Coated inorganic filaments and preparation thereof

Abstract

The present invention relates to a coated filament comprising an inorganic filament and a polymer composition comprising a thermoplastic polymer wherein the polymer composition is in direct contact with the filament and wherein the length of the coated filament is less than 100 mm. In another aspect, the invention relates to a coated filament, filament bundle or tape obtainable by a method for producing coated filaments comprising the following steps: a. Producing uncoated inorganic filaments, preferably uncoated glass filaments, from an inorganic melt; b. Providing a molten polymer composition comprising a thermoplastic polymer; c. Applying the molten polymer composition to the uncoated inorganic filaments, preferably using a roller die, a curtain coater die or a seam die, and solidifying the molten polymer composition, and d. Obtaining coated filaments comprising inorganic filaments coated with the polymer composition, and wherein the inorganic filaments are in direct contact with the polymer composition, and e1. Cutting the coated filaments into segments having a length of less than 100 mm, or e2. Bundling a plurality of the coated filaments into an endless tow or yarn, and optionally cutting the endless tow or yarn into segments having a length of less than 100 mm, or f. Bundling a plurality of said coated filaments into an endless tow or yarn, and g. Producing a tape from the endless tow or yarn to produce a tape having a thickness of 0.2 mm up to and including 2 mm and a width of 10 mm up to and including 500 mm, and wherein the tape has an aspect ratio higher than 10.

Description

Background Art

[0001] There are different methods for producing inorganic fibers as substrates coated with organic materials, such as dip coating, pre-dosed coating process or curtain coating.

[0002] In the pre-dosed coating method, the liquid for coating is extruded between the nozzle and the substrate. This results in shear forces acting on the substrate. In the on-line coating of filaments, this results in the filaments breaking at high speeds.

[0003] In curtain coating, the directions of liquid flow and fiber movement do not match. This results in an immediate change in the flow direction of the liquid for coating. As a result, a high Reynolds number and thus turbulence are generated. This turbulence does not match the movement of the filaments and cannot be controlled, which results in the formation of droplets in the liquid and air entrainment at the contact points.

[0004] This also applies to dip coating.

[0005] Therefore, the present invention is based on the task of remedying the above problems. Summary of the Invention

[0006] The present invention is defined by the subject matter of the appended claims.

[0007] Disclosed is a coated filament comprising an inorganic filament and a polymer composition comprising a thermoplastic polymer, wherein the polymer composition is in direct contact with the filament, and wherein the length of the coated filament is less than 100 mm.

[0008] Since the polymer composition is in direct contact with the filament, this means that there are no components between the surface of the inorganic filament and the coating, and thus this means that there is no adhesion promoter, sizing agent or similar compound between the polymer composition and the inorganic filament. Usually, an adhesion promoter or sizing agent is first applied to the inorganic filament before coating with the polymer composition.

[0009] The following method eliminates the need for a coating with an adhesion promoter etc. between the inorganic filament and the polymer composition.

[0010] The inorganic filaments can be mineral materials such as engineering glass (electrical glass (E-glass, an alumino-borosilicate glass with less than 1 wt% alkali metal oxide); A-glass (a soda-lime glass with little or no boron oxide); AR-glass; electrically / chemically resistant glass (E-CR glass, an alumino-lime-silicate glass with less than 1 wt% alkali metal oxide and high acid resistance); C-glass (a soda-lime glass with a high boron oxide content, which can also be T-glass); D-glass (a borosilicate glass with a low dielectric constant); R-glass (an aluminosilicate glass without MgO and CaO); S-glass (an aluminosilicate glass without CaO but with a high MgO content); M-glass; or basalt; kaolin; alkaline earth metal silicates (AES, a combination of CaO, MgO and SiO 2 ); refractory ceramic fibers (RCF, also known as aluminosilicate, ASW); polycrystalline wool (PCW, containing more than 70% alumina); alumina; metallic materials (steel alloys; aluminum alloys; copper alloys, platinum alloys and pure platinum, especially alloys with rhodium).

[0011] Preferred inorganic filaments are glass fibers, E-glass or E-CR glass.

[0012] The polymer composition comprises a thermoplastic polymer, for example in an amount of at least 95 wt%, for example at least 96 wt%, preferably at least 97 wt%, for example at least 98.5 wt%, based on the polymer composition, and may optionally contain additives, for example in an amount of 0.1 - 5.0 wt% based on the polymer composition.

[0013] Preferably, the polymer composition comprises at least 95 wt%, for example at least 96 wt%, preferably at least 97 wt%, for example at least 98.5 wt% of a thermoplastic polymer, based on the polymer composition, and / or wherein the thermoplastic polymer is selected from acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), polyethylene (PE), polyolefin elastomer (POE), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), polybutadiene (BR), ethylene propylene diene monomer (EPDM), polyamide (PA), thermoplastic polyurethane (TPU) and mixtures thereof, preferably wherein the thermoplastic polymer is polypropylene.

[0014] The thermoplastic polymer may be selected from: polymers soluble in chloroform, carbon tetrachloride or 1-bromonaphthalene, such as acrylic polymers (acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), polyisobutyl methacrylate (PiBMA), poly(n-butyl methacrylate) (PnBMA), poly(ethyl methacrylate) (PEMA), poly(methyl methacrylate) (PMMA)), cellulose acetate butyrate (CAB), fluorinated ethylene propylene (FEP), polyamide (PA) such as polyamide 12 (PA-12), polybutadiene, polycarbonate (PC) such as bisphenol A polycarbonate, polychlorotrifluoroethylene (PCTFE), polyimide such as polyetherimide (PEI), polysulfone such as polyethersulfone (PES), polyethylene (PE) such as UHMWPE, HMWPE, HDPE, LLDPE, LDPE, polyethylene terephthalate (PET), polyisobutene (PiB, butyl rubber), polyisoprene (PiP), polylactic acid (PLA), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polypropylene (PP), atactic PP, isotactic PP, polystyrene (PS), polysulfone (PSU), polyurethane (PU), polyvinyl acetate (PVA), polyvinyl butyral, polyvinyl chloride (PVC), bromine-soluble polymers, acrylic polymers, poly(ethyl methacrylate) (PEMA), poly(methyl methacrylate) (PMMA), cellulose acetate (CA), cellulose acetate butyrate (CAThB), nitrocellulose (nitrocellulose), polycarbonate (PC), bisphenol A polycarbonate, polyphenylene oxide (PPO), polyurethane (PU), polyvinyl acetate (PVA).

[0015] The composition may comprise A) grafted polypropylene grafted with C1) a side chain compound capable of forming hydrogen bonds, and / or B) ungrafted polypropylene, and C2) a compound capable of forming hydrogen bonds, wherein the total amount of A) and B) is at least 70 wt% based on the polypropylene composition, and the polypropylene composition comprises D) low molecular weight polyethylene, such as a low molecular weight polyolefin having a molecular weight of at most 5000 g / mol, in an amount less than 10 wt% based on the polypropylene composition.

[0016] The use of an adhesion promoter, preferably a side chain compound capable of forming hydrogen bonds or / and a compound capable of forming hydrogen bonds, in the polymer composition improves the adhesion between the polymer composition and the inorganic fibers. Surprisingly, it has been found that coated filaments can be produced in which the adhesion promoter is incorporated into the polymer composition itself rather than as an interlayer. This simplifies the production process.

[0017] The coated glass filaments can be in the form of individual glass filaments having a coating. In this case, the coating can be provided on substantially the entire or a part of the surface of the glass filament. The coated glass filaments can be in the form of a plurality of glass filaments (partially) bundled together. In this case, the coating may not be present on the portions of the glass filaments that are in contact with each other.

