Glass fiber reinforced thermoplastic polymer composition comprising a thermoplastic polymer composition having a high flowability

Abstract

The present invention relates to a process for producing a glass fiber reinforced thermoplastic polymer composition and to such a glass fiber reinforced thermoplastic polymer composition. The present invention further relates to an article comprising the glass fiber reinforced thermoplastic polymer composition. The glass fiber reinforced thermoplastic polymer composition has improved white spot performance.

Description

[0001] This invention relates to a method for producing a glass fiber reinforced thermoplastic polymer composition and such a glass fiber reinforced thermoplastic polymer composition. The invention also relates to articles comprising the glass fiber reinforced thermoplastic polymer composition.

[0002] Glass fiber reinforced thermoplastic polymer compositions can be manufactured by a method comprising the steps of unwinding a continuous glass multifiber strand from a package and applying a polypropylene sheath around the multifiber strand to form a sheathed continuous multifiber strand.

[0003] This method is known from international application WO 2009 / 080281. That published patent application discloses a method for producing a long glass fiber reinforced thermoplastic polymer composition, the method comprising the steps of: i) unwinding at least one continuous glass multifiber strand from a package; ii) applying an impregnating agent to the at least one continuous glass multifiber strand to form an impregnated continuous multifiber strand; and iii) applying a thermoplastic polymer sheath around the impregnated continuous multifiber strand to form a sheathed continuous multifiber strand.

[0004] WO2020229411 discloses a method for preparing long glass fiber reinforced compositions using glass fibers of different thicknesses to achieve a balance between free glass, glass fiber distribution, and mechanical properties.

[0005] WO2020229410 discloses a method for preparing tapes reinforced with continuous glass fibers.

[0006] Molded articles made from glass fiber reinforced thermoplastic polymer compositions are expected to have a good visual appearance, such as a surface with fewer white spots. White spots may appear due to insufficient dispersion of the fibers in the article.

[0007] The object of the present invention is to provide a glass fiber reinforced thermoplastic polymer composition that satisfies the above and / or other requirements.

[0008] Therefore, the present invention provides a method for preparing a glass fiber reinforced thermoplastic polymer composition (G), comprising the following steps:

[0009] a) Unwind at least one continuous glass multifiber strand from the packaging;

[0010] b) Apply an impregnating agent to a continuous glass multifiber strand to form an impregnated continuous multifiber strand;

[0011] c) Apply a sheath of thermoplastic polymer composition (X) around the multifiber strand to form a sheathed continuous multifiber strand, wherein the melt flow index (MFI) of the thermoplastic polymer composition (X) is 78 to 180 dg / min as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0012] Unexpectedly, it was found that molded articles made from the glass fiber reinforced thermoplastic polymer composition (G) obtained according to the method of the invention have a good visual appearance with reduced white spots. While not wishing to be bound by any theory, it is believed that the high fluidity of the thermoplastic polymer composition (X) improves the dispersion of the multi-fiber strands in the article, which prevents the formation of white spots.

[0013] The method according to the invention is generally referred to as a wire coating method. Wire coating is typically accomplished by passing a continuous strand of glass multifiber (roving) through a wire coating die. The die is connected to an extruder that supplies molten thermoplastic polymer through an opening substantially perpendicular to the direction in which the glass multifiber strand passes through the die. In this way, the thermoplastic polymer essentially sheaths or encapsulates the glass multifiber strand, which is to be “coated” as “wire.” This method is also disclosed in WO 99 / 00543, the main difference being that WO 99 / 00543 does not require the application of an impregnating agent before sheathing with the thermoplastic polymer and does not restrict the flowability of the thermoplastic polymer.

[0014] WO2009 / 080281A1 discloses a method that includes the following steps:

[0015] a) Unwind at least one continuous glass multifiber strand from the packaging;

[0016] b) Apply an impregnating agent to a continuous glass multifiber strand to form an impregnated continuous multifiber strand;

[0017] c) Apply a thermoplastic polymer sheath around the multifilament strand to form a sheathed continuous multifilament strand.

[0018] However, WO2009 / 080281A1 does not disclose any advantage of the high fluidity of thermoplastic polymers.

[0019] Both WO 99 / 00543 and WO2009 / 080281A1 are incorporated herein by reference.

[0020] The method for producing a glass fiber reinforced thermoplastic polymer composition (G) according to the present invention may further include the following subsequent steps after step c) to obtain a glass fiber reinforced polymer composition (G) in granular form:

[0021] d) Continuous glass multi-fiber strands in the cooling sheath;

[0022] e) Cut the sheathed continuous glass multifiber strands into granules.

[0023] Preferably, step d) is carried out in a water bath.

[0024] In step e), the granules are typically cut to lengths of 2 to 50 mm, preferably 5 to 30 mm, more preferably 6 to 20 mm, and most preferably 10 to 16 mm. The length of the glass fibers is generally the same as the length of the granules.

[0025] Preferably, the total amount of the thermoplastic polymer composition (X) and the impregnated continuous multifiber strands in the granules is at least 95% by weight, at least 98% by weight, at least 99% by weight, at least 99.9% by weight, or 100% by weight relative to the granules.

