Two-step process for rapid structure repair
This invention relates to a two-step process for rapidly repairing structures, which utilizes (a) a water-based emulsion component in the first step, and (b) a polyisocyanate-terminated pre-polymer component in the second step, such that the mixture of (a) and (b) cure in the presence of moisture.
1 . A two-step process for filling a space comprising:
(a) adding a water-based emulsion component to said space,
(b) then adding a polyisocyanate pre-polymer component to said space, wherein said polyisocyanate pre-polymer component comprises a polyisocyanate pre-polymer containing free isocyanate groups
wherein the amount of (a) added to said space is such that (a) contains sufficient water to cure (b).
2 . The process of claim 1 wherein said pre-polymer is the reaction product of a polyol and a polyisocyanate.
3 . The process of claim 2 wherein the content of free isocyanate groups in said pre-polymer is from 10 to 18 percent.
4 . The process of claim 3 wherein the polyol is selected from the group consisting of polyester polyols, polyether polyols, phenolic resole resins, and mixtures thereof.
5 . The process of claim 4 wherein said water-based emulsion comprises water, a polymer, an inorganic filler, and a pH stabilizer.
6 . The process of claim 5 wherein the amount the inorganic filler is calcium carbonate and the polymer is selected from the group consisting of polyvinyl alcohol, styrene butylene rubber, and mixtures thereof.
7 . The process of claim 6 wherein the pH of the water-based emulsion is from about 6.0 to about 7.0.
8 . The process of claim 7 wherein the amount of water in the water-based emulsion is from about 10 parts by weight to about 50 parts by weight, the amount of filler in the water-soluble emulsion is from about 10 parts by weight to about 20 parts by weight, and the amount of stabilizer in the water-soluble emulsion is from about 10 parts by weight to about 15 parts by weight.
9 . The process of claim 7 wherein the weight ratio of water-based emulsion component to polyisocyanate pre-polymer component is from about 1:4 to about 4:1 and the binder is used in amount of 10 weight percent or less.
10 . The process of claim 10 wherein said water-based emulsion further comprises an aggregate.
11 . The process of claim 9 wherein said space to be filled contains an aggregate.
12 . The process of claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , or 11 , 12 , or 13 wherein the polyisocyanate pre-polymer component also contains a catalytically effective amount of a tertiary amine catalyst.
13 . The process of 12 wherein the tertiary amine catalyst is selected from the group consisting of tertiary amine are 2,2′-dimorpholinodiethylether and N,N′-dimethylpiperazine.
14 . The process of claim 12 wherein the amount of divalent metal catalyst is from about 0.5 parts by weight to about 1.5 parts by weight based upon the weight of the polyisocyanate pre-polymer.
15 . The process of claim 14 wherein the amount of aggregate is from 50 parts by weight to about 95 parts by weight based upon 100 parts by weight of said polyisocyanate pre-polymer.
16 . The process of claim 15 wherein space to be filled is an opening in an airport runway.
17 . The process of claim 11 wherein the aggregate is selected from the group consisting of sand, crushed concrete, pea gravel, and rock.