POLYMER COMPOSITION AND MOLDED PART THEREOF

Description

[0001] The invention relates to a polymer composition and a molded part made therefrom.

[0002] In order to mechanically improve polymer compositions, it is known from the prior art to add glass fibers to them.

[0003] The bonding of the glass fibers to the polymer material is the decisive factor that leads to the desired improved mechanical properties.

[0004] There are various solutions to ensure this bond between the glass fibers and the polymer material. For example, it is known to treat the surface of glass fibers with a size that allows the polymer material to adhere.

[0005] Another approach aims to compatibilize the polymer material, causing it to adhere to the glass fiber.

[0006] The German patent application DE 196 46 150 A1 describes a composite resin material consisting of a crosslinking polyurethane resin and a reactive resin and formed by kneading the crosslinking polyurethane resin and the reactive resin at a temperature not lower than the melting point of the reactive resin.

[0007] These techniques are complex, costly and have limited effects.

[0008] The object of the present invention is therefore to provide a polymer composition which comprises a polyolefin, in particular a polypropylene, an impact modifier, a filler and glass fibers.

[0009] This polymer composition is intended to be mechanically enhanced in a simple manner so that the glass fibers are better bonded to the polymer material.

[0010] Furthermore, improved stiffness and reduced creep tendency are to be achieved in order to open up new fields of application for the polymer material. Such a polymer composition should be available without great effort and at a low cost.

[0011] A further object of the invention is to provide a molded part made of such a polymer composition.

[0012] The solution to the first problem, to provide a polymer composition, is according to claim 1.

[0013] Within the scope of the present invention, it has been found that a polymer composition comprising a first polyolefin which is a propylene-ethylene copolymer, a second polyolefin which is a homo-polypropylene, an impact modifier, a filler and glass fibers achieves this object if it is provided that particles containing polyurethane are present in the polymer composition, the glass fibers are short glass fibers with a length of 0.1 to 5 mm and the impact modifier is a polyolefin-1-alpha-olefin copolymer and / or an ethylene-propylene rubber.

[0014] Surprisingly, it was found within the scope of the present invention that the particles containing polyurethane have an adhesion-promoting property, whereby the coupling of the glass fibers to the polypropylene or the adhesion between glass fibers and the polypropylene copolymer or the polypropylene is significantly improved.

[0015] The polyurethane-containing particles present in the polymer composition according to the invention ensure that the polymer material adheres firmly to the glass fibers. Due to the presence of the second polyolefin, which is a homopolypropylene, the polymer composition according to the invention exhibits improved rigidity and a lower tendency to creep while still maintaining sufficient impact strength.

[0016] This results in the improved mechanical properties of the polymer composition according to the invention.

[0017] In the context of the present invention, it may prove to be extremely advantageous if it is provided that the first polyolefin is a propylene-ethylene copolymer with an MFI according to ISO 1133 of 5 to 50 g / 10 min at 2.16 kg and 230 °C and an E-modulus according to EN ISO 527-1 of 700 to 1600 MPa, and the second polyolefin (2.2) is a homo-polypropylene with an MFI according to ISO 1133 of 10 to 200 g / 10 min at 2.16 kg and 230 °C and an E-modulus according to EN ISO 527-1 of 1200 to 2200 MPa.

[0018] With these polypropylene copolymers or polypropylenes defined above, a broad raw material base can be used to provide the polymer composition described above, which is mechanically improved compared to the prior art.

[0019] According to the invention, the impact modifier is a polyolefin-1-alpha-olefin copolymer and / or an ethylene-propylene rubber.

[0020] The selection of the impact modifier for the polymer composition according to the invention from a polyolefin-1-alpha-olefin copolymer and / or an ethylene-propylene rubber makes it possible to precisely adjust the polymer composition according to the technical requirements or according to the customer's specifications with regard to its impact behavior.

[0021] During the investigations on the polymer composition according to the invention, it has been found that it can be very helpful if the filler is selected from talc, chalk, wollastonite, glass beads, carbon fibers and mixtures of the above.

[0022] By selecting the filler for the polymer composition according to the invention from those mentioned above, the mechanics of the polymer composition can be further improved or adapted to the customer's specifications.

