Patent ID: 11932992
Assignee: UPM-KYMMENE CORPORATION
Field: Textile and paper machines (Mechanical engineering)
Classification: CPC C  D  Y | IPC C  D

Claim 6:
7. A method for manufacturing a paper substrate which is suitable for binding silicone in a catalytic hydrosilation. reaction, the method comprising steps of
dissolving polyvinyl alcohol which has a weight average molecular weight of less than 50000 g/mol and degree of hydrolysis in the range of 70% to 99% into water, thereby obtaining a water-based solution containing dissolved polyvinyl alcohol,
adding reactant which is an organic molecule that contains a catenated carbon structure having at least 4 carbon atoms, an aldehyde group and a functional vinyl group into the water-based solution containing the dissolved polyvinyl alcohol, thereby obtaining a reaction mixture
reacting the reactant with the dissolved polyvinyl alcohol in a water-based acetalization reaction, thereby forming acetalized polyvinyl alcohol which contains functional vinyl groups, wherein the functional vinyl groups are part of catenated carbon structures which contain at least 4 carbon atoms, and which have an acetal connectivity with the backbone chain of the acetalized polyvinyl alcohol, and
coating a cellulose fiber-based support layer with the acetalized polyvinyl alcohol, thereby forming a hydrophobic primer layer and the paper substrate, wherein the vinyl group molality of the acetalized polyvinyl alcohol is equal to or higher than 0.2 millimoles per grain of the acetalized polyvinyl alcohol.