Fiber reinforced polymer composition

Abstract

The invention provides a fiber reinforced polymer composition. The present invention relates to a fiber-reinforced thermoplastic molding composition comprising a thermoplastic polymer and reinforcing fibers wherein the composition comprises (i) a thermoplastic polymer selected from the group consisting of polyesters, polyamides, polycarbonates, polyphenylene sulfide (PPS), polyphenylene ether (PPO), polyetheretherketones (PEEK), polyaryletherketones (PAEK), polyamideimides (PAI), polyetherimides (PEI) and liquid crystal polymers (LCP), and combinations thereof, and (ii) a silicon-boron glass fiber consisting essentially of silicon dioxide (SiO2) and diboron trioxide (B2O3).

Description

[0001] This application is a divisional application of the invention patent application filed on March 28, 2018, with application number 201880019341.X and invention title "Fiber Reinforced Polymer Composition". Technical Field

[0002] This invention relates to compositions comprising thermoplastic polymers and reinforcing fibers, particularly glass fibers as reinforcing fibers. The invention also relates to the use of such compositions as thermoplastic molding compositions, and their application in, for example, electronic mobile devices, such as in housings or frames made of thermoplastic molding compositions, or in molded parts used as electronic components in applications such as speaker enclosures, audio jack modules, antennas, connectors (e.g., automotive connectors, DDR4 connectors), and splitters. Background Technology

[0003] Thermoplastic molding compositions are used to mold parts for a wide range of applications. Typically, such compositions are reinforced with reinforcing fibers to increase the mechanical properties of the molded parts, such as tensile modulus, tensile strength, elongation at break, flexural strength, flexural fracture resistance, and impact resistance. For the reinforcing fibers, glass fibers, carbon fibers, or combinations thereof are commonly used. Glass fibers are the most widely used. Most glass fibers are E-type glass. One problem with this type of reinforcing composition is the difficulty in achieving a proper balance of properties. Modulus and strength can often be increased, for example, by increasing the amount of glass fiber, but this may come at the expense of elongation at break and impact resistance. On the other hand, adding impact modifiers can improve elongation at break and impact resistance, but this may come at the expense of tensile strength and other properties, such as chemical resistance. An alternative approach to improving properties is to use glass fibers with different shapes, such as flat glass fibers and glass fibers with elliptical cross-sections. Furthermore, the presence of abrasive components, such as titanium dioxide and laser direct forming (LDS) additives, can reduce the effectiveness of glass fibers as a reinforcing agent. Summary of the Invention

[0004] The object of the present invention is to provide a thermoplastic molding composition comprising a thermoplastic polymer and reinforcing fibers, wherein the thermoplastic molding composition has good mechanical properties, particularly a combination of high elongation with good impact properties and good tensile strength, preferably a combination of high elongation and high impact properties with good tensile strength.

[0005] This objective has been achieved by a composition according to the invention, the composition comprising: (i) Thermoplastic polymers selected from the group consisting of polyesters (PES), polyamides (PA), polycarbonates (PC), polyphenylene sulfides (PPS), polyphenylene oxides (PPO), polyaryletherketones (PAEK), polyetheretherketones (PEEK), polyamide-imide (PAI), polyetherimide (PEI), and liquid crystal polymers (LCP), and combinations thereof; (ii) at least 22% by weight of silicon-borosilicate glass fiber, which mainly comprises silicon dioxide (SiO2) and boron trioxide (B2O3); and (iii) 0-7% by weight of halogen-free flame retardant, The weight percentage (wt%) is relative to the total weight of the composition.

[0006] Compared to corresponding compositions containing reinforcing fibers based on E-glass, the composition according to the invention has the effect of increased tensile elongation while largely maintaining tensile strength; moreover, impact resistance is also often improved.

[0007] In addition to silica-borosilicate glass fibers, the compositions according to the invention may contain E-glass fibers. Compared to corresponding compositions having the same amount of glass fibers consisting entirely of E-glass fibers, this composition has the advantage of better tensile elongation. Preferably, if present, the E-glass fibers are present in an amount of up to 30% by weight, preferably up to 15% by weight, relative to the silica-borosilicate glass fibers.

