Polyimide film, polyimide varnish, and product and layered product using the polyimide film

A polyimide film containing:

• a polyimide expressed by a following general formula (1);
• and
• a structure expressed by a following general formula (A-1), and at least one or more of structures respectively expressed by a following general formula (A-2), a following general formula (A-3) and a following general formula (A-4), as A in the general formula (1),
• wherein among the general formulas (A-2) to (A-4), a general formula (A-5), consisting of the general formula (A-2) and a following general formula (X-1), is at least contained,
• wherein as B in the general formula (1), the polyimide film contains at least one of structures respectively expressed by from the following general formulas (B-1) to (B-4),
• wherein among the general formulas (B-1) to (B-4), a general formula (B-5), consisting of the following general formula (B-1) and a general formula (Y-1), is at least contained, as B in the general formula (1),
• wherein a content of γ-butyrolactone is at least 0.01 mass % and smaller than 3 mass %,
• wherein, in the general formula (1), A represents a bivalent organic group, B represents a tetravalent organic group, and n is 2 or more;
• in the general formula (A-2), X represents a bivalent organic group selected from following general formulas (X-1) to (X-3);
• in the general formula (A-3), a is 0 or 1;
• wherein, in the general formula (B-1), Y represents one of structures selected from following general formula (Y-1) to general formula (Y-3);
• wherein a Yellow Index (YI) is 4 or less,
• wherein the structure expressed by the general formula (A-1) is derived from 3,3′-diaminodiphenyl sulfone (3, 3′-DDS),
• wherein the structure expressed by the general formula (A-5) is derived from 4,4′-diaminodiphenyl sulfone (4, 4′-DDS),
• wherein the structure expressed by the general formula (B-5) is derived from 4,4′-oxydiphthalic dianhydride (ODPA), and
• wherein the 3,3′-DDS is provided at a molar ratio range of 20% to 80% of total constituents of the 3, 3′-DDS and the 4, 4′-DDS.