Shear-resistant pressure-sensitive adhesive with high tack

Patent metadata

Field	Value
Publication number	US-9834636-B2
Application number	US-201415104323-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Dec 18, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Crosslinked pressure-sensitive adhesives (PSAs) based on polymers of branched macromolecules each comprising a main chain and one or more sidechains pendent to the main chain, the constitutional units thereof originating from a) X wt % of one or more acrylic and/or methacrylic esters, with 80<=X<=99.5; b) Y wt % of radically copolymerizable monomers having at least one acid function, with 0.5<=Y<=15; c) Z wt % of vinyl compounds, with 0<=Z<=5, at least one sidechain pendent to the main chain having a number-average molar mass >=1000 g/mol, and the respective amounts of constitutional units originating from a), b) and c) can be the same in each case or differ by not more than 1%, and where a), b) and c) may in each case be the same or different monomers, have detachment properties which can be set independently of one another.

First claim

The invention claimed is:

1. A polymer having a main chain, comprising monomers A), and one or more side chains, comprising macromolecules B), located on the main chain, wherein the constitutional units of the monomers A) and the macromolecules B) are attributable to the following monomers
a) X % by weight of one or more acrylic acid esters and/or methacrylic acid esters, wherein 80≦X≦99.5;
b) Y % by weight radically copolymerizable monomers having at least one acid function, wherein 0.5≦Y≦15;
c) Z % by weight vinyl compounds, wherein 0≦Z≦5

and X+Y+Z is 100,
wherein
at least one side chain of the one or more side chains located on the main chain has a number-average molar mass of at least 1000 g/mol and
the content X, Y and Z of constitutional units attributable to the individual monomers a), b) and c) both in the main chain and in the side chains having a number-average molar mass of at least 1000 g/mol in total is in each case be the same or different,
wherein, in the case where the content is different, an upwards or downwards deviation of not more than 1% is present in each case,
wherein the monomers a), b) and c) for the main chain and side chains is in each case the same monomers or different monomers.

2. The polymer as claimed in claim 1 , wherein 1≦Y≦10.

3. The polymer as claimed in claim 1 , wherein the number of side chains having a number-average molar mass of 1000 g/mol or more is between 1 and 5 in the predominant number of macromolecules.

4. The polymer as claimed in claim 1 , wherein the number-average molecular weight of the polymer is between 100 000 g/mol and 1 500 000 g/mol.

5. The polymer as claimed in claim 1 , wherein there are chosen as monomers a) wholly or predominantly those acrylic acid esters and/or methacrylic acid esters whose homopolymers have a glass transition temperature (differential scanning calorimetry according to DIN 53 765; heating rate 10 K/min) of not more than −10° C.

6. The polymer as claimed in claim 1 , wherein there are chosen as monomers a) wholly or predominantly esters of acrylic acid with linear primary alcohols having from 3 to 10 carbon atoms in the alcohol moiety and/or esters of methacrylic acid with linear primary alcohols having more than 8 carbon atoms in the alcohol moiety.

7. The polymer as claimed in claim 1 , wherein there are chosen as monomers b) one or more carboxylic acids.

8. The polymer as claimed in claim 7 , wherein acrylic acid is chosen as the monomer b).

9. The process for the preparation of a polymer as claimed in claim 1 , wherein the amounts X, Y and Z of monomers a), b) and c) for monomer group A and monomer group B are the same.

10. The polymer according to claim 1 , further comprising:
one or more crosslinker substance present in an amount of from 0.025 to 0.4 by weight based on 100 parts by weight of the polymer to be crosslinked.

11. The polymer according to claim 10 , wherein the one or more crosslinker substances are selected from the group consisting of metal chelates, N,N-Diglycidylamines, epoxides and aziridines.

12. The polymer according to claim 10 , wherein the one or more crosslinker substances consists of isocyanates present in the amount of from 0.1 to 0.4 part by weight, based on 100 parts by weight of the polymer to be crosslinked.

13. A pressure-sensitive adhesive having a polymer component comprising the polymer according to claim 1 , wherein the pressure-sensitive adhesive is crosslinked.

14. The pressure-sensitive adhesive as claimed in claim 13 , wherein the polymer component comprises only one or more polymers as claimed in claim 1 .

15. The pressure-sensitive adhesive as claimed in claim 13 , wherein it is free of resin.

16. A process for the preparation of a polymer as claimed in claim 1 , wherein the polymer is produced by free radical polymerization from a monomer group mixture comprising
A) W % by weight [based on the monomer mixture comprising monomer groups A) and B)] of the following monomers
a) X % by weight [based on monomer group A)] of one or more acrylic acid esters and/or methacrylic acid esters, wherein 80≦X≦99.5;
b) Y % by weight [based on monomer group A)] radically copolymerizable monomers having at least one acid function, wherein 0.5≦Y≦15;
c) Z % by weight [based on monomer group A)] vinyl compounds, wherein 0≦Z≦5

and
B) (100-W) % by weight [based on the monomer mixture comprising monomer groups A) and B)] of the following macromonomers
d) macromonomers terminally functionalized by groups containing at least one ethylenic double bond and the number-average molecular weight of which is 1000 g/mol or more and the constitutional units of which are in turn attributable to the monomers
a) X % by weight of one or more acrylic acid esters and/or methacrylic acid esters, wherein 80≦X≦99.5;
b) Y % by weight radically copolymerizable monomers having at least one acid function, wherein 0.5≦Y≦15;
c) Z % by weight vinyl compounds, wherein 0≦Z≦5,

wherein 80≦W≦95,
wherein the monomers a), b) and c) for monomer group A) and monomer group B) is in each case the same monomers or different monomers, and
wherein the amounts X, Y and Z of monomers a), b) and c) for monomer group A) and monomer group B is in each case the same amounts or different amounts,
wherein, in the case where the amounts are different amounts, an upwards or downwards deviation of not more than 1% is present in each case.

17. The process for the preparation of a polymer as claimed in claim 16 , wherein the monomers a), b) and c) for monomer group A and monomer group B are the same monomers.

Assignees

• Tesa Se

Inventors

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

Classifications

• B32B2307/718

  Weight, e.g. weight per square meter · CPC title

• C09J151/003

  grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds (C09J151/04, C09J151/06 take precedence) · CPC title

• B32B27/08

  of synthetic resin · CPC title

• B32B2405/00

  Adhesive articles, e.g. adhesive tapes · CPC title

• C08F285/00

  Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers · CPC title