Joint fill composition and method
View Patent ↗A composition and method for protecting pipeline joints is disclosed. A mold covers the exposed pipeline joint. A reaction composition including a polyol, an isocyanate, and an ester, preferably 2,2,4-trimethyl-1,2-pentanediol diisobutyrate, is added to the mold and allowed to react to form a polymer.
1. A method for filling a gap at the junction between two lengths of coated pipe, the method comprising:
enclosing the gap with a mold having an opening;
introducing a joint filling composition into the mold; and
allowing the joint fill composition to react and form a foam;
wherein the joint filling composition comprises:
an A-side component comprising between about 75 weight % to about 85 weight %, based on total weight of the A-side component, of polymeric MDI and between about 15 weight % and about 25 weight %, based on total weight of the A-side component, 2,2,4,-trimethyl-1,2-pentanediol diisobutyrate; and
a B-side component comprising between about 35 weight % and about 45 weight %, based on total weight of the B-side component, of amine based polyether polyol, and about 50 weight % to about 65 weight %, based on total weight of the B-side component, 2,2,4-trimethyl-1,2-pentanediol diisobutyrate.
2. The method of claim 1 , wherein an amine catalyst is included in the joint filling composition.
3. The method of claim 1 , wherein the composition further comprises water.
4. The method of claim 1 , wherein the composition further comprises hydrofluorocarbon blowing agent.
5. The method of claim 1 , wherein the composition further comprises a silicone based surfactant.
6. The method of claim 1 , further comprising the step of removing the mold after formation of the foam.
7. The method of claim 1 , wherein the foam comprises a polyurethane foam having an open cell content of about eighty percent or higher.
8. The method of claim 1 , wherein the foam comprises a polyurethane foam having an open cell content of about ninety percent or higher.
9. The method of claim 1 , wherein the foam comprises a polyurethane foam having a density of between about 2 and about 12 pounds per cubic foot.
10. The method of claim 1 , further comprising the step of adding filler material to the mold, after the enclosing step and before the step of introducing the reaction mixture.
11. The method of claim 1 , further comprising the step of adding a permeable membrane into the mold before the step of introducing the reaction mixture.
12. The method according to claim 1 , wherein the composition further comprises a hydrocarbon blowing agent.
13. The method according to claim 1 , wherein the polymeric MDI is an isocyanate prepolymer.