[0008] This composition comprises a thermoplastic polymer selected from the group consisting of polyesters (PES), polyamides (PA), polycarbonates (PC), polyphenylene sulfides (PPS), polyphenylene oxides (PPO), polyaryletherketones (PAEK), polyetheretherketones (PEEK), polyamide-imides (PAI), polyetherimides (PEI), and liquid crystal polymers (LCP), and combinations thereof. This group is referred to herein as group (i). Suitably, the thermoplastic polymer is a semi-crystalline polymer or an amorphous polymer, or a combination thereof. Examples of amorphous polymers are polycarbonates and amorphous semi-aromatic polyamides. Examples of semi-crystalline polymers are semi-crystalline polyesters, aliphatic polyamides, and semi-crystalline semi-aromatic polyamides.

[0009] "Fiber" is understood herein as an elongated body having dimensions of length, width, and thickness, wherein the length dimension is much greater than the transverse dimensions of width and thickness. The term "width" is understood herein as the maximum dimension measured in a transverse cross-section, and the term "thickness" is understood herein as the minimum dimension measured in a transverse cross-section. Fibers may have various cross-sections, having circular or irregular shapes (i.e., non-circular shapes with different widths and thicknesses), for example, bean-shaped, oval, elliptical, or rectangular shapes with a width greater than their thickness. More particularly, the fibers in the compositions according to the invention suitably have an aspect ratio of at least 10, defined by the length / width (L / W) ratio. In a particular embodiment, the glass fiber has a number-average aspect ratio L / W of at least 20. Fibers may also have cross-sections of varying dimensions. Suitably, the fiber has a circular cross-section with a diameter in the range of 5-20 μm, more particularly 7-15 μm, for example 8 μm, or 10 μm or 13 μm. Alternatively, the fiber has a non-circular cross-section with a width in the range of 5-30 μm, more particularly 7-20 μm, such as 8 μm, or 10 μm, or 13 μm, or 15 μm.

[0010] In this context, the term "thermoplastic" in thermoplastic polymers is understood to refer to semi-crystalline polymers with a melt temperature (Tm) in the range of 200°C–360°C, or amorphous polymers with a glass transition temperature (Tg) in the range of 140°C–300°C. The effect is that compositions can be prepared by melt mixing and can be melt-processed to prepare molded parts.

[0011] In the context of semi-crystalline polyamides and semi-crystalline polyesters, the term "semi-crystalline" is understood herein to refer to a polyamide or polyester having a melting temperature (Tm) and a melting enthalpy (ΔHm), as well as a glass transition temperature (Tg). Hereinafter, the melting enthalpy of semi-crystalline polyamides and semi-crystalline polyesters is at least 5 J / g, preferably at least 10 J / g, and even more preferably at least 25 J / g. Polymers with a melting enthalpy less than 5 J / g are understood herein to be amorphous polymers.

[0012] The term “enthalpy of fusion” (ΔHm) is understood herein to refer to the enthalpy of fusion measured on a pre-dried sample in a N2 atmosphere by DSC method according to ISO-11357-1 / 3, 2011 at a heating and cooling rate of 20°C / min. Here (ΔHm) is calculated from the surface below the melting peak during the second heating cycle.

[0013] The term "melting temperature" is understood herein as the temperature measured on a pre-dried sample in a N2 atmosphere by differential scanning calorimetry (DSC) according to ISO-11357-1 / 3, 2011 at a heating and cooling rate of 20°C / min. Here, Tm is the temperature at which the highest melting peak is reached during the second heating cycle.

[0014] In one specific embodiment of the invention, the thermoplastic polymer includes polyamide or semi-crystalline polyester, or combinations thereof. The polyamide may be semi-crystalline polyamide or amorphous polyamide, or mixtures thereof.

[0015] Semi-crystalline polyesters can be, for example, polyethylene terephthalate (PET), polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), polycyclohexyl terephthalate (PCT), polyethylene naphthalate (PEN), polytrimethylene naphthanate (PTN), polybutylene naphthalate (PBN), and polycyclohexyl naphthalate (PCN), as well as blends and copolymers thereof.

[0016] Semi-crystalline aliphatic polyamides are polyamides composed of repeating units derived from aliphatic monomers, such as aliphatic lactams, aliphatic diamines and aliphatic dicarboxylic acids, or combinations thereof. Semi-crystalline aliphatic polyamides can be, for example, PA-6, PA-66, PA-6 / 66, PA-46, PA-410, PA-1010, PA-610, PA-11, and PA-12, as well as their blends and copolymers.

