PURPOSE: To enable a superposed part to be cleaned and also the superposition to be performed without the necessity to apply a roughening process by forming a patch of a top layer part for adhesion which spreads along the back of a main part for repairing the broken spot of a finished product and covers part of the top part of a lower layer part adhesion forming the terminal of the patch extending fully over the external part.
CONSTITUTION: This patch for repairing a rubber or a plastic finished product comprises a main part 1 made of a vulcanized rubber for reinforcing a broken spot and a lower thin layer part for adhesion which is attached to the flat back face of the main part 1 and directly faces a finished product 3 to be repaired. In addition, the lower layer part for adhesion is formed of an unvulcanized rubber and is vulcanized by a promoter to be added through a vulcanization solution and sulfur eluted from the finished product to be repaired. The lower layer part for adhesion gradually spreads in every direction beyond the main part 1 and forms a vulcanized terminal 4. Further, the lower layer part for adhesion is additionally reinforced by the terminal of the main part 1 which forms a serrated pattern 5 spreading fully to the terminal of the lower layer part. The thin lower layer part 2 for adhesion on the back face of the patch which continues from the terminal 4 to the inside passes through the back face of the main part 1 and becomes a lower layer part 6 for adhesion connected to the lower layer part 2 with part of the top part of the main part 1 facing upward.