Cross-linkable adhesive compound with hard and soft blocks as a permeant barrier

Patent metadata

Field	Value
Publication number	US-9487684-B2
Application number	US-201314389596-A
Country	US
Kind code	B2
Filing date	Mar 25, 2013
Priority date	Apr 17, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Adhesive compound as a permeant barrier, comprising (i) block copolymers having a construction A-B-A, (A-B) n , (A-B) n X, or (A-B-A) n X, where X is the radical of the coupling reagent, n is a whole number between 2 and 10, A is a polymer made of a vinyl aromatic compound and B is a polymer block made of an alkene or diene, wherein this polymer block can also be hydrated, with the condition that at least part of the A blocks is sulfonated, optionally with two-block copolymers in the form of A-B as an admixture component, and (ii) at least one tackifier resin.

First claim

The invention claimed is:

1. An adhesive comprised of
(i) block copolymers and also mixtures thereof, having an A-B-A, (A-B) n X, or (A-B-A) n X construction, where X is the radical of a coupling reagent, n is an integer between 2 and 10, A is a polymer block of a vinylaromatic, and B is a polymer block of an alkene or diene, and where the A blocks are sulfonated to the extent of 0.5 to 50 mol %, based on the total monomer units of the A blocks, and diblock copolymers of the form A-B optionally as admixture component, and
(ii) at least one tackifier resin.

2. The adhesive as claimed in claim 1 , wherein B is a hydrogenated polymer block of an alkene or diene.

3. The adhesive as claimed in claim 1 wherein 0.5 to 50 mol % of the block copolymers are in the form of sulfonated copolymers and have sulfonated A blocks, the aromatic moieties of which are sulfonated to an extent of 0.5 to 20 mol % per mole of the monomer unit, based on the total monomer units of the A blocks in the sulfonated copolymer.

4. The adhesive as claimed in claim 1 , further comprising (iii) at least one metal complex with a substitutable complexing agent.

5. The adhesive as claimed in claim 1 , wherein the admixture component is a diblock copolymer of the form A-B, a copolymer with polymer blocks A′ of vinylaromatics and polymer blocks B′ of an alkene or diene.

6. The adhesive as claimed in claim 1 , wherein (i) the A blocks each independently have a T g of more than 40° C. and the B blocks each independently have a T g of less than 0° C.

7. The adhesive as claimed in claim 1 , wherein the B blocks independently are homopolymers or copolymers of monomers selected from the group consisting of ethylene, propylene and 1,3-dienes.

8. The adhesive as claimed in claim 1 , wherein the B blocks are at least partially hydrogenated.

9. The adhesive as claimed in claim 1 , wherein the A blocks independently are homopolymers or copolymers of monomers of at least one vinylaromatic.

10. The adhesive as claimed in claim 1 , wherein the metal complex with a substitutable complexing agent corresponds to a metal chelate of the formula I,
(R 1 O) n M(XR 2 Y) m   (I)

where M is a metal selected from the group consisting of metals of main groups 2, 3, 4, and 5 of the Periodic Table of the Elements and from the transition metals, and R 1 is an alkyl or aryl group,
n is 0 or a larger integer
X and Y in the chelate ligand (XR 2 Y) independently are oxygen or nitrogen, which are optionally bonded to R 2 by a double bond,
R 2 is an alkylene group which joins X and Y and which is linear or branched, and optionally has heteroatom(s) in the alkylene group, nitrogen, or sulfur;
m is an integer, but is at least 1.

11. The adhesive as claimed in claim 10 , wherein the chelate ligand in the metal chelate is formed from the reaction of at least one of the compounds selected from the group consisting of triethanolamine, 2,4-pentanedione, 2-ethyl-1,3-hexanediol and lactic acid.

12. The adhesive as claimed in claim 1 , wherein the overall composition of the adhesive contains
(ii) at 10 to 70 wt %, at least one tackifier resin, and/or an epoxy resin, and
(iii) at least one metal complex with a substitutable complexing agent, and optionally
(iv) up to 20 wt %, a plasticizer, and
(v) 0.0 to 20 wt %, fillers, additives, photoinitiators, accelerators and/or curing agents,
(vi) up to 60 wt %, a reactive resin, and
(i) the block copolymers and/or mixtures comprising them, to 100 wt %.

