Process for preparing polyacrylates

Patent metadata

Field	Value
Publication number	US-9410028-B2
Application number	US-201213717939-A
Country	US
Kind code	B2
Filing date	Dec 18, 2012
Priority date	Aug 12, 2009
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

Process for preparing polyacrylates, by the free-radical polymerization of monomer mixtures comprising at least 70% by weight of at least one acrylic and/or methacrylic ester in the presence of amino acids as regulator substances, and reaction solution comprising one or more solvents and one or more monomers, at least 50% by weight of the solvents being organic solvents, and at least 70% by weight of the monomers being acrylic and/or methacrylic esters, with at least one amino acid being present.

First claim

The invention claimed is:

1. Process for preparing a polyacrylate pressure-sensitive adhesive from a reaction solution consisting of a solvent selected from the group consisting of a single organic solvent or a mixture of two or more organic solvents, one or more monomers, at least 70% by weight of the monomers being acrylic and/or methacrylic esters, free radical initiator and one or more natural or non-natural α-amino acids of the following structural formula

where R 1 , R 2 and R 3 are selected independently of one another, with R 1 selected from the group (i), consisting of
(i) linear and branched C 1 to C 18 alkyl radicals, linear and branched C 2 to C 18 alkenyl radicals, linear and branched C 2 to C 18 alkynyl radicals, arylradicals, cycloaliphatic, aliphatic and aromatic heterocycles, and hydrogen,
and where one of R 2 or R 3 is hydrogen, and the other is selected from the group consisting of group (ii),

(ii) acyl radicals (—C(O)—R′), alkoxycarbonyl radicals (—C(O)—O—R′), carbamoyl radicals (—C(O)—NR′R″), and sulphonyl radicals (—SO 2 R′),
where R′ and R″ are radicals from group i) that are selected independently of one another,

and X is oxygen (O), sulphur (S) or selenium (Se),
and n is a natural number including zero
by free-radical polymerization, wherein the solvent is removed from the polymerization product after the polymerization, down to a residual solvent fraction of not more than 2% and wherein the amino acid or acids remain in the polymerization product when the solvent is removed.

2. Process according to claim 1 wherein the solvent removed is supplied to a recycling operation.

3. Process according to claim 1 , wherein at least one of the organic solvents used is taken from a recycling operation.

4. Process for the free-radical polymerization of monomer mixtures comprising at least 70% by weight of at least one acrylic and/or methacrylic ester, wherein amino acids are present as regulator substances.

5. Process according to claim 1 , wherein the reaction solution is a homogeneous solution.

6. Process according to claim 1 , wherein said at least one amino acid has at least one sulphanyl, selanyl and/or hydroxyl group.

7. Process according to claim 6 , wherein said at least one sulphanyl, selanyl and/or hydroxyl group is terminal.

8. Process according to claim 1 , wherein n is in the range 0≦n≦18.

9. Process according to claim 1 , wherein the acrylic and/or methacrylic ester or esters satisfy the formula

where
R 1 ═H or CH 3
and
R 2 ═H or an unbranched or branched, aliphatic, alicyclic or aromatic, unsubstituted or substituted hydrocarbon radical having 1 to 20 carbon atoms without C═C double bonds.

Assignees

• Tesa Se

Inventors

• Prenzel Alexander
• Beschmann Jennifer

Classifications

• C08K5/36 Primary

  Sulfur-, selenium-, or tellurium-containing compounds {(C08K5/0091 takes precedence)} · CPC title

• C08F2/38

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

• C08F20/18

  with acrylic or methacrylic acids · CPC title