Glass fiber reinforced thermoplastic polymer composition

Abstract

The invention relates to a glass fiber reinforced thermoplastic polymer composition comprising a sheathed continuous multifilament strand comprising a core extending in the longitudinal direction and a polymer sheath tightly surrounding said core, wherein the core comprises at least one continuous glass multifilament strand and wherein the polymer sheath consists of a thermoplastic polymer composition comprising a polyester composition consisting of poly(1,4-butylene terephthalate) and poly(ethylene terephthalate) in a weight ratio of 55:45 to 75:25.

Description

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

[0002] Glass fiber reinforced thermoplastic polymer compositions are known. The use of both short and long glass fibers is known. Articles made from thermoplastic polymer compositions reinforced with short glass fibers have their advantages, but as described in Thomason & Vlug, Comp Part A, 1996, pp. 1075-1084, articles made from thermoplastic polymer compositions reinforced with long glass fibers generally have better stiffness and impact resistance.

[0003] Long glass fiber reinforced thermoplastic polymer compositions, such as STAMAX, available from SABIC. TM The material can be prepared by a method comprising the following sequential steps: unwinding a continuous glass multifiber strand from a roll, and applying a polypropylene sheath around the multifiber strand to form a sheathed continuous multifiber strand.

[0004] This method is described in WO2009 / 080281. The published patent application discloses a method for preparing a long glass fiber reinforced thermoplastic polymer composition, comprising the following sequential steps: i) unwinding at least one continuous glass multifiber strand from a roll, 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 around the impregnated continuous multifiber strand to form a sheathed continuous multifiber strand.

[0005] While known long glass fiber reinforced thermoplastic polymer compositions are satisfactory for many applications, there is a need for compositions that can be used in a wider range of situations.

[0006] One object of the present invention is to provide a glass fiber reinforced thermoplastic polymer composition comprising a sheathed continuous multifiber strand that can be further processed at higher temperatures than known glass fiber reinforced polypropylene compositions. Another object of the present invention is to provide a glass fiber reinforced thermoplastic polymer composition having improved mechanical properties and / or environmental benefits.

[0007] Therefore, the present invention provides a glass fiber reinforced thermoplastic polymer composition comprising a sheathed continuous multifilament strand comprising a longitudinally extending core and a polymer sheath tightly surrounding the core.

[0008] The core comprises at least one continuous glass multifiber strand, and

[0009] The polymer sheath is composed of a thermoplastic polymer composition comprising a polyester composition consisting of poly(1,4-butylene terephthalate) (PBT) and polyethylene terephthalate (PET) in a weight ratio of 55:45 to 75:25.

[0010] The present invention also provides a method for producing a glass fiber reinforced thermoplastic polymer composition according to the invention, wherein a sheathed continuous multifiber strand is prepared by the following sequential steps:

[0011] a) Unwind at least one continuous glass multifiber strand from the roll.

[0012] Optionally b) applying an impregnating agent to at least one continuous glass multifiber strand to form an impregnated continuous multifiber strand, and

[0013] c) Apply a polymer sheath around an optional impregnated continuous multifiber strand to form a sheathed continuous multifiber strand.

[0014] Details relating to steps a)-c) are set forth in WO2009 / 080281A1, which is incorporated herein by reference, except for the type of thermoplastic polymer composition used in accordance with the invention.

[0015] The method for producing glass fiber reinforced thermoplastic polymer compositions according to the present invention may further include the following steps:

[0016] d) Cut the sheathed continuous glass multifiber strands into granules.

[0017] The inventors have surprisingly discovered that the glass fiber reinforced thermoplastic polymer compositions according to the invention can be prepared by using specific polyester compositions. For example, the thermoplastic polymer compositions according to the invention, in granule form, can be further processed at higher temperatures than granules of known glass fiber reinforced polypropylene compositions, for example, by injection molding. This is advantageous because the higher temperature reduces shear stress at the die, which helps to reduce melt fracture. Furthermore, polyester is a low-friction material, which helps to reduce die swell. In addition, the compositions according to the invention crystallize rapidly, requiring less time to obtain granules than granules of polyolefins.