[0017] In the context of semi-aromatic polyamides, the term "semi-aromatic" is understood herein to mean a polyamide derived from a combination of monomers containing aromatic monomers (i.e., monomers containing aromatic units) and non-aromatic monomers (i.e., monomers not containing aromatic groups).

[0018] Semi-aromatic polyamides are polyamides composed of repeating units derived from combinations of aromatic and aliphatic monomers. Aromatic monomers are monomers containing an aromatic ring structure. Suitably, semi-aromatic polyamides contain repeating units derived from aromatic dicarboxylic acids and aliphatic diamines, or repeating units derived from aliphatic dicarboxylic acids and aromatic diamines, or combinations thereof. Examples of aromatic dicarboxylic acids are terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. Examples of aliphatic dicarboxylic acids are adipic acid and sebacic acid. Examples of aromatic diamines are m-phenylenediamine and p-phenylenediamine. Aliphatic diamines can be straight-chain diamines, branched-chain diamines, and alicyclic diamines. Linear aliphatic diamines are suitably linear α-ω C2-C36 diamines, preferably linear C4-C12 diamines, such as 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane and 1,12-diaminododecane.

[0019] Semi-crystalline semi-aromatic polyamides can be, for example, PA-XT homopolymers, PA-XT / XI copolymers, PA-XT / YT copolymers, PA-XT / Y6 copolymers, PA-XT / YI / Z6, PA-XT / YI / Z10, and PA-XT / 6 copolymers, as well as their blends and copolymers, wherein X, Y, and Z represent repeating units derived from diamines, T represents repeating units derived from terephthalic acid, I represents repeating units derived from isophthalic acid, and the 6 in combination with diamines, such as Y6 in PA-XT / Y6 and Z6 in PA-XT / YI / Z6, represents repeating units derived from terephthalic acid, and the 6 that exists alone, separated from other monomer units by a slash ( / ), such as in PA-XT / 6, represents repeating units derived from endopeptides. The diamine can, in principle, be any aliphatic diamine or a combination of aliphatic and aromatic diamines. Examples of semi-crystalline, semi-aromatic polyamides are PA-6T / 10T, PA-6T / 6I, PA-6T / 46, PA-6T / 6, PA-6T / 66, and PA-6T / 6I / 66.

[0020] An example of an amorphous semi-aromatic polyamide is PA-6I / 6T.

[0021] The compositions according to the invention comprise glass fibers primarily comprising silicon dioxide (SiO2) and boron trioxide (B2O3), referred herein as silicon-borosilicate glass fibers. Hereinafter, the term "primarily comprising" is understood to mean that silicon dioxide (SiO2) and boron trioxide (B2O3) are the major components in the glass fibers. Silicon-borosilicate glass fibers may contain other components, but if present, the combined amounts of these components are less than each of silicon dioxide and boron dioxide. Suitably, the silicon-borosilicate glass fibers comprise a combined amount of silicon dioxide and boron trioxide of at least 90% by weight relative to the weight of the silicon-borosilicate glass fibers. In one specific embodiment, the silicon-borosilicate glass fibers consist of: (a) 65-85% by weight of SiO2; (b) 15-30% by weight of B2O3; (c) 0-4% by weight of sodium oxide (Na2O) or potassium oxide (K2O), or combinations thereof; and (d) 0-4% by weight of other components. In another embodiment, the silicon-borosilicate glass fiber comprises: (a) 70-80 wt% SiO2; (b) 18-27 wt% B2O3; (c) 0-3 wt% Na2O or K2O, or a combination thereof; and (d) 0-3 wt% other components. An example is a silicon-borosilicate glass fiber composed of: (a) 70-80 wt% SiO2; (b) 20-25 wt% B2O3; (c) 0-2 wt% Na2O or K2O, or a combination thereof; and (d) 0-2 wt% other components. Here, the weight percentage (wt%), i.e., the weight percentages of (a)-(d), is relative to the weight of the silicon-borosilicate glass fiber.

