Silicone composite that can be reticulated for producing anti-adhesive coatings for flexible supports and additive to promote adhesion contained in this composite

Abstract

The present invention relates to a siloxane composition, which can forming reticular structure or have been reticulated, particularly for creating a coating or water-repellent and anti-adhesive film for flexible substrates such as paper or similar in the form of natural or synthetic polymer films. These compounds are of the type that containing reticulating polyorganosiloxanes that have SiH units and unsaturated polyorganosiloxanes, preferably vinylated, suitable for reacting with the reticulating agent in an addition reaction and in the presence of platinum to form the reticulated anti-adhesive coating on the flexible substrate, plus at least one additive (D) to promote adhesion to it. The objective of the invention is to propose new liquid silicone compounds that can be applied without using a solvent, which is beneficial, that can be reticulated instantly to produce an anti-adhesive and / or water-repellent coating for the flexible substrate, giving very high quality reticulated silicone coatings, particularly in terms of sticking / adhering to the substrate, being harder to rub off and the anti-adhesion profile (sufficiently increase detaching force at high speed); these latter properties are in particular the result of an additive to help it stick. In order to achieve this aim, the invention proposes silicone compounds in which the attachment-enhancing additive is: M [D]ddegrealcoxy ]d [Depoxy ]d [D']d'[M']m'; where 0 is less than or equal to degree is less than or equal to500; 0 is less than or equal to d is less than or equal to 50;1 is less than or equal to d is less than or equal to 40; 0 is less than or equal to d' is less than or equal to 1; 0 is less than m' is less than or equal to 1; d'+m' is less than or equal to 1, optimized for less or equal to 0.5. The invention comprises the use of coatings obtained by reticulation / polyaddition for films on paper and on polymers (PET).

Description

technical field [0001] The present invention relates to crosslinkable or crosslinkable silicone compositions which can be used in particular to form coatings on flexible supports such as paper or similar materials in the form of natural or synthetic polymer films or waterproof non-adhesive film. [0002] These curable, non-adhesive silicone compositions are coated on flexible supports to facilitate removal of adhesive materials reversibly laminated to these supports. [0003] More specifically, the present invention relates to silicone compositions comprising: [0004] ◆One or more functionalized polysiloxanes (POS) with Si-H on the same molecule or different molecules [(M) a′≥0 (M H ) b′≥0 (D H ) c′≥0 (D) d′≥0 ] and Si-alkenyl units, preferably Si-vinyl (Vi) [(M) a″≥0 (M Vi ) b″≥0 (D Vi ) c″≥0 (D) d″≥0 ] units; these Si-H units can react with Si-alkenyl units; the definitions of the above symbols are as follows: M: (R 3 SiO 1 / 2 ); D: (R 2 SiO 2 / 2 ); H or M':...

AI Technical Summary

Problems solved by technology

The disadvantage of this additive is that it contains a large number of SiH units, that is to say at least one SiH unit per molecule or at least 0.24% by weight of SiH units

Due to the bifunctionality and reactivity of these residues, additives of this type are naturally somewhat unstable and therefore their storage is limited; their viscosity rises rapidly until a gel is formed, which may be days or months depending on the circumstances ; so the additive is not available

Images