Process for producing vinyl resin
AssigneeKuraray Co., Ltd.
InventorShigeki Takada
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Abstract
There is disclosed a process for producing a vinyl resin by suspension polymerization of a vinyl compound in the presence of a suspending agent (A) which comprises using a polymerization vessel equipped with a reflux condenser and adding a polyvinyl alcohol (B) having a degree of hydrolysis of at most 85 mol % in an amount of 0.001 to 0.5 part by weight based on 100 parts by weight of said vinyl compound when a polymerization conversion is in the range of 30 to 90%. According to the present invention, there is provided a process for producing a vinyl resin having a high bulk density, which is excellent in anti-foaming effect against the dry foam being generated in the middle to latter period of the suspension polymerization in a polymerization vessel equipped with a reflux condenser which is excellent in productivity.
Claims9
A process for producing a vinyl resin, comprising:
- polymerizing a suspension of at least one vinyl compound in the presence of 0.01 to 1 part by weight, based on 100 parts by weight of said vinyl compound, of a suspending agent, and
- adding, when the polymerization conversion of said vinyl compound is in the range of 30 to 80%, 0.001 to 0.5 part by weight, based on 100 parts by weight of said vinyl compound, of a polyvinyl alcohol having a degree of hydrolysis of 40 to 85 mol % and a viscosity-average degree of polymerization of 70 to 1500, wherein
- the polymerization reaction is conducted in a vessel comprising a reflux condenser, and a portion of the polymerization reaction heat is removed by said reflux condenser.
Dependencies are inferred from the claim text.