[0018] The glass fiber reinforced thermoplastic polymer composition according to the invention exhibits excellent heat resistance, as shown, for example, a Vicat temperature above 200°C measured by ISO 306 / A with a 10N load. This allows lighter plastic parts to be painted together with metal parts, facilitating processes such as efficient automotive body construction; for example, E-coating.

[0019] Sheathed continuous multifiber strands

[0020] The glass fiber reinforced thermoplastic polymer composition according to the invention (which may be in granular form) comprises or is composed of sheathed continuous multifilament strands. The sheathed continuous multifilament strands comprise or are composed of a core and a polymer sheath. The core has a generally cylindrical shape and comprises optionally impregnated continuous multifilament strands containing glass fibers. The core is tightly surrounded at its periphery by a polymer sheath having a generally tubular shape and composed of the thermoplastic polymer composition. The glass fibers have a length substantially equal to the axial length of the granules.

[0021] The core is essentially unsheathed. The sheath is essentially free of glass fibers. This granular structure can be obtained by, for example, the line coating process disclosed in WO2009 / 080281, and differs from the granular structure obtained by, for example, the typical pultrusion process disclosed in US6,291,064.

[0022] Preferably, the polymer sheath is substantially free of glass fibers, meaning that it contains less than 2 wt% glass fibers based on the total weight of the polymer sheath.

[0023] Preferably, the core has a radius of 800-4000 micrometers, and / or the polymer sheath has a thickness of 500-1500 micrometers.

[0024] Preferably, the core accounts for 25-40 wt% of the cross-sectional area of ​​the pellets, and the sheath accounts for 60-75 wt% of the cross-sectional area of ​​the pellets.

[0025] Preferably, the amount of continuous glass multifiber strands is 20-40 wt%, for example 25-35 wt%, relative to the continuous multifiber strands of the sheath. Preferably, the amount of thermoplastic polymer composition is 55-80 wt%, for example 60-70 wt%, relative to the continuous multifiber strands of the sheath. Preferably, the total amount of continuous glass multifiber strands and thermoplastic polymer composition is 100 wt%, relative to the continuous multifiber strands of the sheath.

[0026] Polymer sheath

[0027] The sheath tightly surrounds the core. As used herein, the term "tightly surrounds" 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, which comprises impregnated continuous multifilament strands. However, those skilled in the art will understand that, as a result of process variations, a small gap may form between the polymer sheath and the core.

[0028] The polymer sheath is composed of a thermoplastic polymer composition.

[0029] The thermoplastic polymer composition includes a polyester composition comprising poly(butylene terephthalate) (PBT) and poly(ethylene terephthalate) (PET) in a weight ratio of 55:45 to 75:25, preferably 60:40 to 70:30. In other words, the polyester composition does not contain a third polyester other than PBT and PET.

[0030] Preferably, the thermoplastic polymer composition consists of a polyester composition and conventional additives described below.

[0031] Preferably, the thermoplastic polymer is free of acrylonitrile butadiene styrene (ABS). Preferably, the thermoplastic polymer is free of polyolefins, such as polyethylene or polypropylene.

[0032] Preferably, PEB is a virgin material, and PET is a post-consumer or post-industrial recycled material.

[0033] Virgin plastics are new, direct resins produced using materials such as natural gas or crude oil without any recycled materials. Recycled plastics, on the other hand, are resins that have already undergone their life cycle as virgin plastics. Recycled plastics are typically produced through mechanical or chemical recycling. The most common method for recycling plastic waste is mechanical recycling. This process generally involves the collection, sorting, washing, and grinding of the material. Depending on the source and composition of the waste, these steps may be performed in different sequences, multiple times, or not at all.

[0034] Mechanically recycled polymers can be either post-consumer recycled polymers (PCPs) or post-industrial recycled polymers (PIPs). Post-consumer recycled (PCR) materials refer to materials made from items recycled by consumers. Typically, recyclable items (such as plastics, metals, and cardboard / paper) are collected by local recycling programs and transported to facilities for sorting based on material type. The recycled bales are then purchased and sent to different recyclers for use in various final products. Using PCR content (i.e., recycled materials) in new products generates environmental benefits such as carbon savings and resource efficiency. Furthermore, it reduces the need for virgin raw materials and improves the lifespan of materials. Incorporating PCR into production supports the development of a circular economy.

