Polyamide moulded masses containing semi-crystalline transparent copolyamides for producing highly flexible transparent moulded parts with high notch-impact strength, low water absorbency and excellent resistance to chemicals

Abstract

The invention relates to polyamide moulded masses based on semi-crystalline, transparent copolyamides predominantly based on aliphatic monomers, for producing transparent or pigmentable moulded parts with a high level of flexibility, high notch-impact strength (Charpy), low water absorbency and excellent resistance to chemicals, containing between 40 and 100 wt. % of at least one transparent copolyamide (constituent A) with a maximum glass transition temperature (Tg) of 80 DEG C and a melting temperature of at least 150 DEG C, and a melting enthalpy of at least 20 J / g, preferably at least 30 J / g, consisting of at least two different diamines selected from the group consisting of linear and / or branched-chain aliphatic diamines with between 9 and 14 carbon atoms and cycloaliphatic diamines, especially between 6 and 36 carbon atoms, the concentration of cycloaliphatic diamine being between 10 and a maximum of 40 mol % and the concentration of aliphatic diamine at least 60 mol %, respectively in relation to the total diamine content, and of at least one aliphatic dicarboxylic acid, especially between 6 and 36 carbon atoms, and between 0 and 60 wt. % of at least one other polymer (constituent B) selected from the group consisting of amorphous or semi-crystalline homopolyamides or copolyamides, polyether ester amides, polyether amides, polyester amides or mixtures thereof, between 0 and 10 wt. % of other additives (constituent C) selected from the group consisting of UV stabilisers, heat stabilisers, free-radical scavengers and / or processing auxiliary agents, inclusion inhibitors, lubricants, mould-release auxiliary agents, softeners, functional additives for influencing optical properties, especially the refractive index, impact-resistant modifiers, nanoscale fillers and / or loaders, optical brighteners, dyes or mixtures thereof, the constituents (A), (B) and (C) amounting to 100 wt. %.

Description

technical field [0001] The present invention relates to transparent, impact-resistant, flexible polyamide molding materials with low water absorption and excellent chemical resistance (ie high alcohol resistance), based on partially crystalline but at the same time transparent copolyamides, which mainly Based on aliphatic monomers. The copolyamides present in the molding material are always formed from at least two different diamines, one cycloaliphatic and one having 9 to 14 carbon atoms, and aliphatic dicarboxylic acids. Linear and / or branched aliphatic diamines. However, the size of the crystals is smaller than the wavelength of visible light, so these partially crystalline copolyamides are transparent. The transparent copolyamides are preferably produced from monomers based on renewable raw materials. wherein the biobased content is at least 70%. [0002] The above biobased content according to ASTM D6866-06a is a measure of the proportion of non-mineral (ie renewable)...

AI Technical Summary

Problems solved by technology

The disadvantage is the glass transition temperature (T g ) and moderate stiffness, due to the disadvantages mentioned these partially crystalline polyamides are extremely difficult to process and have their properties like conventional amorphous transparent polyamides

These molding materials result in a transparent tough product, but this product has limited chemical resistance (i.e. alcohol resistance) and limited flexibility

Furthermore, in said polyamide blends there is still a risk of separation of components and a risk of loss of quality (in terms of transparency, color and purity)

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