Fiber polymer composite

Abstract

The present invention relates to a fiber-polymer composite comprising fibers of a first material and a matrix material, the matrix material being in direct contact with at least some of the fibers, characterized in that the matrix material contains at least 5% by weight of an amorphous poly-alpha-olefin, based on the total matrix material, a method for producing the fiber-polymer composite, and uses of the fiber-polymer composite.

Description

Technical Field

[0001] The present invention relates to a fiber polymer composite comprising fibers of a first material and a matrix material, wherein the matrix material is in direct contact with at least a part of the fibers, and the matrix material contains at least 5% by weight of amorphous poly-alpha-olefin based on the total matrix material, a method for manufacturing the fiber polymer composite, and the use of the fiber polymer composite.

Background Art

[0002] Many classifications of fiber reinforcement materials are known in the art, for example, polymer fiber composites, carbon fiber composites, glass fiber composites, metal fiber composites, wood composites (cellulose fiber composites) also known as WPC, and other composites such as ceramic-, nano-, woven / knitted fabric-, and graphene composites.

[0003] These various composite classifications are usually divided into two sub-classifications. The sub-classifications are distinguished by the properties of the matrix material used to embed the fibers. One matrix material is a thermosetting resin, for example, a thermosetting plastic that cannot be deformed by heating after curing. Such thermosetting resins are, for example, most of epoxy resins, crosslinked polyurethanes, crosslinked unsaturated polyester resins, etc. The other matrix material is a thermoplastic, which can be molded when heated, for example, polyamide or polyolefin. The latter has interesting properties and has been known in the market for a long time.

[0004] WO2004103673A2 [Propex / BTG International limited] and subsequent applications and patents granted therefrom, such as EP1631431B1, US9403341B2, US9873239B2, and US2018126708A1, disclose a method for manufacturing a polymer product, comprising: (a) forming a laminate having a continuous layer, namely, a first layer composed of (ii) strands of an oriented polymer material; (ii) a second layer of polymer material; (iii) a third layer composed of strands of an oriented polymer material, wherein the melting peak temperature of the second layer is lower than the melting peak temperatures of the first and third layers; (b) melting a portion of the first layer, completely melting the second layer, and melting a portion of the third layer, and subjecting the laminate to conditions of time, temperature, and pressure sufficient to press-bond the laminate; and (c) cooling the press-bonded laminate. When polypropylene is used as the material for all three layers, a bonding temperature (sometimes referred to as the press-bonding temperature) of 175 °C or higher is used. A thermoplastic composite comprising highly oriented polypropylene tapes in a self-reinforcing polypropylene matrix made of 100% polypropylene is available from Propex Furnishing Solutions GmbH & Co. KG under the trade name CURV®.

[0005] WO2004028803(A1) [Lankhorst Indutech] describes a method for strengthening an article, comprising adhering a tape, film, or thread of a stretched thermoplastic polymer to at least one surface of the article. The thermoplastic material consists essentially of the same composition as the tape, film, or thread. The tape, film, or thread is adhered to the article by means of heat treatment and / or by applying pressure. A reinforcing composite of 100% polypropylene fibers is sold by Lankhorst Yarns BV under the trade name PURE®.

[0006] The main disadvantage of a polymer fiber composite made from a polyolefin thermoplastic matrix material and polyolefin fibers based on the same polyolefin (such as polypropylene) is that when the fibers are embedded in the matrix, the fibers are partially melted or exposed to a temperature close to the glass transition temperature or melting temperature. Fibers that are highly oriented due to being stretched are often used to manufacture polymer fiber composites, but such fibers (partially) lose their orientation due to thermal stress, and thus (partially) lose some of their properties.

[0007] It was also shown by T. Barany et al. (Polymer Testing 28 (2009) 176 - 182”) that it is difficult to prevent the polypropylene matrix from approaching the melting temperature of the polypropylene fibers when the polypropylene matrix is used to embed the polypropylene fibers.

[0008] US10384400B2 [Hyundai Motor Company] describes a method for manufacturing a thermoplastic resin composite, which includes steps of laminating a matrix resin layer and a reinforcing resin layer to produce a resin laminate, thermally bonding the resin laminate, and before performing the step of thermally bonding the resin laminate, using a sewing resin having a draw ratio of less than 10 and a melting point of 150°C or lower (100 - 150°C) to fix one or more selected from the group consisting of the reinforcing resin layer and the resin laminate. The melting point of the reinforcing fibers is 160 - 180°C. This method has the disadvantage that it is necessary to further perform a fixing step using a sewing resin.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

[0010] [Non-Patent Document 1] T. Barany et al. (Polymer Testing 28 (2009) 176 - 182”) [Summary of the Invention] [Problems to be Solved by the Invention]

[0011] Therefore, the problem addressed by the present invention was to provide a polymer fiber composite that is preferably made from a polyolefin thermoplastic matrix material and polyolefin fibers based on the same polyolefin and that does not have one or more of the disadvantages of the prior art. [Means for Solving the Problems]

[0012] Surprisingly, it has been found that by using at least 5 wt% of an amorphous poly-alpha-olefin in the matrix material, one or more of the problems mentioned can be solved.

[0013] Accordingly, the present invention provides a fiber polymer composite comprising fibers of a first material and a matrix material, wherein the matrix material is in direct contact with at least a portion of the fibers and the matrix material comprises at least 5 wt% of an amorphous poly-alpha-olefin based on the total matrix material.

[0014] The present invention also relates to a method for producing a fiber polymer composite as recited in the claims and further described in detail below.

[0015] Furthermore, the present invention also relates to the use of a fiber polymer composite as recited in the claims and further described in detail below.

[0016] By using the amorphous poly-alpha-olefin (APAO) according to the present invention, particularly the APAO with high amorphous and polypropylene content (APP), the difference (delta) between the melting temperature of the polypropylene fiber material and the melting temperature of the material used as the matrix material can be increased.