[0026] Preferably, the method according to the invention is operated at a linear speed of at least 100 m / min, at least 150 m / min, and at most 1000 m / min. The basic linear speed is for higher productivity; excessively high linear speeds can lead to poor product quality.

[0027] Following step e), there may be a step of molding the granules into a (semi-)finished product. The preferred molding method is injection molding. Preferably, the product is an automotive part, such as an exterior automotive part like a bumper, an interior automotive part like a dashboard, or an automotive part under the hood.

[0028] The present invention also relates to the use of a glass fiber reinforced thermoplastic polymer composition (G) obtained according to the method of the present invention in automotive applications.

[0029] The present invention also relates to automotive parts comprising a glass fiber reinforced thermoplastic polymer composition (G) obtained according to the method of the present invention or made therefrom.

[0030] Thermoplastic polymer composition (X)

[0031] In step c) of the method according to the invention, a thermoplastic polymer composition (X) is used. For the purpose of achieving reduced white spots on the surface, it is crucial that the melt flow index (MFI) of the thermoplastic polymer composition be 78 to 180 dg / min, preferably 78 to 148 dg / min, more preferably 95 to 122 dg / min, more preferably 96 to 119 dg / min, and even more preferably 103 to 118 dg / min, as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0032] Thermoplastic polymer in thermoplastic polymer composition (X)

[0033] Preferably, the thermoplastic polymer composition comprises a thermoplastic polymer. Suitable examples of thermoplastic polymers include, but are not limited to, polyamides such as polyamide 6, polyamide 66, or polyamide 46; polyolefins such as polypropylene and polyethylene; polyesters such as polyethylene terephthalate, polybutylene terephthalate; polycarbonate; polyphenylene sulfide; polyurethanes and mixtures thereof.

[0034] Preferably, the amount of thermoplastic polymer is 65.1 to 99.5% by weight, more preferably 85.3 to 99.2% by weight, and even more preferably 93.2 to 99.0% by weight, based on the total amount of the thermoplastic polymer composition (X). In a specific embodiment, the thermoplastic polymer composition consists of a thermoplastic polymer.

[0035] In another embodiment, the thermoplastic polymer composition comprises at least 60% by weight, for example at least 70% by weight, for example at least 75% by weight and / or up to 99% by weight, for example up to 95% by weight, for example up to 90% by weight of a thermoplastic polymer.

[0036] Preferably, the thermoplastic polymer is polypropylene, such as propylene homopolymer, random propylene copolymer, or multiphase propylene copolymer.

[0037] More preferably, the thermoplastic polymer is a propylene homopolymer.

[0038] Preferably, the polypropylene has an MFI of 78 to 180 dg / min, more preferably 78 to 148 dg / min, more preferably 95 to 122 dg / min, more preferably 96 to 119 dg / min, and even more preferably 103 to 118 dg / min, as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0039] 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.

[0040] The random propylene copolymer may contain ethylene or an α-olefin selected from α-olefins having 4 to 10 carbon atoms as a comonomer, preferably ethylene, 1-butene, 1-hexene, or any mixture thereof. Preferably, the amount of comonomer is up to 10% by weight based on the random propylene copolymer, for example, 2-7% by weight based on the random propylene copolymer.

[0041] Polypropylene can be manufactured using any known polymerization technique and any known polymerization catalyst system. Regarding techniques, slurry, solution, or gas-phase polymerization may be mentioned; regarding catalyst systems, Ziegler-Natta, metallocene, or single-point catalyst systems may be mentioned. All of these are known in the art.

[0042] Multiphase propylene copolymers are generally prepared in one or more reactors by polymerizing propylene in the presence of a catalyst and subsequently polymerizing an ethylene-α-olefin mixture. The resulting polymeric material is multiphase, but its specific morphology usually depends on the preparation method and the monomer ratios used.

[0043] Multiphase propylene copolymers can be produced using any conventional techniques known to those skilled in the art, such as multi-stage process polymerization, including bulk polymerization, gas-phase polymerization, slurry polymerization, solution polymerization, or any combination thereof. Any conventional catalyst system can be used, such as Ziegler-Natta or metallocene. Such techniques and catalysts are described, for example, in WO06 / 010414; Polypropylene and other Polyolefins, Ser van der Ven, Studies in PolymerScience 7, Elsevier, 1990; WO06 / 010414, US4399054, and US4472524.

[0044] Preferably, a Ziegler-Natta catalyst is used to produce the multiphase propylene copolymer.

[0045] Multiphase propylene copolymers can be prepared by a method including the following steps:

[0046] - Propylene and optionally ethylene and / or α-olefins are polymerized in the presence of a catalyst system to obtain a propylene-based matrix, and

[0047] Subsequently, ethylene and α-olefins are polymerized in a propylene-based matrix in the presence of a catalyst system to obtain dispersed ethylene-α-olefin copolymers. These steps are preferably carried out in different reactors. The catalyst systems for the first and second steps can be different or the same.