[0023] According to the invention, the glass fibers are short glass fibers with a length of 0.1 to 5 mm.

[0024] By selecting the glass fibers as short glass fibers with a length of 0.1 to 5 mm, a mechanically particularly improved polymer composition can be provided.

[0025] It has been found that such a polymer composition can advantageously contain glass fibers at 10 to 30 wt.%.

[0026] This makes it possible to adjust the content of glass fibers in the polymer composition of the present invention and thus achieve a balance between the improved mechanics and the degree of filling of the polymer composition with glass fibers.

[0027] It has proven very practical in the present invention if it is provided that the particles containing polyurethane have a size of 10 to 300 µm.

[0028] With a size of the particles containing polyurethane ranging from 10 to 300 µm, they can be distributed very evenly and homogeneously in the polymer composition.

[0029] As a result, the effect of the polyurethane-containing particles on the bonding of the polymer material to the glass fibers is particularly effective. In this way, a particularly mechanically enhanced polymer composition according to the present invention can be provided.

[0030] In a very favorable embodiment of the present invention, it can be provided that the particles containing polyurethane are contained in the polymer composition at 0.1 to 7.0 wt.%.

[0031] Investigations have shown that no improvement in the mechanical properties can be achieved if the addition quantity of particles containing polyurethane to the polymer composition is below 0.1% by weight.

[0032] When more than 7.0 wt.% of polyurethane-containing particles are added to the polymer composition, other effects prevail that counteract an improvement in the mechanical properties.

[0033] The polymer composition of the present invention may contain additives such as pigments, processing aids, stabilizers, conductive additives, nucleating agents, release agents, and others.

[0034] By adding the above-mentioned additives, the production, molding, demolding, handling, application, appearance and long-term stability of the polymer composition according to the invention can be improved.

[0035] The polymer composition of the present invention can be formed into a molded article in a molding process of polymer processing.

[0036] For example, the polymer composition can be formed into a molded part through an injection molding process, an extrusion process, a blow molding process, a deep-drawing process, a thermoforming process, or an additive manufacturing process (3D printing). It is also possible to use combinations of the aforementioned processes to produce a molded part.

[0037] The solution to the problem of the present invention, to provide a molded part, is according to claim 10.

[0038] Within the scope of the present invention, it was recognized that a molded part made from the polymer composition as described above can be provided as an improved molded part compared to the prior art due to the improved mechanical properties of the polymer composition. Example

[0039] Compared to a formulation of the polymer composition without the second polyolefin, the mechanical properties with regard to tensile strength and modulus of elasticity of the molded part produced from the polymer composition according to the invention are significantly improved, which is easily recognizable from the examples illustrating the invention according to Table 1.

[0040] Comparison of inventive examples 1 and 2 with the comparative examples: Table 1 Comparison example 1 Inventive Example 1 Comparison example 2 Inventive Example 2 Composition (all data in wt.%) First polyolefin 60 40 55 40 Second polyolefin 0 30 0 20 Impact modifiers 10 5 8 5 filler 12 7 10 8 Glass fibers 15 15 25 25 Particles containing polyurethane 2 2 2 2 Stabilizer 1 0,3 0,3 0,3 0,3 Stabilizer 2 0,2 0,2 0,2 0,2 Adhesion promoter PP-MAH 3 3 3 3 Characteristics MFR value 5.45 g / 10 min 7.65 g / 10 min 4.07 g / 10 min 5.98 g / 10 min DIN EN ISO 1133-1 230°C / 2.16kg density 1.09 g / cm 3 1.05 g / cm 3 1.17 g / cm 3 1.14 g / cm 3 DIN EN ISO 1183-1 Method A Tensile strength 40 N / mm 2 48 N / mm 2 45 N / mm 2 58 N / mm 2 DIN EN ISO 527-1 / -2 Elongation at break 5 % 7 % 9 % 6 % DIN EN ISO 527-1 / -2 Impact strength 23°C after 5.8 39 kJ / m 2 38 kJ / m 2 50 kJ / m 2 41 kJ / m 2 DIN EN ISO 179-1 / 1fU Impact strength - 20°C 36 kJ / m 2 35 kJ / m 2 44 kJ / m 2 38 kJ / m 2 DIN EN ISO 179-1 / 1fU Notched impact strength 23°C 13 kJ / m 2 10 kJ / m 2 15 kJ / m 2 10 kJ / m 2 DIN EN ISO 179-1 / 1eA Flexural modulus of elasticity 3032 N / mm 2 3195 N / mm 2 3956 N / mm 2 4578 N / mm 2 DIN EN ISO 178 Tensile modulus of elasticity 3338 N / mm 2 3551 N / mm 2 4454 N / mm 2 5126 N / mm 2 DIN EN ISO 527-1 / -2 Ignition residue 850°C 26,9 % 21,9 % 34,7 % 33,7 % DIN EN ISO 3451-1, Method A Fiber optic integration good good good good

