Heat-resistant receptacle cap

A heat-resistant receptacle cap, comprising:

• an inner cap, having a first diameter configured to be fitted onto an inlet of a receptacle with a locking hook, a discharge gate connected to the first diameter by a second diameter at a lower base of the inner cap and formed so that contents in the receptacle are discharged at the second diameter, and a container installed at a bottom of the second diameter and has an open upper part to hold additives therein, wherein the second diameter is smaller than the first diameter;
• a heat-resistant membrane seal, configured to heat-seal the first diameter and an upper wall of the container;
• a membrane seal holder, having a fitting ring that fits the heat-resistant membrane seal to a corresponding part for coupling the membrane seal;
• and
• an outer cap, having a membrane seal holder fixing step that is formed on a side wall and configured to separate the membrane seal holder as the receptacle is opened,
• wherein the membrane seal holder is fitted at an upper end of an inner side wall of the outer cap,
• wherein the locking hook is configured to have a horizontal part bent toward an outside of the first diameter and a vertical part that bends downward from an outside of the horizontal part and forms a hook at a lower end of an inner side thereof,
• wherein the hook formed by the vertical part is configured to be coupled to an outer groove at an outside of an upper end of the inlet of the receptacle, and
• wherein an outer hook protrudes from the upper end of the inlet due to the outer groove.