[0017] Therefore, a lower crimping temperature can be used, so that the thermal stress of the fiber is reduced, and as a result, the degree to which the original properties of the fiber are lost is lowered.

[0018] Since APAO exhibits very good wettability with respect to the fiber / fiber material, it can be applied as a very thin film or even sprayed as an aqueous dispersion. The semi-finished product obtained after crimping can still be flexible (with a Young's modulus of about 800 - 1500 MPa) and can exhibit a higher value of penetration energy.

[0019] A further advantage of the present invention is that since the fiber is not melted (not in the melting process), when the matrix material is applied only to one surface of the fiber material, the touch feeling of the obtained semi-finished product is the same as or almost the same as that of the untreated fiber material.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, the fiber polymer composite according to the present invention, the method for producing the fiber polymer composite according to the present invention, and the use of the fiber polymer composite of the present invention will be described by way of example, but the present invention is not intended to be limited to these exemplary embodiments. Hereinafter, when a range, a general formula of a compound, or a classification is defined, these include not only the corresponding range or group of compounds explicitly mentioned, but also all sub-ranges and sub-groups of compounds that can be obtained by excluding individual values (ranges) or compounds. When a document is cited in the context of this specification, its content shall, with respect to the matters specifically referred to, form part of the disclosure content of the present invention as a whole. Hereinafter, when numbers are indicated as percentages, unless otherwise specified, they are weight percentages. Hereinafter, when an average (for example, an average of molar mass, etc.) is defined, unless otherwise specified, they are number averages. Hereinafter, when the properties of a material (for example, viscosity, etc.) are defined, unless otherwise specified, they are the properties of the material at 25 °C. When a chemical formula (empirical formula) is used in the present invention, the specified subscripts may be not only absolute numbers but also average values. The subscripts for polymer compounds are preferably average values.

[0021] The fiber polymer composite according to the present invention includes fibers of a first material and a matrix material, the matrix material being in direct contact with at least a part of the fibers, and the matrix material being characterized in that it contains at least 5% by weight of amorphous poly-alpha-olefin (APAO) based on the whole matrix material.

[0022] The fibers of the first material are preferably selected from polymer fibers, carbon fibers, glass fibers, metal fibers, cellulose fibers, ceramic fibers, nanofibers, woven and knitted fibers, and graphene fibers, more preferably selected from polymer fibers, still more preferably selected from polyolefin fibers, and most preferably selected from polypropylene fibers. Preferably, the melting temperature T m determined by DSC for the polypropylene fibers exceeds 160 °C, preferably exceeds 165 °C.

[0023] The fibers may be present in the form of, for example, yarns, woven or knitted fabrics, cloths, hairs, belts, ribbons, or tapes. Preferably, the fibers are oriented and elongated. The woven fabric is preferably composed of tapes, fiber yarns, or filament yarns, or the woven fabric may contain a mixture of fiber yarns or filament yarns and tapes.

[0024] Particularly suitable examples of commercially available tapes, films, and yarns include those with a nominal weight of 200 g / m available from Superprof (Ef) (Lankhorst-Indutech B.V., Sneek, the Netherlands), Geolon (Ten Cate, the Netherlands), Tiszatextil Ltd., Tiszaujvaros, Hungary) 2 , melting temperature T m A high-tenacity split PP tape having a melting temperature T of 168.6 °C (determined by DSC) and a tensile strength of 280 ± 12 MPa (measured on a single tape), or a nominal weight of 178 g / m available from Lanex a.s. (Bolatice, Czech Republic) 2High-strength PP multifilaments having a melting temperature Tm of 171.6 °C (determined by DSC), a diameter of 27.6 ± 0.6 μm (measured on single fibers), and a tensile strength of 558 ± 26 MPa, fabrics manufactured by Csendes es Csendes Ltd. (Szigetbecse, Hungary) upon request, etc. are mentioned. The tensile test of single fibers was carried out at room temperature on a Zwick Z005 universal testing machine (Zwick GmbH, Ulm, Germany) equipped with a 20 N load cell, with a crosshead speed of 5 mm / min, a preload of 0.01 N, and a clamp length of 50 mm. In each case, 50 single fibers were tested. The tensile test of the tape was carried out at room temperature on a Zwick Z005 universal testing machine (Zwick GmbH, Ulm, Germany) equipped with a 5 KN load cell, with a crosshead speed of 5 mm / min, a preload of 0.1 N, and a clamp length of 50 mm. In each case, 10 single tapes were tested. The DSC test was carried out on a TA DSC Q2000 (TA Instruments, New Castle, DE, USA) at a heating rate of 10 °C / min in the temperature range of -100 to 200 °C. Those results were obtained from the first heating run.

[0025] The matrix material preferably contains 50 wt% to 100 wt%, preferably at least 70 wt%, more preferably at least 90 wt% of one or more APAOs. Further components of the matrix material may in particular be tackifying resins and / or waxes, in particular Fischer-Tropsch wax or polyethylene wax, or fillers, preferably inorganic fillers, in particular MgO, CaSO4 (gypsum), or talc, colorants, dyes and / or flame retardants. A preferred matrix material contains 50 wt% to 100 wt% APAO, 0 wt% to 40 wt% tackifying resin (such as hydrogenated C5 / C9 Escorez (trademark) 5300 from Exxon Mobil Corporation, etc.), and 0 wt% to 10 wt% Fischer-Tropsch wax or PE wax (such as Shell GTL Sarawax SX80, etc.). Most preferably, the matrix material consists of one or more APAOs, preferably one APAO.

[0026] The weight ratio of the matrix material to the fibers is preferably from 1:20 to 1:1, more preferably from 1:15 to 1:2, and most preferably from 1:10 to 1:3.

[0027] Preferably, the amorphous poly-alpha-olefin has a melt viscosity at 190 °C determined by the method defined below of less than 200 Pas, more preferably from 5 to 150 Pas.

