Method for producing one-component moisture-curing polyurethane composition

1. A method for producing a one-component moisture-curing polyurethane composition, the method comprising:

a mixing step in which a liquid component (A) containing a polyol compound having two or more hydroxy groups in each molecule is mixed with a powder component (B) containing a filler so as to obtain a paste-like mixture of the liquid component (A) and the powder component (B);

a dehydration step in which, following the mixing step, at least a portion of the residual moisture in the paste-like mixture is removed;

a prepolymer generation step in which a polyisocyanate compound (C) having two or more isocyanate groups in each molecule is mixed with the paste-like mixture following the dehydration step so as to obtain a mixture containing a urethane prepolymer generated by a reaction between the polyisocyanate compound (C) and the polyol compound in the paste-like mixture; and

a composition generation step in which the mixture is mixed with an aliphatic isocyanate compound (D) having at least two isocyanate groups in each molecule so as to obtain a one-component moisture-curing polyurethane composition.

2. The method for producing a one-component moisture-curing polyurethane composition according to claim 1 , wherein the dehydration step is a step in which the moisture content of the paste-like mixture is controlled to at most 0.050 mass %.

3. The method for producing a one-component moisture-curing polyurethane composition according to claim 1 , wherein in the composition generation step, a curing catalyst for inducing the moisture curing of the one-component moisture-curing polyurethane composition is further added.

4. The method for producing a one-component moisture-curing polyurethane composition according to claim 1 , wherein in the prepolymer generation step, the polyisocyanate compound (C) and the paste-like mixture obtained in the mixing step are added and mixed sequentially.

5. The method for producing a one-component moisture-curing polyurethane composition according to claim 1 , wherein in the prepolymer generation step, after the polyisocyanate compound (C) is mixed with the paste-like mixture obtained in the mixing step, a metal catalyst for accelerating a reaction for generating the urethane prepolymer is mixed.

6. The method for producing a one-component moisture-curing polyurethane composition according to claim 1 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

7. The method for producing a one-component moisture-curing polyurethane composition according to claim 3 , wherein in the prepolymer generation step, the polyisocyanate compound (C) and the paste-like mixture obtained in the mixing step are added and mixed sequentially.

8. The method for producing a one-component moisture-curing polyurethane composition according to claim 4 , wherein in the prepolymer generation step, after the polyisocyanate compound (C) is mixed with the paste-like mixture obtained in the mixing step, a metal catalyst for accelerating a reaction for generating the urethane prepolymer is mixed.

9. The method for producing a one-component moisture-curing polyurethane composition according to claim 7 , wherein in the prepolymer generation step, after the polyisocyanate compound (C) is mixed with the paste-like mixture obtained in the mixing step, a metal catalyst for accelerating a reaction for generating the urethane prepolymer is mixed.

10. The method for producing a one-component moisture-curing polyurethane composition according to claim 3 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

11. The method for producing a one-component moisture-curing polyurethane composition according to claim 4 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

12. The method for producing a one-component moisture-curing polyurethane composition according to claim 5 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

13. The method for producing a one-component moisture-curing polyurethane composition according to claim 7 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

14. The method for producing a one-component moisture-curing polyurethane composition according to claim 8 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.

15. The method for producing a one-component moisture-curing polyurethane composition according to claim 9 , wherein the aliphatic isocyanate compound (D) is at least one type selected from the group consisting of a reaction product of hexamethylene diisocyanate and trimethylolpropane, a biuret of hexamethylene diisocyanate, and an isocyanurate of hexamethylene diisocyanate.