[0041] Regarding the composition of the comparative example and examples 1 and 2 according to the invention: First polyolefin, which is a propylene-ethylene copolymer, MFI according to ISO 1133 of 36 g / 10 min at 2.16 kg and 230 °C and a modulus of elasticity according to EN ISO 527-1 of 1200 MPa; Second polyolefin, which is a homo-polypropylene, MFI according to ISO 1133 of 25 g / 10 min at 2.16 kg and 230 °C and a modulus of elasticity according to EN ISO 527-1 of 1900 MPa, impact modifier: polyolefin-1-alpha-olefin copolymer with an MFR (190 °C / 2.16 kg) of 1.0 g / 10 min according to ASTM D 1238 and a density of 0.857 g / cm3 according to ASTM D 792; Filler talc with the chemical composition SiO2 56 % MgO 31 % Al2O3 3,6 % Fe 2 O 3 0.9% and CaO 0,5 %, a density of 2.8 g / cm 3 according to ISO 787 / 10 and a bulk density of ≥ 0.6 kg / dm 3 according to EN 1097 / 10; Glass fibers Short glass fibers with a moisture content of max. 0.08% according to ISO 3344 and a fiber length of 3.0 to 5.0 mm; Particles containing polyurethane Size 50 to 150 µm; Stabilizer 1 Thermal stabilizer with a density (at 20 °C) of 1.0 to 1.2 g / cm 3 and a melting range (DSC) of 109 to 180 °C; Stabilizer 2 light stabilizer; Adhesion promoter PP-MAH Polypropylene grafted with maleic anhydride, MSA content of 1%.

[0042] From Table 1 it can be seen that the polymer composition according to the invention, comprising a first polyolefin which is a propylene-ethylene copolymer, a second polyolefin which is a homo-polypropylene, an impact modifier, a filler, glass fibers and particles containing polyurethane, is mechanically improved compared to the comparative examples which do not comprise a second polyolefin which is a homo-polypropylene particle.

[0043] In particular, when comparing the composition according to the invention with a comparison composition without the second polyolefin, which is a homo-polypropylene, the present invention improves the tensile strength according to DIN EN ISO 527-1 / -2 with the same content of gas fibers by approximately 20 to 30%, the flexural modulus of elasticity according to DIN EN ISO 178 by approximately 5 to 15% and the tensile modulus of elasticity according to DIN EN ISO 527-1 / -2 by approximately 6 to 15%.

[0044] In particular, the stiffness-toughness balance of the polymer composition according to the invention is improved compared to a composition that does not contain a second polyolefin. The improved stiffness and lower creep tendency resulting from the invention, while still maintaining sufficient impact strength, are extremely advantageous for the polymer composition according to the invention.

[0045] To produce the polymer composition according to the invention, the components—the polyolefin, in particular a polypropylene, the impact modifier, the filler, glass fibers, and the polyurethane-containing particles—are homogeneously mixed together. This can be done in a plant for mixing components for the production of polymer compositions or in an extruder.

[0046] The polymer composition according to the invention thus produced can be formed into molded parts by known polymer molding processes such as extrusion, injection molding, blow molding, foaming, deep drawing, thermoforming, generative manufacturing (3D printing) and others, in particular also by combination of the aforementioned processes.