[0028] The viscosity was determined at 190 °C by measurement using a rotational viscometer, similar to DIN 53 019. The viscosity was determined at 190 °C by measurement using a CAP 2000+ cone-plate viscometer from Brookfield, with a shear rate having a viscosity dependence similar to the following table.

[0029]

Table 0

[0030] Calibration of the Brookfield viscometer was performed using a Newtonian standard sample of 500000 BW type. This was supplied by Zentrum fur Messen und Kalibrieren & Analytik GmbH and provided with a corresponding calibration certificate.

[0031] The number average molecular weight M of the amorphous poly-alpha-olefin is determined by the method defined below n and is preferably from 5000 to 35000 g / mol, more preferably from 10000 to 25000 g / mol.

[0032] The weight average molecular weight M of the amorphous poly-alpha-olefin is determined by the method defined below w and is preferably from 50000 to 150000 g / mol, more preferably from 70000 to 125000 g / mol.

[0033] M w is the weight average molecular weight, and M n is the number average molecular weight. The molecular weights M w and M nIt is determined using HT-GPC [high temperature gel permeation chromatography] described in DIN 55 672. Specifically, the analytical HT-GPC was performed at 150 °C using a PL220 oven (Agilent, Waldbronn) equipped with an integrated isocratic pump. The mobile phase used was 1,2,4-trichlorobenzene (TCB) (Merck, Darmstadt) mixed with approximately 1 g / L of butylhydroxytoluene (BHT) at a flow rate of 1 ml / min, and the stationary phase used was one Agilent PLgel Olexis Guard (50×7.5 mm, precolumn) and three Agilent PLgel Olexis (300×7.5 mm). Detection was performed using an IR detector (model IR4, PolymerChar, Valencia, Spain). The dataset was evaluated using polystyrene calibration EasiCal PS-1 (Agilent) by the software WinGPC (Polymer Standards Service, Mainz).

[0034] The amorphous poly-alpha-olefin has a molecular weight distribution (M w divided by the molecular weight M n ) obtained by dividing by the molecular weight M w / M n ) that is preferably from 4 to 8, more preferably from 4.5 to 7.5.

[0035] The glass transition temperature of the amorphous poly-alpha-olefin, determined in accordance with DIN 53 765, which is known as the DSC (dynamical scanning calorimetry) method, using DSC1 of Mettler Toledo and Stare Software 10.0, is preferably -45 to -20 °C, more preferably -40 to -25 °C, and most preferably -35 to -25 °C. In this specification, the sample is cooled to -90 °C and held at -90 °C for 5 minutes. Subsequently, the first heating curve is obtained up to 200 °C at a rate of 10 Kelvin per minute. The sample is held at 200 °C for 5 minutes. Subsequently, the second cooling is performed to -90 °C at a rate of 10 Kelvin per minute. The sample is held at -90 °C for 5 minutes. Subsequently, the second heating curve is obtained up to 200 °C at a rate of 10 Kelvin per minute. The second heating curve is used to read the numbers.

[0036] The S.A.F.T., which is the thermal stability under a load determined in the same manner as WPS 68, of the amorphous poly-alpha-olefin is preferably 75 to 130 °C, more preferably 80 to 120 °C, and most preferably 85 to 100 °C. The thermal stability under a load explains the thermal stability behavior of the adhered substrate. The method is described in "WPS 68 - Uberarbeitete Methode zur Prufung der Warmestandfestigkeit fur die holzverarbeitende Industrie", Ausgabe Dez. 1989, Technische Kommision Holzklebstoffe im Fachverband Klebstoffindustrie e.V., Dusseldorf. Two rectangular cardboard pieces of 100 mm × 20 mm × 1 mm (length × width × thickness) are used. The molten polymer (about 0.1 g) is applied so as to cover the entire width of the inner square region of 20 mm × 20 mm of the sample of the first cardboard, that is, the region from 40 mm to 60 mm of the test piece. Subsequently, the sample of the second cardboard is rotated 90 degrees with respect to the first cardboard, and the outermost square of 20 mm × 20 mm (that is, covering the entire width of the region from 0 mm to 20 mm) is adhered to the first cardboard so as to form an adhesion overlapping the entire coated region of the first substrate in a T shape. Both are covered with a 2 kg weight for 5 minutes, and the sample is cooled. The material protruding from the 20 mm × 20 mm region is removed. The sample is stored at room temperature for 24 hours. Then, the sample is transferred to a heating chamber with an initial temperature of 50 °C. A 450 g weight is attached to the bottom of the "T structure", and its upper part is fixed. Then, the chamber is heated at a heating rate of 5 °C per hour. Every hour, it is checked whether the adhesion of the sample is broken and whether the weight has decreased. The S.A.F.T. is the temperature interval of 5 °C width within the range where the weight has decreased. The S.A.F.T. is characterized by the average value of the lower limit temperature and the upper limit temperature within the range of 5 °C intervals.

[0037] The amorphous poly-alpha-olefin has a softening point (ring and ball method) determined in accordance with DIN EN 1427, preferably 95 to 125, more preferably 100 to 115 °C, and most preferably 105 to 110 °C. The material is heated at 180 °C and the melt is shaped into a ring. After 24 hours (this time is required for the recrystallization of the amorphous product), the sample is stressed concentrically with a chromium-plated steel ball and the test frame is immersed in a glycerol bath. This is heated at a rate of approximately 5 °C / min. The softening point is the temperature at which the ball touches the bottom plate of the test bench frame.

[0038] A preferred fiber polymer composite according to the present invention is one in which the amorphous poly-alpha-olefin exhibits a plurality of preferred properties, preferably all of the preferred properties, more preferably all of the more preferred properties, and most preferably all of the most preferred properties.

