Semi-continuous integrated process for the production of high impact vinyl aromatic (co)polymers by anionic/radical polymerization in sequence
AssigneePolimeri Europa S.p.A.
InventorsRiccardo Inglese, Leonardo Chiezzi, Fabio Montanari, Alessandro Casalini
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Abstract
Butadiene is anionically polymerized (or block copolimerized with styrene) in a low-boiling non-polar solvent in presence of rganolithiura compounds. At the end of the polymerization, the non-polar solvent is switched with styrene and the new solution is stored in tanks in relation to the type of polybutadiene (or its block copolymer with styrene) obtained. The polybutadiene solution (and/or its block copolymer with styrene) with the desired set of properties is then fed to a production plant of high impact vinyl aromatic (co) polymers.
Claims3
A semi-continuous integrated process for the production of high impact vinyl aromatic (co)polymers, by means of anionic/radical polymerization in sequence, starting from butadiene, which comprises:
- b. anionic polymerizing at least one monomer of butadiene in a batch reactor, in the presence of organolithium compounds and a low-boiling non-polar solvent;
- b1. effecting a chain termination phase of the polymer based on butadiene, at the end of the polymerization, by means of at least one halogen derivative having the general formula:
- R3-M—X (1)
- wherein X represents a halogen, such as chlorine or bromine, M represents an element of Group IV A, such as carbon or silicon, and R is a C1-C8 alkyl radical, or with carboxylic acids, soluble in the low-boiling non-polar solvent, having the general formula:
- R1—COOH (2)
- wherein R1 is an alkyl radical with a number of carbon atoms greater than or equal to 6, for example from 6 to 18;
- and/or
- b2. effecting a first coupling phase of the polymer chain by means of at least one halogen derivative selected from those having the general formula:
- R4-y-M—XY (3)
- with X, M and R having the meaning defined above and y being an integer within the range of 2 to 4, extremes included;
- and/or
- b3. effecting a second coupling phase by means of at least one aromatic derivative selected from those having the general formula:
- (R′)n—Ar (4)
- wherein R′ represents a C2-C5 alkenyl radical, Ar a C6-C18 aromatic radical, possibly substituted by non-electron attractor groups, whereas n is an integer ranging from 2 to 10;
- c. switching in batch the low-boiling non-polar solvent with a vinyl aromatic monomer;
- d. storing in tanks the polymer solution based on butadiene in a vinyl aromatic monomer, according to the polymer grade obtained;
- and
- e. feeding the butadiene-based polymer solution in the vinyl aromatic monomer, together with conventional polymerization additives and possibly a co-monomer, to a polymerization plant, to produce a high impact vinyl aromatic(co)polymer by radical polymerization;
- and
- f. recovering the high impact vinyl aromatic (co)polymer from the polymerization plant.
Dependencies are inferred from the claim text.