[0048] The multiphase propylene copolymer compositions of the present invention consist of a propylene-based matrix and a dispersed ethylene-α-olefin copolymer. The propylene-based matrix typically forms the continuous phase in the multiphase propylene copolymer. The amounts of the propylene-based matrix and the dispersed ethylene-α-olefin copolymer can be determined by methods as known in the art. 13 Measured by C-NMR.

[0049] The propylene-based matrix consists of propylene homopolymers and / or propylene copolymers, wherein the propylene copolymers consist of at least 70% by weight of propylene monomer units and at most 30% by weight of comonomer units selected from ethylene monomer units and α-olefin monomer units having 4 to 10 carbon atoms, based on the total weight of the propylene-based matrix, for example, at least 80% by weight of propylene monomer units and at most 20% by weight of comonomer units, at least 90% by weight of propylene monomer units and at most 10% by weight of comonomer units, or at least 95% by weight of propylene monomer units and at most 5% by weight of comonomer units.

[0050] Preferably, the comonomers in the propylene copolymer based on a propylene matrix are selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene, with ethylene being the most preferred.

[0051] Preferably, the propylene-based matrix is ​​composed of propylene homopolymer.

[0052] The propylene-based matrix may be present, for example, in an amount of 50 to 95% by weight. Preferably, the propylene-based matrix is ​​present in an amount of 60 to 85% by weight, for example at least 65% by weight, or at least 70% by weight and / or at most 78% by weight, based on the total multiphase propylene copolymer.

[0053] Preferably, the propylene-based matrix is ​​semi-crystalline, meaning it is neither 100% amorphous nor 100% crystalline. For example, the propylene-based matrix is ​​at least 40% crystalline, such as at least 50%, at least 60%, and / or at most 80% or 70% crystalline. For example, the propylene-based matrix has a crystallinity of 60 to 70%. For the purposes of this invention, the crystallinity of the propylene-based matrix is ​​measured using differential scanning calorimetry (DSC) according to ISO 11357-1 and ISO 11357-3 (1997), using a scan rate of 10 °C / min, a sample of 5 mg, and a second heating curve using 207.1 J / g as the theoretical standard for 100% crystalline material.

[0054] In addition to the propylene-based matrix, multiphase propylene copolymers also contain dispersed ethylene-α-olefin copolymers. These dispersed ethylene-α-olefin copolymers are also referred to herein as the 'dispersed phase'. The dispersed phase is embedded in the multiphase propylene copolymer in a discontinuous manner. The particle size of the dispersed phase is typically 0.05 to 2.0 micrometers and can be determined by transmission electron microscopy (TEM). The amount of ethylene-α-olefin copolymer dispersed in the multiphase propylene copolymer is sometimes referred to herein as RC.

[0055] The amount of ethylene monomer units in an ethylene-α-olefin copolymer can be, for example, 20 to 65% by weight. The amount of ethylene monomer units in an ethylene-α-olefin copolymer dispersed in a multiphase propylene copolymer may sometimes be referred to herein as RCC2.

[0056] Preferably, the α-olefin in the ethylene-α-olefin copolymer is selected from α-olefins having 3 to 8 carbon atoms. Suitable examples of α-olefins having 3 to 8 carbon atoms include, but are not limited to, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene. More preferably, the α-olefin in the ethylene-α-olefin copolymer is selected from α-olefins having 3 to 4 carbon atoms and any mixture thereof, more preferably propylene, in which case the ethylene-α-olefin copolymer is an ethylene-propylene copolymer.

[0057] The dispersed ethylene-α-olefin copolymer is present in an amount of 50 to 5% by weight. Preferably, the dispersed ethylene-α-olefin copolymer is present in an amount of 40 to 15% by weight based on the total multiphase propylene copolymer, for example, in an amount of at least 22% by weight and / or for example, in an amount of at most 35% by weight or at most 30% by weight.

[0058] In the multiphase propylene copolymer in the composition of the present invention, the sum of the total weight of the propylene-based matrix and the total weight of the dispersed ethylene-α-olefin copolymer is 100% by weight of the multiphase propylene copolymer.

[0059] Preferably, the α-olefin in the ethylene-α-olefin copolymer is selected from α-olefins having 3 to 8 carbon atoms and any mixture thereof. More preferably, the α-olefin in the ethylene-α-olefin copolymer is selected from α-olefins having 3 to 4 carbon atoms and any mixture 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 used 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.

[0060] The thermoplastic polymer composition (X) may further comprise an elastomer of ethylene and an α-olefin comonomer having 4 to 8 carbon atoms. The elastomer of ethylene and the α-olefin comonomer having 4 to 8 carbon atoms may, for example, have a content of 0.850 to 0.915 g / cm³. 3 The density of such elastomers. These types of elastomers are sometimes also called plastic bodies.

[0061] Preferably, the α-olefin comonomer in the elastomer is an acyclic monoolefin, such as 1-butene, 1-pentene, 1-hexene, 1-octene, or 4-methylpentene.

[0062] Therefore, preferably, the elastomer is selected from ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, and mixtures thereof, more preferably wherein the elastomer is selected from ethylene-1-octene copolymers. Most preferably, the elastomer is an ethylene-1-octene copolymer.

