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Hydrophicic and hydrophobic polyether polyurethanes and uses therefor

  • US 5,962,620 A
  • Filed: 08/26/1997
  • Issued: 10/05/1999
  • Est. Priority Date: 08/26/1996
  • Status: Expired due to Fees
First Claim
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1. An amphiphilic polyether polyurethane having improved wet and dry strength comprising the reaction product of a mixture of:

  • a hydrophilic diol of polyoxyethylene diol having a number average molecular weight of about 400 to about 10,000, the amount by weight of the hydrophilic diol in the reaction mixture being from about 1% to about 40%;

    a hydrophobic diol of a polyether polycarbonate diol having a number average molecular weight of about 1,000 to about 2,400 and one or more hydrophobic diols selected from the group consisting of polyoxytetramethylene diol having a number average molecular weight of from about 400 to about 3,000, polyoxypropylene diol having a number average molecular weight of from about 400 to about 3,000, and polydimethylsiloxane polyoxyethylene copolymer having a number average molecular weight of about 500 to about 3,800, the amount by weight of the hydrophobic diol in the reaction mixture being from about 15% to about 50%;

    an alkylene glycol selected from the group consisting of ethylene glycol, propylene glycol, 2-etlyl-1,3-hexanediol, tripropylene glycol, triethylene glycol, 2,-4-pentane diol, 2-methyl-1,3-propanediol, 2,-methyl-1,3-pentanediol, cyclohexanediol, diethylene glycol, cyclohexanedimethanol, dipropylene glycol, and mixtures thereof;

    an organic diisocyanate; and

    water in an amount by weight of about 0.20% to about 0.80% of the reaction mixture, the ratio of NCO to OH of the diols, the alkylene glycol and the water being from about 0.7 to about 1.1,wherein said polyurethane has a water absorption value of about 0.5% to about 25% after 24 hours in water and an expansion value of about 0.1% to about 20% after 24 hours in water.

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