US 12,139,598 B2
Process and apparatus for manufacture of processable polyvinyl alcohol
John Williams, Chirbury (GB); Sian Griffiths, Glan Conwy (GB); and Robert Ashworth, Colwyn Bay (GB)
Assigned to Aquapak IP Limited, Birmingham (GB)
Filed by Aquapak Polymers Limited, Birmingham (GB)
Filed on Jul. 6, 2021, as Appl. No. 17/368,164.
Claims priority of application No. 20184345 (EP), filed on Jul. 6, 2020.
Prior Publication US 2022/0002518 A1, Jan. 6, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C08L 29/04 (2006.01); B29B 7/48 (2006.01); C08F 2/01 (2006.01); C08F 2/44 (2006.01); C08F 116/06 (2006.01); C08J 3/05 (2006.01); C08J 3/18 (2006.01); C08K 5/053 (2006.01); C08K 5/092 (2006.01); C08K 5/098 (2006.01); C08K 5/12 (2006.01); C08K 5/3412 (2006.01); B29K 229/00 (2006.01)
CPC C08L 29/04 (2013.01) [B29B 7/487 (2013.01); C08F 2/01 (2013.01); C08F 2/44 (2013.01); C08F 116/06 (2013.01); C08J 3/05 (2013.01); C08J 3/18 (2013.01); C08K 5/053 (2013.01); C08K 5/092 (2013.01); C08K 5/098 (2013.01); C08K 5/12 (2013.01); C08K 5/3412 (2013.01); B29K 2229/04 (2013.01); C08J 2329/04 (2013.01); C08K 2201/014 (2013.01); C08L 2201/50 (2013.01); C08L 2205/025 (2013.01)] 13 Claims
 
1. A method for manufacture of plasticized homopolymeric polyvinyl alcohol, the method comprising the steps of:
introducing into a mixing reactor a polyvinyl alcohol polymer consisting of polyvinyl alcohol or a blend thereof having a degree of hydrolysis greater than 93 wt %;
wherein the mixing reactor comprises a blending chamber having a primary inlet, a primary outlet and at least two inter-engaging components extending between the primary inlet and primary outlet, the components being arranged to apply a shearing force to the polymer while the polymer is conveyed by the components from the inlet through a reaction zone to the outlet;
one or more secondary inlets located downstream from the primary inlet for introducing ingredients consisting of water, a plasticizer and a reactive stabilizer to the chamber;
wherein the plasticizer is selected from the group consisting of: diglycerol, triglycerol, fructose, ribose, xylose, D-mannitol, triacetin, pentaerythritol, dipentaerythritol, methyl pentanediol, 1,2-propanediol, 1,4-butanediol, 2-hydroxy-1,3-propanediol, 3-methyl-1,3-butanediol, 3,3-dimethyl-1,2-butanediol, caprolactam, tricyclic trimethylolpropane formal, erucamide and mixtures thereof;
wherein the reactive stabilizer is selected from the group consisting of:
sodium stearate, potassium oleate, sodium benzoate, calcium stearate, dimethyl propionic acid, and mixtures thereof;
wherein the blending chamber comprises a plurality of heated regions arranged so that the ingredients are subjected to a temperature profile whereby the temperature increases from the inlet to the outlet;
a secondary outlet located between the reaction zone and primary outlet arranged to allow removal of water from the chamber;
reacting water, plasticizer, reactive stabilizer and the polyvinyl alcohol polymer in the reaction zone to form the plasticized polymer; and
allowing the plasticized polymer to pass from the primary outlet.