[0022] The composition may contain a thermoplastic polymer and reinforcing fibers, in amounts that vary over a wide range. Suitably, the composition contains a thermoplastic polymer selected from group (i) above, wherein the amount of group (i) is 30-90% by weight, for example 35-80% by weight, or 30-75% by weight, more particularly 40-70% by weight.

[0023] In embodiments where the thermoplastic polymer comprises polyamide or semi-crystalline polyester or a combination thereof, the polyamide, or polyester, or combination thereof is suitably present in an amount of 30-90% by weight, for example, in the range of 35-80% by weight, more particularly 40-70% by weight. In this embodiment, one or more other selected thermoplastic polymers from group (i) may also be present. Suitably, the total amount of the polyamide or polyester or combination thereof and one or more other selected thermoplastic polymers from group (i) is maintained in the range of 30-90% by weight, for example, in the range of 35-80% by weight, more particularly 40-70% by weight. The amount of thermoplastic polymer is, for example, 35% by weight, 45% by weight, 55% by weight, 65% by weight, or 75% by weight. Here, weight percentage (wt%) is relative to the total weight of the composition.

[0024] In addition to borosilicate glass fibers, the reinforcing fibers in the composition may include other reinforcing fibers, such as carbon fibers and glass fibers other than borosilicate glass fibers. The reinforcing fibers may also consist of or be substantially composed of borosilicate glass fibers. The composition suitably contains at least 22% by weight, preferably at least 25% by weight, and more preferably at least 30% by weight of glass fibers as reinforcing fibers. The glass fibers are suitably present in an amount of up to 70% by weight, and more particularly up to 60% by weight. In a preferred embodiment, the composition contains 22-70% by weight of glass fibers (which contain at least 22% by weight of borosilicate glass fibers). In another preferred embodiment, the amount of borosilicate glass fibers present is in the range of 25-70% by weight, for example, in the range of 30-60% by weight. The amount of borosilicate glass fibers is, for example, 25% by weight, 30% by weight, 40% by weight, 50% by weight, or 65% by weight. Here, weight percentage (wt%) is relative to the total weight of the composition.

[0025] These embodiments of glass fiber are suitably combined with any thermoplastic polymer selected from any group (i) or any combination thereof, and may also be combined with embodiments in which the thermoplastic polymer comprises polyamide or polyester or a combination thereof.

[0026] In addition to thermoplastic polymers and reinforcing fibers, the compositions according to the invention may contain one or more other components. As other components, any auxiliary additives suitable for use in thermoplastic molding compositions may be used. Suitable additives include inorganic fillers, impact modifiers, stabilizers (e.g., heat stabilizers, antioxidants, and UV stabilizers), flame retardants (halogenated flame retardants, halogen-free flame retardants), plasticizers, conductive agents and / or antistatic agents, carbon black, lubricants and release agents, nucleating agents, crystallization promoters, crystallization delayers, dyes and pigments, and any other auxiliary additives that may be used in thermoplastic molding compositions, and mixtures thereof.

[0027] These additives can be used in varying amounts. However, it is preferred that these additives be present in limited quantities. In the compositions according to the invention, the amount of halogen-free flame retardant (if present) is at most 7% by weight relative to the total weight of the composition. Suitably, the amount of halogen-free flame retardant is 0-6% by weight, for example 3% by weight, 4% by weight, or 5% by weight. The halogen-free flame retardant can be any halogen-free flame retardant. Preferably, the halogen-free flame retardant is a metal diphosphonate or a metal bisphosphonate, or a mixture thereof. Suitably, the metal (bis)phosphonate is a metal dialkyl phosphonate. An example of this is aluminum diethylphosphonate.

[0028] The filler is understood herein as a particulate material composed of particles having regular spherical or irregular shapes, having length, width, and thickness dimensions, and having an aspect ratio of less than 10, defined by the length / width ratio. Suitablely, the number-average aspect ratio of the filler is at most 5.

[0029] Examples of fillers suitable for use in the compositions of the present invention include, but are not limited to, silica, silicate, alumina, talc, diatomaceous earth, clay, kaolin, quartz, glass, mica, titanium dioxide, molybdenum disulfide, gypsum, iron oxide, zinc oxide, montmorillonite, calcium carbonate, glass powder, and glass beads.

[0030] Preferably, the composition further comprises at least one component selected from polymer impact modifiers, LDS additives, and titanium dioxide, or combinations thereof. It should be noted that the terms "one or more" and "at least one" are used interchangeably and have the same meaning herein.