[0063] Preferably, the density of the elastomer is at least 0.865 g / cm³. 3 And / or at most 0.910 g / cm³ 3 For example, the density of the elastomer is at least 0.850, for example at least 0.865, for example at least 0.88, for example at least 0.90 and / or for example at most 0.915, for example at most 0.910, for example at most 0.907, for example at most 0.906 g / cm³. 3 More preferably, the density of the elastomer is from 0.88 to at most and including 0.907 g / cm³. 3 Most preferably, the density of the elastomer is from 0.90 to at most and including 0.906 g / cm³. 3 .

[0064] The elastomer suitable for use in this invention is commercially available, for example, from ExxonChemical, Inc., Houston, Texas, under the trademark EXACT. TM Purchased, or available from Dow Chemical Company, Midland, Michigan, under the trademark ENGAGE. TM The polymer (a series of metallocene-catalyzed plastics) is available, or can be purchased from the MITSUIChemicals Group in Minato, Tokyo, under the trademark TAFMER. TM Purchased, or obtained from SK Chemicals under the trademark Nexlene TM Purchased.

[0065] Elastomers can be prepared using methods known in the art, for example, 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, the ligand being coordinated to the transition metal cation via said 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 types of multiphase, multisite Ziegler-Natta catalysts.

[0066] 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, as measured according to ISO 1133 using 2.16 kg weight and at 190°C.

[0067] 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%, for example, 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 typically be up to 97.5 mol%, for example, up to 95 mol% or up to 90 mol.

[0068] In a preferred embodiment, the thermoplastic polymer composition (X) comprises a thermoplastic polymer, wherein the thermoplastic polymer is a propylene homopolymer having an MFI of 78 to 180 dg / min, preferably 78 to 148 dg / min, preferably 95 to 122 dg / min, more preferably 96 to 119 dg / min, and even more preferably 103 to 118 dg / min, as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0069] Other additives in thermoplastic polymer composition (X)

[0070] Thermoplastic polymer composition (X) may contain other commonly used additives, such as nucleating and clarifying agents, stabilizers, release agents, fillers, peroxides, plasticizers, antioxidants, lubricants, antistatic agents, crosslinking agents, antiscratch agents, high-performance fillers, impact modifiers, foaming agents, deacidifying agents, recycling additives, coupling agents, antimicrobial agents, antifogging additives, slip additives, anti-blocking additives, polymer processing aids, flame retardants, and the like. These additives are well known in the art. Those skilled in the art will understand how to select the type and amount of additives so that they do not adversely affect the target properties.

[0071] Preferably, the amount of the thermoplastic polymer composition (X) is 25 to 75% by weight relative to the total amount of the glass fiber reinforced polymer composition (G), for example, 25 to 45% by weight, 45 to 60% by weight, or 60 to 75% by weight.

[0072] Glass multifiber strand

[0073] Fiberglass is typically supplied as multiple continuous, very long filaments, and in the form of strands, rovings, or yarns. A filament is a single fiber that reinforces the material. A strand is multiple bundled filaments. Yarn is a collection of strands, such as strands twisted together. Rovings refer to a collection of strands wound into a package.

[0074] For the purposes of this invention, glass multifiber strands are defined as multiple bundled glass fibers.

[0075] Glass multifiber strands and their preparation are known in the art.

[0076] The filament density of a continuous glass multifiber strand can vary within a wide range. For example, a continuous glass multifiber strand may have at least 500, for example, at least 1,000 glass filaments per strand and / or up to 10,000, for example, up to 5,000 grams per 1,000 meters. Preferably, the amount of glass filaments per strand is between 500 and 10,000 grams per 1,000 meters.

[0077] Preferably, the thickness of the glass fiber is 5 to 50 μm, more preferably 10 to 30 μm, and even more preferably 15 to 25 μm. Typically, the glass fiber has a circular cross-section, meaning that the thickness as defined above refers to the diameter. Glass fibers generally have a circular cross-section.

[0078] The length of the glass fiber filaments is generally unrestricted, as it is approximately equal to the length of the sheathed continuous multifilament strand. However, for practical reasons of manipulating the strands, it may be necessary to cut the sheathed continuous multifilament strands into shorter strands. For example, the length of the sheathed continuous multifilament strand may be at least 1 m, for example at least 10 m, for example at least 50 m, for example at least 100 m, for example at least 250 m, for example at least 500 m, and / or for example at most 25 km, for example at most 10 km.

[0079] Preferably, the continuous glass multifiber strand contains at most 2% by weight, preferably 0.10 to 1% by weight, of a sizing agent based on the continuous glass multifiber strand. The amount of sizing agent can be determined using ISO 1887:2014.

[0080] The sizing composition is typically applied to the glass fibers before they are bundled into continuous glass multifiber strands.

[0081] Suitable examples of sizing compositions include solvent-based compositions, such as organic materials dissolved in aqueous solutions or dispersed in water, and melt- or radiation-cured compositions. Preferably, the sizing composition is an aqueous sizing composition.

[0082] As described in the art, for example in documents EP1460166A1, EP0206189A1 or US4338233, aqueous sizing compositions may include film-forming agents, coupling agents and other additional components.