[0039] Thus, the preferred fiber polymer composite has a melt viscosity at 190 °C of less than 200 Pas, a number average molecular weight M n of 5000 to 35000 g / mol, a weight average molecular weight M w of 50000 to 150000 g / mol, and a glass transition temperature of -45 to -20 °C, and contains an amorphous poly-alpha-olefin. The most preferred fiber polymer composite has a melt viscosity at 190 °C of 5 to 150 Pas, a number average molecular weight M n of 10000 to 25000 g / mol, a weight average molecular weight M w of 70000 to 125000 g / mol, and a glass transition temperature of -35 to -25 °C, and contains an amorphous poly-alpha-olefin.

[0040] The APAO is preferably a propene-rich or 1-butene-rich APAO, more preferably a propene-rich APAO. The preferred propene-rich APAO is based on propene as a monomer in a range of preferably more than 50% by weight, preferably in the range of 51% to 98% by weight, more preferably in the range of 60% to 75% by weight, based on all monomers. Further, the propene-rich APAO may contain 1-butene and / or ethene as comonomers, preferably 1-butene and ethene, or may contain only 1-butene. The total of 1-butene and ethene here is less than 50% by weight based on all monomers, preferably the ethene content is in the range of 0% to 25% by weight, more preferably more than 0% to 15% by weight.

[0041] The determination of the content of the monomers that form the basis of the polymer and the microstructure (isotacticity [% of mmmm-pentads]) was carried out by high-temperature 13 13C NMR spectroscopy as described by A. Zambelli et al.: Macomolecules, 8, 687 (1975) and A. Filho, G. Galland: J. Appl. Polym. Sci., 80, 1880 (2001). 13 The 13C NMR spectroscopy was performed using an NMR-spectrometer AVANCE III HD from Bruker equipped with a cryoprobe system and a frequency of 500 MHz. The software Bruker Topspin 3.5 was used to display and analyze the spectra.

[0042] The polymer sample was dissolved at about 120 °C using a 5 mm diameter NMR tube in 1,1,2,2-tetrachloroethane-d2 containing 0.05 mol / L of Cr(acac)3 as a relaxant in an amount to obtain a solution containing about 50% by weight of the polymer sample based on the total solution.

[0043] The measurement parameters were as follows. Number of scans: 2000 (corresponding to a measurement time of about 2 hours) Pulse Program: zgig30 (Decoupling with Inverse Gate by 30° Pulse) D1: 3 seconds (Delay between each pulse) Temperature: 120 °C (393 K)

[0044] The intensity of the signal corresponds to the molar ratio of the monomer components. Subsequently, by using the molar mass of the monomer components (e.g., ethylene, propylene, 1-butene, etc.), the molar ratio was converted to weight %. The tacticity (if necessary) can be determined from the splitting of the signal of the methyl group with respect to propylene (for details, see J.C. Randall, Polymer Sequence determination, Academic Press, New York 1977).

[0045] The amorphous poly-alpha-olefin according to the present invention may preferably contain at least one antioxidant in an amount of 0.01 wt% to 3 wt%. The antioxidant used may be any substance as long as it is a known substance as an antioxidant and / or inhibitor, i.e., a substance that stops the progress of the free radical reaction. The amorphous poly-alpha-olefin according to the present invention preferably contains a sterically hindered amine, such as a piperidine derivative, and preferably contains a sterically hindered phenol, such as Irganox 1010, Naugard XL1, Songnox 1035, etc. Thereby, the deterioration and / or yellowing of APAO can be prevented or reduced.

[0046] Suitable APAOs are, for example, those available under the trade name VESTOPLAST® from Evonik Resource Efficiency GmbH. Preferred APAOs are the 700 types of such VESTOPLAST® APAOs, preferably VESTOPLAST® 708, 750, or 792. Other options may be APAOs from Rextac LLC, such as 1115 or 1230, or APAOs from Eastman, such as Eastoflex™ P1010 or P1023.

[0047] The method for manufacturing a fiber polymer composite according to the present invention comprises: a) preparing a structure comprising one or more fibers; b) contacting at least one surface of the structure with an amorphous poly-alpha-olefin; c) optionally, contacting the amorphous poly-alpha-olefin with one surface of a further structure comprising one or more fibers; d) optionally, repeating steps b) and c) one or more times; e) heat-treating the product obtained from step b), c), or d) by applying a temperature of 115 to 145 °C, preferably 120 to 140 °C, and preferably a pressure of at least 0.2 MPa, more preferably 0.4 to 4 MPa characterized by comprising.

[0048] The heat treatment in step e) is preferably carried out over a period of 15 seconds to 1200 seconds, more preferably 30 seconds to 500 seconds, and most preferably 45 seconds to 90 seconds.

[0049] The multi-layer / fiber polymer composite can be manufactured by performing step d) the required number of times to obtain a fiber polymer structure comprising the required number of structures comprising fibers. It is preferred to repeat step d) 1 to 10 times, more preferably 2 to 6 times, to obtain a multi-layer / multi-fiber polymer composite comprising 2 to 11, more preferably 3 to 7, structures comprising one or more fibers.

[0050] The structure comprising one or more fibers can be selected from the fibers or fiber-containing structures as described above.

[0051] The amorphous poly-alpha-olefin can be selected from one of the above-mentioned APAOs.

[0052] It is preferable to bring the amorphous poly-alpha-olefin into contact with a structure containing one or more fibers by applying a film or dispersion of the amorphous poly-alpha-olefin.

[0053] APAO can be brought into contact with the structure containing fibers alone or as a mixture containing APAO.

[0054] When the APAO or the mixture containing APAO is applied as a film, the thickness of the film is preferably 1 to 2000 μm, more preferably 10 to 500 μm, and most preferably 40 to 80 μm.

[0055] The fiber polymer composite according to the present invention can be used for all kinds of reinforced articles, particularly as a flexible tape or for manufacturing the same. Such reinforced articles can be used, for example, in the automotive / body industry or the shipbuilding industry.

[0056] The reinforced article according to the present invention contains or consists of the fiber polymer composite according to the present invention.

