Patent ID: 6387452
Filing Date: 2002-05-14
Classification: B05D,C09D,D21H

Abstract:
A process for the continuous coating of a traveling support strip to render it anti-adhesive, the coating comprising:i) at least one polyorganosiloxane A; ii) at least one crosslinking agent B that is crosslinkable with polyorganosiloxane A via hydrosilylation or dehydrogenopolycondensation; iii) an effective amount of a catalyst C; the process comprising:a) continuously preparing in a premixing means a first premix selected from the group consisting of AB, AC, and BC; b) continuously preparing in a mixing means a homogenous mixture of components A, B and C by mixing the premix with the component not present in the premix Or by mixing the premix with a second premix comprising the component not present in the first premix, the homogeneous mixture being prepared under the following conditions: aa) a bath lifetime BLT of less than 10 hours; bb) a differential scanning calorimetry DSC signature having at least one Gaussian peak showing: aaa) a peak start temperature T1; bbb) a peak summit temperature T2; ccc) a peak end temperature T3; â€ƒthe Gaussian peak having the following: aaaa) T3&lE;110Â° C. bbbb) &Dgr;T=T3âˆ’T1&lE;30Â° C.; and cccc) &Dgr;T=&Dgr;TrefÂ±10Â° C. wherein &Dgr;Tref=&Dgr;T3,refâˆ’&Dgr;T1,ref is obtained from the DSC signature peak of a reference ABC mixture having A, B and C, the homogenous mixture being prepared at a flow rate corresponding to the rate of consumption of the homogenous mixture at a coating member and the maintenance of a buffer reserve; â€ƒwherein metered amounts of components A, B, and C are introduced into the premixing means and the mixing means in a sequenced and iterative manner and wherein, for each component A, B, and C, volumetric metering means are used which are capable of ensuring the supply of metered amounts of each of these components, as well as, at least partially, their circulation in a continuous flow, along the entire length of the operating line; c) conveying the homogenous mixture from the mixing means to the coating means; d) coating the traveling support strip with the homogenous mixture from the coating means; e) allowing the crosslinking to occur.