to protect the fibers from interfilament abrasion and to provide integrity and processability of the fiber strands after drying. Suitable film-forming agents are miscible with the polymer to be reinforced. For example, for reinforced polypropylene, suitable film-forming agents generally comprise polyolefin waxes.

[0076] Coupling agent is generally used to improve the adhesion between matrix thermoplastic polymer and fiber reinforcement. Suitable examples of coupling agents known in the art for glass fiber include organofunctional silane. More specifically, the coupling agent added to the sizing composition is aminosilane, such as aminomethyl-trimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl-trimethoxysilane, γ-aminopropyl-trimethoxysilane, γ-methylaminopropyl-trimethoxysilane, δ-aminobutyl-triethoxysilane, 1,4-aminophenyl-trimethoxysilane. Preferably, in the tape of the present invention, the sizing composition contains aminosilane to achieve good adhesion to thermoplastic matrix. The sizing composition may also include any other component known to those skilled in the art to be suitable for the sizing composition. Suitable examples include but are not limited to lubricants (for preventing damage to strands due to wear), antistatic agents, crosslinking agents, plasticizers, surfactants, nucleating agents, antioxidants, pigments and mixtures thereof.

[0077] Typically, after the sizing composition is applied to the glass filaments, the filaments are bundled into continuous glass multifilament strands and then wound onto spools to form a package.

[0078] In the tape of the present invention, the impregnated continuous multifilament strand is prepared from a continuous glass multifilament strand and an impregnating agent, and specifically by applying the impregnating agent to the continuous glass multifilament strand, preferably in an amount of 0.50 to 18.0 wt. %, such as 0.5 to 10.0 wt. %, or such as 10.0 to 18.0 wt. %, based on the sheathed continuous multifilament strand.

[0079] The optimum amount of the impregnating agent applied to the continuous glass multifilament strand depends on the polymer sheath, the size (diameter) of the glass filaments forming the continuous glass strand, and the type of sizing composition. Typically, the amount of the impregnating agent applied to the continuous glass multifilament strand is based on the amount of the sheathed continuous multifilament strand such as at least 0.50 wt %, preferably at least 1.0 wt %, preferably at least 1.5 wt %, preferably at least 2 wt %, preferably at least 2.5 wt % and / or at most 10.0 wt %, preferably at most 9.0 wt %, more preferably at most 8.0 wt %, even more preferably at most 7.0 wt %, even more preferably at most 6.0 wt %, even more preferably at most 5.5 wt %, or such as at least 10.0 wt %, preferably at least 11 wt %, preferably at least 12 wt % and / or at most 18 wt %, preferably at most 16 wt %, preferably at most 14%. Preferably, the amount of impregnating agent is based on the sheathed continuous multifilament strand 1.5 to 8 wt %, even more preferably 2.5 wt % to 6.0 wt %. A greater amount of impregnating agent increases the impact energy per unit thickness (J / mm). However, the amount of impregnating agent should not become too high for cost-effectiveness and low emissions (volatile organic compounds) and mechanical properties.

[0080] For example, the ratio of impregnant to continuous glass multifilament strand is from 1:4 to 1:30, preferably from 1:5 to 1:20.

[0081] Preferably, the viscosity of the impregnating agent is from 2.5 to 200 cSt at 160°C, more preferably at least 5.0 cSt, more preferably at least 7.0 cSt and / or at most 150.0 cSt at 160°C, preferably at most 125.0 cSt, preferably at most 100.0 cSt.

[0082] Impregnants with viscosities above 100 cSt are difficult to apply to continuous glass multifilament strands. Low viscosity is desirable to promote good fiber wetting, but impregnants with viscosities below 2.5 cSt are difficult to handle, for example, it is difficult to control the amount to be applied; and the impregnant may become volatile. For the purposes of this disclosure, unless otherwise specified, impregnant viscosity is measured at 160°C according to ASTM D 3236-15 (Standard Test Method for Apparent Viscosity of Hot-Melt Adhesives and Coatings, Brookfield Viscometer Model RVDV 2, Spindle #27, 5 rpm).