[0057] The present invention is particularly suitable for strengthening automobile doors, mudguards, bumpers, engine covers, rear seats of automobiles, and dashboards. Therefore, the present invention can contribute to making automobiles safer (in particular, improving the resistance to fragments of articles such as dashboards after a collision), making them more resistant to impacts of stones (rubble) (in particular, for mudguards), or making them more resistant to loads stored in automobiles (in particular, for the rear seats of automobiles).

[0058] Regarding articles for building marine yachts, in addition to the strengthening effect, the low weight of the tape film or yarn contributes to reducing the weight of the ship and making it less likely to sink because the metal content is reduced.

[0059] Such reinforced articles may be protective shields or panels for counter protection (e.g., banks, ticket offices, etc.) or wall / facade protection, or part of a structure such as a building wall, floor, and / or ceiling, or tubes, pipes, etc.

[0060] The subject matter of the present invention will be described in detail in the following examples, but it is in no way intended to limit the subject matter of the present invention thereto.

Examples

[0061] Constituent materials of the fibers used: Fabric 1: Consists of high-elongation split PP tapes (woven fabric of split PP yarns) with a nominal weight of 200 g / m (Tiszatextil Ltd., Tiszaujvaros, Hungary). This reinforcing tape has a melting temperature T 2 of 168.6 °C (determined by DSC) and a tensile strength of 280 ± 12 MPa (measured on a single tape). m

[0062] Fabric 2: Consists of high-strength PP multifilaments with a nominal weight of 178 g / m (Lanex a.s., Bolatice, Czech Republic). The reinforcing fibers have a melting temperature T 2 of 171.6 °C (determined by DSC) and a tensile strength of 558 ± 26 MPa. The diameter of the fibers is 27.6 ± 0.6 μm (measured on single fibers). The high-strength woven fabric is manufactured in small quantities by Csendes es Csendes Ltd. (Szigetbecse, Hungary) according to our request, so its availability is limited. m

[0063] Matrix materials used: As matrix materials, four different grades of propene-rich VESTOPLAST® (708, 750, 792, 888; provided by Evonik Resource Efficiency GmbH, Marl, Germany) were used. The properties and compositions of the grades of VESTOPLAST® used are shown in Table 1.

[0064]

Table 1

[0065] Determination of density at 23 °C according to DIN EN ISO 1183-1.

[0066] Determination of tensile strength / elongation at break according to DIN EN ISO 527-3, modified type 5. Tensile strength represents the tensile and elongation properties of test specimen type 3 with a thickness of 2 mm.

[0067] Determination of shear modulus at 23 °C according to DIN EN ISO 6721-2. This part defines the general principles of methods for determining the dynamic rheological properties of polymer melts, and part 2 describes the torsional pendulum method.

[0068] The content of the monomers that form the basis of APAO can be determined using the above high temperature 13 by C-NMR spectroscopy.

[0069] Differential scanning calorimetry (DSC) was performed on VESTOPLAST® samples, as well as on the fibers and tapes for reinforcement. Based on the difference in the melting ranges of VESTOPLAST® and the PP tapes, a very wide processing range was found to exist. Thus, it is even possible to reliably manufacture the composite at a relatively low processing temperature that avoids the molecular relaxation of the reinforcing material (which causes both rigidity and strength to be significantly lost, reducing the reinforcing effect). However, compared to the VESTOPLAST® 700 series, VESTOPLAST® 888 exhibits different melting behavior. Since VESTOPLAST® 888 has a small melting peak at approximately 160 °C, it cannot be processed by extrusion below this temperature. For stable processing and coating, it was necessary to set the die temperature to 180 °C. This temperature promotes the molecular relaxation of the reinforcing material to be coated even at a high drawing speed, thereby shortening the residence time in this temperature range.

[0070] Instrumented falling weight impact (IFWI) tests were performed (the method is described in detail in Example 4 below). In tests at room temperature, the result of the highest energy absorption capacity was obtained, but unexpectedly high energy absorption was demonstrated in the results of VESTOPLAST® 888 at -40 °C.

[0071] (Example 1) Manufacture of Fiber Polymer Composite A fiber polymer composite was produced using a fabric guiding device attached to a cast film extrusion line, Labtech LE 25 - 30C (Labtech Engineering Co., Samutprakarn, Thailand). The slot die has a width of 200 mm and the gap can be set between 0.1 and 1.0 mm. During production, a reinforcing fabric (200 mm wide) is guided by the device to the flat film die of the extruder, where the matrix film is extruded directly onto the fabric. After extrusion, the coated fabric is guided towards the winder by a polytetrafluoroethylene (PTFE) roller while being cooled. Also, a PTFE film is added during the winding process to avoid the coated fabrics sticking to each other.

[0072] The fiber content of the composite is determined by the thickness of the matrix film and the degree of relaxation of the fabric during bonding / crimping. The thickness of the matrix film depends on the following extrusion parameters: - The rotational speed of the extruder screw - The distance between the lips of the die - The pulling speed of the coated fabric and is determined by these factors.

[0073] Since the matrix material film and the reinforcing fabric are adhered to each other and cannot be separated, the thickness of the matrix film cannot be directly measured. Nevertheless, after measuring the width of the fabric, the width of the matrix layer, and the length and weight of the coated fabric, the formula: h = (m - b f lρ A,f ) / (ρ Vp b Vp l) (where h is the thickness of the matrix film, m is the weight of the coated fabric, b f is the width of the coated fabric, l is the length of the coated fabric, ρ A,f is the areal density of the fabric, ρ Vp is the density of the matrix material, b Vp(which is the width of the coating of the matrix material), the thickness of the matrix film can be calculated.

[0074] In order to make the fiber content of the composite 70 to 80% by weight, the thickness of the matrix material layer was selected to be about 60 μm.