[0018] In some preferred embodiments, the glass filaments provided with a coating are obtained by recycling polymer-coated glass filaments, such as epoxy resin-coated chopped glass filaments. The polymer, such as epoxy resin, can be removed from the polymer-coated glass filaments, for example, by burning off the polymer, to obtain uncoated glass filaments. A coating of a polypropylene composition can be directly provided on the uncoated glass filaments so obtained to obtain coated glass filaments. Due to the increasing awareness of sustainability, the use of recycled materials is highly desirable.

[0019] The coated glass filaments comprise a coating of a polymer composition (preferably a polypropylene composition) that is directly provided on the glass filaments. Since there is no sizing composition, the problems associated with sizing compositions are solved.

[0020] Preferably, the polypropylene composition used comprises C1) a side-chain compound capable of forming hydrogen bonds (as part of the grafted polypropylene) and / or C2) a compound capable of forming hydrogen bonds. The presence of C1) and / or C2) in the polypropylene composition improves the adhesion to the glass fibers. Compounds C1) and C2) have a hydrogen atom or a functional group that produces a hydrogen atom through (partial) hydrolysis of the functional group, which can form hydrogen bonds with the glass filaments. The hydrogen bonds improve the adhesion of the polypropylene composition to the glass filaments. In some cases, in addition to forming hydrogen bonds, a condensation reaction between the silanol groups on the glass surface and the hydrogen atoms can produce ester bonds or ether bonds, thereby producing covalent bonds with the glass surface.

[0021] Preferably, the polypropylene composition comprises:

[0022] - A) grafted polypropylene grafted with a C1) side-chain compound selected from: acid anhydrides (such as maleic anhydride, itaconic anhydride), vinyl oligosilanes, acryloyloxy oligosilanes, epoxy (meth)acrylates, and combinations thereof;

[0023] - A) grafted polypropylene grafted with a C1) side-chain compound selected from: acid anhydrides (such as maleic anhydride, itaconic anhydride), vinyl oligosilanes, acryloyloxy oligosilanes, epoxy (meth)acrylates, and combinations thereof, and

[0024] B) non-grafted polypropylene;

[0025] -A) Grafted polypropylene grafted with a C1) side chain compound selected from the following: acid anhydrides (such as maleic anhydride, itaconic anhydride), vinyl oligosilanes, acryloyloxy oligosilanes, epoxy (meth)acrylates, and combinations thereof;

[0026] B) Non-grafted polypropylene, and

[0027] C2) Compounds selected from the following: oligosilanes (such as vinyl oligosilanes, aminopropyl oligosilanes, acryloyloxy oligosilanes), copolymers of ethylene and 2-hydroxyethyl methacrylate, epoxy (meth)acrylates, polyamides, organometallic compounds having pyrophosphate groups, and combinations thereof; or

[0028] -A) Grafted polypropylene grafted with a C1) side chain compound selected from the following: acid anhydrides (such as maleic anhydride, itaconic anhydride), vinyl oligosilanes, acryloyloxy oligosilanes, epoxy (meth)acrylates, and combinations thereof;

[0029] B) Non-grafted polypropylene, and

[0030] C2) Compounds selected from the following: vinyl oligosilanes, acryloyloxy oligosilanes, copolymers of ethylene and 2-hydroxyethyl methacrylate, epoxy (meth)acrylates, organometallic compounds having pyrophosphate groups, and combinations thereof.

[0031] A) Grafted polypropylene

[0032] The polypropylene composition used may contain grafted polypropylene. The grafted polypropylene is polypropylene grafted with a C1) side chain compound capable of forming hydrogen bonds.

[0033] Suitable examples of C1) include acid anhydrides (such as maleic anhydride, itaconic anhydride), oligosilanes (such as vinyl oligosilanes, aminopropyl oligosilanes, acryloyloxy oligosilanes), epoxy (meth)acrylates, polyamides, and combinations thereof. Those skilled in the art know how to obtain A) by grafting C1) onto polypropylene. When C1) is maleic anhydride, the double bond of maleic anhydride is consumed to effect grafting, and a succinic anhydride bond is formed connecting to the polypropylene. An example of epoxy (meth)acrylate is glycidyl methacrylate.

[0034] Preferably, C1) includes acid anhydrides (such as maleic anhydride, itaconic anhydride). Most preferably, C1) includes maleic anhydride. This produces good adhesion between the polypropylene composition and the glass filaments. Preferably, C2) has an unsaturated group capable of reacting with non-grafted polypropylene to form hydrogen bonds, or C2) has a hydrophobic group (such as the copolymer of ethylene and 2-hydroxyethyl methacrylate (PE-HEMA)).

[0035] Preferably, the amount of C1) is 0.5 - 10 wt%, such as 0.6 - 5.0 wt%, 0.7 - 3.0 wt%, 0.8 - 2.0 wt%, based on the amount of A).

[0036] C2) is capable of forming a hydrogen-bonding compound

[0037] The polypropylene composition used may comprise B) ungrafted polypropylene and C2) a compound capable of forming hydrogen bonds.

[0038] Suitable examples of C2) include oligosilanes (such as vinyl-oligosilane, aminopropyl-oligosilane, acryloyloxy-oligosilane), copolymers of ethylene and 2-hydroxyethyl methacrylate (PE-HEMA), epoxy resins, polyamides, organometallic compounds having pyrophosphate groups, and combinations thereof.

[0039] When the polypropylene composition comprises A), C2) is preferably a compound selected from the following: oligosilanes (such as vinyl-oligosilane, aminopropyl-oligosilane, acryloyloxy-oligosilane), copolymers of ethylene and 2-hydroxyethyl methacrylate (PE-HEMA), epoxy (meth)acrylates, polyamides, organometallic compounds having pyrophosphate groups, and combinations thereof.

[0040] When the polypropylene composition does not comprise A), C2) is preferably a compound selected from the following: vinyl-oligosilane, acryloyloxy-oligosilane, copolymers of ethylene and 2-hydroxyethyl methacrylate, epoxy (meth)acrylates, organometallic compounds having pyrophosphate groups, and combinations thereof.

[0041] Preferably, C2) is selected from oligosilanes (such as vinyl-oligosilane, aminopropyl-oligosilane, acryloyloxy-oligosilane), organometallic compounds having pyrophosphate groups, and combinations thereof. This gives good adhesion between the polypropylene composition and the glass filaments.

[0042] Preferably, C2) comprises vinyl-oligosilane or acryloyloxy-oligosilane, more preferably vinyl-oligosilane. This gives particularly good adhesion between the polypropylene composition and the glass filaments.

[0043] It has been found that oligosilanes have a low enough volatility to react with polypropylene to achieve the desired effect.

[0044] Preferably, the polypropylene composition does not contain or substantially does not contain alkoxysilane compounds having a molecular weight of less than 300 (e.g., γ-aminopropyltriethoxysilane (APTES), γ-glycidoxypropyltrimethoxysilane (GPTMS), γ-methacryloxypropyltrimethoxysilane (MPTMS), vinyltriethoxysilane (VTES)). Preferably, the amount of such alkoxysilane compounds having a molecular weight of less than 300 is less than 10 wt%, less than 5.0 wt%, less than 3.0 wt%, less than 1.0 wt%, less than 0.5 wt%, or 0 wt% based on the polypropylene composition.

