Synthetic resin cap, closing device, and container-filled beverage

A closing device, comprising:

• a container having a container opening;
• and
• a synthetic resin cap fitted in the container opening and having:
• a cap body having a top plate and a cylindrical section extending downward from a periphery thereof and having, in an inner peripheral surface thereof, a threaded section that engages with a thread of the container opening;
• and
• a circular inner seal projection formed integrally with the cap body on an inner surface of the top plate and fitting into the container opening, wherein
• an angle of circumference along which the threaded section is formed is from 680° to 720°;
• the threaded section is divided by dividing sections into a plurality of divided threaded sections each having substantially an equal circumferential formation angle;
• the dividing sections are provided around an entire circumference of the threaded section at substantially equal intervals selected from 45° to 90° in the circumferential direction;
• and
• the divided threaded section which is immediately below the divided threaded section at the nearest position to the top plate and the divided threaded section which is immediately above the divided threaded section at the farthest position from the top plate are formed continuously by a connecting section which has substantially the same circumferential formation angle as that of the dividing sections.

A container-filled beverage in which a beverage is filled inside a closing device comprising:

• a container having a container opening;
• and
• a synthetic resin cap having:
• a cap body having a top plate and a cylindrical section extending downward from a periphery thereof and having, in an inner peripheral surface thereof, a threaded section that engages with a thread of the container opening;
• and
• a circular inner seal projection formed integrally with the cap body on an inner surface of the top plate and fining into the container opening, wherein
• an angle of circumference along which the threaded section is formed is from 680° to 720°;
• the threaded section is divided by dividing sections into a plurality of divided threaded sections each having substantially an equal circumferential formation angle;
• the dividing sections are provided around an entire circumference of the threaded section at substantially equal intervals selected from 45° to 90° in the circumferential direction;
• and
• the divided threaded section which is immediately below the divided threaded section at the nearest position to the top plate and the divided threaded section which is immediately above the divided threaded section at the farthest position from the top plate are formed continuously by a connecting section which has substantially the same circumferential formation angle as that of the dividing sections.