[0075] In order to specify the above extrusion parameters for making the film thickness 60 μm, a plurality of preliminary tests were conducted. In these tests, the rotational speed of the screw of the extruder and the distance between the lips of the die were set to 70 min⁻¹ and 0.5 mm, respectively, the pulling speed of the coated cloth was changed in 0.5 m / min increments in the range of 3 to 10 m / min, and the rotational speed of the winder was set accordingly. The thickness of the matrix material film at each point was calculated, and the pulling speed required to make the film thickness 60 μm was obtained by linear interpolation. The required pulling speeds for all matrices are summarized in Table 2. The temperature of the die was 120 °C for VESTOPLAST® 708, 750, and 792, and 180 °C for VESTOPLAST® 888 (stable production could only be ensured at this temperature). The first roll was heated to 40 °C. The obtained coated cloth had a thickness of 55 to 65 μm and a width of 150 to 160 mm depending on the viscosity and the pulling speed.

[0076] [Table 2] Table 2: Pulling speed required to make the film thickness 60 μm

[0077] (Example 2) Manufacture of multi-fiber polymer composite To manufacture a fiber polymer composite (multi-fiber polymer composite) containing a plurality of layers of the coated cloth of Example 1, a double belt press (DBP) type Reliant Powerbond-HPC, Reliant, Lukon, UK was used.

[0078] The coated fabrics were stacked on top of each other in four layers (with the coated sides facing up), and the uncoated fabric layer was placed on the top of the package. The semi-finished product had a length of 1.5 m. To facilitate the easy separation of the first 60 mm portion of the peel test specimen before testing, a thin PTFE film piece was inserted between the first coated fabric and the second coated fabric.

[0079] To determine the suitable bonding speed of DBP, preliminary tests were conducted several times. To obtain uniform properties in the longitudinal direction, a tensile speed of 1.5 m / min and a pressure of 6 bar (6 bar is the maximum adjustable pressure value of DBP) were used at all bonding temperatures (120 °C, 140 °C, 160 °C). At each matrix and each bonding temperature, at least three multi-fiber polymer composites were manufactured.

[0080] At high temperatures, relaxation phenomena occur in the highly oriented PP tape (fabric). Due to this phenomenon, not only does the fiber reinforcement ability decrease, but also the length and width of the fabric decrease, and the thickness increases. Due to this effect, the areal density of the reinforcing fabric increases, and thereby the fiber content of the composite increases. The degree of relaxation can be calculated from the initial area of the semi-finished product and the area of the composite obtained after bonding using the following formula: s=(1-(b2l2) / (b1l1))·100, (where s (%) is the degree of relaxation of the fabric, b1 and l1 are the initial width and length of the semi-finished product, respectively, and b2 and l2 are the width and length of the composite after bonding, respectively). The degree of relaxation of Fabric 1 for all matrices and bonding temperatures is shown in Table 3a.

[0081]

Table 3a

[0082] Also, along with relaxation, the changed areal density is also calculated using the following formula: ρ A * =(1 + s)*ρ A , (where ρ A * is the changed areal density of the fabric, s is the degree of relaxation, and ρ A is the initial areal density of the fabric) can be calculated.

[0083] The width of the reinforcing fabric was wider than the width of the matrix material coated thereon. As a result, the ends of the composite sheet did not contain sufficient matrix material to achieve a satisfactory level of bonding, so the ends of the composite were removed using a manual sheet shearing machine. The fiber content was measured after measuring the length, width, and weight of the composite sheet, using the following formula: f = 5b * l * ρ A * / m * 100, (where f is the fiber content of the composite, b * and l * are the width and length of the composite, respectively, ρA * is the changed areal density of the reinforcing fabric, and m is the weight of the composite sheet) can be calculated. Table 3b includes the fiber content of the fiber-polymer composite obtained using Fabric 1.

[0084]

Table 3b

[0085] The bonding / crimping of the fiber-polymer composite obtained in Example 2 was evaluated by density measurement, peel test, and microscopic observation. The density was found not to be affected by the type of matrix, but to increase slightly as the bonding temperature increased (see Example 4 for details).

[0086] (Example 3) Production of a multi-fiber polymer composite from Fabric 2 Example 1 and 2 were repeated at a bonding temperature of 120°C using Fabric 2 and VESTOPLAST® 708 and 792 as the matrix materials, respectively. All other steps and parameters were the same as those already shown for Fabric 1 in Examples 1 and 2.

[0087] (Example 4) Testing and Results of Fiber-Polymer Composites Test specimens were cut out from the fiber-polymer composites obtained in Examples 2 and 3 using a manual sheet shearing machine.

[0088] Due to some differences in the fiber content of the fiber-polymer composite samples, the results of the mechanical tests were normalized to 75 wt% by multiplying the determined test values by the ratio of (75%) / (determined reinforcing material content).

[0089] Density: The density of the fiber-polymer composite samples was evaluated in anhydrous ethanol at 23°C according to EN ISO 1183-1. The results are shown in Table 4a below.

[0090] Interlaminar Shear Strength: The interlayer (peel) strength of the fiber polymer composite sample was determined by peeling the material layer for surface reinforcement of the composite sheet and the matrix layer at a crosshead speed of 152 mm / min using a Zwick Z020 (load cell 20 kN) universal testing machine on a rectangular test piece of 25 mm × 300 mm. The standard recommends using a special peeling device that can be attached to the crosshead of the tensile testing machine. However, since the elastic modulus of the composite is relatively low, the test piece was directly fixed to the grips of the tensile testing machine. As a result, the results of the peel test cannot be compared with the interlayer strengths of other types of fiber-reinforced composites. Nevertheless, based on the results of the peel tests performed, the effects of the matrix material and the bonding temperature on the interlayer strength of the composite based on VESTOPLAST (registered trademark) can be investigated. To initiate peeling, we inserted a small piece of polytetrafluoroethylene film between the first coated fabric and the second coated fabric when constructing the layer (see Example 2 for details). The values of the peel strength obtained in this test are shown in Table 4a below.

[0091] Static tension: The static tension test was performed on a rectangular test piece of 25 mm × 200 mm (width × length) of the fiber polymer composite sample using a Zwick Z250 (load cell 20 kN) universal testing machine at a crosshead speed of 5 mm / min. The results of the static tension test (e.g., tensile strength and Young's modulus) are shown in Table 4a below.