[0045] Preferably, C2) comprises an organometallic compound having a pyrophosphate group, preferably a titanate pyrophosphate compound or a zirconate pyrophosphate compound. This gives particularly good adhesion between the polypropylene composition and the glass filaments. Suitable examples include neopentyl(diallyl)oxytris(dioctyl)pyrophosphate titanate, cyclo(dioctyl)pyrophosphate dioctyl titanate, dicyclo(dioctyl)pyrophosphate titanate, neopentyl(diallyl)oxytris(N-ethylenediamino)titanium ethoxide, cyclo[bis(neopentyl(diallyl))]pyrophosphate bis(neopentyl(diallyl))zirconate, bis(dioctyl)pyrophosphate oxyethylene titanate, and the 2-(N,N-dimethylamino)isobutanol adduct of bis(dioctyl)pyrophosphate oxyethylene titanate.

[0046] Preferably, the amount of C2) is 0.2 - 10 wt%, such as 0.3 - 5.0 wt%, 0.4 - 3.0 wt%, 0.5 - 2.0 wt% based on the total amount of B) and C2).

[0047] D) Low molecular weight polyolefin

[0048] The polypropylene composition comprises D) low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol, and the amount thereof is less than 10 wt% based on the polypropylene composition. It should be understood that this includes the case where the polypropylene composition does not contain D) low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol. If the polypropylene composition contains D) low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol, then the amount thereof is less than 10 wt% based on the polypropylene composition. Thus, this feature can also be expressed as "in the polypropylene composition, the amount of D) low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol is less than 10 wt% based on the polypropylene composition".

[0049] Preferably, the polypropylene composition does not contain or substantially does not contain low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol. Preferably, the amount of such low molecular weight polyethylene is less than 10 wt%, less than 5.0 wt%, less than 3.0 wt%, less than 1.0 wt%, less than 0.5 wt%, or 0 wt% based on the polypropylene composition.

[0050] Preferably, the polypropylene composition does not contain or substantially does not contain low molecular weight polyolefins having a number average molecular weight of at most 5000 g / mol. For example, the content of such low molecular weight polyolefins (the sum of low molecular weight polyethylene having a number average molecular weight of at most 5000 g / mol and any other polyolefins having a number average molecular weight of at most 5000 g / mol) based on the polypropylene composition is less than 10 wt%, less than 8.0 wt%, less than 5.0 wt%, less than 3.0 wt%, less than 1.0 wt%, less than 0.5 wt%, or 0 wt%.

[0051] Additives

[0052] The polymer composition such as the polypropylene composition may further comprise additives such as flame retardants, pigments, lubricants, slip agents, flow promoters, antistatic agents, processing stabilizers, long-term stabilizers, and / or UV stabilizers. The amount of the additives may be, for example, 0.1 - 5.0 wt%.

[0053] Preferably, the total amount of A), B), C2), D), and the additives is 100 wt% based on the polypropylene composition.

[0054] Preferred compositions

[0055] Preferably, the melt viscosity of the polypropylene composition at the melt temperature of the polymer composition is at most 25 Pa·s, preferably 1.0 - 25 Pa·s, more preferably 1.0 - 20 Pa·s, even more preferably 1.8 - 19.4 Pa·s, or 1.0 - 15 Pa·s, even more preferably 1.0 - 10 Pa·s, and most preferably 1.0 - 5.0 Pa·s, where the melt temperature of the polymer composition is determined on a 5 mg sample using differential scanning calorimetry with a heating and cooling rate of 10 °C / min on the second heating curve, and where the melt viscosity is determined according to ISO 6721-10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%.

[0056] In some preferred embodiments, the amount of A) is at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt%, or 100 wt% based on the polypropylene composition.

[0057] In some preferred embodiments, the total amount of B) and C2) is at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt%, or 100 wt% based on the polypropylene composition.

[0058] In some preferred embodiments, the polypropylene composition comprises A) and B). Preferably, the total amount of A) and B) is at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 93 wt%, at least 95 wt%, at least 97 wt%, at least 99 wt%, or 100 wt% based on the polypropylene composition. Preferably, the amount of A) is 1.0 - 30 wt%, such as 2.0 - 25 wt%, 3.0 - 20 wt%, or 4.0 - 10 wt% based on the total amount of A) and B).

[0059] In some preferred embodiments, the polypropylene composition comprises A), B) and C2). Preferably, the amount of B) is at least 65 wt% based on the total amount of A), B) and C2). Preferably, the amount of A) is 1.0 - 30 wt%, such as 2.0 - 25 wt%, 3.0 - 20 wt%, or 4.0 - 10 wt% based on the total amount of A) and B). Preferably, the amount of C2) is 0.2 - 10 wt%, such as 0.3 - 5.0 wt%, 0.4 - 3.0 wt%, 0.5 - 2.0 wt% based on the total amount of B) and C2). In a particularly preferred embodiment, the amount of A) is 1.0 - 5.0 wt%, the amount of B) is 90 - 98 wt%, and the amount of C) is 1.0 - 5.0 wt% based on the total amount of A), B) and C).

[0060] In a particularly preferred embodiment where the polypropylene composition comprises A), B) and C2), C1) is selected from acid anhydrides (such as maleic anhydride, itaconic anhydride), and C2) comprises an organometallic compound having a pyrophosphate group, preferably a titanate pyrophosphate compound or a zirconate pyrophosphate compound.

[0061] Another aspect

[0062] The present invention further provides a multifilament yarn comprising a plurality of coated glass filaments in a bundle. The multifilament yarn may further comprise uncoated glass filaments, but preferably at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt% of the multifilament yarn is coated glass filaments.

[0063] The melt viscosity of the polymer composition at the melt temperature of the polymer composition can be 1.0 - 25 Pa·s, for example 1.8 - 19.4 Pa·s, where the melt temperature of the polymer composition is determined on a 5 mg sample using differential scanning calorimetry with a heating and cooling rate of 10 °C / min on the second heating curve, and where the melt viscosity is determined according to ISO 6721-10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%.

[0064] Preferably, the polymer composition satisfies Inequality 1:

[0065] η ≤ (82 × e^0.007×(ACTO)) + 5 (Inequality 1)

[0066] where η represents the melt viscosity measured at the melt temperature of the polymer composition, in Pa·s, where the melt temperature of the polymer composition is determined on a 5 mg sample using differential scanning calorimetry with a heating and cooling rate of 10 °C / min on the second heating curve, and where the melt viscosity is determined according to ISO 6721-10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%, and where ACTO represents the amount of active oxygen in the polymer composition, in ppm.

[0067] The active oxygen content of the complex is calculated based on the concentration of the peroxide and the active oxygen content of the peroxide, as can be seen in the supplier's technical data sheet.

[0068] The polymer composition can be applied to the glass filaments in a molten state. At the application temperature (for example 250 °C or 290 °C), the melt viscosity of the polymer composition should not be too high.

[0069] Preferably, the melt viscosity of the polymer composition (for example, a polypropylene composition) at the melt temperature of the polymer composition is at most 25 Pa·s, preferably 1.0 - 25 Pa·s, more preferably 1.0 - 20 Pa·s, even more preferably 1.8 - 19.4 Pa·s or 1.0 - 15 Pa·s, even more preferably 1.0 - 10 Pa·s, most preferably 1.0 - 5.0 Pa·s, where the melt temperature of the polymer composition is determined on a 5 mg sample using differential scanning calorimetry with a heating and cooling rate of 10 °C / min on the second heating curve, and where the melt viscosity is determined according to ISO 6721-10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%.

[0070] The polypropylene composition can be obtained by i) polymerizing monomers to obtain an intermediate polypropylene and ii) visbreaking the intermediate polypropylene.

[0071] For example, the intermediate polypropylene can have a melt flow index of 1.0 - 100 dg / min at 230 °C and 2.16 kg according to ISO 1133-1:2011.

[0072] The visbreaking can be carried out by melt mixing the intermediate polypropylene with at least one of a peroxide, a hydroxylamine ester, and a sulfur compound.