[0031] Suitablely, the composition contains 0.01-10% by weight, preferably 0.01-5% by weight, of a polymeric impact modifier. The advantage of the composition of the present invention is that it requires less polymeric impact modifier while improving elongation at break and impact resistance, while tensile strength is better maintained. By combining silica-borosilicate glass fibers and the polymeric impact modifier, the balance between tensile strength and elongation at break with impact resistance can be further optimized.

[0032] In the compositions according to the invention, the polymer impact modifier is suitably a rubber or elastomer, such as an acrylic polymer, a polyolefin polymer, a styrene polymer, a silicone polymer, and combinations thereof, as well as functionalized modifiers. Functionalized polymer impact modifiers are understood herein to be impact modifiers in which the polymer contains functional groups capable of reacting with amine or carboxyl end groups in the polyamide. Examples of such functional groups are epoxy groups, anhydride groups, and carboxylic acid groups. When using a non-functionalized polymer impact modifier, the composition preferably contains a compatibilizer.

[0033] Polymer impact modifiers are described, for example, in Additives for Plastics Handbook, edited by J. Murphy, 2001 (ISBN = 0080498612). Examples of functionalized polymers are functionalized semi-crystalline polyolefins, such as maleicated (i.e., maleic anhydride-functionalized) polyethylene, maleicated polypropylene, and maleicated ethylene-propylene copolymers (available as EXXELOR™ PO), acrylate-modified polyethylene (available as SURLYN®), methacrylic acid-modified polyethylene, and acrylic acid-modified polyethylene (available as PRIMACOR®).

[0034] In another preferred embodiment, the composition does not contain a polymer impact modifier. The advantage is that, compared to corresponding compositions based on E-glass, this composition offers improved mechanical properties without compromising the chemical resistance associated with polymer impact modifiers. This composition is advantageously suited for automotive hood applications.

[0035] The composition suitably contains an LDS additive in an amount of 0.1-15% by weight, preferably 2-10% by weight. The advantage of the composition of the present invention lies in the combination of the LDS additive and the silicon-borosilicate glass fiber; although the LDS additive has a negative impact on mechanical properties, the composition exhibits better mechanical properties in terms of tensile strength, elongation at break, and impact resistance.

[0036] Compositions containing LDS additives are used to produce molded parts, which also serve as carriers for conductive circuits. The conductive circuits are manufactured using a so-called laser direct forming process, in which the molded part is treated with a laser beam to create activated structures on the part, and then the part is metal-plated to form conductive circuits with activated structure patterns.

[0037] The present invention also relates to circuit carriers obtainable by laser direct forming methods, wherein the carrier is a molded part comprising a composition according to the invention or a specific embodiment thereof, or made of a composition according to the invention or a specific embodiment thereof. LDS additives are generally metal compounds capable of being activated by electromagnetic radiation to form elemental metal nuclei. Examples of LDS additives that can be used herein are metal compounds and metal oxides containing at least one of copper, antimony, or tin, as well as mixed metal compounds, such as spinel-based compounds. Such spinel-based compounds suitably contain copper, chromium, iron, cobalt, or nickel, or a mixture of two or more of the foregoing, and preferably contain copper.

[0038] Examples of mixed metal oxides are oxides of at least tin and one or more secondary metals derived from antimony, bismuth, aluminum, and molybdenum. Examples of copper compounds are copper salts, such as copper hydroxide, copper phosphate, copper sulfate, cuprous thiocyanate; or combinations thereof.

[0039] LDS additives are suitable for use in combination with white pigments, such as titanium dioxide (TiO2; which may be anatase or rutile, or a combination thereof), zinc oxide (ZnO), zinc sulfide (ZnS), barium sulfate (BaSO4), and barium titanate (BaTiO3).

[0040] The compositions according to the invention and their various embodiments suitably contain titanium dioxide in an amount ranging from 0.1 to 15% by weight, preferably 2 to 10% by weight. Here, titanium dioxide is present as an additional component besides the silica-borosilicate glass fiber and the thermoplastic polymer, for example, as a white pigment. The advantage of compositions containing a combination of titanium dioxide and silica-borosilicate glass fiber is that, despite the negative impact of titanium dioxide on mechanical properties, the compositions exhibit better mechanical properties in terms of tensile strength, elongation at break, and impact resistance.

