Resin particles include mother particles containing a biodegradable resin and a plasticizer, in which an amount of a metal element having an ionic valence of 2 or more, obtained by fluorescent X-ray analysis, is 0.002% by mass or more and 2.0% by mass or less with respect to a total amount of the resin particles.

Resin particles include mother particles containing a biodegradable resin and a plasticizer, in which an amount of a metal element having an ionic valence of 2 or more, obtained by fluorescent X-ray analysis, is 0.002% by mass or more and 2.0% by mass or less with respect to a total amount of the resin particles.

Resin particles include mother particles containing a biodegradable resin, and a coating layer containing at least one selected from the group consisting of a quaternary ammonium salt-containing polymer, polyacrylamide, polyvinylpyrrolidone, and polylysine on a surface of the mother particles.

Resin particles include mother particles containing a biodegradable resin, and a coating layer containing at least one selected from the group consisting of a quaternary ammonium salt-containing polymer, polyacrylamide, polyvinylpyrrolidone, and polylysine on a surface of the mother particles.

A polarizing plate protective film which prevents deterioration of polarization performance in a high temperature, high humidity environment, and a polarizing plate and display device using the film including a compound represented by the following General Formula (I).

(X-L.sub.nz  General Formula (I)

X represents a formyl group, a boronic acid group, or a group represented by the following General Formula (I-B) or a group represented by the following General Formula (I-C), where L represents a single bond or divalent linking group, and n represents an integer equal to or greater than 2. When n is 2, Z represents a single bond or a divalent group, and when n≧3, Z represents an n-valent group.

##STR00001##

R.sup.A and R.sup.B represent an alkyl group, a cycloalkyl group, an aryl group, or an acyl group. R.sup.A and R.sup.B may be bonded to each other to form a ring. * represents a bond to be bonded to L.

Biodegradable thermoformed articles are disclosed. The thermoformed articles are formed from a biodegradable polymer composition. The polymer composition contains a cellulose ester polymer, a plasticizer, and one or more other additives. Thermoformed articles can be made in accordance with the present disclosure having low haze and high clarity.

Biodegradable thermoformed articles are disclosed. The thermoformed articles are formed from a biodegradable polymer composition. The polymer composition contains a cellulose ester polymer, a plasticizer, and one or more other additives. Thermoformed articles can be made in accordance with the present disclosure having low haze and high clarity.

A method for preparing stably dispersed cellulose nanofibers comprises the following steps: 1) mixing cellulose and an organic solvent, the percentage of the cellulose being 1% to 15% in weight; 2) adding an esterification agent into the resultant mixture of step 1), the molar ratio of the esterification agent to the cellulose being from 1:0.1 to 4; and 3) physically breaking the resultant mixture of step 2) until a suspension liquid with stably dispersed cellulose nanofibers of 2-1000 nm in diameter and 10-100 μm in length is obtained, an esterification reaction of hydroxyl group(s) on the surface of cellulose fibers occurring at the time of the breaking. Also disclosed are dispersed cellulose nanofibers with improved compatibility to the matrix than the untreated cellulose and an improved strength of the composite materials.

A method for preparing stably dispersed cellulose nanofibers comprises the following steps: 1) mixing cellulose and an organic solvent, the percentage of the cellulose being 1% to 15% in weight; 2) adding an esterification agent into the resultant mixture of step 1), the molar ratio of the esterification agent to the cellulose being from 1:0.1 to 4; and 3) physically breaking the resultant mixture of step 2) until a suspension liquid with stably dispersed cellulose nanofibers of 2-1000 nm in diameter and 10-100 μm in length is obtained, an esterification reaction of hydroxyl group(s) on the surface of cellulose fibers occurring at the time of the breaking. Also disclosed are dispersed cellulose nanofibers with improved compatibility to the matrix than the untreated cellulose and an improved strength of the composite materials.

A resin composition includes a cellulose derivative of which a weight average molecular weight is 10,000 or greater and less than 75,000 and in which at least one hydroxyl group is substituted with an acyl group having 1 to 6 carbon atoms.