[0035] Additives in thermoplastic polymer compositions of polymer sheaths

[0036] The thermoplastic polymer composition of the polymer sheath may contain other conventional additives, such as nucleating and clarifying agents, stabilizers, fillers, plasticizers, antioxidants, lubricants, antistatic agents, antiscratch agents, impact modifiers, deacidifying agents, recycling additives, coupling agents, antibacterial agents, antifogging additives, slip additives, anti-blocking additives, polymer processing aids, flame retardants, colorants, etc. These additives are well known in the art. Those skilled in the art will know how to select the type and amount of additives so that they do not adversely affect the target properties. The amount of additives may be, for example, 0.1-50 wt% of the thermoplastic polymer composition, such as 0.1-25 wt%, or 1.0-5.0 wt%.

[0037] In some preferred embodiments, the additives in the thermoplastic polymer composition of the polymer sheath include coupling agents.

[0038] Suitable examples of coupling agents include functionalized polyolefins grafted with acid or anhydride functional groups. The polyolefin is preferably polyethylene or polypropylene, more preferably polypropylene. The polypropylene can be a propylene homopolymer or a propylene copolymer. The propylene copolymer can be a propylene-α-olefin copolymer comprising at least 70 wt% propylene and at most 30 wt% α-olefin, such as ethylene, for example, at least 80 wt% propylene and at most 20 wt% α-olefin, for example, at least 90 wt% propylene and at most 10 wt% α-olefin, based on the total weight of the propylene-based matrix. 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).

[0039] The amount of coupling agent can be, for example, 0.5-3.0 wt% based on the sheathed continuous multifiber strands, preferably 1.0-2.0 wt%.

[0040] In some preferred embodiments, the additives in the thermoplastic polymer composition of the polymer sheath include flame retardants. These flame retardants may include organic and / or inorganic flame retardants.

[0041] In some preferred embodiments, the amount of flame retardant, particularly organic flame retardant, is 0.1-50 wt% relative to the thermoplastic polymer composition of the polymer sheath, for example at least 1.0 wt%, at least 5.0 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, and / or at most 45 wt%, or at most 40 wt%.

[0042] core

[0043] The sheathed continuous multifiber strands comprise a longitudinally extending core. The core comprises optionally impregnated continuous multifiber strands, which include at least one continuous glass multifiber strand. The impregnated continuous multifiber strands are prepared from continuous glass multifiber strands and an impregnating agent.

[0044] Preferably, at least 90 wt% of the core is formed by at least one optionally impregnated continuous multifiber strand, more preferably at least 93 wt%, even more preferably at least 95 wt%, even more preferably at least 97 wt%, even more preferably at least 98 wt%, for example at least 99 wt%. In a preferred embodiment, the core consists of at least one optionally impregnated continuous multifiber strand.

[0045] In the context of this invention, "extending in the longitudinal direction" means "oriented in the direction of the long axis of the continuous multifilament strands of the sheath".

[0046] glass fiber

[0047] Continuous multifilament strands contain glass filaments. Glass fibers are typically supplied in the form of multiple continuous, very long filaments and can be in the form of strands, rovings, or yarns. A filament is a single fiber that reinforces the material. A strand is a bundle of multiple filaments. A yarn is a collection of strands, such as strands twisted together. Rovings refer to a collection of strands wound into a spool.

[0048] For the purposes of this invention, glass multifiber strands are defined as multiple bundles of glass fibers.

[0049] Glass multifiber strands and their preparation are known in the art.

[0050] The fiber density of continuous glass multifiber strands can vary over a wide range. For example, continuous glass multifiber strands can have a density of 1,000-10,000 g / 1,000 m.

[0051] Preferably, the continuous glass multifiber strand has a density of 1000-2900 g / 1000 m, more preferably 1500-2800 g / 1000 m.