[0041] In a preferred embodiment, the composition comprises an LDS additive and titanium dioxide. Its advantage lies in the fact that the composition exhibits even better LDS performance, while also possessing better mechanical properties than corresponding compositions containing E-glass fibers instead of silicon-borosilicate glass fibers. E-glass fibers are most widely used in thermoplastic molding compositions and typically consist of silicon dioxide (SiO2, about 53-57 wt%), aluminum oxide (Al2O3, about 12-15 wt%), and calcium oxide (CaO) with magnesium oxide (MgO) (together about 22 to 26 wt%) and smaller amounts of boron oxide (B2O3, about 5 to 8 wt%) and other trace components (typically less than 1 to 2 wt%).

[0042] Compositions containing LDS additives are advantageously suited for applications in integrated electronic devices. Combinations with white pigments are particularly suitable for applications requiring light color combined with high elongation, impact resistance, and temperature resistance.

[0043] For LDS applications, the thermoplastic polymer preferably comprises a semi-crystalline polymer with a melting temperature of at least 270°C, preferably at least 290°C, and even more preferably at least 310°C. This has the advantage that the composition is more suitable for lead-free soldering processes. For such applications, compositions comprising semi-crystalline, semi-aromatic polyamides are the best candidates.

[0044] The compositions according to the invention and their various specific and preferred embodiments can be prepared using standard melt mixing equipment for preparing fiber-reinforced thermoplastic molding compositions via a standard melt mixing process. The compositions can be prepared, for example, in a twin-screw extruder or a kneader.

[0045] This composition can be used to manufacture molded parts. Molded parts can be manufactured using standard melt processes, such as injection molding and extrusion.

[0046] The present invention also relates to molded parts made from compositions according to the invention. Examples of such molded parts include, but are not limited to, housings and frames for electronic mobile devices. Frames for electronic mobile devices may be, for example, outer frames or middle frames. The composition is also advantageously used in molded parts for electrical components in applications such as speaker enclosures, audio jack modules, antennas, connectors, and splitters. Connector components may be, for example, part of automotive connectors or DDR4 connectors. Detailed Implementation

[0047] The present invention is further illustrated by the following examples and comparative experiments.

[0048] Material

[0049] PA-1 = Semi-crystalline semi-aromatic polyamide: PA-10T, Tm 305℃

[0050] PA-2 = Aliphatic polyamide: PA-410, Tm 245℃

[0051] PA-3 = Amorphous polyamide: PA-6I / 6T

[0052] PA-4 = Semi-crystalline semi-aromatic polyamide: PA-4T / 6T / 66, Tm 325℃

[0053] PBT = semi-crystalline polyester, polybutylene terephthalate

[0054] GF-A = E-glass fiber (Ø10μm), a standard grade for thermoplastic molding compositions.

[0055] GF-B = Silicon-Borosilicate Glass Fiber (Ø10μm), (75 wt% SiO2; 22 wt% B2O3; 3 wt% other oxides)

[0056] MRA-1 = Release agent: Ethylene-acrylic acid copolymer (AC540A)

[0057] MRA-2 = Pentaerythritol Tetrastearate

[0058] IM = Polymer impact modifier: Chemically modified ethylene acrylate copolymer (Fusabond A560)

[0059] Filler = mica

[0060] FR = Halogen-free flame retardant: Aluminum diethylphosphinate

[0061] LDS = LDS Additive: Copper chromite black spinel (Sheppard Black 1G)

[0062] Black pigment = carbon black masterbatch, 20% of PA-6 (Cabot PA3785)

[0063] White pigment = zinc sulfide (ZnS)

[0064] PTFE = Polytetrafluoroethylene (anti-drip grade)

[0065] complex

[0066] Polyamide composition

[0067] Polyamide compositions are prepared on a twin-screw extruder using standard compounding conditions. The temperature of the extruded melt is typically about 350-360°C. After melt compounding, the resulting melt is extruded into filaments, cooled, and cut into pellets.

[0068] Polyester Composition

[0069] Polyester compositions are prepared on a twin-screw extruder using standard compounding conditions. The temperature of the extruded melt is typically about 250-260°C. After melt compounding, the resulting melt is extruded into filaments, cooled, and cut into pellets.