[0083] Preferably, the melting point of the impregnating agent (the lowest melting temperature in the melting temperature range) is at least 20° C. lower than the melting point of the thermoplastic polymer composition. More preferably, the impregnating agent has a melting point that is at least 25 or 30° C. lower than the melting point of the thermoplastic polymer composition. For example, when the thermoplastic polymer composition has a melting point of about 160° C., the melting point of the impregnating agent may be at most about 140° C.

[0084] Suitable impregnating agents are compatible with the thermoplastic polymer to be reinforced and possibly even soluble in said polymer.The skilled person can select suitable combinations based on general knowledge and can also find such combinations in the art.

[0085] Suitable examples of impregnants include low molar mass compounds, for example low molar mass or oligomeric polyurethanes, polyesters such as unsaturated polyesters, polycaprolactone, polyethylene terephthalate, polyalphaolefins such as highly branched polyethylene and polypropylene, polyamides such as nylon, and other hydrocarbon resins.

[0086] For reinforced polypropylene, the impregnating agent preferably comprises a highly branched poly-alpha-olefin, such as highly branched polyethylene, a modified low molecular weight polypropylene, a mineral oil, such as paraffin or silicon and any mixtures of these compounds.

[0087] The impregnating agent preferably comprises at least 20 wt%, more preferably at least 30 wt%, more preferably at least 50 wt%, such as at least 99.5 wt%, such as 100 wt% of a branched polyalphaolefin, most preferably a branched polyethylene.

[0088] In order to achieve an impregnant viscosity of 2.5 to 200 cSt at 160°C, the branched polyalphaolefin may be mixed with an oil selected from the group consisting of: mineral oil, such as paraffin oil or silicone oil; hydrocarbon oil; and any mixture thereof.

[0089] Preferably, the impregnating agent is non-volatile and / or substantially solvent-free. In the context of the present invention, "non-volatile" means that the impregnating agent has a boiling point or boiling range above the temperature at which the impregnating agent is applied to the continuous multifilament glass strand. In the context of the present invention, "substantially solvent-free" means that the impregnating agent contains less than 10% solvent by weight, preferably less than 5% solvent by weight, based on the weight of the impregnating agent. In a preferred embodiment, the impregnating agent does not contain any organic solvents.

[0090] Impregnating agent can be further mixed with other additives known in the art. Suitable examples include lubricants, antistatic agents, UV stabilizers, plasticizers, surfactants, nucleating agents, antioxidants, pigments, dyes, and adhesion promoters, such as modified polypropylene with maleated reactive groups, and any combination thereof, provided that viscosity remains within the desired range. Any method known in the art can be used to apply liquid impregnating agent to continuous glass multifilament strands. The application of liquid impregnating agent can be carried out using a mold. Other suitable methods of applying impregnating agent to continuous multifilament strands include an applicator, roller, and hot melt applicator with a belt. Such methods are for example described in documents EP0921919B1, EP0994978B1, EP0397505B1, WO2014 / 053590A1, and the references cited therein. The method used should enable a constant amount of impregnating agent to be applied to continuous multifilament strands.

[0091] The polymer sheath is composed of a thermoplastic polymer composition.

[0092] Preferably, the thermoplastic polymer has a melt flow rate (MFR) of 20 to 150 dg / min, preferably 25 to 120 dg / min, such as 35 to 100 dg / min, measured according to ISO 1133 (2.16 kg / 230°C).

[0093] Thermoplastic polymer The composition preferably comprises a thermoplastic polymer.

[0094] Suitable examples of thermoplastic polymers include, but are not limited to, polyamides such as polyamide 6, polyamide 66, or polyamide 46; polyolefins, for example, polypropylene and polyethylene; polyesters, such as polyethylene terephthalate, polybutylene terephthalate; polycarbonates; polyphenylene sulfide; polyurethanes, and mixtures thereof.

[0095] The thermoplastic polymer is preferably a polyolefin, more preferably a polyolefin selected from the group consisting of polypropylene or an elastomer of ethylene and an α-olefin comonomer having 4 to 8 carbon atoms, and any mixtures thereof.

