Adhesive film, optical member comprising same, and optical display device comprising same
Inventors
Kim, Do Young • Kim, Young Jong • Lee, Seung Hoon • CHO, Seong Heun • KIM, Il Jin
Assignees
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Publication Number
US-12344772-B2
Publication Date
2025-07-01
Expiration Date
Abstract
Provided are an adhesive film, an optical member comprising same, and an optical display device comprising same, the adhesive film comprising a (meth)acryl-based binder containing an aromatic group and a hydroxyl group, inorganic particles, and a trigger polymer, wherein the trigger polymer has a melting point of about 0° C. or more, the adhesive film has a haze of about 2% or less, and an adhesive film has a ratio of adhesive strength of about 10 or more according to Equation 1.
Core Innovation
The invention relates to an adhesive film that includes a (meth)acrylic based binder containing an aromatic group and a hydroxyl group, inorganic particles, and a trigger polymer. The trigger polymer is defined by a melting temperature (Tm) of about 0° C. or more, and the adhesive film is characterized by a low haze of about 2% or less.
The adhesive film further achieves an adhesive strength ratio of about 10 or more, calculated according to Equation 1 using initial adhesive strength (A) and adhesive strength (B) after the adhesive film is attached to a glass plate and left at 50° C. for 1,000 sec. The binder comprises a (meth)acrylic copolymer formed from a monomer mixture that includes a first aromatic group-containing (meth)acrylic monomer represented by Formula 1.
The adhesive film is also defined with specific adhesion targets, including an initial adhesive strength of about 100 gf/inch or less on glass and an adhesive strength of about 500 gf/inch or more after being left at 50° C. for 1,000 sec. The invention is documented as being used in optical members and optical display devices, including optical member structures that stack an LED panel and a touchscreen panel, with the adhesive film and an optical film.
Claims Coverage
The document provides two independent claims for an adhesive film. Across the independent claims, the inventive features consistently include the (meth)acrylic binder chemistry with aromatic and hydroxyl groups, inorganic particles, a trigger polymer with Tm of about 0° C. or more, low haze, and quantified adhesion performance measured by an adhesive strength ratio and/or explicit initial and post-attachment adhesive strength thresholds.
Adhesive film with (meth)acrylic binder containing aromatic and hydroxyl groups
An adhesive film comprising a (meth)acrylic based binder containing an aromatic group and hydroxyl group, inorganic particles and a trigger polymer.
Trigger polymer with melting temperature (Tm) of about 0° C. or more
The trigger polymer has a melting temperature (Tm) of about 0° C. or more.
Low haze of about 2% or less
The adhesive film has a haze of about 2% or less.
Adhesive strength ratio of about 10 or more based on Equation 1
The adhesive film has an adhesive strength ratio of about 10 or more, as calculated according to Equation 1 where A is initial adhesive strength with respect to a glass plate, and B is adhesive strength with respect to the glass plate after the adhesive film is attached to the glass plate and left at 50° C. for 1,000 sec.
Binder is a (meth)acrylic copolymer from a monomer mixture including Formula 1 aromatic monomer
The (meth)acrylic based binder comprises a (meth)acrylic copolymer of a monomer mixture, the monomer mixture comprising a first aromatic group-containing (meth)acrylic monomer represented by Formula 1.
Adhesive film with explicit adhesion thresholds on glass
The adhesive film has an initial adhesive strength of about 100 gf/inch or less with respect to a glass plate, and the adhesive film has an adhesive strength of about 500 gf/inch or more with respect to the glass plate after the adhesive film is attached to the glass plate and left at 50° C. for 1,000 sec.
Overall, the independent-claim coverage is directed to an adhesive film whose performance is jointly defined by (i) (meth)acrylic binder chemistry with aromatic and hydroxyl groups and a defined Formula 1 aromatic monomer structure, (ii) inorganic particles, (iii) a trigger polymer having Tm of about 0° C. or more, and (iv) low haze plus quantified adhesion behavior measured by the adhesive strength ratio and/or by explicit initial and post-attachment adhesive strength thresholds on glass.
Stated Advantages
Low haze of about 2% or less.
High adhesion after heat attachment, expressed by an adhesive strength ratio of about 10 or more and/or adhesive strength of about 500 gf/inch or more after being left at 50° C. for 1,000 sec.
Improved light extraction in optical members by reducing refractive-index mismatch at an interface portion between a touchscreen panel and the adhesive film using a patterned passivation layer.
Documented Applications
Optical members that include an LED panel, a touchscreen panel, the adhesive film, and an optical film, with a patterned passivation layer at an interface portion between the touchscreen panel and the adhesive film.
Optical display devices that include the adhesive film.
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