[0070] Injection molding - Fabrication of test bars for mechanical testing

[0071] Dry granular material is injection molded into a mold to form a test strip conforming to ISO 527 Type 1A; the test strip is 4 mm thick. The polyamide composition is injection molded into a suitable test mold using a standard injection molding machine. The test strip is prepared using a single-gated mold for standard test strips or a double-gated mold for producing test strips with weld lines, each gate located at opposite ends of the sample and resulting in weld line formation, while applying the same conditions as for standard test strips. For the polyamide compositions of Example IV (EX IV) and Comparative Experiment AC (CE AC), the T-melt setting temperature in the injection molding machine is approximately 320°C, and for the compositions of Example VI (EX-VI) and Comparative Experiment D (CE-D), it is approximately 340°C; the mold temperature is 120°C. For the polyester composition, the T-melt setting temperature in the injection molding machine is approximately 260°C; the mold temperature is 80°C.

[0072] test

[0073] Melting temperature (Tm)

[0074] Melt temperature (Tm) was measured using a Mettler Toledo Star System (DSC) in a nitrogen atmosphere with a heating and cooling rate of 20 °C / min. For the measurement, approximately 5 mg of pre-dried powdered polymer was used as the sample. Pre-drying was performed under high vacuum, i.e., less than 50 mbar and 130 °C, for 16 hours. The sample was heated from 0 °C to approximately 30 °C above the melt temperature at a rate of 20 °C / min, immediately cooled to 0 °C at a rate of 20 °C / min, and then heated again at a rate of 20 °C / min to approximately 30 °C above the melt temperature. The melt temperature (Tm) was determined by the peak value of the melt peak during the second heating cycle according to the method of ISO-11357-1 / 3,2011.

[0075] Tensile properties

[0076] Tensile modulus (TM), tensile strength (TS) and elongation at break (EaB) were measured in a tensile test according to ISO 527 / 1 at 23°C and a tensile rate of 5 mm / min.

[0077] Bending performance

[0078] Flexural modulus (FM), flexural strength (FS), and flexural fracture (FB) are measured in the flexural test according to ISO 178, which is a standard test method for flexural properties at 23°C and a rate of 2 mm / min.

[0079] Impact performance

[0080] Charpy notch impact resistance was tested at 23°C according to the method of ISO 179 / 1eA.

[0081] The Izod notched impact resistance was tested at 23°C according to the method of ISO 180 / 1A.

[0082] Various compositions and test results are listed in Tables 1-3.

[0083] Table 1. Composition and mechanical properties of Examples I-IV and Comparative Experiments A and B

[0084] Compared to Comparative Experiment A (CE-A) based on conventional glass fiber (E-glass), EX-I, II, and III based on silica-borosilicate glass fiber all exhibited relatively slightly lower tensile strength (TS), while showing significantly higher elongation at break (EaB) and higher impact strength (for both Charpy and Izod) compared to CE-A. A significantly increased EaB compared to CE-A was observed by replacing half of the glass fiber, as in EX-III.

[0085] EX-I has a 4.5% lower density by weight, and EX-II has a 10% lower density; parts can be designed to be thicker to compensate for the reduced tensile strength while exhibiting a higher EaB, or designed to have the same dimensions with a higher EaB and better impact resistance.

[0086] Similar results were observed for Example IV, a composition based on silicon-borosilicate glass fiber, and Comparative Experiment A, based on conventional glass fiber (E-glass), both containing 10% by weight PTFE. These compositions do indeed exhibit lower mechanical properties compared to their PTFE-free counterparts; however, EX-IV possesses the same tensile strength as CE-B, while exhibiting higher EaB and impact resistance than CE-B.

[0087] Table 2: Composition of Example V and Comparative Experiment C (LDS level) and Example VI and Comparative Experiment D (PPA level) and mechanical properties

[0088] Comparative experiments C and Example V, based on conventional glass fiber (E-glass) and silicon-borosilicate glass fiber respectively, both achieved LDS ratings. The results show that EX-V outperforms CE-C for all TS, EaB, FS, FB, and impact resistance properties.