[0073] Preferably, the melt mixing is carried out at a temperature of 160 - 300 °C. When the melt mixing is carried out in the presence of a peroxide, the melt mixing is preferably carried out at a temperature of 200 - 300 °C, such as 220 - 280 °C, or 240 - 260 °C. When the melt mixing is carried out in the presence of a hydroxylamine ester, the melt mixing is preferably carried out at a temperature of 280 - 300 °C.

[0074] When the visbreaking is carried out in the presence of a peroxide, the period of time for which the melt mixing is carried out is at least 3 times, such as 4 - 7 times, or 5 - 6.5 times, the half-life of the organic peroxide at the temperature of the melt mixing.

[0075] Preferably, the amount of peroxide in the visbreaking step ii) is selected such that the polypropylene composition contains active oxygen at a concentration of at least 200 ppm, preferably 200 - 1000 ppm, based on the polypropylene composition.

[0076] Preferably, the amount of peroxide in the visbreaking step ii) is selected such that the polypropylene composition contains active oxygen at a concentration of at least 300 ppm, preferably at least 400 ppm, more preferably at least 525 ppm, based on the polypropylene composition.

[0077] In some embodiments, the peroxide comprises a first peroxide having a half-life of 1 hour at a first temperature T 1 / 2 1 of 120 - 145 °C, preferably 125 - 140 °C, more preferably 128 - 137 °C. Examples of the first peroxide include 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (e.g., Trigonox TM 101 manufactured by AkzoNobel), which has a T 1 / 2 1 of 134 °C.

[0078] Preferably, the first peroxide has a half-life of 0.1 hour at a temperature of 140 - 180 °C, more preferably 150 - 170 °C.

[0079] In some embodiments, the peroxide is included at a second temperature T above 145 °C and up to 180 °C, preferably up to 170 °C, such as above 145 °C and up to 150 °C, or at least 155 °C and up to 170 °C 1 / 2 A second peroxide having a 1-hour half-life.

[0080] In addition, the second peroxide preferably has a half-life of 0.1 hour at a temperature of 165 - 188 °C. Examples of the second peroxide include 3,6,9-triethyl-3,6,9-trimethyl-1,4,6-triperoxynonane (e.g., Trigonox TM 301 manufactured by Nouryon) which has a T 1 / 2 2 of 146 °C and a half-life of 0.1 hour at a temperature of 170 °C) and 3,3,5,7,7-pentamethyl-1,2,4-trioxepane (e.g., Trigonox TM 311 manufactured by Nouryon) which has a T 1 / 2 2 of 166 °C and a half-life of 0.1 hour at a temperature of 185 °C).

[0081] In some embodiments, the peroxide is the first peroxide or the second peroxide.

[0082] In some embodiments, the peroxide includes the first peroxide and the second peroxide.

[0083] Preferably, the amount of the peroxide is 100 - 10000 ppm relative to the intermediate polypropylene.

[0084] Preferably, the amount of the first peroxide is 100 - 2000 ppm relative to the intermediate polypropylene.

[0085] Preferably, the amount of the second peroxide is 100 - 8000 ppm, preferably 1000 - 8000 ppm relative to the intermediate polypropylene.

[0086] Preferably, the sulfur compound has the formula R 1 -S-H, where R 1 represents a C8 - C18 alkyl group.

[0087] A polymer composition having a specific viscosity can be particularly effectively used for high-speed coating of inorganic filaments.

[0088] A coating having a polymer composition can be a spot (dot) coating or a mantle coating. In the case of a spot coating, the coating does not completely encapsulate the filaments but is distributed on the filaments in the form of spaced spots, which cover 1 - 90%, 5 - 90%, 10 - 90% of the fiber surface. In the case of a mantle coating, the coating substantially completely encapsulates the filaments, which covers more than 90% of the fiber surface. The filament diameter of the coated filaments can be >2 μm and <50 μm, and / or the thickness of the polymer composition layer can be >0.5 μm and <5 μm.

[0089] The filament diameter of the coated filaments can be >3 μm and <30 μm, preferably >8 μm and <10 μm. The thickness of the polymer composition layer can be >0.02 μm and <3 μm, >0.1 μm and <3 μm, >0.2 μm and <3 μm, preferably >0.7 μm and <0.9 μm. Fibers (filament bundles) of different diameters can be made from several filaments.

[0090] A filament bundle comprising a plurality of the above - mentioned coated filaments is also disclosed.

[0091] After coating with the polymer composition, the coated filaments can be immediately combined or spun into a filament bundle. Thus, the still - fluid polymer composition will bond the filaments together. Thus, the bonding within the filament bundle is particularly stable and can be further improved by a bonding promoter, preferably by a compound capable of forming hydrogen bonds present in the polymer composition, especially in the case of a spot coating.

[0092] A filament bundle can contain 2 - 5000 coated filaments. A filament bundle of the present invention, a so - called yarn, is also disclosed.

[0093] A method for producing coated filaments is also disclosed, which comprises the following steps:

[0094] a. Producing uncoated inorganic filaments from an inorganic melt, preferably uncoated glass filaments;

[0095] b. Providing a molten polymer composition comprising a thermoplastic polymer;

[0096] c. Applying the molten polymer composition to the uncoated inorganic filaments, preferably applying using a roll die, a curtain coater die or a slot die, and solidifying the molten polymer composition, and

[0097] d. Obtaining coated filaments comprising inorganic filaments coated with the polymer composition, wherein the inorganic filaments are in direct contact with the polymer composition, and

[0098] e1. Cut the coated filaments into segments having a length of 100 mm or longer, or

[0099] e2. Bundle a plurality of the coated filaments into a filament tow or yarn, and optionally cut the filament tow or yarn into segments having a length of 100 mm or longer.

[0100] Also disclosed is a coated filament, filament tow or tape which can be obtained by a method for producing a coated filament comprising the following steps:

[0101] a. Produce an uncoated inorganic filament from an inorganic melt, preferably an uncoated glass filament;

[0102] b. Provide a molten polymer composition comprising a thermoplastic polymer;

[0103] c. Apply the molten polymer composition to the uncoated inorganic filament, preferably using a roll die, a curtain coater die or a slot die, and solidify the molten polymer composition, and

[0104] d. Obtain a coated filament comprising an inorganic filament coated with the polymer composition, wherein the inorganic filament is in direct contact with the polymer composition, and

[0105] e1. Cut the coated filament into segments having a length of less than 100 mm, or

[0106] e2. Bundle a plurality of the coated filaments into a filament tow or yarn, and optionally cut the filament tow or yarn into segments having a length of less than 100 mm, or

[0107] f. Bundle a plurality of the coated filaments into a filament tow or yarn, and

[0108] g. Produce a tape from the filament tow or yarn to produce a tape having a thickness of 0.2 mm up to and including 2 mm and a width of 10 mm up to and including 500 mm, and wherein the aspect ratio of the tape is higher than 10.

[0109] It has surprisingly been found that very high production speeds are possible by applying the said method. In this method, the molten polymer composition can be distributed in the direction of gravity. In this method, the inorganic melt and / or the uncoated inorganic filaments can be distributed in the direction of gravity.

[0110] Inorganic filaments are generally produced by drawing from an inorganic melt. In a nozzle drawing process, glass granules are metered and melted in a nozzle box - sleeve. The melt emerges through the nozzle in the form of filaments and solidifies so that the individual filaments can be wound onto a drawing drum. For this purpose, the apparatus can include, for example, a storage container for the glass granules.

[0111] Downstream of the nozzle, such as a glass fiber sleeve, is a coating device from which a molten polymer composition is dispensed.

[0112] During the application process, the direction of the uncoated inorganic filaments and the direction of the polymer composition can be at an (absolute) angle of no more than 45°, 25°, 10°, 5°, 1°, or 0° relative to each other at the contact position.

