Flame-retardant insulation bar for windows and doors

A flame-retardant insulation bar manufactured by extruding an insulation composition at 250 to 300° C., comprising:

• 60 parts by weight of a polyamide base resin;
• 30 parts by weight of a reinforcing agent;
• 20 parts by weight of an organophosphorus-based flame retardant;
• and
• 10 parts by weight of an additive,
• wherein
• an amount of the polyamide base resin is at least half of a total amount of the insulation composition,
• the polyamide base resin is consisted of at least one selected from the group consisting of polyamide 6, polyamide 12, polyamide 66, polyamide 6/66, polyamide 6/12, polyamide 6/6T, polyamide 6/6I, and copolymers thereof, has a relative viscosity of 2.0, and has heat conductivity of 0.40 W/m·K or less, wherein the relative viscosity is based on 1 g of the polyamide base resin in 100 ml of 96% sulfuric acid at 20° C.,
• the reinforcing agent is a glass fiber having an aspect ratio of 400 or less but greater than 1,
• the organophosphorus-based flame retardant is triphenyl phosphate, and
• the flame-retardant insulation bar has heat conductivity of 0.5 W/m·K or less and a UL94 flame-retardant grade of V-2 or higher, and satisfies at least one of following conditions (i) to (v):
• (i) a flexural strength of 2,000 kg/cm2 or more;
• (ii) a flexural modulus of 50,000 kg/cm2 or more;
• (iii) an impact strength 10 kg·cm/cm or more;
• (iv) a melt index (280° C.) of 5 g/10 min or more;
• and
• (v) a melt viscosity (100 S−1, 280° C.) of 5,000 Pa·S or more.