Waterproof tape for automobile battery and manufacturing method thereof
The present invention provides a waterproof tape for an automobile battery which comprises a filler layer having formed on one side of a base film to exhibit excellent viscosity while being thin and has excellent shock resistance and an excellent waterproof property, and a manufacturing method.
1. A method for manufacturing a waterproof tape for an automobile battery, comprising:
preparing a base film;
disposing an adhesive layer on one side of the base film; and
disposing a filler layer on another 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,
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 forming a second coating film with 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 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 a 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 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, in the step of preparing the hydrocarbon dispersion.
5. The method 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 the base film is colored with the black coloring agent having at least one of carbon black and iron sulfide in the step of preparing the base film.
8. The method of claim 1 , wherein the filler layer is colored with the black coloring agent having at least one of carbon black and iron sulfide in the step of disposing the filler layer.