[0052] Continuous glass multifilament strands can have filament diameters of 5-50 μm, more preferably 10-30 μm, and even more preferably 15-25 μm. Typically, glass filaments have a circular cross-section, meaning that the thickness as defined above corresponds to the diameter. Glass filaments are typically circular in cross-section.

[0053] Preferably, the ratio of the length to the diameter of the glass fiber in the granules (L / D ratio) is 500-1000.

[0054] The length of the glass fiber filaments is, in principle, unlimited, as it is essentially equal to the length of the continuous multifiber strands encased in the sheath. However, for practical reasons, it may be necessary to cut the continuous multifiber strands encased in the sheath into shorter strands. For example, the length of the continuous multifiber strands encased in the sheath 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.

[0055] Preferably, the glass fiber strands are coated with a sizing agent composition (i.e., a coating) to improve adhesion to the polymer matrix. The sizing agent composition may be applied to substantially all or a portion of the glass fibers in the thermoplastic composition. The sizing agent provides coated glass fibers that can be bonded or non-bonded to the thermoplastic polymer composition of the sheath. Preferably, the coated glass fibers are bonded to the polyester in the thermoplastic polymer composition of the sheath.

[0056] The sizing agent composition may include polyepoxides, poly(meth)acrylates, poly(aryl ethers), polyurethanes, or combinations thereof. The polyepoxide may be a phenolic epoxy resin, an epoxidized carboxylic acid derivative (e.g., a reaction product of an ester of a polycarboxylic acid having one or more unesterified carboxyl groups and a compound containing more than one epoxy group), an epoxidized diene polymer, an epoxidized polyene polymer, or a combination thereof.

[0057] The sizing agent composition may also contain a silane coupling agent to promote adhesion to the glass fiber. The silane coupling agent may be tri(C) 1-6 Alkoxy) monoaminosilane, tri(C 1-6 Alkoxy)diaminosilane, tri(C 1-6 Alkoxy)(C 1-6 Alkylurea)silane, tri(C 1-6 Alkoxy (epoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (glycidoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (Mercapto C) 1-6 Alkyl)silanes or combinations thereof. For example, silane coupling agents are (3-aminopropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (2-(3,4-epoxycyclohexyl)ethyl)triethoxysilane, (3-mercaptopropyl)trimethoxysilane, (3-(2-aminoethylamino)propyl)triethoxysilane, (3-ureidopropyl)triethoxysilane, or combinations thereof. Preferably, the silane coupling agent is aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, or combinations thereof.

[0058] Other materials that may be included in the sizing agent composition include, but are not limited to, antistatic agents, coupling agents, lubricants, wetting agents, or the like.

[0059] The sizing composition may be present in an amount of 0.1-5 wt% based on the weight of at least one continuous glass multifiber strand. The sizing composition may be applied to the glass fibers by any means, such as immersing the glass multifiber strand in the sizing composition or contacting the glass multifiber strand with an aqueous emulsion or suspension of the sizing composition. Other coating methods include applying an aqueous dispersion of the sizing composition continuously to the uncoated glass multifiber strand via rollers, followed by a heat treatment or curing step.

[0060] Typically, after applying a sizing agent composition to glass fibers, the fibers are bundled into continuous glass multifiber strands and then wound onto a spool to form a package.

[0061] Impregnating agent

[0062] The continuous glass multifiber strands are optionally impregnated with an impregnating agent, preferably in an amount of 0.50-18.0 wt% relative to the continuous multifiber strands encased in the sheath.

[0063] Preferably, the amount of impregnating agent relative to the continuous multifilament strands of the sheath is 1.0-10.0 wt%, particularly 2.5-5.0 wt%. This results in the composition according to the invention having particularly good impact resistance.

[0064] For example, the weight ratio of the impregnating agent to the continuous glass multifiber strands is in the range of 1:4 to 1:30, preferably 1:5 to 1:20, and more preferably 1:6 to 1:13.

[0065] Preferably, the impregnating agent contains microcrystalline wax, preferably in an amount of at least 70 wt% based on the weight of the impregnating agent. It should be understood in this regard that the microcrystalline wax can be a single microcrystalline wax or a blend of several microcrystalline waxes.

