US 12,252,607 B2
Process for manufacture of plasticized homopolymeric polyvinyl alcohol and plasticized polyvinyl alcohol polymer obtained therefrom
John Williams, Chirbury (GB); Sian Griffiths, Conwy (GB); and Robert Ashworth, Conwy (GB)
Assigned to Aquapak IP Limited, Birmingham (GB)
Appl. No. 18/014,793
Filed by Aquapak IP Limited, Birmingham (GB)
PCT Filed Jul. 6, 2021, PCT No. PCT/EP2021/068686
§ 371(c)(1), (2) Date Jan. 6, 2023,
PCT Pub. No. WO2022/008521, PCT Pub. Date Jan. 13, 2022.
Claims priority of application No. 20184345 (EP), filed on Jul. 6, 2020.
Prior Publication US 2023/0348638 A1, Nov. 2, 2023
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)] 14 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 comprising polyvinyl alcohol or a blend thereof having a degree of hydrolysis in the range of 93 wt % or greater;
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 the primary outlet, the inter-engaging components being arranged to apply a shearing force to the polyvinyl alcohol polymer while the polyvinyl alcohol polymer is conveyed by the components from the primary inlet through a reaction zone to the primary outlet;
one or more secondary inlets located downstream from the primary inlet for introducing reactants comprising a processing aid, a plasticizer and a reactive stabilizer to the blending chamber to form a reaction mixture;
wherein the plasticizer comprises two compounds selected from the group consisting of: diglycerol, triglycerol, xylose, D-mannitol, dipentaerythritol, triacetin, 1,4 butanediol, 3,3-dimethyl-1,2-butanediol, caprolactam and mixtures thereof;
wherein the reactive stabilizer is selected from the group consisting of:
potassium oleate, sodium benzoate, and mixtures thereof;
wherein the blending chamber comprises a plurality of heated regions arranged so that the mixture is subjected to a temperature profile whereby the temperature increases from the primary inlet to the primary outlet;
a secondary outlet located between the reaction zone and primary outlet arranged to allow removal of processing aid from the chamber;
reacting the processing agent, plasticizer and polyvinyl alcohol polymer in the reaction zone to form plasticizer polyvinyl alcohol polymer; and
allowing the plasticized polyvinyl alcohol polymer to pass from the primary outlet.