13. The adhesive as claimed in claim 8 , wherein the fraction in wt % of the vinylaromatics of the A blocks in the (i) copolymer in relation to the overall composition of the adhesive is at least 20 to 85 wt %.

14. The adhesive as claimed in claim 1 , wherein the molar ratio of the sulfonic acid groups in the (i) sulfonated copolymer to the ligand (XR 2 Y) in the (iii) metal complex of the formula I is in the range from 1:3 to 3:1, with a fluctuation range of plus/minus 0.5.

15. The adhesive as claimed in claim 1 , having a SAFT of greater than or equal to 150° C.

16. The adhesive as claimed in claim 1 , comprising as tackifier resins at least one hydrogenated hydrocarbon resin.

17. The adhesive as claimed in claim 1 , comprising an epoxy resin, an acrylate and/or a methacrylate, and wherein the adhesive, optionally together with at least one reactive resin, comprises at least one photoinitiator absorbing UV light below 350 nm.

18. The adhesive as claimed in claim 1 , wherein the chelate-crosslinked adhesive has a WVTR of less than or equal to 100 g/m 2 ·d, and/or the chelate-crosslinked adhesive has an OTR of less than or equal to 3000 g/m 2 ·d·bar.

19. The adhesive as claimed in claim 1 , said adhesive being a pressure-sensitive adhesive or a hotmelt adhesive.

20. A process for producing an adhesive which comprises mixing
(i) block copolymers and also mixtures thereof, having an A-B-A, (A-B) n X, or (A-B-A) n X construction, where X is the radical of a coupling reagent, n is an integer between 2 and 10, A is a polymer block of a vinylaromatic, and B is a polymer block of an alkene or diene, this polymer block being hydrogenated, with the proviso that at least some of the A blocks are sulfonated, and diblock copolymers of the form A-B, optionally, as admixture component, and
(ii) at least one tackifier resin.

21. The process for producing an adhesive as claimed in claim 20 , wherein additionally
(iii) at least one metal complex with a substitutable complexing agent and optionally as (ii) tackifier resin a substantially fully hydrogenated hydrocarbon resin, (iv) a plasticizer, and optionally (v) a filler, additive, accelerator, photoinitiator and/or optionally (vi) a reactive resin, together with at least one photoinitiator, are added.

22. An adhesive obtainable by a process according to claim 20 .

23. A method for applying the adhesive of claim 1 to an element, wherein the adhesive is partially crosslinked prior to application or is partially crosslinked or crosslinked to completion after application, by heating of the adhesive and/or of the element before, during, or after the application of the adhesive to the element.

24. The method of claim 23 , wherein the adhesive is thermally partially crosslinked prior to an application, and following the application, crosslinking to completion is accomplished thermally and/or with UV light after the application.

25. An adhesive assembly for formation of temperature-stable barrier layers, having a SAFT of greater than or equal to 180° C., for preventing the diffusion of permeants, for encapsulating an electronic arrangement, or for encapsulating an optoelectronic arrangement, wherein said assembly comprises the adhesive of claim 1 .

26. A sheetlike bonding means comprising the adhesive of claim 1 , the sheetlike bonding means being a sheetlike element of the adhesive or an adhesive tape, the adhesive tape having a carrier and, on at least one side of the carrier, the applied adhesive, and the adhesive of the sheetlike bonding means being substantially dried.

Assignees

• Tesa Se

Inventors

• Krawinkel Thorsten
• Keite-Telgenbüsher Klaus
• Grünauer Judith
• Ellinger Jan

Classifications

• C08F8/36

  Sulfonation; Sulfation · CPC title

• C09J5/06

  involving heating of the applied adhesive · CPC title

• C09J153/00

  Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers · CPC title

• C09J153/025 Primary

  modified · CPC title

• C09J11/06

  organic · CPC title