[0083] Film-forming agents are typically present in an effective amount to protect fibers from interfilament abrasion and to provide the 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 contain polyolefin waxes.

[0084] Coupling agents are generally used to improve the adhesion between the matrix thermoplastic polymer and the fiber reinforcement. Suitable examples of coupling agents known in the art for use with glass fibers include organofunctional silanes. More specifically, coupling agents added to the sizing composition are aminosilanes, such as aminomethyl-trimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl-trimethoxysilane, γ-aminopropyl-trimethoxysilane, γ-methylaminopropyl-trimethoxysilane, δ-aminobutyl-triethoxysilane, and 1,4-aminophenyl-trimethoxysilane. Preferably, the sizing composition contains aminosilanes to achieve good adhesion to the thermoplastic matrix. The sizing composition may also contain any other additional components known to those skilled in the art as suitable for sizing compositions. Suitable examples include, but are not limited to, lubricants (used to prevent damage to the strands due to abrasion), antistatic agents, crosslinking agents, plasticizers, surfactants, nucleating agents, antioxidants, pigments, and mixtures thereof.

[0085] Typically, after the sizing composition is applied to the glass fibers, the fibers are bundled into continuous glass multifiber strands and then wound onto a spool to form a package.

[0086] Preferably, the amount of glass fiber strands is 20 to 70% by weight relative to the glass fiber reinforced polymer composition (G), for example, 20 to 35% by weight, 35 to 50% by weight, or 50 to 70% by weight. Since higher concentrations of glass fibers generally result in more white spots, the effects of the present invention may be more pronounced when the concentration of glass fibers is higher.

[0087] Coupling agent

[0088] The impregnated continuous multifiber strands may contain a coupling agent as part of the aforementioned sizing agent. Alternatively, the thermoplastic polymer composition (X) may contain a coupling agent.

[0089] The coupling agent may be a functionalized polyolefin grafted with acid or anhydride functional groups. The polyolefin is preferably polyethylene or polypropylene, more preferably polypropylene. The polypropylene may be a propylene homopolymer or a propylene copolymer. The propylene copolymer may be a propylene-α-olefin copolymer comprising at least 70% by weight of propylene and at most 30% by weight of an α-olefin, such as ethylene, based on the total weight of the propylene-based matrix; for example, comprising at least 80% by weight of propylene and at most 20% by weight of an α-olefin; for example, comprising at least 90% by weight of propylene and at most 10% by weight of an α-olefin. Preferably, the α-olefin in the propylene-α-olefin copolymer is selected from α-olefins having 2 or 4-10 carbon atoms and is preferably ethylene. Examples of acid or anhydride functional groups include (meth)acrylic acid and maleic anhydride. Particularly suitable materials are, for example, maleic acid-functionalized propylene homopolymers (e.g., Exxelor PO 1020 supplied by Exxon).

[0090] The amount of coupling agent may be, for example, 0.5 to 3.0% by weight, preferably 1.0 to 2.0% by weight, based on the total amount of the glass fiber-reinforced polymer composition (G).

[0091] Impregnating agent

[0092] Preferably, the amount of impregnating agent in step b) of the method according to the invention is 0.50 to 18.0% by weight, for example 0.5 to 10.0% by weight, or for example 10.0 to 18.0% by weight, based on the total weight of the glass fiber reinforced polymer composition (G).

[0093] The optimal amount of impregnating agent applied to the continuous glass multifiber 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 impregnating agent applied to the continuous glass multifiber strand is, for example, 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 up to 10.0 wt%, preferably up to 9.0 wt%, more preferably up to 8.0 wt%, even more preferably up to 7.0 wt%, even more preferably up to 6.0 wt%, even more preferably up to 5.5 wt%, or for example, at least 10.0 wt%, preferably at least 11 wt%, preferably at least 12 wt%, and / or up to 18 wt%, preferably up to 16 wt%, preferably up to 14%. Preferably, the amount of impregnating agent is 1.5 to 8 wt%, even more preferably 2.5 wt% to 6.0 wt%, based on the sheathed continuous multifiber strand. A larger amount of impregnating agent increases the impact energy per unit thickness (J / mm). However, for cost-effectiveness, low emissions (volatile organic compounds), and mechanical properties, the amount of impregnating agent should not become excessive.

[0094] For example, the ratio of impregnating agent to continuous glass multifiber strands is 1:4 to 1:30, preferably 1:5 to 1:20.

[0095] Preferably, the viscosity of the impregnating agent is 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, more preferably at most 100.0 cSt.

[0096] Impregnating agents with a viscosity higher than 100 cSt are difficult to apply to continuous glass multifiber strands. Low viscosity is required to promote good wetting properties of the fibers, but impregnating agents with a viscosity lower than 2.5 cSt are difficult to handle, for example, it is difficult to control the amount to be applied; and the impregnating agent may become volatile. For the purposes of this invention, unless otherwise specified, the viscosity of the impregnating agent is measured at 160°C according to ASTM D3236-15 (Standard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coatings, Brookfield Viscometer RVDV2, #27 Rotor, 5 r / min).

