Patent ID: 8835591

Claim:
A method for preparing an isocyanate group-containing prepolymer from an isocyanate group-containing component and an isocyanate group-reactive component, which comprises mixing continuously the components in a mixing device and immediately after being mixed introducing continuously the reaction mixture into a storage or transport vessel, where the reaction between the components is completed, wherein in a first step of a batch production only a first reaction component is initially directed through the mixing device into the vessel, before in a second step the second reaction component is directed into the mixing device in addition to the first reaction component, where it is mixed with the first reaction component, wherein to end the batch production the metering of the second reaction component is stopped and the mixing device is rinsed with the first reaction component, and wherein the reaction component directed through the mixing device in the first step of the batch production is the isocyanate group-containing component and the reaction component directed into the mixing device in the second step is the isocyanate group-reactive component.