Electrically debondable UV activated adhesives

Patent metadata

Field	Value
Publication number	US-12545813-B2
Application number	US-202418631645-A
Country	US
Kind code	B2
Filing date	Apr 10, 2024
Priority date	Oct 10, 2022
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

Curable and cured compositions as well as articles containing the curable or cured compositions are provided. The cured compositions are typically a semi-structural or structural adhesive. Advantageously, the cured compositions can be removed (e.g., de-bonded) from the various surfaces of the articles after the useful lifetime of the articles, to correct misplacement of a part during manufacturing, or to repair the electronic device. The separation step occurs using a direct current electric potential across the cured composition.

First claim

What is claimed is:

1 . A curable composition comprising:
a film forming polymeric material; an epoxy resin; a photoacid generator; and an ionic liquid that has a melting point less than 100 degrees Celsius and that has an anion selected from SbF 6 − , PF 6 − , or a mixture thereof.

2 . The curable composition of claim 1 wherein the film forming polymeric material comprises a (meth)acrylic-based block copolymer, a statistical (meth)acrylic-based copolymer, or a combination thereof.

3 . The curable composition of claim 1 wherein the curable composition comprises (meth)acrylic-based block copolymer, wherein the (meth)acrylic-based block copolymer is a triblock copolymer of formula A-B-A with the A blocks microphase separating from the B block, wherein the A block has a glass transition temperature equal to at least 50 degrees Celsius and the B block has a glass transition temperature equal to no greater than 20 degrees Celsius as measured using Dynamic Mechanical Analysis.

4 . The curable composition of claim 2 wherein the curable composition comprises 10 to 40 weight percent of the (meth)acrylic-based block copolymer based on a total weight of resin components in the curable composition.

5 . The curable composition of claim 2 wherein the curable composition comprises greater than 40 wt. % of the (meth)acrylic-based block copolymer based on a total weight of resin components in the curable composition.

6 . The curable composition of claim 2 wherein the curable composition comprises statistical (meth)acrylic-based copolymer having a glass transition temperature no greater than 20 degrees Celsius when measured using Dynamic Mechanical Analysis.

7 . The curable composition of claim 2 wherein the statistical (meth)acylate-based copolymer is crosslinked.

8 . The curable composition of claim 2 wherein the curable composition contains 20 to 60 weight percent of the statistical (meth)acrylic-based copolymer based on a total weight of resin components in the curable composition.

9 . The curable composition of claim 2 wherein the curable composition comprises greater than 60 weight percent up to 90% of the statistical (meth)acrylic-based copolymer based on a total weight of resin components in the curable composition.

10 . The curable composition of claim 2 wherein the statistical (meth)acrylic-based copolymer comprises monomeric units derived from a (meth)acrylate macromer having a number average molecular weight of at least 300 Daltons, a polyol, or a combination thereof.

11 . The curable composition of claim 1 wherein the statistical (meth)acrylic-based comprises at least 10 wt. % of polymerized units of a (meth)acrylate monomer having a Tg of at least 30° C.

12 . The curable composition of claim 1 wherein the film forming polymeric material comprises polyurethane, polyester, polyvinyl acetal, a block copolymer of styrene and isoprene or butadiene, or a combination thereof.

13 . The curable composition of claim 1 wherein the film forming polymeric material has a molecular weight greater than 50,000 Daltons.

14 . The curable composition of claim 1 wherein the photoacid generator is an aryl-containing iodonium salt or a triaryl sulfonium salt.

15 . The curable composition of claim 1 wherein the ionic liquid is an ammonium salt of Formula (VI), a sulfonium salt of Formula (VII), an imidazolium salt of Formula (VIII), a pyridinium salt of Formula (IX), or a pyrrolidinium salt of Formula (X)

wherein
each R 20 , R 21 , R 22 , R 23 , and R 24 is independently an alkyl, a hydroxy-substituted alkyl, or an ether-containing group of formula —(R 30 —O) y —R 31 wherein R 30 is an alkylene, R 31 is an alkyl, and y is an integer in a range of 1 to 10; and
X − is SbF 6 − or PF 6 − .

16 . A first article comprising:
a layer of a curable composition according to claim 1 wherein the curable composition has a first surface and a second surface opposite the first surface; and a first substrate or a first release liner positioned adjacent to a first surface of the first curable composition.

17 . The first article of claim 16 wherein the layer of curable composition comprises an electrically conductive layer.

18 . A second article comprising:
a first substrate; a second substrate; and a layer of cured composition of claim 1 positioned between the first substrate and the second substrate, wherein the first substate is bonded to the second substrate with the first cured composition.

19 . The second article of claim 18 wherein the first substrate, the second substrate, or both are electrically conductive or the layer of cured composition comprises an electrically conductive layer.

20 . A method for separating the second article of claim 18 the comprising applying a direct current electric potential across the cured composition to separate the first substrate from the second substrate.

Assignees

• 3M Innovative Properties Company

Inventors

• Moughton Adam O
• Maher Michael J
• Satrijo Andrew
• Janoski Jonathan E
• Hedegaard Aaron T
• Shafer Kathleen S
• Volp Kelly A
• Kennedy Michael K
• Lhila Ramesh C

Classifications

• C09J2453/00

  Presence of block copolymer · CPC title

• C09J2400/163

  in the substrate · CPC title

• C08L2203/20

  use in electrical or conductive gadgets · CPC title

• C08L51/006

  grafted on to block copolymers containing at least one sequence of polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C08K2201/001

  Conductive additives · CPC title