[0097] Preferably, the melting point (lowest melting temperature in the melting temperature range) of the impregnating agent is at least 20°C lower than the melting point of the thermoplastic polymer composition. More preferably, the impregnating agent has a melting point 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.

[0098] A suitable impregnating agent is compatible with the thermoplastic polymer to be reinforced and may even be soluble in the polymer. Those skilled in the art can select a suitable combination based on general knowledge, and such combinations can also be found in the art.

[0099] Suitable examples of impregnating agents include low molar mass compounds such as low molar mass 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.

[0100] Preferably, for reinforced polypropylene, the impregnating agent comprises highly branched polyalphaolefins, such as highly branched polyethylene, modified low molecular weight polypropylene, mineral oils, such as paraffin or silicone, and any mixture of these compounds.

[0101] Preferably, the impregnating agent comprises at least 20% by weight, more preferably at least 30% by weight, more preferably at least 50% by weight, for example at least 99.5% by weight, for example 100% by weight, of branched polyalphaolefin, most preferably branched polyethylene.

[0102] To achieve a viscosity of 2.5 to 200 cSt at 160°C, branched polyalphaolefins can be mixed with oils selected from: mineral oils, such as paraffin oils or silicone oils; hydrocarbon oils; and any mixtures thereof.

[0103] Preferably, the impregnating agent is non-volatile and / or substantially solvent-free. In the context of this invention, "non-volatile" means that the impregnating agent has a boiling point or boiling range higher than the temperature at which the impregnating agent is applied to a continuous multi-filament glass strand. In the context of this invention, "substantially solvent-free" means that the impregnating agent contains less than 10% by weight of solvent, preferably less than 5% by weight, based on the amount of impregnating agent. In a preferred embodiment, the impregnating agent does not contain any organic solvents.

[0104] The 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 tackifiers, such as modified polypropylene with maleic acid reactive groups, and any combination thereof, provided that the viscosity is maintained within the desired range. Any method known in the art can be used to apply the impregnating agent to a continuous glass multifiber strand. The application of the impregnating agent can be performed using a die. Other suitable methods for applying the impregnating agent to a continuous multifiber strand include applicators with belts, rollers, and hot melt applicators. Such methods are described, for example, in documents EP0921919B1, EP0994978B1, EP0397505B1, WO2014 / 053590A1, and the references cited therein. The method used should enable the application of a constant amount of impregnating agent to the continuous multifiber strand.

[0105] Preferably, the amount of impregnated continuous multifiber strands obtained in step b) of the method according to the invention is 25 to 75% by weight relative to the glass fiber reinforced thermoplastic polymer composition (G), for example 25 to 40% by weight, 40 to 55% by weight, or 55 to 75% by weight. Preferably, the total amount of the impregnated continuous multifiber strands and the polymer sheath is 100% by weight relative to the sheathed continuous multifiber strands.

[0106] Glass fiber reinforced thermoplastic polymer composition (G)

[0107] This invention relates to a glass fiber reinforced thermoplastic polymer composition (G). This glass fiber reinforced thermoplastic polymer composition (G) can be prepared, for example, by the method according to the invention.

[0108] The glass fiber reinforced thermoplastic polymer composition (G) is a sheathed continuous multifiber strand comprising a longitudinally extending core and a polymer sheath tightly surrounding the core, wherein the core comprises an impregnated continuous multifiber strand containing at least one continuous glass multifiber strand, wherein at least one continuous glass multifiber strand is impregnated with an impregnating agent, wherein the polymer sheath is composed of a thermoplastic polymer composition (X), wherein the MFI of the thermoplastic polymer composition (X) is 78 to 180 dg / min as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0109] The core of the sheathed continuous multifiber strand comprises impregnated continuous multifiber strands, such as one or more impregnated continuous multifiber strands. For example, the impregnated continuous multifiber strands can be prepared in step b) of the invention. Preferably, one or more impregnated continuous multifiber strands form a core of at least 90% by weight, more preferably at least 93% by weight, even more preferably at least 95% by weight, even more preferably at least 97% by weight, even more preferably at least 98% by weight, for example at least 99% by weight. In a preferred embodiment, each core consists of one or more impregnated continuous multifiber strands.

[0110] In the context of this invention, "extending in the longitudinal direction" means "oriented in the long axis direction of a sheathed continuous multifilament strand".

[0111] As used herein, the term "closely surrounding" should be understood to mean that the polymer sheath is substantially in complete contact with the core. In other words, the sheath is applied to the core in such a manner that there is no intentional gap between the inner surface of the sheath and the core containing the impregnated continuous multifilament strands. Nevertheless, those skilled in the art will understand that a small gap may form between the polymer sheath and the glass filaments due to process variations. Therefore, preferably, the polymer sheath contains less than 5% by weight, more preferably less than 2% by weight, of the filaments based on the total weight of the polymer sheath.

[0112] In one embodiment, the thermoplastic polymer composition (X) of the polymer sheath is the thermoplastic polymer composition (X) used in step c) of the method according to the invention.

