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Transparent, impact-resistant polyesterurethane laminates

  • US 4,041,208 A
  • Filed: 05/21/1974
  • Issued: 08/09/1977
  • Est. Priority Date: 06/21/1971
  • Status: Expired due to Term
First Claim
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1. An optically-clear, energy-absorbing laminate, comprising at least one glass sheet bonded to a sheet of a substantially unreacted isocyanate free, thermoplastic, transparent polyesterurethane that is the reaction product of (a) essentially linear hydroxy-terminated polyester having a liquidus temperature of at least 44°

  • C., said polyester being selected from the group consisting of poly(1,4-butylene adipate) and poly(1,4-butylene azelate) having a molecular weight of about 2000, (b) 4,4'"'"'-methylene-bis-(cyclohexyl isocyanate), and (c) aliphatic diol containing from 4 to 8 carbon atoms, the mole ratio of (c) to (a) being from about 1.5;

    1 to about 5;

    1, the isocyanate groups provided by (b) being substantially numerically equivalent to the sum of hydroxyl groups provided by (c) and (a) whereby to provide a polyesterurethane that is substantially free of unreacted isocyanate groups, said mole ratio of (c) to (a) being so proportioned within said range that a rigidly held laminate prepared from about 0.030 inch thick sheeting of said polyesterurethane sandwiched between two 12" ×

    12" ×

    1/8" glass sheets is non-brittle at 0°

    F. and exhibits a mean penetration velocity of at least 20 miles per hour at laminate temperatures of 0°

    F. and 70°

    F., and a mean penetration velocity of at least 17 miles per hour at a laminate temperature of 120°

    F. when impacted with a five pound free falling steel ball.

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