[0047] Within the scope of the present invention, it has surprisingly been found that so-called painted scrap material from the production of painted components made of polypropylene for the automotive industry can be advantageously used for the production of the polymer composition according to the invention. By crumbling these components, it is possible to produce particles containing polyurethane. In the polymer composition according to the invention, these particles bring about the improved mechanical properties - as explained above. The use of such crumbled scrap material from the production of painted components for the automotive industry is also advantageous from the perspective that it already provides polypropylene, impact modifiers, fillers, and the particles containing polyurethane, so that only glass fibers need to be added and this mixture then needs to be homogenized.

[0048] The present invention finds broad application in components made from the polymer composition according to the invention. The invention can be used advantageously, particularly for components subject to particular mechanical stresses.

[0049] For example, components for automotive exterior trim parts, such as bumper covers, sills, spoilers, fenders and tailgate trims, are equipped with so-called locking or reinforcing parts for stabilization.

[0050] Such components can be advantageously produced from the polymer composition according to the invention.

[0051] Components made from the polymer composition according to the invention can also be used in other areas, such as industrial and construction products, window and facade construction, and furniture construction.

[0052] The invention can be used advantageously wherever it is important that better rigidity and lower creep tendency while still having sufficient impact strength of the polymer composition according to the invention are decisive for the respective application.

[0053] Further important features and advantages of the invention emerge from the subclaims, from the figure and from the associated figure description.

[0054] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0055] The present invention is explained in more detail with reference to the attached figure.

[0056] This shows: Fig. 1 a schematic representation of the polymer composition according to the invention.

[0057] In Fig. 1 The polymer composition 1 according to the invention is shown in a schematic representation.

[0058] The polymer composition (1) according to the invention comprises a first polyolefin (2.1), in particular a polypropylene, a second polyolefin (2.2) which is a homo-polypropylene, an impact modifier (3), a filler (4), glass fibers (5) and particles (6) containing polyurethane.

[0059] The first polyolefin (2.1), the second polyolefin (2.2), the impact modifier (3), the filler (4), the glass fibers (5) and the particles (6) containing polyurethane are homogeneously distributed in the polymer composition (1).

[0060] The present invention has been described in detail with reference to the embodiment of the present invention shown only schematically in the figure. It is understood that the present invention is not limited to the embodiment shown, but the scope of the present invention is derived from the claims. List of reference symbols

[0061] 1Polymer composition 2.1First polyolefin 2.2Second polyolefin 3Impact modifier 4Filler 5Glass fibers 6Particles containing polyurethane 10Molded part

Claims

1. Polymer composition (1) having a first polyolefin (2.1), which is a propylene-ethylene copolymer, a second polyolefin (2.2), which is a homo-polypropylene, an impact modifier (3), a filler (4), glass fibres (5) and particles (6) containing polyurethane, characterised in that the glass fibres (5) are short glass fibres with a length of 0.1 to 5 mm, and the impact modifier (3) is a polyolefin-1-alpha-olefin copolymer and / or an ethylene-propylene rubber.

2. Polymer composition (1) according to claim 1, characterised in that the first polyolefin (2.1) is a propylene-ethylene copolymer having an MFI in accordance with ISO 1133 of 5 to 50 g / 10 min at 2.16 kg and 230°C and having a modulus of elasticity in accordance with EN ISO 527-1 of 700 to 1600 MPa, and the second polyolefin (2.2) is a homo-propylene having an MFI in accordance with ISO 1133 of 10 to 200 g / 10 min at 2.16 kg and 230°C and having a modulus of elasticity in accordance with EN ISO 527-1 of 1200 to 2200 MPa.

3. Polymer composition (1) according to claim 1 or 2, characterised in that the filler (4) is selected from talc, chalk, wollastonite, glass beads, carbon fibres and mixtures of the above.

4. Polymer composition (1) according to any one of the preceding claims, characterised in that the glass fibres (5) are contained at 10 to 30% by weight.

5. Polymer composition (1) according to any one of the preceding claims, characterised in that the particles (6), which contain polyurethane, have a size of 10 to 300 µm.

6. Polymer composition (1) according to any one of the preceding claims, characterised in that the particles (6), which contain polyurethane, are contained at 0.1 to 7.0% by weight.

7. Polymer composition (1) according to any one of the preceding claims, characterised in that additives such as pigments, processing aids, stabilisers, conductivity additives, nucleating agents, release agents and others are contained.

8. Moulded part (10) made of the polymer composition (1) according to any one of claims 1 to 7.