[0113] In other words, the direction of the uncoated inorganic filaments and the direction of the polymer composition are substantially parallel to each other.

[0114] The angle is measured from the position where the polymer composition first wets the filaments towards the position where the polymer composition first directly contacts the filaments (first application point). The sides of the angle are a straight line imagined through the filaments and a directly opposite straight line on the surface of the polymer composition between the wetting position and the first contact position.

[0115] By specifying the angle or substantial parallelism, unwanted forces (warping forces, turbulence caused by changes in the direction of the polymer composition) are reduced, enabling rapid wetting of the filaments to occur.

[0116] When applying the polymer composition to the uncoated inorganic filaments, the moving speed of the polymer composition can be 50% - 110%, 95% - 105%, or 99% - 101% of the moving speed of the inorganic filaments. Optionally or additionally, the moving speed of the inorganic filaments can be 500 - 3000 m / min, 1250 - 1750 m / min, or 1450 - 1550 m / min.

[0117] Furthermore, by keeping the speeds of the filaments and the polymer composition as equal as possible, the occurrence of unwanted forces (warping forces, turbulence caused by changes in the direction of the polymer composition) can be reduced, enabling rapid wetting of the filaments.

[0118] Specifically, the combination of a low angle between the polymer composition and the filaments at the application position and (almost) the same dispensing speed of the polymer composition and the filaments enables a very high production speed.

[0119] The inorganic melt or / and the uncoated inorganic filaments can be electrostatically charged during production. The polymer can also be electrostatically charged.

[0120] The static charge can provide better adhesion between the polymer and the uncoated inorganic filaments, and vice versa.

[0121] After coating with the polymer composition, the coated filaments can also undergo further modification. For example, an adhesion promoter, a crosslinking agent, a lubricant, or a film image can be applied to the coated filaments.

[0122] The polymer composition used in the method can be provided by mixing a thermoplastic polymer containing a bonding promoter (e.g., a graft polymer) and a thermoplastic polymer not containing a bonding promoter (e.g., a non-graft polymer). The thermoplastic polymers can be provided in solid or fluid form and then mixed, which results in a dry blend or a wet blend, respectively. The solid polymer composition can be provided as pellets.

[0123] In this way, the ratio of the thermoplastic polymer containing a bonding promoter to the thermoplastic polymer not containing a bonding promoter can be appropriately adjusted. The mixing of the polymers can be carried out in an additional mixing device or an extruder.

[0124] After coating with the polymer composition, the coated filaments can be immediately combined or spun into a filament bundle. Thus, the polymer composition, which is still fluid, can bond the filaments together. Therefore, the bonding within the filament bundle is particularly stable and can be further improved by the presence of a bonding promoter in the polymer composition, especially in the case of spot coating.

[0125] There is also disclosed a coating apparatus for producing coated filaments from the uncoated inorganic filaments according to the above, comprising:

[0126] a. a heating device for producing a fluid polymer composition, such as a molten polymer composition containing a thermoplastic polymer;

[0127] b. a nozzle arranged to discharge the fluid polymer composition obtained from the heater in the direction of gravity and arranged to bring the fluid polymer composition into contact with the uncoated inorganic filaments at an application position and to start wetting the uncoated inorganic filaments at a wetting position;

[0128] c. a supply line between the heater and the nozzle;

[0129] d. the nozzle is arranged such that the angle α between the application position and the start of wetting position is 0° - 45°, 0° - 25°, 0° - 10°, or 0° - 1°, the sides of the angle being an imaginary straight line passing through the filament and an imaginary straight line passing through the surface of the polymer directly opposite the filament.

[0130] In other words, the direction of the uncoated inorganic filaments and the direction of the polymer composition are substantially parallel to each other.

[0131] In the present application, the terms "die" and "nozzle" are used interchangeably.

[0132] The coating apparatus can be arranged to dispense the polymer composition via the nozzle under pressure. This can be achieved by an extruder, an additional pump contained in the device, or a pressure vessel.

[0133] By a defined angle or basic parallelism, undesired forces (warping forces, turbulences due to the change in direction of the polymer composition) are reduced, whereby rapid wetting of the filaments can occur.

[0134] The coating device should be arranged to distribute the molten polymer composition in the direction of gravity. The coating device is arranged to distribute the inorganic melt and / or the uncoated inorganic filaments in the direction of gravity.

[0135] The nozzle provided to distribute the polymer composition can be a wide slot nozzle, a curtain coater or a roll coater. The nozzle preferably distributes the molten polymer composition in a direction substantially parallel to the direction of the uncoated filaments at the application position.

[0136] The wide slot nozzle has a front face that includes the nozzle opening. The front face is a flat plane. Since the front face is a flat plane, the polymer composition travels along the lower part of the flat plane by gravity drive after leaving the nozzle. This lower part (and upper part) of the front face is parallel to the fibers guided through the coating device.

[0137] The curtain coater also has a front face that includes the nozzle opening. The front face can be divided into an upper part above the nozzle opening and a lower part below the nozzle opening. The lower part forms a lip. The lower part is configured to allow the polymer composition to travel along the lower part of the flat plane by gravity drive after leaving the nozzle. This lower part (lip) of the front face forms an angle with the fibers guided through the coating device. The angle can be 5 - 45°, 10 - 40°, or about 30°. The upper part of the front face is parallel to the fibers guided through the coating device. Thus, the upper part and the lip of the curtain coater form an angle of 5 - 45°, 10 - 40°, or about 30°.

[0138] It has surprisingly been found that the curtain coater is particularly useful because the application position is at the lower end of the front face. Thus, the polymer composition is not restricted between the front face and the fibers for an extended time or distance, thereby further reducing the shear forces and other forces that interfere with the coating process.

[0139] The wide slot nozzle can also be used, but the application position of the polymer composition is directly at the nozzle opening. Thus, the polymer composition is restricted between the front face and the fibers for a certain time or distance.

[0140] The nozzle for distributing the polymer composition, in particular a wide slot nozzle, a curtain coater or a roll coater, is suitable for distributing the molten polymer composition in the direction of gravity (e.g., just before it impinges on the uncoated filaments).

[0141] By a defined angle or basic parallelism, undesired forces (shear forces, turbulences due to the change in direction of the polymer composition) are reduced, whereby rapid wetting of the filaments can occur.

[0142] The polymer composition may comprise an adhesion promoter, which improves the adhesion between the inorganic filaments and the polymer composition. Thus, the polymer composition may comprise an adhesion promoter.

[0143] Surprisingly, in the process of the present invention, when using an adhesion promoter, sizing of the inorganic fibers is not required.

[0144] The polymer composition can be melted by a suitable heating device (e.g., a (single-screw or twin-screw) extruder).

[0145] The coating device may further comprise a reservoir for the polymer composition containing the adhesion promoter and a reservoir for the polymer composition without the adhesion promoter.

[0146] In this way, the ratio of the polymer composition containing the adhesion promoter to the polymer composition without the adhesion promoter can be appropriately adjusted. Mixing of the polymer compositions can be carried out in the additional mixing device or extruder described above. The polymer can be provided in solid or fluid form (which results in dry mixing or wet mixing).

[0147] Also disclosed is a device for manufacturing a filament bundle, which comprises:

[0148] a. a nozzle configured to generate uncoated inorganic filaments from an inorganic melt;

[0149] b. the coating device described above;

[0150] c. a fiber bundling device configured to produce a coated filament bundle from the coated filaments.

[0151] The device for producing a filament bundle does not comprise a device for coating the uncoated inorganic filaments with, for example, an adhesion promoter, between the nozzle (which is arranged to generate uncoated inorganic filaments from an inorganic melt) and the coating device.

