METHOD FOR PRODUCING NON-COLORED POLYACRYLATE ADHESIVE COMPOUNDS WITH A NARROW MOLAR MASS DISTRIBUTION

• US 20140288242A1
• Filed: 09/28/2012
• Published: 09/25/2014
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Tesa SE (Maxingvest AG)
• Original Assignee: Tesa SE (Maxingvest AG)
• Inventors: Prenzel, Alexander
• Granted Patent: US 9,540,458 B2
• Time in Patent Office: Days
• US Class Current: 525/327.1
• CPC Class Codes: C08F 2/38 Polymerisation using regulators, e.g. chain terminating agents , e.g. telomerisation
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 220/1807 C7-(meth)acrylate, e.g. heptyl (meth)acrylate or benzyl (meth)acrylate
• CPC Class Codes: C08F 220/1808 C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• CPC Class Codes: C08F 2438/03 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 Class Codes: C08F 2800/20 as weight or mass percentages
• CPC Class Codes: C08F 2810/20 leading to a crosslinking, either explicitly or inherently
• CPC Class Codes: C08F 2810/30 leading to the formation or introduction of aliphatic or alicyclic unsaturated groups
• CPC Class Codes: C08F 2810/40 taking place solely at one end or both ends of the polymer backbone, i.e. not in the side or lateral chains
• CPC Class Codes: C08F 293/005 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
• CPC Class Codes: C08F 8/00 Chemical modification by after-treatment graft polymers, block polymers, crosslinking with unsaturated monomers or with polymers C08F251/00 - C08F299/00; of conjugated diene rubbers C08C
• CPC Class Codes: C08F 8/42 Introducing metal atoms or metal-containing groups
• CPC Class Codes: C08F 8/48 Isomerisation; Cyclisation
• CPC Class Codes: C09J 153/005 Modified block copolymers

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.

Claims

1. A method for producing acrylate-based polymers,

wherein first a controlled radial 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”

),

the majority of the CTA molecules being 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 chemical compound which has at least two conjugated double bonds is added to the polymers obtained.

3. 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.

4. 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.

5. 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.

6. The method as claimed in claim 1, wherein

the chain transfer agent (CTA) is

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

8. The method as claimed in claim 1, wherein the acrylate-based polymers obtained are used as adhesives or further-processed to adhesives.

9. The method as claimed in claim 8, wherein

the adhesives are pressure sensitive adhesives.

10. Acrylate-based polymers, having cyclo-1-X-hex-3-ene units in the polymer chains, with X═

S, O and/or N.