[0066] Microcrystalline wax is a known material, described in detail in, for example, WO2015 / 062825, page 5, line 17–page 7, line 9, which is incorporated herein by reference. Generally, microcrystalline wax is a refined mixture of solid saturated aliphatic hydrocarbons, prepared by deoiling certain fractions from the petroleum refining process. Microcrystalline wax differs from refined paraffin wax in that it has a more branched molecular structure and longer hydrocarbon chains (higher molecular weight). Therefore, the crystal structure of microcrystalline wax is much finer than that of paraffin, which directly affects many of the material's mechanical properties. Compared to paraffin, microcrystalline wax is tougher, more flexible, and generally has a higher melting point. The fine crystal structure also allows microcrystalline wax to bind solvents or oils, thus preventing the composition from sweating out. Microcrystalline wax can be used to modify the crystallization properties of paraffin.

[0067] Microcrystalline waxes are also quite different from so-called isotactic polymers. First, microcrystalline waxes are petroleum-based, while isotactic polymers are polyalphaolefins. Second, isotactic polymers have a very high degree of branching, exceeding 95%, while the branching degree of microcrystalline waxes is typically in the range of 40-80 wt%. Finally, the melting point of isotactic polymers is generally relatively lower than that of microcrystalline waxes. In conclusion, microcrystalline waxes form a distinct category of materials that should not be confused with either paraffin wax or isotactic polymers.

[0068] The impregnating agent may also contain natural waxes, synthetic waxes, or isotactic polymers, preferably in an amount of up to 30 wt% relative to the impregnating agent. Typical natural waxes are animal waxes such as beeswax, lanolin, and tallow; plant waxes such as carnauba wax, candelilla wax, and soy wax; and mineral waxes such as paraffin wax, ceresin wax, and lignite wax. Typical synthetic waxes include olefinic polymers such as polyethylene wax or polyol ether-ester waxes, chlorinated naphthalene, and Fischer-Tropsch-derived waxes. A typical example of an isotactic polymer or hyperbranched polymer is Vybar 260 as described above. In one embodiment, the remaining portion of the impregnating agent contains or consists of one or more components of highly branched polyalphaolefins (e.g., polyethylene wax) and paraffin wax.

[0069] In a preferred embodiment, the impregnating agent comprises at least 80 wt%, more preferably at least 90 wt%, or even at least 95 wt%, or at least 99 wt% of microcrystalline wax. Most preferably, the impregnating agent consists essentially of microcrystalline wax. In one embodiment, the impregnating agent is paraffin-free. The term "consistently of" should be interpreted as the impregnating agent comprising at least 99.9 wt% microcrystalline wax based on the weight of the impregnating agent.

[0070] Microcrystalline waxes preferably possess one or more of the following properties:

[0071] -The dropping melting point at 60-90°C, as determined by ASTM D127.

[0072] -The freezing point is 55-90°C, as determined by ASTM D938.

[0073] - Penetration at 25°C, measured according to ASTM D1321, ranging from 7 / 10 to 40 / 10 mm.

[0074] - Viscosity at 140°C, measured according to ASTM D445, at 10-25 mPa·s.

[0075] In even more preferred embodiments, microcrystalline waxes possess a combination of all these properties.

[0076] Microcrystalline waxes preferably further possess the following characteristics:

[0077] - An oil content of 0-5 wt%, preferably 0-2 wt%, based on microcrystalline wax, as determined by ASTM D721.

[0078] Preferably, the viscosity of the impregnating agent is 2.5-200 mm at 160°C. 2 / s, more preferably at least 5.0mm 2 / s, more preferably at least 7.0mm 2 / s, and / or at 160°C for up to 150.0mm 2 / s, preferably up to 125.0mm 2 / s, preferably up to 100.0mm 2 / s, measured according to ASTM D445.

[0079] Liquid impregnating agents can be applied to continuous glass multifiber strands using any method known in the art. A die can be used for the application of the liquid impregnating agent. Other suitable methods for applying impregnating agents to continuous multifiber strands include applicators with belts, rollers, and hot-melt applicators. Such methods are described, for example, in documents EP0921919B1, EP0994978B1, EP0397505B1, WO2014 / 053590A1, and the referenced documents. The method used should enable the application of a constant amount of impregnating agent to the continuous multifiber strand.

