Vinyl-terminated prepolymers having low viscosity and good water solubility
AssigneeSika Technology AG
InventorsMarkus Haufe, Max Hug
Life of this patent
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Abstract
A polyether having a functional group that is reactive to isocyanate with at least one polyisocyanate, which has an average isocyanate functionality in the range of 2.4 to 3.5, and at least one vinyl compound, which has a functional group that is reactive to isocyanate, wherein the molar ratio of polyether to vinyl compound lies in the range of 3:1 to 1:3 and the ratio of the sum of the molar quantities of polyether and vinyl compounds to isocyanate groups lies in the range of 1.5:1 to U.5. Corresponding vinylterminated prepolymers have the advantage of low visocity together with good water solubility and therefore can be used advantageously for applications as injection agents.
Claims20
A method for sealing of built structures, tunnels or mines with an injection medium, comprising:
- providing an injection medium comprising a vinyl-terminated prepolymer by reaction of
- i) a polyether having a functional group reactive toward isocyanates with
- ii) at least one polyisocyanate having a mean isocyanate functionality in the range from 2.4 to 3.5, and
- iii) at least one vinyl compound having a functional group reactive toward isocyanates,
- wherein the molar ratio of polyether i) to vinyl compound iii) is in the range from 3:1 to 1:3 and the ratio of the sum total of the molar amounts of polyether and vinyl compound to isocyanate groups ii) is in the range from 1.5:1 to 1:1.5,
- wherein the polyether has exactly one functional group reactive with NCO group or the vinyl compound has exactly one functional group reactive with NCO group,
- wherein the proportion of the polyether in the vinyl-terminated prepolymer obtained via the reaction amounts to at least 30% by weight, based on the total weight of the prepolymer, and
- wherein the vinyl-terminated prepolymer is injected into a cavity together with a free-radical initiator and optionally further components;
- and
- polymerizing said injection medium.
A process for producing an injection medium, comprising preparing a vinyl-terminated polymer by a method comprising:
- i) the addition of at least one polyisocyanate having a mean isocyanate functionality in the range from 2.4 to 3.5 either to a polyether constituent having a functional group reactive toward isocyanates or to at least one vinyl compound constituent having a functional group reactive toward isocyanates,
- ii) allowing the isocyanate groups to react with the functional groups reactive toward isocyanates,
- iii) depending on the constituent initially charged in step i), the addition of the other constituent to the reaction product formed from polyisocyanate and the initially charged constituent, and
- iv) allowing the reaction product formed from polyisocyanate and the initially charged constituent to react with the other constituent,
- wherein the other constituent is the at least one vinyl compound constituent having a functional group reactive toward isocyanates when the constituent initially charged in step i) is the polyether constituent having a functional group reactive toward isocyanates, and vice versa, and the addition of a free-radical initiator and optionally further components,
- wherein the molar ratio of polyether to vinyl compound is in the range from 3:1 to 1:3 and the ratio of the sum total of the molar amounts of polyether and vinyl compound to isocyanate groups ii) is in the range from 1.5:1 to 1:1.5,
- wherein the polyether has exactly one functional group reactive with NCO group or the vinyl compound has exactly one functional group reactive with NCO group,
- wherein the proportion of the polyether in the vinyl-terminated prepolymer obtained via the reaction amounts to at least 30% by weight, based on the total weight of the polymer.
A process for producing an injection medium, comprising the preparation of a vinyl-terminated prepolymer by a method comprising:
- i) the addition of at least one polyisocyanate having a mean isocyanate functionality in the range from 2.4 to 3.5 to a mixture of a polyether having a functional group reactive toward isocyanates and at least one vinyl compound having a functional group reactive toward isocyanates,
- ii) allowing the polyisocyanate to react with the polyether and the vinyl compound,
- wherein the molar ratio of polyether to vinyl compound is in the range from 3:1 to 1:3 and the ratio of the sum total of the molar amounts of polyether and vinyl compound to isocyanate groups ii) is in the range from 1.5:1 to 1:1.5,
- wherein the polyether has exactly one functional group reactive with NCO group or the vinyl compound has exactly one functional group reactive with NCO group,
- wherein the proportion of the polyether in the vinyl-terminated prepolymer obtained via the reaction amounts to at least 30% by weight, based on the total weight of the polymer.
Dependencies are inferred from the claim text.