Pressure-sensitive adhesive tape
Provided are a pressure-sensitive adhesive tape, a polishing pad, a method of manufacturing the same, a polishing device and a method of manufacturing a glass substrate. The illustrative pressure-sensitive adhesive tape may be a pressure-sensitive adhesive tape for a polishing material. The pressure-sensitive adhesive tape may be effectively fixed to a surface plate without bubbles, and have excellent resistance to water and a polishing solution and shear strength applied in a polishing process. In addition, the pressure-sensitive adhesive tape may be easily removed from a carrier or surface plate for a polishing pad without residues after polishing.
1. A polishing pad, comprising:
a pressure-sensitive adhesive tape comprising a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer; and
a polishing material attached to the first pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape, wherein the polishing material includes a polyurethane-based polishing layer,
wherein the pressure-sensitive adhesive tape comprises:
a base layer;
the first pressure-sensitive adhesive layer located on one surface of the base layer; and
the second pressure-sensitive adhesive layer located on the other surface of the base layer, the second pressure-sensitive adhesive layer including an acid-free pressure-sensitive adhesive resin consisting of a lipophilic monomer represented by a compound of Formula 1 at 10 to 30 parts by weight, a (meth)acrylic acid ester monomer other than the lipophilic monomer represented by the compound of Formula 1 at 50 to 99 parts by weight, and a crosslinkable monomer not having a carboxyl group at 0.1 to 10 parts by weight, in a polymerized state,
wherein the first pressure-sensitive adhesive layer includes a pressure-sensitive adhesive resin consisting of a (meth)acrylic acid ester monomer other than the lipophilic monomer represented by the compound of Formula 1:
where R 1 to R 3 are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, R 4 is an aryl group having 6 to 25 carbon atoms or —C(═O)—O—X, where X is a methyl group, a tert-butyl group, or a cycloalkyl group having 6 to 12 carbon atoms,
at 50 to 99 parts by weight and a crosslinkable monomer at 0.1 to 10 parts by weight in a polymerized state,
wherein the acid-free pressure-sensitive adhesive resin is a pressure-sensitive adhesive not having a carboxyl group,
wherein the acid-free pressure-sensitive adhesive resin has a molecular weight (Mw) of from 800,000 to 2,000,000, and
wherein according to Equation 1:
Gel fraction (%)= B/A× 100 [Equation 1]
where A is a weight of the pressure-sensitive adhesive layer, and B is a dry weight of an insoluble content obtained after the pressure-sensitive adhesive layer having the weight A is precipitated in ethyl acetate at room temperature for 48 hours,
the first pressure-sensitive adhesive layer has a gel fraction according to Equation 1 of 40 to 48%, and
the second pressure-sensitive adhesive layer has a gel fraction according to Equation 1 of 65 to 76%.
2. The polishing pad according to claim 1 , wherein the first pressure-sensitive adhesive layer includes a pressure-sensitive adhesive resin and a tackifier having a glass transition temperature or softening point of 85° C. or more.
3. The tape polishing pad according to claim 2 , wherein the first pressure-sensitive adhesive layer includes the tackifier at 1 to 70 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin.
4. The polishing pad according to claim 2 , wherein the tackifier is a hydrocarbon resin or hydrogenated product thereof, a rosin resin or hydrogenated product thereof, a rosin ester resin or hydrogenated product thereof, a terpene resin or hydrogenated product thereof, a terpene phenol resin or hydrogenated product thereof, a polymerized rosin resin, or a polymerized rosin ester resin.
5. The polishing pad according to claim 2 , wherein the first pressure-sensitive adhesive layer further includes a multifunctional crosslinking agent at 0.001 to 7 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin.
6. The polishing pad according to claim 1 , wherein the second pressure-sensitive adhesive layer further includes a multifunctional crosslinking agent at 0.01 to 10 parts by weight with respect to 100 parts by weight of the acid-free pressure-sensitive adhesive resin.
7. The tape polishing pad according to claim 1 , wherein the second pressure-sensitive adhesive layer further includes a plasticizer at 0.5 to 30 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin.
8. A polishing device, comprising:
a stand on which a target to be polished is loaded; and
a carrier or surface plate for a polishing pad to which the polishing pad of claim 1 is attached by the second pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape.
9. A method of manufacturing a polishing pad, comprising:
attaching a polishing material to the first pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the polishing pad of claim 1 at 50° C. or more.
10. The method according to claim 9 , wherein the attaching of the first pressure-sensitive adhesive layer to the polishing material is performed by a hot-roll lamination method.
11. A method of manufacturing a polished glass substrate, comprising:
polishing a surface of a glass substrate using the polishing pad of claim 1 .
12. The method according to claim 11 , wherein the polished glass substrate is a glass substrate manufactured in a floating type.
13. The method according to claim 11 , wherein the polished glass substrate is a glass substrate for a liquid crystal display (LCD).