Curable resin compositions, prepregs, and their cured forms

Abstract

This invention provides a resin composition and its cured form exhibiting excellent copper foil adhesion and excellent modulus of elasticity. A curable resin composition contains a maleimide resin and an aprotic polar solvent, wherein the maleimide resin in the curable resin composition has the structure represented by formula (1) or formula (2), and the content of the aprotic polar solvent relative to the maleimide resin is 0.1% to 3.0% by weight. (In formulas (1) and (2), there are multiple X, R1, and p that exist independently. X represents any one of the structures represented by formulas (1-a) to (1-f) below; R1 represents an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 1 to 20 carbon atoms that may have substituents; p is an integer from 0 to 4; n is the average number of repetitions, and 1 < n < 10; formula (2) has structural units (a) and (b), which are bonded by * respectively, and the repetition position can be random; m and o are the average number of repetitions, and 1 ≦ m ≦ 1000 and 1 ≦ o ≦ 1000) (In formulas (1-a) to (1-f), multiple R2, R3, q, and t exist independently. R2 represents an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 1 to 20 carbon atoms that may have substituents. R3 represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 1 to 20 carbon atoms that may have substituents. q is an integer from 0 to 4, and t is an integer from 0 to 3. r is the average of the number of repetitions, and 1 < r < 10. * indicates the bond position.)