Impregnated reinforcing fiber yarn and its use in producing composite materials

A pre-impregnated yarn comprising:

• a bundle of reinforcing fiber filaments having a bundle interior and a bundle outer side,
• a first resin composition comprising:
• at least one urethane resin, H1, produced from a reaction of a bifunctional aromatic epoxy compound based on bisphenol A, an aromatic polyisocyanate, and a polyalkylene glycol,
• an oxyalkylated bisphenol A resin, H2, and
• aromatic polyhydroxy ether P1, which has an acid value in a range of from 40 to 55 mg KOH/g and an average molecular weight in a range of from 4000 to 5000 g/mol, and
• a second resin composition;
• wherein:
• the reinforcing fiber filaments are impregnated with the first resin composition infiltrated into the pre-impregnated yarn and the reinforcing fiber filaments are at least partially connected via the first resin composition,
• a weight ratio of the resin H1 to the resin H2 is in a range of from 1:1 to 15:1;
• a mixture of the resins H1 and H2 has a viscosity in a range of from 10 to 10,000 Pa·s at ambient temperature;
• the first resin composition is present in a concentration in a range of from 0.1 to 4 wt % relative to a total weight of the pre-impregnated yarn;
• the second resin composition is on the bundle outer side in the form of particles or drops adhering to the reinforcing fiber filaments,
• the second resin composition is solid at ambient temperature;
• has a melting temperature in a range of from 80 to 150° C., and is present on the bundle outer side in a concentration in a range of from 0.5 to 14 wt % relative to the total weight of the pre-impregnated yarn;
• at least 40% of a surface of the bundle outer side is free from the second resin composition;
• and
• the bundle interior is free from the second resin composition.