Polarizing plate protective film, polarizing plate, liquid crystal display device, and production method of polarizing plate protective film

A polarizing plate protective film comprising a polymer having at least one of an ester bond and an amide bond, and a compound which generates a base by an action of an acid, the compound being at least one selected from a group consisting of:

• an oxime compound;
• wherein the oxime compound is represented by formula (2)
• in formula (2), R4 and R5 each independently represents an alkyl group,
• R6 represents a hydrogen atom, an alkyl group, an aryl group, an acyl group or a group represented by formula (N1),
• R4 and R5 may be combined with each other to form a ring,
• in formula (N1), RN1 and RN2 each independently represents a hydrogen atom, an alkyl group or an aryl group,
• * represents a bond connecting to the oxygen atom, and
• RN1 and RN2 may be combined with each other to form a ring,
• a hydrazone compound;
• and
• a compound represented by formula (1);
• wherein, in the formula (1),
• R1 and R2 each independently represents an alkyl group, and R1 and R2 and combined with each other to form a ring, and
• R3 represents an alkyl group or an aryl group,
• wherein the hydrazone compound is represented by formula (3);
• wherein the formula (3),
• R7 and R8 each independently represents an alkyl group,
• R9 and R10 each independently represents a hydrogen atom, an alkyl group or an aryl group, wherein the aryl group has an aromatic ring which is not directly bonded to N, provided that at least one of R9 or R10 represents an alkyl group or an aryl group, wherein the aryl group has an aromatic ring which is not directly bonded to N,
• R7 and R8 may be combined with each other to form a ring having from 5 to 7 carbon atoms, and R9 and R10 may be combined with each other to form a ring having from 5 to 7 carbon atoms,
• R7 to R10 and the ring formed therefrom may have a substituent which is selected from the group consisting of an alkyl group, an aryl group, a hydroxyl group, an acyl group, an alkyl ether group, an aminocarbonyl group, an imino group represented by −N=CR21R22 in which R21 and R22 each independently represents an alkyl group or an aryl group, and a group formed by combining two or more thereof,
• wherein a content of the compound is 0.01 parts by weight and less than 2 parts by weight, with respect to 100 parts by weight of the polymer having the at least one of an ester bond and an amide bond, a pKa of the base's conjugated acid is less than 4, and a maximum value of energy absorption of the compound is a wavelength of less than 300 nm,
• wherein the at least one of an ester bond and an amide bond of the polymer, is susceptible to hydrolysis at high temperature and high humidity environment to generate the acid, and
• wherein the polymer is at least one selected from a (meth)acrylic resin and a cellulose acylate.