Pressure-sensitive adhesive composition for foldable display
The present application relates to a pressure-sensitive adhesive composition for a foldable display and a use thereof. The pressure-sensitive adhesive composition of the present application has excellent bending reliability while having appropriate adhesive force and cohesive force, thereby being useful for forming a pressure-sensitive adhesive layer for a foldable display having improved release force.
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, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees, of 10 gf/in or less; and
a second pressure-sensitive adhesive comprising a second silicone gum and a second MQ resin, and having a peel force on a glass substrate, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees, of 200 gf/in to 400 gf/in,
wherein said first pressure-sensitive adhesive is contained in an amount of 5 wt % to 50 wt % relative to the total solid content of the composition,
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), and
the composition satisfies Equation 1 below:
A< 20 gf/in [Equation 1]
wherein, A means a peel force of a pressure-sensitive adhesive layer formed by curing the pressure-sensitive adhesive composition on a fluorine-based release film, as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees.
2. 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.
3. 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 %.
4. 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.
5. 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 1.5 mol %.
6. The pressure-sensitive adhesive composition for a foldable display according to claim 1 ,
wherein the second pressure-sensitive adhesive has a storage elastic modulus measured at −40° C. of 10 Pa or less.
7. 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.
8. 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.
9. 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.
10. A foldable display comprising a pressure-sensitive adhesive layer which is a cured product of the pressure-sensitive adhesive composition for a foldable display of claim 1 attached to an adherend.
11. The foldable display according to claim 10 ,
wherein the adherend is a base film, and said base film and said pressure-sensitive adhesive layer form covalent bonds via silanol groups contained in said pressure-sensitive adhesive layer.
12. The foldable display according to claim 10 ,
wherein the pressure-sensitive adhesive layer has a peel force on the adherend as measured at a peel rate of 0.3 m/min and a peel angle of 180 degrees of 2,000 gf/in or more.