[0113] In a preferred embodiment, the thermoplastic polymer composition (X) of the polymer sheath comprises a thermoplastic polymer, wherein the thermoplastic polymer is a propylene homopolymer having an MFI of 78 to 180 dg / min, preferably 78 to 148 dg / min, preferably 95 to 122 dg / min, more preferably 96 to 119 dg / min, and even more preferably 103 to 118 dg / min, as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0114] Preferably, the amount of thermoplastic polymer is 65.1 to 99.5% by weight, more preferably 85.3 to 99.2% by weight, and even more preferably 93.2 to 99.0% by weight, based on the total amount of the thermoplastic polymer composition (X).

[0115] In one embodiment, the impregnating agent in the sheathed continuous multifiber strand is the impregnating agent used in step b) of the method according to the invention.

[0116] In one embodiment, at least one continuous glass multifiber strand in the sheathed continuous multifiber strand is at least one continuous glass multifiber strand used in step a) of the method according to the invention.

[0117] The present invention also relates to the use of glass fiber reinforced thermoplastic polymer compositions (G) in automotive applications.

[0118] The present invention also relates to automotive parts comprising a glass fiber reinforced thermoplastic polymer composition (G), wherein the amount of the glass fiber reinforced thermoplastic polymer composition (G) is at least 95% by weight based on the total weight of the automotive part.

[0119] Automotive parts can be prepared, for example, by injection molding a glass fiber reinforced thermoplastic polymer composition (G).

[0120] It should be noted that the present invention relates to any possible combination of features described herein, preferably, in particular, those combinations of features presented in the claims, which are individually defined or combined in the independent claims. Therefore, it is to be understood that all combinations of features relating to compositions according to the invention, all combinations of features relating to methods according to the invention, and all combinations of features relating to compositions according to the invention and features relating to methods according to the invention are described herein.

[0121] It should be further noted that the terms 'comprising,' 'including,' and 'containing' do not exclude the presence of other elements. However, it should also be understood that descriptions of products / compositions comprising certain components also disclose products / compositions composed of those components. Products / compositions composed of these components may be advantageous because they provide a simpler and more economical method for preparing the product / composition. Similarly, it should be understood that descriptions of methods including certain steps also disclose methods composed of those steps. Methods composed of these steps may be advantageous because they provide a simpler and more economical method.

[0122] The present invention will now be illustrated by means of the following embodiments, but the present invention is not limited thereto.

[0123] experiment

[0124] Material

[0125] PP1: PP1 is PP 595A, commercially available from SABIC. PP 595A is a propylene homopolymer. The MFI of PP 595A is 46 dg / min, measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0126] PP2: PP2 is TI2600C, commercially available from Braskem. TI2600C is a multiphase propylene homopolymer. The MFI of TI2600C is 66 dg / min, measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0127] PP3: PP3 is TI2900C, commercially available from Braskem. TI2900C is a propylene homopolymer. The MFI of TI2900C is 115 dg / min, measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

[0128] Glass fiber strands: TUFRov LFT9000, commercially available from PPG Glass Fiber, is used. TUFRov LFT9000 glass fibers have a diameter of 19 micrometers, and the glass fiber strands have a density of 3000 tex (tex refers to the weight of glass per 1000m).

[0129] Impregnating agent: Highly branched polyethylene wax, with a density of 890-960 kg / m³ 3 Dynamic viscosity: 40-58 mPa·s at 100°C (ASTM D3236) (Dicera 13082 Paramelit).

[0130] Talc: HTPultra 5c is an ultrafine talc commercially available from IMI FABIC. The average talc particle size (D50) of HTPultra 5c is 0.65 μm, measured according to sedimentation analysis and Stockes's Law (ISO 13317-3:2001).

[0131] Additive package: The additive package consists of 70% by weight Exxelor PO1020 from ExxonMobil as a coupling agent, 10% by weight Sabostab UV 119 from SABO as a UV stabilizer, and 20% by weight from BASF. B 225 is a stabilizer component. Percentages are based on the total amount of the additive package.

[0132] method

[0133] Using the PP1, PP2, PP3, glass fiber strands, impregnating agent, and additive package given in Table 1, glass fiber reinforced polymer compositions were prepared using the following method:

[0134] Unwind the glass fiber strands;

[0135] An impregnating agent is applied to glass fiber strands to form impregnated strands;

[0136] In the sheathing step, which is performed online directly after the impregnation step, a thermoplastic polymer sheath is applied around the impregnated filaments. Molten PP1, PP2, or PP3, along with an additive package, is fed into the wire coating die at the extruder head using a 75mm twin-screw extruder (manufactured by Berstorff, screw UD ratio 34) at approximately 250°C. The linear speed is 200 m / min.

[0137] The sheathed filaments are then cooled in a water bath and subsequently cut into 15mm long pellets.

[0138] Samples and Evaluation

[0139] The obtained granules were injection molded into plates with dimensions of 510 × 310 × 2 mm. The number of visible white spots on one side of the plate was counted. A total of 15 plates were evaluated for each composition, and the average white spot (WS) value was calculated, as shown in Table 1.

[0140] result

[0141] Table 1. Compositions and vitiligo performance of the embodiments.

