Pressure-sensitive adhesive composition

A surface protective film comprising:

• a base layer for surface protection;
• and
• a pressure-sensitive adhesive layer on the base layer,
• wherein the surface protective film is capable of being detachably attached on a surface to be protected,
• wherein the pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive composition in a cross-linked state, and the pressure-sensitive adhesive composition comprises:
• a polymer;
• and
• a compound represented by the Formula 3,
• wherein the polymer consists of:
• a polymerization unit of an alkyl (meth)acrylate;
• a polymerization unit of a monomer represented by the Formula 1 and/or a monomer containing a nitrogen atom;
• a polymerization unit of a first monomer, which is represented by the Formula 2 and in which the number of carbon atom of alkylene groups A and B of the Formula 2 is from 1 to 3;
• and
• a polymerization unit of a second monomer, which is represented by the Formula 2 and in which the number of carbon atom of alkylene groups A and B of the Formula 2 is from 4 to 8,
• wherein the ratio of the weight of the first monomer to the weight of the second monomer is in a range of about 2.5 to 25,
• wherein the polymerization unit of the first monomer is in an amount at 1 to 25 parts by weight, and the polymerization unit of the second monomer is in an amount at 0.1 to 3 parts by weight,
• wherein the alkyl (meth)acrylate consists of at least one selected from methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and
• wherein the pressure-sensitive adhesive composition in the cross-linked state has a low-speed peel strength measured at a peel angle of 180 degrees and a peel rate of 0.3 m/min with respect to an adherend having a surface energy of 30 mN/m or less in a range of about 1 to 40 gf/25mm, and has a high-speed peel strength measured at a peel angle of 180 degrees and a peel rate of 30 m/min with respect to an adherend having a surface energy of 30 mN/m or less in a range of about 10 to 150 gf/25mm,
• wherein
• wherein Q of the Formula 1 represents hydrogen, or an alkyl group, U represents an alkylene group, Z represents hydrogen, an alkyl group, or an aryl group, m is a number ranging from 1 to 20;
• wherein
• wherein M1 to M5 of Formula 3 are each independently R1—N, (R2) (R3)-C, or (R4) (R5)—C where R1 represents hydrogen, an alkyl group, or alkoxy group, R2 and R3 each independently represent an alkyl group, and R4 and R5 each independently represent hydrogen, or an alkyl group, L represents an alkylene group, or an alkylidene group, and P represents an alkyl group, or a substituent represented by the following Formula 4, provided that at least one of M2 to M4 in Formula 3 is R1-N, and Ml, M2, M3, M4 or M5 present directly adjacent to M2, M3 or M4 that is R1—N is (R2)(R3)—C;
• wherein
• wherein M6 to M10 each independently represent R1—N, (R2)(R3)—C, or (R4)(R5)—C where R1 represents hydrogen, an alkyl group, or an alkoxy group, R2 and R3 each independently represent an alkyl group, and R4 and R5 each independently represent hydrogen, or an alkyl group, provided that at least one of M7 to M9 in Formula 4 is R1—N, and M6, M7, M8, M9 or M10 present directly adjacent to M7, M8 or M9 that is R1—N is (R2)(R3)—C;
• and
• wherein
• wherein Q of the Formula 2 represents hydrogen, A and B each independently represent an alkylene group, and n is a number ranging from 0 to 10.