[0092]

Table 4a

[0093] From the results in Table 4a, it can be seen that the peel strength of the fiber-polymer composite increases as the molecular weight (Mw) of VESTOPLAST® (the matrix material) increases (from type 708 to type 792), indicating that the interaction between layers has been significantly improved. VESTOPLAST® 888 showed a medium peel strength value. Raising the bonding temperature resulted in only a slight improvement, especially for samples with a larger Mw (VESTOPLAST® 792, 888).

[0094] As a result of the tensile test, when tested at room temperature, it was shown that for the fiber-polymer composite bonded at 140°C, the tensile strength was slightly improved compared to that bonded at 120°C. When the bonding temperature was 160°C, a significant decrease occurred. When tested at 80°C, there was no significant difference due to either the bonding temperature or the type of matrix.

[0095] Instrumented falling weight impact The instrumented falling weight impact (IFWI) test was carried out using a Fractovis 6785 device (Ceast, Pianezza, Italy) with the following settings: maximum energy: 593.4 J; dart diameter: 20 mm; support ring diameter: 40 mm; dart weight: 60.5 kg, and drop height: 1 m. The IFWI test was performed on a 110 mm × 110 mm square specimen of the fiber polymer composite in the case of Fabric 1, and a 150 mm × 150 mm square specimen was used for the composite manufactured with Fabric 2. Also, the test was carried out at 23 °C on a composite based on VESTOPLAST® 792 using a dart with a diameter of 15.9 mm in order to clarify the effect of the dart diameter on the penetration energy of the composite. The penetration energy was calculated from the total dissipated energy divided by the thickness of the test sample. The results are shown in Table 4b and Table 4c below.

[0096]

Table 4b

[0097] From the results in Table 4b, there are only slight differences among the fiber polymer composites based on the VESTOPLAST® 700 series, but it can be seen that VESTOPLAST® 888, especially the composites bonded at 120 °C and 140 °C, showed high penetration energy at room temperature, probably because the bonding was less sufficient. Increasing the bonding temperature improved the bonding and the interaction between the matrix / reinforcing materials, thereby reducing the damping ability of the fiber polymer composite.

[0098] The penetration energy of the composite bonded at 120 °C and 140 °C was higher than that of the composite tested at room temperature when tested at -40 °C and +80 °C.

[0099] Since VESTOPLAST® 888 itself has an unexpectedly high penetration energy value at -40 °C, VESTOPLAST® 888 was also tested at -60 °C. At -60 °C, VESTOPLAST® 888 behaves similarly to other grades of VESTOPLAST® investigated at -40 °C. The reason why VESTOPLAST® 888 behaves differently at lower temperatures may be due to the fact that the glass transition temperature (T g ) of VESTOPLAST® 888 is lower.

[0100] The failed IFWI test specimens were visually analyzed. The failure behavior at low temperatures was tape breakage and matrix deformation with moderate delamination, but at higher test temperatures, significant wrinkles and folds also occurred.

[0101]

Table 4c

[0102] From the results in Table 4c, it can be seen that the penetration energy is greater in the case of a dart with a diameter of 20 mm.

[0103] Also, an IFWI test was conducted using the sample obtained in Example 4 (based on Fabric 2). To more securely grip the sample with the clamp unit of the falling weight impact tester, the sample size was increased from 110×110 mm to 150×150 mm. The results are shown in Table 5.

[0104]

Table 5

[0105] Due to the test at 80°C, both the matrix and the reinforcing material softened significantly, so the clamping force of the equipment's clamp was not sufficient to keep the test piece in the correct position. As a result, dirt creased the test piece in the support ring. Therefore, the value determined at 80°C is only for information purposes.

[0106] Comparing the results shown in Table 4b and Table 5, it is clear that by using a more robust fabric such as Fabric 2, which is a woven fabric of high-strength PP multifilaments for example, the impact energy absorption capacity can be further significantly improved.

[0107] Morphology The morphology of the fiber polymer composite was observed using a scanning electron microscope (SEM) and an optical microscope (LM).

[0108] The SEM images of the peeled sample surface were taken using a Jeol JSM 6380 LA scanning electron microscope (JEOL Ltd., Tokyo, Japan). Before SEM, the surface of the test sample was coated with gold by sputtering.

[0109] Optical microscope images of the cut surface prepared by a cryomicrotome at -50 °C were taken using an Olympus BX51M optical microscope (Olympus, Hamburg, Germany).

[0110] Some of the samples produced in Example 2 were peeled off and examined using a scanning electron microscope (SEM). What the SEM images showed was that the matrix of the composite bonded at 120 °C exhibited some delamination, and the surface of the tape remained generally intact. For the composite based on VESTOPLAST® 888, the tape / matrix interaction was insufficient. For the fiber-polymer composite bonded at 160 °C, some fibrillation of the tape was observed, and it was also observed that the adhesion of the tape / matrix was much improved.

[0111] The samples produced in Example 2 were observed using an optical microscope. The main difference in the samples bonded at various temperatures was that the composite maintained a laminated structure at 120 °C, but was deformed at 160 °C. The structure bonded at 140 °C was the same as that of the fiber-polymer composite bonded at 120 °C. The destruction of the structure was probably due to high temperature, high pressure, and intensive relaxation.

[0112] (Example 5) Comparison with other fiber-polymer composites For various fiber-polymer composites known in the art and / or commercially available, the values of the penetration energy and tensile strength were determined using the above test methods. The results are shown in Tables 6a and 6b below.