[0152] The device may comprise a plurality of nozzles for dispensing uncoated inorganic filaments.

[0153] However, the device for producing a filament bundle may include a device immediately downstream of the coating device for further modifying the coated filaments (e.g., an additional coating device, an irradiation device, a heating device, a cooling device, etc.).

[0154] The device may further include a filament guide and a bobbin for receiving the filament bundle downstream of the coating device or optionally an additional device for further modifying the coated filaments. Description of the Drawings

[0155] Figure 1Schematically shows a front view of an apparatus for producing a filament tow according to the present invention.

[0156] Figure 2 Shows Figure 1 A schematic side view of the apparatus of.

[0157] Figure 3 Schematically shows the process of coating an uncoated inorganic filament with a polymer composition.

[0158] Figure 4 Schematically shows the process of coating an uncoated inorganic filament with a polymer composition using a slot die.

[0159] Figure 5 Schematically shows the process of coating an uncoated inorganic filament with a polymer composition using a curtain coater.

[0160] Figure 6 Schematically shows the process of coating an uncoated inorganic filament with a polymer composition using a roll coater. Detailed Description

[0161] Figure 1 And Figure 2 Shows a front view and a side view of an apparatus for producing a filament tow according to the present invention. It can be used to carry out a glass drawing process according to the present invention.

[0162] Pellets made of an inorganic material (especially glass) are fed from a storage container furnace 1 (sleeve). There, the inorganic material is metered and melted. The melt leaves through a nozzle between cooling fins (not shown) and thus solidifies. The inorganic material forms the core of the filaments and the polymer composition, which is also in the form of filaments subsequently. The uncoated inorganic filaments 3 are then passed through a coating device having a nozzle for dispensing a fluid polymer composition (such as a molten polymer composition containing a thermoplastic polymer). The apparatus for producing a filament tow may further comprise a reservoir of an adhesion promoter, which feeds the molten polymer composition to the nozzle of the coating device through a conduit.

[0163] Thereafter, the coated filaments can be passed through a modification device 17 (for example, a sizing device comprising a post-sizing roll and a sizing bath for applying an additional aqueous solution such as a sizing liquid or a coating, preferably a silane-containing solution). Subsequently, the filament tow can be made from individual filaments in an assembly device 6. The filament tow travels through a yarn guide 8 to a bobbin 9, where the fibers are wound up and can be used for further processing.

[0164] Figure 3 Schematically shows in a side view the process of coating an uncoated inorganic filament 3 with a polymer composition 15 in a coating device.

[0165] The uncoated inorganic filaments 3 are fed through the coating device from top to bottom in the direction of gravity g. Thus, it exhibits a velocity V 丝 . The molten polymer composition 15 (e.g., containing a bonding promoter) is directed substantially parallel to the inorganic filaments 3. This is achieved by using nozzles for dispensing (e.g., 12, 13, 14), which ultimately also dispense the molten polymer composition 15 in the direction of gravity. The position where the polymer composition is applied to the filaments is the application position 10. However, wetting has not occurred at this position because the wetting process takes a certain amount of time. The position where the polymer composition 15 wets the filaments 3 (i.e., begins direct contact) is the position where wetting 11 starts. After wetting begins, the surface tension of the polymer composition causes it to spread around the filaments. Depending on the amount of the dispensed polymer composition and / or the viscosity properties of the polymer composition, a spot coating or sheath coating of the polymer composition may appear on the filaments.

[0166] The angle α between the application position and the start position of wetting can be 0° - 25°, 0° - 10°, or 0° - 1°. The sides of the angle are an imaginary straight line passing through the filaments and a line directly opposite the filaments passing through the surface of the polymer.

[0167] The polymer composition 15 moves in the direction of gravity at a velocity V 聚 . V 聚 and V 丝 have substantially the same magnitude, so there are no undesirable forces or effects between the polymer compositions on the filaments.

[0168] Figure 4 Schematically shows the process of coating uncoated inorganic filaments with the polymer composition 15 using a wide slot die 12.

[0169] In the wide slot die 12 defined by the present invention, the polymer composition 15 is dispensed through a horizontal channel and flows vertically downward due to gravity. The wide slot nozzle 12 is arranged such that when the polymer composition is dispensed, the vertically discharged polymer composition meets the filaments, and the vertically discharged polymer composition and the filaments have substantially the same velocity.

[0170] Figure 5 Schematically shows the process of coating uncoated inorganic filaments 3 with the polymer composition 15 using a curtain coater 13.

[0171] In the curtain coater 13 as defined in the present invention, the polymer composition 15 is distributed through a horizontal channel, flows over the lip due to gravity, and then is discharged vertically. In the curtain coater 13 as defined in the present invention, the polymer composition 15 is distributed through a horizontal channel and flows on the lip due to gravity, and then is discharged vertically. The curtain coater described herein has the following advantages: no pressure from the polymer composition is applied to the filaments, which prevents the fibers from breaking at high speeds.

[0172] Figure 6 Schematically shows the process of coating uncoated inorganic filaments with a polymer composition using a roll coater 14.

[0173] In the roll coater 14 as defined in the present invention, the polymer composition 15 is distributed through a horizontal channel and is fed over the top of the roll. By rotating the roll, the polymer composition flows over the roll in the direction of the filaments. Due to gravity, the polymer composition flows out vertically. The roll coater 14 is arranged such that when the polymer composition is being dispensed, the vertically discharged polymer composition impinges on the filaments and the vertically discharged polymer composition and the filaments have substantially the same velocity. Between the discharge channel and the vertical discharge position of the polymer composition 15 and the tip of the roll, spaced-apart blades 16 on the roll can adjust the amount of the discharged polymer composition 15. As described herein, the roll coater has the following advantages: no pressure from the polymer composition is applied to the filaments, which prevents the fibers from breaking at high speeds.

[0174] Screening experiments to determine suitable thermoplastic polymers

[0175] Samples of the polymer composition were prepared from the components in Table 1 below: If all components are solids, a powder blend is made by mixing the powders in a plastic bag, and polymer powders in pellet form are pulverized by cryogenic grinding. In the case of liquid additives, the additives are dissolved in a suitable solvent, spread on powdered polypropylene (PP), and the solvent is evaporated overnight in a fume hood, after which the powder is thoroughly mixed with the additives by shaking in a plastic bag.

[0176] The mixture thus formed was added to a Thermo Scientific Process 11 (P11) 11 mm diameter, twin-screw, co-rotating extruder at 300 g / h by means of a loss-in-weight feeder. The L / D was 45, it had a unit consisting of conveying elements and 3 kneading elements, the speed was 250 rpm, and the barrel had 8 heating zones set at 40, 120, 180, 200, 200, 200, and 200 °C, and the die head was set at 200 °C. The extrudate was cooled in a water bath with flowing tap water and pelletized.

[0177] IFSS measurement (Interfacial Shear Strength)

[0178] Samples of coated glass filaments were prepared from pellets, and the interfacial shear strength was determined by the Microbond test as described in L. Yang and J. L. Thomason: Development and application of micromechanical techniques for characterising interfacial shear strength (IFSS) in fibre-thermoplastic composites - Polymer Testing 31 (2012) 895 - 903). The pellets of the composition obtained above were melted, and filaments were drawn from the melt. Loose knots were made from the filaments, and a glass filament was placed in a loose knot. The knot was tightened, and the excess PP filaments were cut off, which produced a small PP filament knot around the glass filament. It was heated under nitrogen to melt the PP composition, which formed droplets of the PP composition around the filament. After cooling, the droplets solidified. The glass filament was pulled out to determine the interfacial shear strength.

