Patent ES-8400467-A1 (ES)
Title: Crystalline controlled vinylidene chloride contg. interpolymer prepn.
IPC: C08L27/08
Filed: 1982-08-11
Abstract: EP--68461 A Prepn. in aq. emulsion of a novel, crystalline, controlled interpolymer compsn. is claimed, the interpolymer comprises (a) 86-92 mol.% vinylidene chloride, (b) 14-8 mol.% methyl methacrylate and (meth)acrylonitrile or methacrylic acid in a molar ratio of comonomer to MMA of 0.2-5:1 and (c) 0.5-1.0 wt.% itaconic acid based on wt. of (a) and (b). The interpolymer has a relative viscosity of 1.3-1.7 at 25 deg.C as a 1% soln. in THF. - The prepn. comprises (A) initiating emulsion polymerisation by forming a seed latex  and (1) adding a first monomer charge comprising 3-8 wt.% monomer mixt. of(a), (b), (c) to an aq. emulsion polymerisation medium contg. 0.5-1.0 wt.% itaconic acid (based on the monomer mixt.), (2) adding polymerisation initiator and (3) continuing seed latex formation under autogenous pressure until a drop in the vapour pressure of 12.4-15.2kPa occurs. - (B)  adding (1) second monomer in an amt. 85-92 wt.% of monomer mixt. at a constant rate to continually provide excess unreacted monomers of 2-10 wt.% based on the medium and (2) initiator  as in (A)(2); and - (C)  completing polymerisation in a predetermined time interval  by: (1) continuing to add initiator at the same  rate   and (2) adding third monomer  in amt. 2-12 wt.% of monomer mixt. as in (A)(1), the third charge being added such that the vapour pressure of onomers in the polymerisation medium is reduced smoothly . - The process reduces the at. of unreacted mixed monomers remaining without large variation in polymer compsn. esp. from high vinylidene chloride fractions. The interpolymer  show increased solubility in org. solvents, low permeability to moisture and oxygen and good crystallisation rate for a film EPAB- EP--68461 B Prepn. in aq. emulsion of a novel, crystalline, controlled interpolymer compsn. is claimed, the interpolymer comprises (a) 86-92 mol.% vinylidene chloride, (b) 14-8 mol.% methyl methacrylate and (meth)acrylonitrile or methacrylic acid in a molar ratio of comonomer to MMA of 0.2-5:1 and (c) 0.5-1.0 wt.% itaconic acid based on wt. of (a) and (b). The interpolymer has a relative viscosity of 1.3-1.7 at 25 deg.C as a 1% soln. in THF. - The prepn. comprises (A) initiating emulsion polymerisation by forming a seed latex  and (1) adding a first monomer charge comprising 3-8 wt.% monomer mixt. of(a), (b), (c) to an aq. emulsion polymerisation medium contg. 0.5-1.0 wt.% itaconic acid (based on the monomer mixt.), (2) adding polymerisation initiator and (3) continuing seed latex formation under autogenous pressure until a drop in the vapour pressure of 12.4-15.2kPa occurs. - (B)  adding (1) second monomer in an amt. 85-92 wt.% of monomer mixt. at a constant rate to continually provide excess unreacted monomers of 2-10 wt.% based on the medium and (2) initiator  as in (A)(2); and - (C)  copleting polymerisation in a predetermined time interval  by: (1) continuing to add   initiator at the same  rate - and (2) adding third monomer  in amt. 2-12 wt.% of monomer mixt. as in (A)(1), the third charge being added such that the vapour pressure of onomers in the polymerisation medium is reduced smoothly . - The process reduces the at. of unreacted mixed monomers remaining without large variation in polymer compsn. esp. from high vinylidene chloride fractions. The interpolymer  show increased solubility in org. solvents, low permeability to moisture and oxygen and good crystallisation rate for a film (43pp) - EP--68461 B Prepn. in aq. emulsion of a novel, crystalline, controlled interpolymer compsn. is claimed, the interpolymer comprises (a) 86-92 mol.% vinylidene chloride, (b) 14-8 mol.% methyl methacrylate and (meth)acrylonitrile or methacrylic acid in a molar ratio of comonomer to MMA of 0.2-5:1 and (c) 0.5-1.0 wt.% itaconic acid based on wt. of (a) and (b). The interpolymer has a relative viscosity of 1.3-1.7 at 25 deg.C as a 1% soln. in THF. - The prepn. comprises (A) initiating emulsion polymerisation by forming a seed latex  and (1) adding a first monomer charge comprising 3-8 wt.% monomer mixt. of(a), (b), (c) to an aq. emulsion polymerisation medium contg. 0.5-1.0 wt.% itaconic acid (based on the monomer mixt.), (2) adding  polymerisation initiator and (3) continuing seed latex formation under autogenous pressure until a drop in the vapour pressure of 12.4-15.2kPa occurs. - (B)  adding (1) second monomer in an amt. 85-92 wt.% of monomer mixt. at a constant rate to continually provide excess unreacted monomers of 2-10 wt.% based on the medium and (2) initiator  as in (A)(2); and - (C)  completing polymerisation in a predetermined time interval  by: (1) continuing to add initiator at the same  rate - and (2) adding third monomer  in amt. 2-12 wt.% of monomer mixt. as in (A)(1), the third charge being added such that the vapour pressure of onomers in the polymerisation medium is reduced smoothly . - The process reduces the at. of unreacted mixed monomers remaining without large variation in polymer compsn. esp. from high vinylidene chloride fractions. The interpolymer  show increased solubility in org. solvents, low permeability to moisture and oxygen and good crystallisation rate for a film