Polyamide moulding compound and use thereof

Abstract

The present invention relates to polyamide moulding compounds which have very low distortion with good mechanical properties. This is achieved by a combination of transparent polyamide with fibrous reinforcing materials and also particulate fillers. The moulding compounds according to the invention are used for the production of any moulded articles, semi-finished products or finished products.

1 . Polyamide moulding compound comprising 40 to 79% by weight at least of a transparent polyamide, 15 to 49% by weight at least of a fibrous reinforcing material and 6 to 30% by weight of a particulate filler and also if necessary, as complement to 100% by weight, at least one further additive, polyamide oligomers being excluded as additive.  
   
   
       2 . Polyamide moulding compound according to  claim 1 , 
 characterised in that it comprises 40 to 69% by weight, preferably 40 to 55% by weight, of the transparent polyamide, 25 to 49% by weight, preferably 30 to 49% by weight, of the fibrous reinforcing material and 6 to 30% by weight of the particulate filler and also if necessary, as complement to 100% by weight, at least one further additive.    
   
   
       3 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the at least one fibrous reinforcing material is selected from the group comprising glass fibres, carbon fibres, metal fibres, aramide fibres, whiskers and mixtures thereof.    
   
   
       4 . Polyamide moulding compound according to  claim 3 , 
 characterised in that the glass fibres have a diameter of 5 to 20 μm, in particular 5 to 10 μm.    
   
   
       5 . Polyamide moulding compound according to  claim 3 , 
 characterised in that the glass fibres have a round, oval or rectangular cross-section.    
   
   
       6 . Polyamide moulding compound according to  claim 3 , 
 characterised in that glass fibres made of E-glass are contained.    
   
   
       7 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the at least one particulate filler is selected from the group comprising talcum, mica, silicates, quartz, titanium dioxide, wollastonite, kaolin, silicic acids, magnesium carbonate, magnesium hydroxide, chalk, ground or precipitated calcium carbonate, lime, feldspar, barium sulphate, permanently magnetic or magnetisable metals or alloys, glass balls, hollow glass balls, hollow spherical silicate fillers and mixtures thereof.    
   
   
       8 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the at least one transparent polyamide is selected from the group of polyamides, the light transmission of which, measured according to ASTM D 1003-61 on a plate comprising the polyamide with a thickness of 2 mm, is at least 70%, preferably at least 86%, particularly preferred at least 90%.    
   
   
       9 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the at least one transparent amorphous polyamide is selected from the group of polyamides which, in the differential scanning calorimetry, DSC according to ISO 1357-1/-2 at a heating rate of 20° C./min, have a melting heat of at most 5 J/g, preferably at most 3 J/g and particularly preferred at most 1 J/g.    
   
   
       10 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the transparent polyamide is an amorphous polyamide which was obtained from respectively at least one polyamide-forming diamine and/or dicarboxylic acid and/or amino acid or lactam.    
   
   
       11 . Polyamide moulding compound according to  claim 9 , 
 characterised in that there are selected as diamine aliphatic and/or cycloaliphatic diamines with 6 to 17 C-atoms and/or diamines with partially aromatic structures with 6 to 17 C-atoms, as dicarboxylic acid aliphatic and/or aromatic dicarboxylic acids with 6 to 12 C-atoms and as amino acid α, ω amino acids with 6 to 12 C-atoms.    
   
   
       12 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the polyamides are selected from the group of homo- and/or copolyamides based on PA 6I, PA 6I/6T, PA MXDI/6I, PA MXDI/MXDT/6I/6T, PA MXDI/12I, PA MXDI, PA MACM12, PA MACMI/12, PA MACMI/MACMT/12, PA 6I/MACMI/12, PA 6I/6T/MACMI/MACMT, PA 6I/6T/MACMI/MACMT/12, PA MACM6/11, PA MACMI/MACM12, MACM being able to be replaced by PACM up to 55% by mol, in particular up to 50% by mol.    
   
   
       13 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the additives are selected from the group comprising impact strength modifiers, bonding agents, halogen-containing flameproofing agents, halogen-free flameproofing agents, stabilisers, age-protecting agents, antioxidants, antiozonants, light protection agents, UV stabilisers, UV absorbers, UV blockers, inorganic heat stabilisers, organic heat stabilisers, conductivity additives, carbon black, optical lighteners, processing aids, nucleation agents, crystallisation accelerators, crystallisation inhibitors, flow aids, lubricants, mould-release agents, softeners, pigments, colourants, marking materials and mixtures thereof.    
   
   
       14 . Polyamide moulding compound according to  claim 1 , 
 characterised in that the polyamide moulding compound contains from 21 to 60% by weight of the fibrous reinforcing materials and the particulate fillers in total.    
   
   
       15 . Moulded article, produced from a polyamide moulding compound according to  claim 1 .  
   
   
       16 . Moulded article according to  claim 14 , 
 characterised in that the moulded article has a distortion of less than or equal to 2.7%, in particular less than or equal to 2.3%.    
   
   
       17 . Moulded article according to  claim 14 , 
 characterised in that the moulded article has a modulus of elasticity in tension of greater than or equal to 8000 MPa, in particular greater than or equal to 10000 MPa.    
   
   
       18 . Moulded article according to  claim 14 , 
 characterised in that the moulded article has a tensile strength of greater than or equal to 100 MPa, in particular 140 MPa.    
   
   
       19 . Moulded article according to  claim 14 , 
 characterised in that the polyamide moulding compound has a breaking elongation of greater than or equal to 1.5%, in particular 2.0%.    
   
   
       20 . Use of the polyamide moulding compound according to  claim 1  for the production of distortion-free moulded articles.  
   
   
       21 . Use according to the  claim 1 , 
 characterised in that the moulded articles are selected from the group comprising fibres, films, pipes, hollow bodies or other semi-finished products or finished products from injection moulding, extrusion, pultrusion, injection blowing or other shaping technologies.