[0080] Other aspects

[0081] The present invention provides granules comprising or consisting of a glass fiber reinforced thermoplastic polymer composition according to the present invention.

[0082] The granules typically have a length of 2-50 mm, preferably 5-30 mm, more preferably 6-20 mm, and most preferably 10-16 mm. The length of the glass fibers is usually substantially the same as the length of the granules.

[0083] The total amount of thermoplastic polymer composition and continuous multifiber strands in the granules is preferably at least 95 wt%, at least 98 wt%, at least 99 wt%, at least 99.9 wt%, or 100 wt% based on the granules.

[0084] The granules according to the invention are preferably prepared by a method comprising the following sequential steps:

[0085] a) Unwind at least one continuous glass multifiber strand from the roll.

[0086] b) Applying an impregnating agent to at least one continuous glass multifiber strand to form an impregnated continuous multifiber strand, and

[0087] c) Applying a sheath of a thermoplastic polymer composition around an impregnated continuous multifiber strand to form a sheathed continuous multifiber strand, and

[0088] d) Cut the sheathed continuous glass multifiber strands into granules.

[0089] Step d) can be followed by a step of molding the granules into a (semi-)finished product. Suitable examples of molding methods include injection molding, compression molding, extrusion, and compression extrusion. Injection molding is widely used to produce articles such as automotive exterior parts (e.g., bumpers), automotive interior parts (e.g., dashboards), or automotive parts under the hood. Extrusion is widely used to produce articles such as bars, sheets, and tubes. Articles may have wall thicknesses of, for example, 0.1–10 mm.

[0090] Therefore, the present invention also relates to molded articles comprising a glass fiber reinforced thermoplastic polymer composition or granules according to the present invention, wherein the articles are selected from automotive exterior parts (e.g., bumpers), automotive interior parts (e.g., dashboards), and automotive parts under the hood.

[0091] The present invention also relates to a method for manufacturing molded articles by molding a glass fiber reinforced thermoplastic polymer composition or granules according to the invention, wherein the articles are selected from automotive exterior parts (e.g., bumpers), automotive interior parts (e.g., dashboards), and automotive parts under the hood. The molding step can be performed at a temperature above 230°C, for example, 250-280°C.

[0092] It should be noted that the present invention relates to the subject matter defined individually in the independent claims or in combination with any possible combination of features described herein, and particularly preferred to be those combinations of features present in the claims. Therefore, it should be understood that all combinations of features relating to the compositions according to the invention; all combinations of features relating to the methods according to the invention; and all combinations of features relating to the compositions according to the invention and the methods according to the invention are described herein.

[0093] It should also be noted that the term "comprising / including" does not exclude the presence of other elements. However, it should also be understood that a description of a product / composition comprising certain components also discloses a product / composition composed of those components. A product / composition composed of these components can be advantageous because it provides a simpler and more economical method for preparing the product / composition. Similarly, it should be understood that a description of a method including certain steps also discloses a method composed of those steps. A method composed of these steps can be advantageous because it provides a simpler and more economical method.

[0094] The present invention will now be described through the following embodiments, but is not limited thereto.

[0095] Example

[0096] Materials used

[0097] PP: A homopolymer of polypropylene with the following properties: Density: 905 kg / m³ 3 Melt flow rate (MFR): 47 dg / min at 230℃ and 2.16 kg (test method: ISO 1133), melting point: 160-175℃.

[0098] PBT: Valox 195 from SABIC, intrinsic viscosity = 0.66 dl / g, Mn = 25,000 g / mol, Mw = 60,800 g / mol, melting point: 215℃.

[0099] PBT / PET: A blend of PBT and recycled PET in a weight ratio of 65:35, with an intrinsic viscosity of 0.535 dl / g, Mn of 24,000 g / mol, and Mw of 64,800 g / mol. The melting points of PBT and recycled PET are 219°C and 248°C, respectively.

[0100] PBT / ABS: XENOY HTX950 from SABIC, which is a mixture of PBT and ABS in a weight ratio of 72:28.

