Method for producing non-colored polyacrylate adhesive compounds with a narrow molar mass distribution

Patent metadata

Field	Value
Publication number	US-9540458-B2
Application number	US-201214356477-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Nov 16, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Method for producing polyacrylate adhesive compounds with a narrow molar mass distribution by radical polymerization and subsequent decolorization of colored reaction products resulting therefrom.

First claim

The invention claimed is:

1. A method for producing a pressure-sensitive acrylate-based adhesive polymer having a glass transition temperature T g,A of less than 15° C., a weight average molecular weight range of 100,000 to 500,000, and a polydispersity of 2-3.5, wherein first a controlled radical polymerization reaction of an initial reaction charge comprising at least one acrylate-based monomer is carried out in the presence of at least one chain transfer agent (CTA) having at least one functional S—C═X group, where X═S, O or N, the CTA being selected from the group consisting of dithioesters, dithiocarbonates, dithiocarbamates, trithiocarbonates, imidodithiocarbonates, and xanthates (“RAFT CTAs”), wherein CTA molecules are incorporated into the polymer chains that form, whereby the polymer chains have the functional group of the incorporated CTA, wherein
at least one chemical compound which has at least two conjugated double bonds (“conjugated diene”) is contacted with the polymers thus obtained, so that hetero-Diels-Alder reactions are brought about between the double bonds C═X of the functional groups S—C═X incorporated into the polymer chains and the conjugated double bonds of the conjugated diene.

2. The method as claimed in claim 1 , wherein the polymers obtained are admixed with at least one chemical compound from which it is possible in situ to generate a chemical compound which has at least two conjugated double bonds.

3. The method as claimed in claim 1 , wherein the compounds having the conjugated double bonds in the unit C═C—C═C are not heterosubstituted.

4. The method as claimed in claim 1 , wherein the conjugated dienes are selected from the group consisting of 1,3-butadiene, 1-methoxy-1,3-butadiene, 2,4-hexadiene, (2E)-2,4-pentanedienoic acid, sorbic acid and its esters, 2,4-hexadiene-1,6-dicarboxylic acid and its esters, 1,3-cyclohexadiene, 1-methoxy-1,3-cyclohexadiene, anthracene, substituted and unsubstituted furans, substituted and unsubstituted thiophenes, substituted and unsubstituted cyclopentadienes, (E)-1-methoxy-3-trimethylsilyloxy-1,3-butadiene, 1-(trimethylsiloxy)-1,3-butadiene, 1-(triethylsiloxy)-1,3-butadiene, and (1E,3Z)-1-methoxy-2-methyl-3-(trimethylsilyloxy)-1,3-pentadiene.

5. The method as claimed in claim 1 , wherein the chain transfer agent (CTA) used is a dithioester.

6. An adhesive composition comprising the acrylate-based polymers according to claim 1 .

7. The adhesive composition as claimed in claim 6 , wherein the adhesive composition is a pressure sensitive adhesive.

8. The method as claimed in claim 1 , wherein the chain transfer agent (CTA) is

wherein R 2 is selected from the group consisting of the groups a) to m), R III and R IV are radicals selected from the group consisting of the groups a) to g):
a) branched and unbranched C 1 to C 18 alkyl, branched and unbranched C 3 to C 18 alkenyl, and branched and unbranched C 3 to C 18 alkynyl radicals
b) ethenyl and ethynyl radicals
c) unsubstituted or substituted phenyl radicals, and unsubstituted or substituted benzyl radicals
d) C 3 to C 12 cycloalkyl radicals
e) aromatic heterocyclic radicals
f) substituted radicals of group a):
f1) radicals of group a) each substituted by at least one OH group, halogen atom or silyl ether,
f2) radicals of group a) each substituted by at least one ester, amine, carbonate, cyano, isocyano and/or epoxide group and/or by sulfur,

g) substituted radicals of group b):
g1) radicals of group b) each substituted by at least one OH group, halogen atom or silyl ether,
g2) radicals of group b) each substituted by at least one ester, amine, carbonate, cyano, isocyano and/or epoxide group and/or by sulfur,

h) —NH 2 , —NHR I , —NR I R II , —NH—C(O)—R I , —NR I —C(O)—R II ,—NH—C(S)—R I , —NR I —C(S)—R II ,

 where R I and R II are radicals selected independently of one another from groups a) to g)
i) —S—R I , —S—C(S)—R I , where R I is a radical selected from one of groups a) to g),
k) —O—R I , —O—C(O)—R I , where R I is a radical selected from one of groups a) to g),
I) —P(O)(OR III )(OR IV ), where R III and R IV are identical or radicals selected independently of one another from groups a) to g),
m) C 2 to C 18 heteroalkyl radicals having at least one O atom and/or at least one NR I group in the carbon chain, where R I is a radical selected from one of groups a) to g).

Assignees

• Tesa Se

Inventors

• Prenzel Alexander

Classifications

• C08F2810/20

  leading to a crosslinking, either explicitly or inherently · CPC title

• C08F2438/03

  Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX] · CPC title

• C08F2810/30

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

• C09J153/005

  Modified block copolymers · CPC title

• C08F2/38

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