[0096] In one embodiment, it is preferred that the thermoplastic polymer composition comprises at least 80% by weight of a thermoplastic polymer, such as at least 90% by weight of a polyolefin, at least 93% by weight, such as at least 95% by weight, such as at least 97% by weight of a thermoplastic polymer, such as at least 98% by weight or such as at least 99% by weight of a thermoplastic polymer, based on the thermoplastic polymer composition. In a specific embodiment, the thermoplastic polymer composition consists of a thermoplastic polymer.

[0097] In another embodiment, the thermoplastic polymer composition comprises at least 60 wt%, such as at least 70 wt%, such as at least 75 wt% and / or up to 99 wt%, such as up to 95 wt%, such as up to 90 wt% thermoplastic polymer.

[0098] The polypropylene may be, for example, a propylene homopolymer or a random propylene-α-olefin copolymer or a heterophasic propylene copolymer.

[0099] Propylene homopolymers can be obtained by polymerizing propylene under suitable polymerization conditions. Propylene copolymers can be obtained by copolymerizing propylene with one or more other α-olefins, preferably ethylene, under suitable polymerization conditions. The preparation of propylene homopolymers and copolymers is described, for example, in Moore, EP (1996) Polypropylene Handbook. Polymerization, Characterization, Properties, Processing, Applications, Hanser Publishers: New York.

[0100] The α-olefin in the random propylene α-olefin copolymer is, for example, an α-olefin selected from the group of α-olefins having 2 or 4 to 10 C atoms, preferably ethylene, 1-butene, 1-hexene or any mixture thereof. The amount of α-olefin is preferably up to 10 wt.-%, based on the propylene α-olefin copolymer, for example 2-7 wt.-%, based on the propylene α-olefin copolymer.

[0101] Polypropylene can be produced by any known polymerization technique and using any known polymerization catalyst system. As techniques, slurry, solution or gas phase polymerization may be mentioned; as catalyst systems, Ziegler-Natta, metallocene or single-site catalyst systems may be mentioned. All are known in the art per se.

[0102] Heterophasic propylene copolymers are generally produced in one or more reactors by polymerizing propylene in the presence of a catalyst and subsequently polymerizing a propylene-α-olefin mixture. The resulting polymeric material is heterophasic, but the specific morphology generally depends on the preparation method and the monomer ratio.

[0103] The heterophasic propylene copolymer as defined herein consists of a propylene based matrix and a dispersed ethylene-α-olefin copolymer.

[0104] The propylene based matrix typically forms the continuous phase in the heterophasic propylene copolymer.

[0105] The propylene-based matrix consists of a propylene homopolymer and / or a propylene-α-olefin copolymer consisting of at least 70 mass-% propylene and at most 30 mass-% of an α-olefin, such as ethylene, based on the total mass of the propylene-based matrix, for example, at least 80 mass-% propylene and at most 20 mass-% α-olefin, for example, at least 90 mass-% propylene and at most 10 mass-% α-olefin.

[0106] Preferably, the α-olefin in the propylene-α-olefin copolymer is selected from the group of α-olefins having 2 or 4 to 10 carbon atoms, and is preferably ethylene.

[0107] Preferably, the propylene based matrix consists of a propylene homopolymer.

[0108] The melt flow index (MFI) of the propylene-based matrix (before being mixed into the composition of the present invention) may be, for example, from 0.3 to 200 dg / min, measured according to ISO 1133 (2.16 kg / 230°C).

[0109] The propylene based matrix is ​​for example present in an amount of 50 to 85 wt.-%, based on the total heterophasic propylene copolymer.

[0110] In addition to the propylene-based matrix, the heterophasic propylene copolymer comprises a dispersed ethylene-α-olefin copolymer. The dispersed ethylene-α-olefin copolymer is also referred to herein as the 'dispersed phase'. The dispersed phase is discontinuously embedded in the heterophasic propylene copolymer.

[0111] The MFI of the dispersed ethylene α-olefin copolymer may vary between wide ranges and may be, for example, from 0.001 to 10 dg / min measured according to ISO 1133 (2.16 kg / 230° C.), as calculated using the following formula:

[0112]

[0113] where MFR Heterophasic is the melt flow rate of the heterophasic propylene copolymer measured according to ISO 1133 (2.16 kg / 230° C.),

[0114] MFR PP is the MFR of the propylene based matrix of the heterophasic propylene copolymer measured according to ISO 1133 (2.16 kg / 230°C),

[0115] Matrix content is the amount (in wt. %) of propylene-based matrix in the heterophasic propylene copolymer, and

[0116] The rubber content is the amount (in wt%) of ethylene α-olefin copolymer in the heterophasic propylene copolymer.