[0179] In CE1, the polymer composition was applied to glass filaments which had an aminosilane sizing composition for optimizing the adhesion to PP. In CE2 - CE4, E5, RE6 - RE7, E8 - E19, the polymer composition was applied to glass filaments supplied by Fibrecoat GmbH without any sizing composition.

[0180] Materials:

[0181] A)

[0182] Type C1) MAH: Exxelor PO1020 from Exxon Mobil, polypropylene grafted with maleic anhydride (0.9 wt% anhydride)

[0183] Type C1) ITA: Scona TSPP 8219GA from BYK Chemie GmbH, polypropylene grafted with itaconic anhydride (2 wt% anhydride)

[0184] Type C1) epoxy resin: Scona TPPP 8104FA from Chemie GmbH, polypropylene grafted with glycidyl methacrylate (2.5 wt% glycidyl methacrylate)

[0185] B)

[0186] PP595A from SABIC, a propylene homopolymer with an MFR of 47 dg / min at 230 °C and 2.16 kg according to ISO 1133

[0187] C2)

[0188] PA: Radipol S24HA from Radicii Group, polyamide 6

[0189] PE-HEMA: Poly(ethylene-hydroxyethyl methacrylate) containing 12 wt% hydroxyethyl methacrylate

[0190] Vinyl-oligosilane: Silquest G-170 from Momentive Performance Materials

[0191] Aminopropyl-oligosilane: Silquest VX-225 from Momentive Performance Materials

[0192] Acryloyloxy-oligosilane: Silquest A-274 from Momentive Performance Materials

[0193] Titanate pyrophosphate: Ken-React LICA 38 from Kenrich Petrochemicals, Inc., neopentyl(diallyl)oxy tris(dioctyl) pyrophosphate titanate

[0194] The compounds mentioned above as C2) have hydrogen atoms capable of forming hydrogen bonds or functional groups that generate hydrogen atoms through (partial) hydrolysis of the group.

[0195] Other materials

[0196] EVA: Poly(ethylene-vinyl acetate) containing 10 wt% vinyl acetate

[0197] Zirconate phosphate: Ken-React ZN 12 from Kenrich Petrochemicals, Inc., isooctyl hydrogen phosphate zirconium complex

[0198] The compounds mentioned above as other materials do not have hydrogen atoms capable of forming hydrogen bonds and do not have functional groups that generate hydrogen atoms through (partial) hydrolysis of the group.

[0199] Other measurement methods

[0200] Melt viscosity

[0201] The melt viscosity is measured according to ISO 6721-10:2015 on pellets or extruded blocks inserted into a plate-to-plate oscillatory shear rheometer. An MCR 502 rotational rheometer from Anton Paar is used. The sample is melted within a 25 mm diameter test geometry at the measurement temperature (oven set at 250 °C or 290 °C), and the sample is preheated in the oven for 1 minute to obtain a fully melted sample, and trimmed to a 1 mm gap, after which oscillatory shear is applied at an angular frequency of 1 rad / s and a shear strain of 5%. During the test, the variation of the melt viscosity over time is monitored.

[0202] Standard linear polypropylene homopolymers with different melt flow rates are used to calibrate the rheometer.

[0203] Melting temperature

[0204] The melting temperature is determined by differential scanning calorimetry using a second heating curve, where the first heating rate is 10 °C / min, the first cooling rate is 10 °C / min, the second heating rate is 10 °C / min, and the sample weight is 5 mg.

[0205] In CE1, glass filaments with a sizing composition coated with a composition containing maleic anhydride-grafted polypropylene produce a high IFSS.

[0206] CE2 shows that applying polypropylene to glass filaments without a sizing composition produces a low IFSS of less than 10 MPa.

[0207] The comparison of CE3 and CE4 with CE2 shows that using a compound that does not have a hydrogen atom capable of forming a hydrogen bond and does not have a functional group that produces a hydrogen atom through (partial) hydrolysis of a group still produces a low IFSS of less than 10 MPa.

[0208] The comparison of E5, RE6, RE7 and E8 to E19 with CE2 shows that using a compound that has a hydrogen atom capable of forming a hydrogen bond or has a functional group that produces a hydrogen atom through (partial) hydrolysis of a group produces a high IFSS of more than 10 MPa.

[0209] Table 1

[0210]

[0211] The ILSS of the bare glass filaments with pure anhydride-grafted PP is very high (E5 and E11), even exceeding that of the sized glass filaments with PP / PP-g-MAH 97 / 3 resin (CE1). Diluting PP-g-MAH in the PP homopolymer decreases the ILSS value (E13 - E15), but even diluting to 3 wt% of PP-g-MAH (E13) still produces a relatively high ILSS. The effect of epoxy-grafted PP is lower than that of anhydride-grafted PP (E12 compared with E4 and E11).

[0212] Adding oligosilanes to PP produces a high ILSS (E8 and E10 compared with CE2). When comparing different types of oligosilanes, the combination of aminopropyl-oligosilane and PPMAH (E18) has the lowest effect. Acryloxy-oligosilane (E19) has a slightly higher effect, and vinyl-oligosilane (E10) has a relatively high effect. Increasing the vinyl-oligosilane level to 8 wt% produces a slight increase (E8).

[0213] Adding both oligosilanes and grafted PPMAH to PP has no significant effect on the ILSS. The addition of both produces a lower ILSS than adding either of them alone (E17 compared with E10, E17 compared with E13).

[0214] Adding titanate pyrophosphate produces a high ILSS (E9 compared with CE2). Adding both titanate pyrophosphate and grafted PPMAH to PP significantly increases the ILSS. The addition of both produces a higher ILSS than adding either of them alone (E16 compared with E9, E16 compared with E13).

[0215] Higher ILSS values are produced via special interactions of alcohol or amine / amide groups, but still at the lower end of all the tested samples, RE6 and RE7.

[0216] The compositions are prepared as described below for application to freshly spun glass filaments.

[0217] Composition Group 1: Blend

[0218] Manufactured by extrusion in an ESDE 35 mm 27 L / D single-screw extruder (model ESE 1 - 35 - 27) 514M12 and Several blends of PP595A, and the barrel temperatures are set at 150, 240, 290, 290, and 290 °C. The extruder feeds the melt pump and the slot die. The melt filter, the melt pump, the pipe to the die head, and the die head temperature are all set at 290 °C. The viscosity is also measured at 290 °C. In Table 1, it shows The correlation between the content of 514M12 material and the melt viscosity.

[0219] Table 1: Extruded Viscosity of 514M12 / PP 595A blends

[0220]

[0221] Composition Group 2: Visbreaking PP595A

[0222] Visbreaking was carried out on a Krauss-Maffei-Berstorff ZE 25A 25 mm co-rotating twin-screw extruder with 48 L / D. The screw contains conveying elements with kneading sections. The barrel has 11 zones with set temperatures of 40, 120, 160, 190, 190, 190, 190, 190, 190, 190 and 190 °C, and the die temperature was also set at 190 °C. PP595A pellets were fed by a loss-in-weight feeder. The peroxide mixture was dissolved in Linpar 10 - 13 oil and fed into the extruder at barrel zone 4 by a liquid pump. The amounts of peroxide and active oxygen are shown in Table 2. The extrudate was cooled in a water bath with flowing tap water and pelletized. The melt viscosity was measured at 250 °C.