[0113] [Table 6a] Table 6a: Comparison of the penetration energy between the fiber-polymer composite according to the present invention and known and / or commercially available fiber-polymer composites MM: Matrix material; FPC: Fiber polymer composite; V: VESTOPLAST (registered trademark); CT: Bonding temperature (°C); PE23: Penetration energy (J / mm) obtained in the test at 23°C;

[0114] * In the case of Fabric 2, holes were formed in the test piece. However, during the test, since the clamping force for keeping the test piece in the correct position was insufficient, the test piece was also severely deformed. Most of the high penetration energy is due to this undesirable deformation. Nevertheless, it is certain that the composite produced from Fabric 2 has a larger penetration energy value because the strength and toughness of Fabric 2 are higher, but the exact value is somewhat lower than that.

[0115]

Table 6b

[0116] More detailed information on fiber polymer composites not according to the present invention can be found in the following references. [1]www.curvonline.com (2019.06.08.) [2]www.ditweaving.com (2019.06.10.) [3]Swolfs Y., Van den Fonteyne W., Baets J., Verpoest I.: Failure behavior of self-reinforced polypropylene at and below room temperature. Applied Science and Manufacturing, 65, 100 - 107 (2014). [4] Swolfs Y., Zhang Q., Baets J., Verpoest I.: The influence of process parameters on the properties of hot compacted self-reinforced polypropylene composites. Composites Part A: Applied Science and Manufacturing, 65, 38 - 46(2014). [5] Barany T., Izer A., Czigany T.: High performance self-reinforced polypropylene Composites. Materials Science Forum, 537, 121 - 128(2007). [6] Barany T., Izer A., Karger-Kocsis J.: Impact resistance of all-polypropylene composites composed of alpha and beta modifications. Polymer Testing, 28, 176 - 182(2009).

[0117] From the results shown in Table 6a, it is clear that the fiber polymer composite according to the present invention exhibits a much higher penetration energy value than the fiber polymer composites known in the art. Therefore, the fiber polymer composite according to the present invention is much more stable with respect to penetration by, for example, bullets or arrows, and thus can be better used for manufacturing bulletproof or safety clothing.

[0118] From the results shown in Table 6b, it is clear that the fiber polymer composite according to the present invention exhibits a lower tensile strength value than those known in the art, and therefore is not more brittle.

[0119] This example shows that a fiber polymer composite based on a propylene-rich APAO matrix material has good mechanical properties and excellent mechanical energy damping properties. From this example, it becomes clear that in particular VESTOPLAST® 792 and 750, which are propylene-rich APAOs, exhibit excellent mechanical properties and mechanical energy damping properties. From this example, it becomes clear that a processing (bonding / calendaring) temperature of 120 to 140 °C is sufficient to obtain a useful fiber polymer composite. This temperature range is much lower than the temperatures used for processing other (all-) polypropylene composites known in the art. Thus, energy is saved and the reinforcing material is processed more gently (with less heat).

Claims

**Claim 1**: A fiber polymer composite comprising fibers of a first material selected from polypropylene fibers having a melting temperature Tm determined by DSC exceeding 160 °C and a matrix material, wherein the matrix material is in direct contact with at least a part of the fibers, and the matrix material contains 50 wt% to 100 wt% of propene-rich amorphous poly-alpha-olefin based on the total matrix material, the melt viscosity of the amorphous poly-alpha-olefin at 190 °C is less than 200 Pa·s, the number average molecular weight Mn is 5000 to 35000 g / mol, the weight average molecular weight Mw is 50000 to 150000 g / mol, the glass transition temperature is -45 to -20 °C, the softening point is 95 to 125 °C, and it is characterized by being used for a reinforcing article, the fiber polymer composite. **Claim 2**: The fiber polymer composite according to claim 1, characterized in that the melt viscosity of the amorphous poly-alpha-olefin at 190 °C is 5 to 150 Pa·s. **Claim 3**: The fiber polymer composite according to claim 1, characterized in that the number average molecular weight Mn of the amorphous poly-alpha-olefin is 10000 to 25000 g / mol. **Claim 4**: The fiber polymer composite according to claim 1, characterized in that the weight average molecular weight Mw of the amorphous poly-alpha-olefin is 70000 to 125000 g / mol. **Claim 5**: The fiber polymer composite according to claim 1, characterized in that the molecular weight distribution (Mw / Mn) of the amorphous poly-alpha-olefin is 4 to 8. **Claim 6**: The fiber polymer composite according to claim 1, characterized in that the glass transition temperature of the amorphous poly-alpha-olefin is -40 to -25 °C. **Claim 7**: The fiber polymer composite according to claim 1, characterized in that S.A.F.T., which is the thermal stability of the amorphous poly-alpha-olefin under load, is 75 to 130 °C. **Claim 8**: The fiber polymer composite according to claim 1, characterized in that the softening point of the amorphous poly-alpha-olefin is 100 to 115 °C. **Claim 9** The fiber polymer composite according to claim 1, wherein the amorphous poly-alpha-olefin is based on propene as a monomer in the range of more than 50% by weight based on all monomers, and the total of 1-butene and ethene as monomers is less than 50% by weight based on all monomers.

10. A method for producing the fiber polymer composite according to claim 1, comprising: a) preparing a structure comprising one or more fibers selected from polypropylene fibers; b) contacting at least one surface of the structure with a propylene-rich amorphous poly-alpha-olefin having a melt viscosity of less than 200 Pa·s at 190 °C, a number average molecular weight Mn of 5000 to 35000 g / mol, a weight average molecular weight Mw of 50000 to 150000 g / mol, a glass transition temperature of -45 to -20 °C, and a softening point of 95 to 125 °C; c) optionally, contacting the amorphous poly-alpha-olefin with one surface of a further structure comprising one or more fibers selected from polypropylene fibers; d) optionally, repeating steps b) and c) one or more times; e) heat-treating the product obtained from step b), c), or d) by applying a temperature of 115 to 145 °C and a pressure of at least 0.2 MPa. A method characterized by comprising the above steps.

11. The method according to claim 10, characterized in that the amorphous poly-alpha-olefin is brought into contact with a structure comprising one or more fibers by applying a film or dispersion of the amorphous poly-alpha-olefin.

Images