[0117] The dispersed ethylene-α-olefin copolymer is for example present in an amount of 50 to 15 wt.-%, based on the total heterophasic propylene copolymer.

[0118] For example, the amount of ethylene in the ethylene-α-olefin copolymer (RCC2) is 20 to 65 wt% based on the ethylene-α-olefin copolymer.

[0119] As is well known in the art, the amount of propylene-based matrix and dispersed ethylene-α-olefin copolymer, and the amount of ethylene in the ethylene α-olefin copolymer can be determined by 13 C-NMR determination.

[0120] In the heterophasic polypropylene the sum of the total weight of the propylene based matrix and the total weight of the dispersed ethylene-α-olefin copolymer is 100 wt%.

[0121] The α-olefin in the ethylene-α-olefin copolymer is preferably selected from the group of α-olefins having 3 to 8 carbon atoms and any mixtures thereof, preferably the α-olefin in the ethylene-α-olefin copolymer is selected from the group of α-olefins having 3 to 4 carbon atoms and any mixtures thereof, more preferably the α-olefin is propylene, in which case the ethylene-α-olefin copolymer is an ethylene-propylene copolymer. Examples of suitable α-olefins having 3 to 8 carbon atoms that can be employed as ethylene comonomers to form ethylene α-olefin copolymers include, but are not limited to, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene.

[0122] Elastomers of ethylene and an α-olefin comonomer having 4 to 8 carbon atoms may, for example, have a molecular weight of 0.850 to 0.915 g / cm 3 This type of elastomer is sometimes also called a plastomer.

[0123] The α-olefin comonomer in the elastomer is preferably an acyclic monoolefin such as 1-butene, 1-pentene, 1-hexene, 1-octene or 4-methylpentene.

[0124] Thus, the elastomer is preferably selected from the group consisting of ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer and mixtures thereof, more preferably wherein the elastomer is selected from ethylene-1-octene copolymer. Most preferably, the elastomer is ethylene-1-octene copolymer.

[0125] Preferably, the density of the elastomer is at least 0.865 g / cm 3 and / or up to 0.910 g / cm 3 For example, the density of the elastomer is at least 0.850, such as at least 0.865, such as at least 0.88, such as at least 0.90 and / or such as at most 0.915, such as at most 0.910, such as at most 0.907, such as at most 0.906 g / cm 3 More preferably, the elastomer has a density of 0.88 up to and including 0.907 g / cm 3 Most preferably, the elastomer has a density of 0.90 up to and including 0.906 g / cm 3 .

[0126] Elastomers suitable for use in the present invention are commercially available, for example, from Exxon Chemical Corporation of Houston, Texas under the trademark EXACT TM Available from Dow Chemical Company, Midland, Michigan, under the trademark ENGAGE TM The polymers are commercially available (a series of metallocene-catalyzed plastomers) or under the trademark TAFMER from MITSUI Chemicals Group of Tokyo, Minato. TM Available from SK Chemicals under the trademark Nexlene TM Purchased.

[0127] Elastomers can be prepared using methods known in the art, such as by using a single-site catalyst, i.e., a catalyst in which the transition metal component is an organometallic compound and at least one ligand has a cyclopentadienyl anionic structure that is coordinated to the transition metal cation via a bond of the anionic structure. This type of catalyst is also known as a "metallocene" catalyst. Metallocene catalysts are described, for example, in U.S. Patent Nos. 5,017,714 and 5,324,820. Elastomers can also be prepared using conventional heterogeneous, multisite Ziegler-Natta catalysts.

[0128] Preferably, the elastomer has a melt flow index of 0.1 to 40 dg / min (ISO 1133, 2.16 kg, 190° C.), for example at least 1 dg / min and / or at most 35 dg / min. More preferably, the elastomer has a melt flow index of at least 1.5 dg / min, for example at least 2 dg / min, for example at least 2.5 dg / min, for example at least 3 dg / min, more preferably at least 5 dg / min and / or preferably at most 30 dg / min, more preferably at most 20 dg / min, more preferably at most 10 dg / min, measured according to ISO 1133 using a 2.16 kg weight and at a temperature of 190° C.