[0223] Table 2 Melt viscosity of PP at 250 °C as a function of active oxygen

[0224] 6 7 T101 [ppm] 0 1200 T301 [ppm] 0 1000 Reactive oxygen species [ppm] 0 196 Viscosity at 250 °C [Pa·s] 198.6 20

[0225] Table 3 Melt viscosity of PP at 250 °C as a function of active oxygen

[0226] 8 9 10 T101 [ppm] 0 1200 1200 T301 [ppm] 0 3000 6000 Reactive oxygen species [ppm] 0 344 566 Viscosity at 250 °C [Pa·s] 173 6.6 3.1

[0227] Composition Group 3: Visbreaking PP595A

[0228] Visbreaking was carried out on a Krauss-Maffei-Berstorff ZE40A-UTX 40 mm co-rotating twin-screw extruder with 43 L / D on a larger scale using peroxide masterbatch. The screw contains conveying elements with 3 kneading sections. The peroxide was added as a 20 wt% masterbatch batch together with PP595A pellets. The temperature profile set points were 20, 20, 30, 50, 100, 150, 230, 230, 230, 230, 235, 260 and 260 °C. The samples were extruded at 175 rpm and 100 kg / h. The amounts of peroxide and active oxygen are shown in Table 3. The melt viscosity was measured at 250 °C.

[0229] The active oxygen content of the formulation is calculated based on the concentration of the peroxide and the active oxygen content of the peroxide, as visible in the supplier's technical data sheet.

[0230] For example, Sample 7 contains 1200 ppm of Trigonox 101 and 1000 ppm of Trigonox 301. The active oxygen content of Trigonox 101 is 10.14%, and the active oxygen content of Trigonox 301 is 7.4%, so the active oxygen content of this sample is calculated to be 196 ppm.

[0231] List of reference numerals

[0232] 1 Sleeve (furnace)

[0233] 2 Nozzle

[0234] 3 Inorganic uncoated filaments

[0235] 4 Coating device

[0236] 5 Coated inorganic filaments

[0237] 6 Assembly device

[0238] 7 Filament bundle

[0239] 8 Thread guide

[0240] 9 Coil

[0241] 10 Line / position of initial contact

[0242] 11 Line / position where wetting begins

[0243] 12 Wide slot nozzle

[0244] 13 Curtain coater

[0245] 14 Roll coater

[0246] 15 Polymer composition

[0247] 16 Knife

[0248] 17 Modifying device

[0249] α Angle between the polymer composition and the inorganic filaments between the wetting position and the initial contact position.

[0250] V 聚 Velocity and direction of output of the molten polymer composition.

[0251] V 丝 Velocity and direction of output of the inorganic filaments.

Claims

1. A coated filament comprising an inorganic filament and a polymer composition comprising a thermoplastic polymer, wherein the polymer composition is in direct contact with the filament, and wherein the length of the coated filament is less than 100 mm.

2. The coated filament according to claim 1, wherein the polymer composition comprises at least 95 wt% of the thermoplastic polymer based on the polymer composition, and / or wherein the thermoplastic polymer is selected from acrylonitrile - butadiene - styrene (ABS), acrylonitrile - styrene - acrylate (ASA), polyethylene (PE), polyolefin elastomer (POE), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), polybutadiene (BR), ethylene - propylene - diene monomer (EPDM), polyamide (PA), thermoplastic polyurethane (TPU), and mixtures thereof, preferably wherein the thermoplastic polymer is polypropylene.

3. The coated filament according to claim 1 or 2, wherein the polymer composition comprises a polypropylene composition, the polypropylene composition comprising A) grafted polypropylene grafted with C1) a side - chain compound capable of forming hydrogen bonds, and / or B) ungrafted polypropylene, and C2) a compound capable of forming hydrogen bonds, wherein the total amount of A) and B) is at least 70 wt% based on the polypropylene composition, and the polypropylene composition comprises D) low - molecular - weight polyethylene having a molecular weight of at most 5000 g / mol, the amount of the low - molecular - weight polyethylene being less than 10 wt% based on the polypropylene composition.

4. The coated filament according to any one of claims 1 - 3, wherein the melt viscosity of the polymer composition at the melt temperature of the polymer composition is 1.0 - 25 Pa·s, wherein the melt temperature of the polymer composition is measured on a 5 mg sample using differential scanning calorimetry on the second heating curve with a heating and cooling rate of 10 °C / min, and wherein the melt viscosity is measured according to ISO 6721 - 10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%.

5. The coated filament according to claim 4, wherein the polymer composition satisfies Inequality 1: η ≤ (82×e^0.007×(ACTO)) + 5 (Inequality 1) where η represents the melt viscosity measured at the melt temperature of the polymer composition, in units of Pa·s, wherein the melt temperature of the polymer composition is measured on a 5 mg sample using differential scanning calorimetry on the second heating curve with a heating and cooling rate of 10 °C / min, and wherein the melt viscosity is measured according to ISO 6721 - 10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%, and wherein ACTO represents the amount of active oxygen in the polymer composition, in units of ppm.

6. The coated filament according to any one of the preceding claims, wherein the coating is a dot coating or a topcoat.

7. A filament tow comprising a plurality of coated filaments according to any one of the preceding claims.

8. An article comprising a coated filament according to any one of claims 1 - 6 or a filament tow according to claim 7.

9. A coated filament, filament tow or tape obtainable by a process for producing a coated filament comprising the steps of: a. producing an uncoated inorganic filament, preferably an uncoated glass filament, from an inorganic melt; b. providing a molten polymer composition comprising a thermoplastic polymer; c. applying the molten polymer composition to the uncoated inorganic filament, preferably by means of a roll die, a curtain coater die or a slot die, and solidifying the molten polymer composition, and d. obtaining a coated filament comprising an inorganic filament coated with the polymer composition, wherein the inorganic filament is in direct contact with the polymer composition, and e1. cutting the coated filament into segments having a length of less than 100 mm, or e2. bundling a plurality of said coated filaments into a filament tow or yarn, and optionally cutting the filament tow or yarn into segments having a length of less than 100 mm, or f. bundling a plurality of said coated filaments into a filament tow or yarn, and g. producing a tape from the filament tow or yarn to produce a tape having a thickness of 0.2 mm up to and including 2 mm and a width of 10 mm up to and including 500 mm, and wherein the aspect ratio of the tape is higher than 10.

10. A coated filament according to claim 9, wherein the melt viscosity of the polymer composition at the melt temperature of the polymer composition is 1.0 - 25 Pa·s, wherein the melt temperature of the polymer composition is measured on a 5 mg sample using differential scanning calorimetry on the second heating curve with a heating and cooling rate of 10 °C / min, and wherein the melt viscosity is measured according to ISO6721 - 10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%.

11. A coated filament according to claim 10, wherein the polymer composition satisfies inequality 1: η ≤ (82 × e^0.007×(ACTO)) + 5 (Inequality 1) where η represents the melt viscosity measured at the melt temperature of the polymer composition in Pa·s, wherein the melt temperature of the polymer composition is measured on a 5 mg sample using differential scanning calorimetry on the second heating curve with a heating and cooling rate of 10 °C / min, and wherein the melt viscosity is measured according to ISO6721 - 10:2015 by applying oscillatory shear to the molten sample at an angular frequency of 1 rad / s and a shear strain of 5%, and wherein ACTO represents the amount of active oxygen in the polymer composition in ppm.

12. A coated filament according to any one of claims 9 - 11, wherein during the application step, the polymer composition contacts the uncoated inorganic filament at an angle of at most 45°, 10°, 5°, 1° or 0°.

13. The coated filament according to any one of claims 9 - 12, wherein when the organic polymer is applied to the uncoated inorganic filament, the application speed of the polymer is 50% - 110%, 95% - 105% or 99% - 101% of the moving speed of the inorganic filament, and / or the moving speed of the inorganic filament is 500 - 3000 m / min, 1250 - 1750 m / min or 1450 - 1550 m / min.

14. The coated filament according to any one of claims 9 - 13, wherein the polymer composition is melted using a melting device, such as an extruder, such as a single - screw or twin - screw extruder.

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