GLASS FIBRE REINFORCED COMPOSITE CONTAINING POLYPROPYLENE WITH NARROW MWD Russian patent published in 2024 - IPC C08J3/05 C08F4/6592 C08F110/06 

FIELD: composite materials.

SUBSTANCE: invention relates to a fibre-reinforced composite containing polypropylene having a very narrow molecular weight distribution (MWD) and glass fibre, to the manufacture of the specified fibre-reinforced composite, as well as to products containing the specified fibre-reinforced composite. The fibre reinforced composite for automotive applications has a melt flow index of MFR₂ measured in accordance with ISO 1133 at a load of 2.16 kg at 230°C, from 10 to 100 g/10 min and includes: (a) from 59 to 90 wt. %, based on fibre reinforced composite, polypropylene, (b) from 9.0 to 40 wt. %, based on the fibre reinforced composite, of short glass fibres that have an average fibre length of 2.0 to 10.0 mm, and (c) 0.05 to 5.0 wt. %, based on the fibre-reinforced composite, compatibilizer, which is polar modified polypropylene. In this case, the total amount of polypropylene, glass fibre and compatibilizer in the fibre-reinforced composite is at least 95 wt. %. Additionally, polypropylene is characterized by the fact that (i) it has a melting point Tm determined by DSC in accordance with ISO 11357-3 at a heating and cooling rate of 10°C/min, from 152 to 160°C, (ii) it is a propylene homopolymer or a copolymer of propylene and ethylene, where the comonomer content, determined by ¹³C-NMR spectroscopy, is not more than 0.5 wt. %, (iii) has a melt flow index MFR₂ measured in accordance with ISO 1133 under a load of 2.16 kg at 230°C, from 20 to 500 g/10 min, (iv) has a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 3.0, (v) has 2,1-regiodefects determined by ¹³C-NMR spectroscopy, from 0.10 to 0.90%. A method for producing a fibre-reinforced composite is also described, including the stage of visbreaking polypropylene obtained by polymerization of propylene or propylene and ethylene in the presence of a metallocene catalyst, as well as an automobile product containing at least 90 wt. % of fibre reinforced composite.

EFFECT: provision of a fibre-reinforced composite characterized by a VOC emission level below 6.0 mcg/g, an FOG (low-volatile or condensable organic compounds) emission level below 40 mcg/g, and Charpy impact strength from 30.0 to 75.0 kJ/m², as well as a high level of resistance to thermal deformation and good workability.

15 cl, 3 tbl, 3 ex