[0089] Comparative Experiment D and Example VI both consist of semi-aromatic polyamide compositions, based on conventional glass fiber (E-glass) and silicon-borosilicate glass fiber, respectively. The results show that EX-VI exhibits better performance than CE-D for all TS, EaB, FS, FB, and impact resistance properties.

[0090] Table 3. Composition and mechanical properties of Examples VII-VIII and Comparative Experiment EF (all PBT grade)

[0091] Comparative Experiment E and Example VII both contain 30% glass fiber in the PBT grade, based on conventional glass fiber (E-glass) and silicon-borosilicate glass fiber, respectively. The results show that EX-VII has a TS comparable to CE-E, and exhibits better performance than CE-E in terms of TS, EaB, and impact resistance.

[0092] Comparative Experiment F and Example VIII are both PBT grades with 40% glass fiber by weight, based on conventional glass fiber (E-glass) and silicon-borosilicate glass fiber, respectively. The results show that EX-VIIII has a TS comparable to CE-F, and exhibits better performance than CE-F in terms of TS, EaB, and impact resistance.

Claims

1. A composition comprising a thermoplastic polymer and glass fiber, wherein the composition comprises: (i) Thermoplastic polymers selected from the group consisting of polyesters (PES), polyamides (PA), polycarbonates (PC), polyphenylene sulfides (PPS), polyphenylene oxides (PPO), polyether ether ketones (PEEK), polyarylether ketones (PAEK), polyamide imides (PAI), polyether imides (PEI), and liquid crystal polymers (LCP), and combinations thereof; (ii) at least 22% by weight of silicon-borosilicate glass fiber, which mainly comprises silicon dioxide (SiO2) and boron trioxide (B2O3); and (iii) 0-7% by weight of halogen-free flame retardant, The weight percentage (wt%) is relative to the total weight of the composition.

2. The composition according to claim 1, wherein, The thermoplastic polymer includes polyamide or semi-crystalline polyester, or a combination thereof.

3. The composition according to claim 1 or 2, wherein, The silicon-borosilicate glass fiber comprises silicon dioxide and boron trioxide in a combined amount of at least 90% by weight, relative to the weight of the silicon-borosilicate glass fiber.

4. The composition according to claim 3, wherein, The silicon-borosilicate glass fiber comprises: (a) 65-85% by weight of SiO2; (b) 15-30% by weight of B2O3; (c) 0-4% by weight of sodium oxide (Na2O) or potassium oxide (K2O) or a combination thereof; and (d) 0-4% by weight of other components; wherein the weight percentage (wt%) is relative to the weight of the silicon-borosilicate glass fiber.

5. The composition according to any one of claims 1-4, wherein, The composition comprises E-glass fiber in an amount of up to 30% by weight, preferably up to 15% by weight, relative to the weight of the silicon-borosilicate glass fiber.

6. The composition according to any one of claims 1-5, wherein, The composition comprises: a) 30-75% by weight of the thermoplastic polymer of group (i); b) 25-70% by weight of the aforementioned silicon-borosilicate glass fiber; and c) 0-7% by weight of halogen-free flame retardant, The weight percentage (wt%) is relative to the total weight of the composition.

7. The composition according to any one of claims 1-5, wherein, The composition comprises: a) 30-75% by weight of polyamide or semi-crystalline polyester, or a combination thereof; b) 25-70% by weight of glass fiber, comprising at least 22% by weight of the aforementioned silicon-borosilicate glass fiber; and c) 0-7% by weight of halogen-free flame retardant, The weight percentage (wt%) is relative to the total weight of the composition.

8. The composition according to any one of claims 1-7, wherein, The composition contains a polymer impact modifier.

9. The composition according to any one of claims 1-8, wherein, The composition contains a laser direct forming (LDS) additive.

10. The composition according to any one of claims 1-9, wherein, The composition also contains a white pigment containing titanium dioxide.

11. A molded part comprising the composition of any one of claims 1-10.

12. Use of the composition according to any one of claims 1-10 or a molded part comprising the composition according to any one of claims 1-10 in the housing or frame of an electronic mobile device.

13. An electronic mobile device, comprising a housing or frame, wherein the housing or frame is made of the composition according to any one of claims 1-10.

14. Use of the composition according to any one of claims 1-10 or a molded part comprising the composition according to any one of claims 1-10 in a speaker enclosure, audio jack module, antenna or connector portion.

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