[0101] Coupling agent: Exxelor PO1020 powder (PP-g-MA) from ExxonMobil: Density: 900 kg / m³ 3 Melting point: 162℃, MFR: 430 dg / min at 230℃ and 2.16 kg (Test method: ASTM D1238)

[0102] LGF1: Glass roving with a diameter of 19 micrometers and a sizing agent composition of 3000 tex (tex refers to grams of glass / 1000m) without sizing agent composition. The sizing agent composition contains a silane coupling agent, which is a tri(C) 1-6 Alkoxy) monoaminosilane, tri(C 1-6 Alkoxy)diaminosilane, tri(C 1-6 Alkoxy)(C 1-6 Alkylurea)silane, tri(C 1-6 Alkoxy (epoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (glycidoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (Mercapto C) 1-6 Alkyl)silanes or combinations thereof.

[0103] LGF2: A glass roving with a diameter of 17 micrometers and a thickness of 2400 tex (tex refers to grams of glass per 1000m) containing a sizing composition. The sizing composition contains a silane coupling agent, which is a tri(C) 1-6 Alkoxy) monoaminosilane, tri(C 1-6 Alkoxy)diaminosilane, tri(C 1-6 Alkoxy)(C 1-6 Alkylurea)silane, tri(C 1-6 Alkoxy (epoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (glycidoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (Mercapto C) 1-6 Alkyl)silanes or combinations thereof.

[0104] Impregnating agent: Dicera 13802 microcrystalline wax with the following properties

[0105] -Dropping point of 81°C as determined by ASTM D127

[0106] - Freezing point of 63-70°C as determined by ASTM D938

[0107] - Penetration of 16 / 10 mm at 25°C, as measured according to ASTM D1321.

[0108] - Viscosity at 140°C, measured according to ASTM D445, at 15-25 mPa·s.

[0109] Peak melting temperature -51℃

[0110] Acid value of -0.2 mg KOH / g

[0111] Density at 20°C: -0.91 g / cc

[0112] Stabilizer: Irganox® B 225, commercially available from BASF, 50 wt% tris(2,4-di-tert-butylphenyl) phosphite and 50 wt% pentaerythritol tetrakis[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate].

[0113] Preparation of continuous multifiber strands with sheathing (line coating)

[0114] Using the wire coating process described in the examples of WO2009 / 080281A1, sheathed continuous multifiber strands were prepared using the components given in Table 1. An impregnating agent was applied to the LGF to obtain impregnated continuous glass multifiber strands.

[0115] Thermoplastic polymers (PP, PBT, PET, and ABS), coupling agents (where applicable), and other additives shown in Table 1 are fed into an extruder to shear the impregnated continuous glass multifiber strands using an extruder head line coating die. The shearing step is performed in series immediately following the impregnation step. The resulting sheared continuous multifiber strands are cut into pellets with a length of 8-15 mm and a diameter of 3-4 mm.

[0116] Table 1

[0117]

[0118] Test methods

[0119] The following tests were performed, and the results are shown in Tables 2 and 3.

[0120]

[0121] The Vicat softening temperature of the composition of Example 2 is about 214°C, while that of the composition of Comparative Example 1 is about 165°C. This indicates that Example 2 can withstand higher temperatures in applications without sacrificing mechanical properties such as modulus compared to Comparative Example 1. Therefore, the granules of Example 2 are suitable for eCoat applications, which require components to withstand bath temperatures of 180-200°C.

[0122] Table 2

[0123]

[0124] As shown in Table 2, compared with pure PBT, a mixture of PBT and recycled PET at a weight ratio of 65:35 unexpectedly improved the mechanical properties of the wire-coated granules in terms of tensile modulus, tensile strength, and cantilever beam impact strength as a sheath material. Furthermore, the TVOC results were significantly reduced, indicating a substantial improvement in the control of volatile content in the granules.

[0125] Table 3

[0126]

[0127] Similarly, as can be seen from Table 3, a mixture of PBT and recycled PET in a weight ratio of 65:35 unexpectedly improved the mechanical properties of the wire-coated granules in terms of tensile strength, flexural strength, and cantilever beam impact strength as a sheath material compared to pure PBT, which is highly desirable for structurally complex and large components.

