US 11,898,013 B2
Process for producing a water-repellent and release coating on a support
Frederic Magd, Tassin la Demi Lune (FR); Frederic Marchal, Lyons (FR); Yassine Maadadi, Meyzieu (FR); and Thierry Walter, Fontaines sur Saone (FR)
Assigned to ELKEM SILICONES FRANCE SAS, Lyons (FR)
Appl. No. 16/499,171
Filed by Elkem Silicones France SAS, Lyons (FR)
PCT Filed Mar. 29, 2018, PCT No. PCT/EP2018/058261
§ 371(c)(1), (2) Date Sep. 27, 2019,
PCT Pub. No. WO2018/178321, PCT Pub. Date Oct. 4, 2018.
Claims priority of application No. 1700348 (FR), filed on Mar. 30, 2017.
Prior Publication US 2021/0108105 A1, Apr. 15, 2021
Int. Cl. C09D 5/22 (2006.01); C08G 77/12 (2006.01); C08F 2/24 (2006.01); C09D 5/02 (2006.01); C08G 77/20 (2006.01); C09D 183/06 (2006.01)
CPC C08G 77/12 (2013.01) [C08F 2/24 (2013.01); C08G 77/20 (2013.01); C09D 5/022 (2013.01); C09D 183/06 (2013.01)] 11 Claims
 
1. A process for producing a water-repellent and release coating on a support S, optionally on a flexible support S comprising paper or of synthetic polymer film, the process comprising:
1) Preparing an aqueous silicone emulsion E1 which can be crosslinked into a silicone elastomer by a polyaddition reaction, comprising:
at least one organopolysiloxane A having, per molecule, at least two unsaturated functional groups of C2-C6 alkenyl type, bonded to the silicon,
at least one organopolysiloxane B having, per molecule, at least three hydrogen atoms bonded to the silicon,
at least one polyaddition catalyst C,
at least one emulsifying agent D,
water,
optionally at least one crosslinking inhibitor F,
optionally at least one pH-fixing agent G chosen so as to maintain the pH of the emulsion E1 between 5 and 9
optionally at least one formulation additive H, and
at least one additive X which is a linear organopolysiloxane comprising siloxyl units (I.1) to (I.3) having the formulae below:

OG Complex Work Unit Math
and not comprising units of formula (I.4):

OG Complex Work Unit Math
in which:
a=1 and b=1 or 2;
d=1 and e=1 or 2;
the symbol Y represents a radical comprising a hydrocarbon-based group having from 2 to 20 carbon atoms and an epoxy function, with optionally one or more heteroatoms such as an oxygen atom, and
the symbols Z1, Z2 and Z3, which may be identical or different, represent a monovalent hydrocarbon-based group having from 1 to 30 carbon atoms, with the following conditions:
the additive X comprises, per molecule, at least two siloxyl units (I.1) bearing epoxyfunctional hydrocarbon-based groups, at least three siloxyl units (I.3) bearing hydrosiloxyl groups and a total number N of siloxyl units of between 7 and 30, and
the additive X has a content of siloxyl units (I.1) of greater than or equal to 200 mmol per 100 g of additive X;
2) applying on at least one face of said flexible support S the aqueous silicone emulsion E1, and
3) removing the water and carrying out the crosslinking, optionally by heating to a temperature of between 80° C. and 220° C.