Patent AT-E427341-T1 (AT)
Inventor: STIPPELMANN GEORG
Filed: 2006-12-28
Granted: 2009-04-15
Abstract: Reinforced polyamide molding materials, comprise: a polyamide matrix containing (wt.%): (A) aliphatic, partly crystalline polyamides (0-60) with a solution viscosity of more than 1.3 to less than 1.9 (preferably 1.4 to less than 1.9), and (B) at least one amorphous or microcrystalline polyamide (0-60); a filler component containing (wt.%): (C) flat glass fibers (40-80) with elongated shape and the glass fibers have a non-circular cross-sectional area, and (D) particle like or layer like fillers (0-40); and optionally (E) up to 5 wt.% of usual additives and adjuvants. Reinforced polyamide molding materials with high notch impact strength, containing low viscous polyamides and flat glass fibers as a reinforcing medium, comprise: a polyamide matrix containing (wt.%): (A) at least one aliphatic, partly crystalline polyamide (0-60, preferably 20-60) with a solution viscosity (eta r e l), measured in meta-cresol (0.5 wt.%) of more than 1.3 to less than 1.9 (preferably more than 1.35 to less than 1.9, especially more than 1.4 to less than 1.9), and (B) at least one amorphous or microcrystalline polyamide (0-60, preferably 0-50, especially optionally 0-20, particularly 0-15) based on aliphatic, cycloaliphatic or aromatic diamines, dicarboxylic acids, lactams and/or aminocarboxylic acids, optionally with 6-36 carbon atoms, or a mixture of such homopolyamides and/or copolyamides, where the components (A) and (B) fulfill the condition: (A)+(B) is of 20-60 wt.% and that, in the case of a mixture of components (A) and (B), at least 50 weight parts aliphatic blocks (A) are present in the mixture; a filler component containing (wt.%): (C) flat glass fibers (40-80) with elongated shape and the glass fibers have a non-circular cross-sectional area and a size ratio of the main cross-sectional axis to the secondary cross-sectional axis of 2-5 (preferably optionally of 3-4), and (D) particle like or layer like fillers (0-40), with the prerequisite that carbon fibers are excluded; and optionally (E) up to 5 wt.% of usual additives and adjuvants, where the weight of the components (A)-(E) sums up to 100%. Independent claims are included for the following: (1) preparation of polyamide molding materials using usual compounding machines at barrel temperatures set to 240-320[deg] C, where firstly the polymeric part is molten and then cut flat glass fibers and/or other fillers are added; (2) preparation of polyamide molding materials involving producing firstly a compound, respectively from the components (A) and/or (B) and the fillers (C) and optionally (D) and optionally the additives (E) in granular form and then these granules are mixed, and then further granules of the components (A) and (B) are optionally added, and then the granules are processed; (3) production of molded parts from the polyamide molding materials by injection molding, extrusion, pultrusion, blow molding; and (4) manufacturing of molded parts, involving molding such a part by injection molding with a reinforced polyamide molding material, where the reinforced polyamide molding material has a notch impact strength of more than 25 kJ/m 2> (measured according to Charpy at 23[deg] C, according to ISO 179/2-1 eA).