[0128] Adding recycled PET to PBT resulted in a significant improvement in Tg compared to PBT alone, thus achieving higher stiffness at higher temperatures within the pellet.

[0129] The DSC test results show that adding recycled PET reduces the energy required to melt the matrix, indicating a simpler method, a wider processing window, and lower energy consumption.

[0130] DMA test results show that adding recycled PET increases Tg, thus increasing the application service temperature limit, which is higher than that of PBT alone (Tg of 66°C). Similarly, using ABS with PBT significantly increases Tg, but produces lower physical properties than unreinforced (straight) PBT composites, making it undesirable for high-performance structural components.

Claims

1. A glass fiber reinforced thermoplastic polymer composition comprising a sheathed continuous multifilament strand, the sheathed continuous multifilament strand comprising a longitudinally extending core and a polymer sheath tightly surrounding the core, The core comprises at least one continuous glass multifiber strand, and The polymer sheath is composed of a thermoplastic polymer composition comprising a polyester composition consisting of poly(1,4-butylene terephthalate) and poly(ethylene terephthalate) in a weight ratio of 55:45 to 75:

25.

2. The glass fiber reinforced thermoplastic polymer composition according to claim 1, wherein at least one continuous glass multifiber strand is impregnated with an impregnating agent.

3. The glass fiber reinforced thermoplastic polymer composition according to claim 2, wherein the impregnating agent is microcrystalline wax.

4. The glass fiber reinforced thermoplastic polymer composition according to claim 2, wherein the amount of impregnating agent is 2.5-5.0 wt% relative to the continuous multifiber strands of the sheath.

5. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein at least one continuous glass multifiber strand comprises a sizing agent composition comprising a silane coupling agent, the silane coupling agent being tri(C) 1-6 Alkoxy) monoaminosilane, tri(C 1-6 Alkoxy)diaminosilane, tri(C 1-6 Alkoxy)(C 1-6 Alkylurea)silane, tri(C 1-6 Alkoxy (epoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (glycidoxy C) 1-6 Alkyl)silane, tri(C) 1-6 Alkoxy (Mercapto C) 1-6 Alkyl)silanes or combinations thereof.

6. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein the continuous glass multifiber strands have a density of 1000-2900 g / 1000 m, more preferably 1500-2800 g / 1000 m.

7. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein the thermoplastic polymer composition is free of acrylonitrile butadiene styrene (ABS).

8. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein the thermoplastic polymer composition comprises a polyester composition and additives.

9. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein poly(1,4-butylene terephthalate) is a virgin material and poly(ethylene terephthalate) is a post-consumer or post-industrial recycled material.

10. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein the weight ratio of poly(1,4-butylene terephthalate) to poly(ethylene terephthalate) in the polyester composition is from 60:40 to 70:

30.

11. The glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims, wherein the amount of glass multifiber strands is 20-40 wt% based on the sheathed continuous multifiber strands, and the amount of thermoplastic polymer composition is 55-80 wt% based on the sheathed continuous multifiber strands.

12. Granules comprising a glass fiber reinforced thermoplastic polymer composition according to any one of the preceding claims.

13. A method for preparing a glass fiber reinforced thermoplastic polymer composition according to any one of claims 1-11, comprising the following sequential steps: a) Unwind at least one continuous glass multifiber strand from the roll. Optionally b) applying an impregnating agent to at least one continuous glass multifiber strand to form an impregnated continuous multifiber strand, and c) Applying a polymer sheath around an optional impregnated continuous multifiber strand to form a sheathed continuous multifiber strand, and Optionally d) the sheathed continuous glass multifiber strands are cut into granules.

14. A molded article comprising a glass fiber reinforced thermoplastic polymer composition according to any one of claims 1-11 or granules according to claim 12.

15. A method for manufacturing molded articles by molding the glass fiber reinforced thermoplastic polymer composition according to any one of claims 1-11 or the granules according to claim 12 at a temperature of at least 230°C, preferably 250-280°C.

Images