Process for producing short-chain end-group-functionalized macromolecules based on styrene

Patent metadata

Field	Value
Publication number	US-10316117-B2
Application number	US-201415104288-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Dec 18, 2013
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

End-group-functionalized oligomers with controlled degrees of functionality based on styrene are produced by reacting the monomer with a regulator by means of free-radical polymerization. At least some of the quantity of regulator is added according to a prescribed program so that at every juncture t the value of the quantitative fraction added up to said juncture does not fall short of the value of the respective conversion U(t) in the polymerization reaction at said juncture t by more than 5 percentage points and does not exceed said value U(t) by more than 5 percentage points.

First claim

The invention claimed is:

1. A process for producing end-group-functionalized oligomers based on styrene by means of free-radical polymerization, starting from an amount of monomer comprising at least 90 mol % styrene, wherein
the polymerization is started by self-initiation
and is controlled by means of a difunctional regulator comprising the functional groups R F1 and R F2 , where the group R F1 is an unsubstituted sulfanyl group and where the group R F2 of the regulator is selected from the group consisting of hydroxyl groups (—OH), carboxyl groups (—COOH), ester groups (—COOR), primary amino groups (—NH 2 ), secondary amines (—NHR),
wherein the molar ratio of the total monomers used to the regulator is from 5:1 to 200:1

wherein
the total amount of monomer is initially charged,
the batch with the monomer comprises not more than 10% by weight of a solvent,
up to 5% by weight of the total amount of regulator is added to the amount of monomer prior to the start of the reaction,
the temperature of the amount of monomer is controlled such that the polymerization starts by self-initiation, and
the further addition of regulator to the polymerization reaction is carried out continuously or in discrete steps, until a polymerization conversion of at least 85% is achieved, and in such a manner that at all times the following condition (I) is met:
C ( t )−0.05≤ X reg ( t )≤ C ( t )+0.05  (I)

wherein
C(t)=polymerization conversion up to the time point t
C(t)=n mon (t)/n mon,tot
n mon (t)=total amount of reacted monomers in the course of the polymerization reaction up to the time point t
n mon,tot =amount of all monomers used n mon,tot (amount converted)
X reg (t)=fractional amount of regulator X reg (t)=R(t)/R B
R(t)=total amount of regulator added up to the time point (t)
R B =total amount of regulator.

2. The process as claimed in claim 1 , wherein condition (I) is met up to a polymerization conversion of at least 90%.

3. The process as claimed in claim 1 , wherein a still remaining, previously unadded amount of regulator is added continuously or periodically.

4. The process as claimed in claim 1 , wherein the amount of monomer, in addition to styrene, comprises up to 10 mol % of other vinyl aromatic compounds.

5. The process as claimed in claim 1 , wherein, apart from styrene and optionally other vinyl aromatic compounds, no further monomers are present in the amount of monomer.

6. The process as claimed in claim 1 , wherein the polymerization is carried out at a temperature of at least 100° C.

7. The process as claimed in claim 1 , wherein the polymerization is carried out free of solvent.

8. The process as claimed in claim 1 , wherein the molar ratio of the total monomers used to the regulator is from 10:1 to 200:1.

9. The process as claimed in claim 1 , wherein the regulator is selected from the group consisting of 2-aminoethanethiol, 2-mercaptoethanol, 3-mercaptopropionic acid, 2-mercaptopropionic acid and 2-mercaptoacetic acid, and combinations thereof.

10. The process as claimed in claim 1 , wherein the number-average molecular weight of the resulting oligomers is in the range of 1000 g/mol to 20 000 g/mol.

11. The process as claimed in claim 1 , wherein the polydispersity of the resulting polymers is not greater than 2.5.

12. The process as claimed in claim 1 , wherein the polymerization product is purified by removing unreacted monomers and/or by-products from the polymerization product.

13. The process as claimed in claim 1 , wherein
in a subsequent process step, the oligomers obtained by the process of claim 1 are reacted with at least one compound Z having a functional group R F3 and an olefinic double bond to give a refunctionalized oligomer,
wherein at least that part of the compound Z comprising the olefinic double bond is linked to the oligomers by reaction of the functional group R F2 with the functional group R F3 .

14. The process as claimed in claim 13 , wherein the reaction of the group R F2 with the functional group R F3 is a substitution reaction.

15. The process as claimed in claim 13 wherein the reaction of the group R F2 with the functional group R F3 is carried out at a temperature of at least 100° C.

16. The process as claimed in claim 13 , wherein the polymerization and the reaction of the group R F2 with the functional group R F3 are carried out in the same reactor.

17. The process as claimed in claim 13 , wherein the compound Z having the functional group R F3 and an olefinic double bond is selected from the group consisting of acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, acrylic anhydride, methacrylic anhydride, glycidyl acrylate, glycidyl methacrylate, maleic anhydride, acryloyl chloride, methacryloyl chloride, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, 4-chloromethylstyrene, itaconic anhydride, 3,4-epoxycyclohexylmethyl acrylate, and epoxycyclohexylmethyl methacrylate.

18. The process as claimed in claim 13 , wherein the resulting refunctionalized oligomers have on average 0.95 to 1.05 olefinic double bonds introduced by the compound Z.

19. A refunctionalized oligomer obtained by the process of claim 13 .

Assignees

• Tesa Se

Inventors

• Zöllner Stephan
• Prenzel Alexander
• Lühmann Bernd
• Pütz Benjamin
• Ritter Helmut

Classifications

• C08F2810/40

  taking place solely at one end or both ends of the polymer backbone, i.e. not in the side or lateral chains · CPC title

• C08F2/38

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title

• C08G18/8116

  esters of acrylic or alkylacrylic acid having only one isocyanate or isothiocyanate group · CPC title

• C08F2810/30

  leading to the formation or introduction of aliphatic or alicyclic unsaturated groups · CPC title

• C08F2400/02

  Control or adjustment of polymerization parameters · CPC title