Lignin-modified novolac-type phenol resin, method for producing same, molding material, resin composition, and grindstone

A method for producing a lignin-modified novolac-type phenol resin, the method comprising:

• causing a lignin compound, a phenol compound, and an aldehyde compound to react in a presence of an acid catalyst under conditions in which a molar ratio (F/P) of the aldehyde compound to the phenol compound is equal to or more than 0.5, to obtain a lignin-modified novolac-type phenol resin,
• wherein the lignin-modified novolac-type phenol resin has a weight average molecular weight of equal to or more than 5500.