Pressure-sensitive adhesive composition for foldable display

Patent metadata

Field	Value
Publication number	US-10920113-B2
Application number	US-201716331767-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 9, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

The pressure-sensitive adhesive composition of the present application has excellent bending reliability, and also excellent adhesive force and cohesive force.

First claim

The invention claimed is:

1. A pressure-sensitive adhesive composition for a foldable display comprising:
a first pressure-sensitive adhesive comprising a first silicone gum and a first MQ resin, and having a peel force on a glass substrate of 10 gf/in or less, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees;
a second pressure-sensitive adhesive comprising a second silicone gum and a second MQ resin and having a peel force on a glass substrate of 200 gf/in to 400 gf/in, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees;
and
any one additive selected from the group consisting of a borane compound, a borate compound and a mixture thereof, and
wherein MQ resin is a silicone compound having at least a three-dimensional reticular steric molecular structure comprising a monofunctional siloxane unit (M Unit) and a tetrafunctional siloxane unit (Q unit).

2. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein a peel force of a pressure-sensitive adhesive layer formed by curing the pressure-sensitive adhesive composition on a glass substrate, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees is 20 gf/in or more.

3. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the first or second silicone gum is represented by Formula 1 below:

wherein, R 1 and R 6 are each independently a silyl group or silanol group with or without an alkyl group, an alkenyl group or an aryl group, R 2 to R 5 are each independently an alkyl group, an alkenyl group or an aryl group, and n and m are each independently an integer in a range of 1 to 10,000.

4. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the first pressure-sensitive adhesive comprises the first MQ resin in a content of less than 5 wt %.

5. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the first silicone gum has a number average molecular weight in a range of 400,000 to 800,000.

6. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the first silicone gum has a vinyl group content in a range of 0.5 to 1 mol %.

7. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the first pressure-sensitive adhesive is contained in a range of 5 wt % to 50 wt % relative to the total solid content of the composition.

8. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the second pressure-sensitive adhesive comprises the second MQ resin in a content of 40 wt % or less.

9. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the second silicone gum is a linear polydimethylsiloxane containing hydroxy groups at both ends.

10. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the borane compound is represented by Formula 3 below:

wherein, R 4 to R 6 are each independently hydrogen, halogen, an alkyl group having 1 to 6 carbon atoms, or a silyl group.

11. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the borate compound is represented by Formula 4 below:

wherein, R 7 to R 9 are each independently hydrogen, halogen, an alkyl group having 1 to 6 carbon atoms, or a silyl group.

12. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the additive is contained in a range of 0.01 to 5 wt % relative to the total solid content of the pressure-sensitive adhesive composition.

13. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein a storage elastic modulus (G′) after curing is 5×10 6 Pa or less within a temperature range of −40° C. to 90° C.

14. A foldable display comprising a pressure-sensitive adhesive layer which is a cured product of a pressure-sensitive adhesive composition for a foldable display of claim 1 attached to an adherend.

15. The foldable display according to claim 14 ,
wherein the pressure-sensitive adhesive layer has a peel force on the adherend of 2,000 gf/in or more, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees.

Assignees

• Lg Chemical Ltd

Inventors

• Park Hyon Gyu
• Roh Dong Kyu
• Kwon Yoon Kyung
• Park Byung Su
• Lee Hui Je

Classifications

• C09J2301/408

  additives as essential feature of the adhesive layer · CPC title

• G06F1/16

  Constructional details or arrangements · CPC title

• C09J183/04 Primary

  Polysiloxanes · CPC title

• C09J2203/326

  for bonding electronic components such as wafers, chips or semiconductors · CPC title

• C09J11/06

  organic · CPC title