Double-sided tape for touch screen panel and manufacturing method thereof

1. A method for manufacturing a double-sided tape for a touch screen panel, comprising:

preparing a base film and coloring the base film black;

disposing a shock resistant filler layer on an upper side of the base film by coating a paste including an acrylic binder and a shock resistant filler having a plurality of hollow fine particles;

disposing first and second adhesive layers on an upper side of the shock resistant filler layer and a lower side of the base film, respectively; and

disposing a release layer on a lower side of the second adhesive layer,

wherein the plurality of hollow fine particles are manufactured by the steps of:

preparing a hydrocarbon dispersion by adding 2-20 parts by weight of liquid hydrocarbon with respect to a total of 100 parts by weight of the hollow fine particles and a dispersing agent having a surfactant into water;

preparing a particulate crystal by adding 15-40 parts by weight of a thermoplastic material into the hydrocarbon dispersion, with respect to the total of 100 parts by weight of the hollow fine particles, and forming a first coating film by the thermoplastic material surrounding the dispersed liquid hydrocarbon;

forming an unexpanded microsphere by heating the particulate crystal and removing the dispersed liquid hydrocarbon; and

forming an expanded microsphere constituting each of the plurality of hollow fine particles by heating the unexpanded microsphere and expanding the first coating film.

2. The method of claim 1 , wherein the plurality of hollow fine particles are manufactured by further the step of arranging a second coating film containing 50-80 parts by weight of calcium carbonate with respect to the total of 100 parts by weight of the hollow fine particles, on a circumference of the first coating film of the expanded microsphere.

3. The method for of claim 2 , wherein the step of forming the second coating film comprises the steps of:

inputting the expanded microsphere and the calcium carbonate into a reactor, and inserting air thereto at a temperature of 130-150° C., thereby floating the expanded microsphere and the calcium carbonate inside the reactor; and

forming the second coating film by embedding the calcium carbonate on an outer wall of the first coating film of the expanded microsphere.

4. The method of claim 1 , wherein, in the step of preparing the hydrocarbon dispersion, the liquid hydrocarbon comprises 1-10 parts by weight of 2-methylbutane and 1-10 parts by weight of 2-methylpropane, with respect to the total of 100 parts by weight of the hollow fine particles.

5. The method for of claim 1 , wherein the thermoplastic material is a copolymer of acrylonitrile and one or more of phosphate methacrylate and alkali strippable polyester acrylate, in the step of preparing the particulate crystal.

6. The method of claim 1 , wherein the unexpanded microsphere is heated at a temperature of 70-190° C., in the step of forming the expanded microsphere.

7. The method of claim 1 , wherein at least one of carbon black and iron sulfide is used as a black coloring agent, in the step of coloring the base film black.

8. The method of claim 1 , wherein the shock resistant filler contains 5-60 parts by weight with respect to 100 parts by weight of the acrylic binder, in the step of disposing the shock resistant filler layer.