Process for producing composite elements, comprising the steps of: 1) providing a first outerlayer; 2) applying an adhesion promoter component to the first outerlayer, wherein the adhesion promoter component comprises a one-component adhesion promoter and/or a first reaction mixture which reacts to afford an adhesion promoter and wherein the first reaction mixture is obtained from a plurality of components, wherein at least one isocyanate component and at least one isocyanate-reactive component are used therefor; 3) applying a second reaction mixture which reacts to afford a polyurethane/polyisocyanurate foam to the first outerlayer, so that the adhesion promoter component applied to the first outerlayer is at least partially contacted by the second reaction mixture; characterized in that the adhesion promoter component is applied to the first outerlayer in a predetermined pattern, in the case where in step 2) a one-component adhesion promoter is applied: the one-component adhesion promoter is ejected from a nozzle in the form of individual droplets under instruction from a control unit until the predetermined pattern has been applied; in the case where in step 2) a first reaction mixture is applied the application of the first reaction mixture to the first outerlayer in step 2) comprises the steps of: 2a) applying a droplet of a first component selected from the components employed for the first reaction mixture according to the predetermined pattern to the first outerlayer; 2b) applying a droplet of a further component selected from the components employed for the first reaction mixture according to the predetermined pattern to a previously applied droplet of another component of the first reaction mixture, so that a previously applied droplet of another component is at least partially contacted; 2c) repeating the steps 2a) and 2b) until the predetermined pattern has been applied using all components of the first reaction mixture; wherein in step 2a) and/or step 2b) the application of the droplets is carried out such that under instruction from a control unit an individual droplet is ejected from a nozzle. 1) providing a first outerlayer; 2) applying an adhesion promoter component to the first outerlayer, wherein the adhesion promoter component comprises a one-component adhesion promoter and/or a first reaction mixture which reacts to afford an adhesion promoter and wherein the first reaction mixture is obtained from a plurality of components, wherein at least one isocyanate component and at least one isocyanate-reactive component are used therefor; 3) applying a second reaction mixture which reacts to afford a polyurethane/polyisocyanurate foam to the first outerlayer, so that the adhesion promoter component applied to the first outerlayer is at least partially contacted by the second reaction mixture; 2a) applying a droplet of a first component selected from the components employed for the first reaction mixture according to the predetermined pattern to the first outerlayer; 2b) applying a droplet of a further component selected from the components employed for the first reaction mixture according to the predetermined pattern to a previously applied droplet of another component of the first reaction mixture, so that a previously applied droplet of another component is at least partially contacted; 2c) repeating the steps 2a) and 2b) until the predetermined pattern has been applied using all components of the first reaction mixture;