[0142] CE1 CE2 IE1 PP1 (wt%) 50 PP2 (wt%) 50 PP3 (wt%) 50 Talc (wt%) 3 3 3 Glass fiber strands (by weight %) 40 40 40 Impregnating agent (wt%) 4 4 4 Additive package (by weight %) 3 3 3 WS 4.3 2.9 2.1

[0143] As shown in Table 1, only the IE1 according to the present invention has improved vitiligo performance.

Claims

1. A method for preparing a glass fiber reinforced thermoplastic polymer composition (G), comprising the following steps: a) Unwind at least one continuous glass multifiber strand from the packaging; b) Apply an impregnating agent to the continuous glass multifiber strand to form an impregnated continuous multifiber strand; c) Apply a sheath of thermoplastic polymer composition (X) around the impregnated continuous multifiber strand to form a sheathed continuous multifiber strand, wherein the melt flow index (MFI) of the thermoplastic polymer composition (X) is 78 to 180 dg / min as measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

2. The method according to claim 1, wherein the thermoplastic polymer composition (X) comprises a thermoplastic polymer.

3. The method according to claim 2, wherein the thermoplastic polymer is polypropylene.

4. The method according to claim 2, wherein the thermoplastic polymer is a propylene homopolymer.

5. The method according to any one of claims 1-4, wherein the MFI of the thermoplastic polymer composition (X) is 78 to 148 dg / min.

6. The method according to any one of claims 1-4, wherein the MFI of the thermoplastic polymer composition (X) is 95 to 122 dg / min.

7. The method according to any one of claims 1-4, wherein the MFI of the thermoplastic polymer composition (X) is 96 to 119 dg / min.

8. The method according to any one of claims 1-4, wherein the MFI of the thermoplastic polymer composition (X) is 103 to 118 dg / min.

9. The method according to any one of claims 1-4, wherein the amount of the glass multifiber strands in the composition is 20 to 70% by weight based on the total weight of the glass fiber reinforced thermoplastic polymer composition.

10. The method according to any one of claims 1-4, wherein the amount of the glass multifiber strands in the composition is 20 to 35% by weight based on the total weight of the glass fiber reinforced thermoplastic polymer composition.

11. The method according to any one of claims 1-4, wherein the amount of the glass multifiber strands in the composition is 35 to 50% by weight based on the total weight of the glass fiber reinforced thermoplastic polymer composition.

12. The method according to any one of claims 1-4, wherein the amount of the glass multifiber strands in the composition is 50 to 70% by weight based on the total weight of the glass fiber reinforced thermoplastic polymer composition.

13. The method according to any one of claims 1-4, wherein the method is operated at a linear speed of at least 100 m / min.

14. The method according to any one of claims 1-4, wherein the method further comprises the following subsequent steps after step c) to obtain the glass fiber reinforced thermoplastic polymer composition (G) in granular form: d) Cooling the sheathed continuous glass multifiber strands; e) Cut the sheathed continuous glass multifiber strands into granules.

15. The method of claim 14, wherein the cooling step d) is carried out in a water bath.

16. The method of claim 14, wherein the pellets obtained in cutting step e) have a length of 2 to 50 mm.

17. A glass fiber reinforced thermoplastic polymer composition (G) comprising a sheathed continuous multifilament strand, said sheathed continuous multifilament strand comprising a longitudinally extending core and a polymer sheath tightly surrounding said core, The core comprises an impregnated continuous multifiber strand containing at least one continuous glass multifiber strand, wherein the at least one continuous glass multifiber strand is impregnated with an impregnating agent. The polymer sheath is composed of a thermoplastic polymer composition (X). The MFI of the thermoplastic polymer composition (X) is 78 to 180 dg / min, measured according to ISO 1133-1:2011 at a load of 2.16 kg and a temperature of 230 °C.

18. The glass fiber reinforced thermoplastic polymer composition of claim 17, wherein the thermoplastic polymer composition (X) comprises a thermoplastic polymer, wherein the amount of the thermoplastic polymer is 65.1 to 99.5 by weight based on the total amount of the thermoplastic polymer composition (X).

19. The glass fiber reinforced thermoplastic polymer composition of claim 17, wherein the thermoplastic polymer composition (X) comprises a thermoplastic polymer, wherein the amount of the thermoplastic polymer is 85.3 to 99.2 by weight based on the total amount of the thermoplastic polymer composition (X).

20. The glass fiber reinforced thermoplastic polymer composition of claim 17, wherein the thermoplastic polymer composition (X) comprises a thermoplastic polymer, wherein the amount of the thermoplastic polymer is 93.2 to 99.0 by weight based on the total amount of the thermoplastic polymer composition (X).

21. The glass fiber reinforced thermoplastic polymer composition according to any one of claims 18-20, wherein the thermoplastic polymer is a propylene homopolymer.

22. Use of the glass fiber reinforced thermoplastic polymer composition according to any one of claims 17-20 in automotive applications.

23. Use of the product of the method according to any one of claims 1 to 16 in automotive applications.

24. An automotive component comprising a glass fiber reinforced thermoplastic polymer composition (G) according to any one of claims 17-21, wherein the amount of the glass fiber reinforced thermoplastic polymer composition is at least 95% by weight based on the total weight of the automotive component.