Highly elastic aqueous adhesive composition and method of surface-treating molded article using the same
Disclosed are a adhesive composition and a method of surface-treating a molded article using the same. In particular, the adhesive composition may be eco-friendly because smell and VOC generation from the organic solvent are reduced by adding a water-dilutable polyurethane resin having a hydroxyl group to a waterborne polyurethane resin, thereby improving properties such as elastic recoverability and scratch resistance while satisfying conventional properties.
1. An adhesive composition comprising:
an amount of about 10 to 23.1% by weight of a water-dilutable polyurethane resin having a hydroxyl group;
an amount of about 20 to 40% by weight of a waterborne polyurethane resin;
an amount of about 5 to 20% by weight of a hardener;
an amount of about 3 to 10% by weight of an extender pigment;
an amount of about 0.1 to 5.0% by weight of a wetting agent;
an amount of about 0.1 to 3.0% by weight of a slip agent;
an amount of about 0.1 to 2.0% by weight of an antifoaming agent;
an amount of about 0.01 to 2.00% by weight of a hardening accelerator;
an amount of about 0.5 to 5.0% by weight of a light stabilizer;
an amount of about 0.1 to 3.0% by weight of a thickener; and
an amount of about 20 to 40% by weight of a solvent;
all the % by weight based on the total weight of the adhesive composition,
wherein the water-dilutable polyurethane resin having a hydroxyl group comprises: a) an amount of about 1 to 10% by weight of isocyanate having two or more functional groups on average; b) an amount of about 2.21 to 9.93% by weight of dimethylpropionic acid; c) an amount of about 55 to 80% by weight of polyester polyol; d) an amount of about 5 to 20% by weight of solvent and e) an amount of about 1 to 5% by weight of neutralizing agent, all the % by weight based on the total weight of the water-dilutable polyurethane resin having a hydroxyl group.
2. The adhesive composition according to claim 1 , wherein the isocyanate having two or more functional groups on average is one or more selected from the group consisting of toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and multi-functional isocyanate derived therefrom.
3. The adhesive composition according to claim 1 , wherein a weight-average molecular weight (Mw) of the polyester polyol is of about 500 to 5000.
4. The adhesive composition according to claim 1 , wherein the solvent is one or more selected from the group consisting of N-methylpyrrolidone, acetone, methylethylketone, dimethylformamide, glycoletherester and hydrogenated furan.
5. The adhesive composition according to claim 1 , wherein the neutralizing agent is N-methyldiethanolamine, triethanolamine or a mixture thereof.
6. The adhesive composition according to claim 1 , wherein the waterborne polyurethane resin comprises one or more polyols selected from the group consisting of polyacrylic polyol, polyester polyol and polycarbonate polyol.
7. The adhesive composition of claim 1 , consisting essentially of:
an amount of about 10 to 23.1% by weight of a water-dilutable polyurethane resin having a hydroxyl group;
an amount of about 20 to 40% by weight of a waterborne polyurethane resin;
an amount of about 5 to 20% by weight of a hardener;
an amount of about 3 to 10% by weight of an extender pigment;
an amount of about 0.1 to 5.0% by weight of a wetting agent;
an amount of about 0.1 to 3.0% by weight of a slip agent;
an amount of about 0.1 to 2.0% by weight of an antifoaming agent;
an amount of about 0.01 to 2.00% by weight of a hardening accelerator;
an amount of about 0.5 to 5.0% by weight of a light stabilizer;
an amount of about 0.1 to 3.0% by weight of a thickener; and
an amount of about 20 to 40% by weight of a solvent;
all the % by weight based on the total weight of the adhesive composition.
8. The adhesive composition according to claim 7 , wherein the water-dilutable polyurethane resin having a hydroxyl group consists essentially of: a) an amount of about 1 to 10% by weight of the isocyanate having two or more functional groups on average; b) an amount of about 1 to 10% by weight of the hydrophilic polyol having two or more functional groups on average; c) an amount of about 55 to 80% by weight of the polyester polyol; d) an amount of about 5 to 20% by weight of the solvent; and e) an amount of about 1 to 5% by weight of the neutralizing agent, all the % by weight based on the total weight of the water-dilutable polyurethane resin having a hydroxyl group.
9. The adhesive composition of claim 1 , consisting of:
an amount of about 10 to 23.1% by weight of a water-dilutable polyurethane resin having a hydroxyl group;
an amount of about 20 to 40% by weight of a waterborne polyurethane resin;
an amount of about 5 to 20% by weight of a hardener;
an amount of about 3 to 10% by weight of an extender pigment;
an amount of about 0.1 to 5.0% by weight of a wetting agent;
an amount of about 0.1 to 3.0% by weight of a slip agent;
an amount of about 0.1 to 2.0% by weight of an antifoaming agent;
an amount of about 0.01 to 2.00% by weight of a hardening accelerator;
an amount of about 0.5 to 5.0% by weight of a light stabilizer;
an amount of about 0.1 to 3.0% by weight of a thickener; and
an amount of about 20 to 40% by weight of a solvent;
all the % by weight based on the total weight of the adhesive composition.
10. A method of surface-treating a molded plastic article for vehicle interior materials, the method comprising:
applying an adhesive composition of claim 1 to the molded plastic article; and
applying a pile on the molded plastic article.
11. The method according to claim 10 , wherein the adhesive composition is spread in a thickness of about 30 to 40 μm.
12. The method according to claim 10 , wherein the pile is a nylon/polyester partition yarn.