[0129] Preferably, the amount of ethylene incorporated into the elastomer is at least 50 mol%. More preferably, the amount of ethylene incorporated into the elastomer is at least 57 mol%, such as at least 60 mol%, at least 65 mol%, or at least 70 mol%. Even more preferably, the amount of ethylene incorporated into the elastomer is at least 75 mol%. The amount of ethylene incorporated into the elastomer can generally be up to 97.5 mol%, such as up to 95 mol%, or up to 90 mol%.

[0130] Thermoplastic polymer composition can contain conventional additive, for example nucleator and clarifying agent, stabilizing agent, release agent, filler, peroxide, softening agent, antioxidant, lubricant, antistatic agent, crosslinking agent, anti-scratch agent, high-performance filler, pigment and / or coloring agent, impact modifier, fire retardant, foaming agent, acid scavenger, circulation additive, coupling agent, biocide, anti-fog additive, smooth additive, anti-blocking additive, polymer processing aid and analogue.This type of additive is well known in the art. The technician will understand how to select the type and amount of additive so that they can not adversely affect the target properties. In a specific embodiment, the thermoplastic polymer composition is made up of thermoplastic polymer and additive.

[0131] Preferably, the amount of the impregnated continuous multifilament strand is 10 to 70 wt %, such as 15 to 70 wt %, such as 20 to 70 wt % or such as 25 to 70 wt %, based on the sheathed continuous multifilament strand. Preferably, the sum of the amount of the impregnated continuous multifilament strand and the polymer sheath is 100 wt %.

[0132] Although the present invention has been described in detail for purposes of illustration, it is to be understood that such detail is solely for that purpose and variations may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the claims.

[0133] Furthermore, it is to be noted that the present invention relates to all possible combinations of the features described herein, preferably in particular those combinations of features presented in the claims. Thus, it is to be understood that all combinations of features relating to the composition according to the invention, all combinations of features relating to the method according to the invention, and all combinations of features relating to the composition according to the invention and of features relating to the method according to the invention are described herein.

[0134] It is further noted that the terms 'comprising' and 'including' do not exclude the presence of other elements. However, it is also understood that a description of a product / composition comprising certain components also discloses a product / composition consisting of these components. A product / composition consisting of these components may be advantageous because it provides a simpler and more economical method for preparing the product / composition. Similarly, it is also understood that a description of a method comprising certain steps also discloses a method consisting of these steps. A method consisting of these steps may be advantageous because it provides a simpler and more economical method.

Claims

1. A method of producing a tape comprising a plurality of impregnated continuous multifilament strands and a polymer sheath closely surrounding the plurality of impregnated continuous multifilament strands, wherein each of the plurality of impregnated multifilament strands extends in a longitudinal direction, wherein each of the plurality of impregnated continuous multifilament strands comprises at least one continuous glass multifilament strand, wherein the at least one continuous glass multifilament strand is impregnated with an impregnant, The method comprises the following steps: a) unwinding the continuous glass multifilament strand from a package, wherein the sizing composition is applied to the glass filaments before the glass filaments are bundled into the continuous glass multifilament strand, b) applying the impregnating agent to the continuous glass multifilament strand to form the plurality of impregnated continuous multifilament strands, c) placing the plurality of impregnated continuous multifilament strands in parallel alignment in a longitudinal direction, and d) applying a sheath of a thermoplastic polymer composition around said plurality of impregnated continuous multifilament strands of step c) to form said tape, wherein steps c) and d) are performed in a die having guide members arranged to place the plurality of impregnated continuous multifilament strands in parallel alignment in a longitudinal direction, wherein downstream of the guide members, the plurality of impregnated continuous multifilament strands pass through the melt of the thermoplastic polymer composition inside the die, wherein the guide member is provided with an elongated hole having an oval cross-section, wherein the elongated hole is arranged to accommodate the plurality of impregnated continuous multifilament strands in a plane, and The impregnating agent comprises wax. 2 . The method according to claim 1 , wherein the number of the impregnated continuous multifilament strands in the plurality of impregnated continuous multifilament strands is at least 4.

3. A method according to claim 1 or claim 2, wherein the guide member is provided with a plurality of elongated holes aligned in parallel in the longitudinal direction and arranged in a plane, wherein each of the elongated holes is arranged to accommodate an impregnated continuous multifilament strand.

4. The method according to any one of claims 1 to 2, further comprising the step e) of applying pressure and optionally heat to the strip obtained from step d).

5. The method according to claim 4, wherein step e) is performed by: e1) applying pressure to the strip while optionally heating the strip, and e2) cooling and solidifying the product obtained from step e1).

6. The method according to claim 5, wherein step e1) is performed by the following sequential steps: e1a) maintaining the strip of step d) in a molten state, and e2a) applying pressure to the strip obtained in step d) to adjust the thickness of the strip and to compact the strip.

7. The method according to claim 4, wherein the method further comprises the step f) of cutting the strip obtained from step e) into a desired length, and wherein the strip obtained from step d) is subjected to step e) without being cut.

8. The method according to any one of claims 1 to 2, further comprising the step g) of cutting the strip obtained from step d) into desired lengths.

9. The method according to claim 8, further comprising the step h) of applying heat and pressure to the strip obtained from step g).

10. The method according to claim 9, wherein step h) is performed by the following sequential steps: g1) heating the strip and applying pressure to the strip, and g2) cooling and solidifying the product obtained from step g1).

11. The method according to claim 10, wherein g1) is performed by the following sequential steps: g1a) melting the strip of step d), and g2a) applying pressure to the product obtained from step g1a) in order to adjust the thickness of the strip and to compact the strip.

12. The method of any one of claims 1-2, wherein the continuous glass multifilament strand unwound in step a) and the impregnated continuous multifilament strand formed in step b) are not cut during steps a)-d).

13. The method according to any one of claims 1 to 2, wherein the amount of the impregnating agent is 0.50 to 18 wt % based on the sheathed continuous multifilament strand, and / or wherein the impregnating agent has a melting point at least 20° C. lower than the melting point of the thermoplastic polymer composition and has a viscosity at 160° C. of 2.5 to 200 cSt measured according to ASTM D 3236-15, and / or wherein the continuous glass multifilament strand comprises up to 2 wt. % of a sizing composition, based on the continuous glass multifilament strand, and / or wherein the sheath is composed of a thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises at least 60% by weight of a thermoplastic polymer, and / or wherein the amount of the impregnated continuous multifilament strand is 10 to 70 wt % based on the sheathed continuous multifilament strand; and wherein the amount of the sheath is 30 to 90 wt % based on the sheathed continuous multifilament strand; and wherein the sum of the amounts of the impregnated continuous multifilament strand and the sheath is 100 wt %.

14. The method according to claim 13, wherein the amount of the impregnating agent is 1.5 to 8 wt % based on the sheathed continuous multifilament strand, and / or wherein the sheath is composed of a thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises at least 80% by weight of a thermoplastic polymer, and / or wherein the amount of the impregnated continuous multifilament strand is 25 to 70 wt % based on the sheathed continuous multifilament strand; and wherein the amount of the sheath is 30 to 75 wt % based on the sheathed continuous multifilament strand.

15. The method according to any one of claims 1 to 2, wherein the thermoplastic polymer is a polyolefin, wherein the polyolefin is selected from the group consisting of polypropylene or an elastomer of ethylene and an α-olefin comonomer having 4 to 8 carbon atoms, and any mixtures thereof, and / or wherein the thermoplastic polymer composition has a melt flow rate of 20 to 150 dg / min measured at 2.16 kg / 230° C. according to ISO 1133, and / or wherein the thermoplastic polymer composition comprises at least 80 wt% of the thermoplastic polymer based on the thermoplastic polymer composition.

16. A strip obtainable by the method according to any one of claims 1 to 15.

17. A laminate or woven fabric comprising a plurality of tapes according to claim 16.

18. An article comprising the tape according to claim 16 or the laminate or woven fabric according to claim 17.

19. Use of the tape according to claim 16, the laminate according to claim 17 or the article according to claim 18 in automotive applications.

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