A magnetic toner includes toner particles. The toner particles each include a toner mother particle. The toner mother particle includes a polyester resin domain, a vinyl resin domain, and a magnetic powder. A vinyl resin constituting the vinyl resin domain includes a repeating unit having a non-ring-opened oxazoline group. An area rate of an area in which the vinyl resin domain is exposed in a surface area of the toner mother particle is at least 0.02% and no greater than 1.00%.

The invention relates a novel polyglycolic acid. The polyglycolic acid comprises branched repeating units and linear repeating units. The polyglycolic acid may be produced from methyl glycolate by polycondensation in the presence of structure regulators, and exhibit excellent melt strength and thermal stability while maintaining good flowability and suitability for use in melt blow molding.

The invention relates a novel polyglycolic acid. The polyglycolic acid comprises branched repeating units and linear repeating units. The polyglycolic acid may be produced from methyl glycolate by polycondensation in the presence of structure regulators, and exhibit excellent melt strength and thermal stability while maintaining good flowability and suitability for use in melt blow molding.

The present invention relates to a functional resin composition comprising a biomass-derived component, and more particularly to a functional resin composition comprising: a biomass-derived component; an aromatic dicarboxylic acid; an alcohol component; a chain extender; and a multifunctional compound. The biomass-derived component is biomass-derived succinic acid alone or a mixture of biomass-derived succinic acid alone and fossil-derived aliphatic dicarboxylic acid. The functional resin composition comprising these components has excellent processability, moldability, tearing strength and tensile strength, and does not easily change over time due to its excellent hydrolysis resistance.

The present invention relates to a functional resin composition comprising a biomass-derived component, and more particularly to a functional resin composition comprising: a biomass-derived component; an aromatic dicarboxylic acid; an alcohol component; a chain extender; and a multifunctional compound. The biomass-derived component is biomass-derived succinic acid alone or a mixture of biomass-derived succinic acid alone and fossil-derived aliphatic dicarboxylic acid. The functional resin composition comprising these components has excellent processability, moldability, tearing strength and tensile strength, and does not easily change over time due to its excellent hydrolysis resistance.

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a polyester resin having a structure represented by Formula (1) at a terminal and a charge transport material, and in a case where a weight-average molecular weight Mw of the polyester resin is defined as A (×10,000), a value of a ratio M1/M2 of a mass M1 of the charge transport material to a mass M2 of an entire charge transport layer is defined as Cs, and an average thickness of the charge transport layer is defined as Ds (μm), expressions of 7≤A≤40, 0.28≤Cs≤0.55, 27≤Ds≤50, and 5.0≤(A×Ds)/(Cs×100)≤70 are satisfied,

##STR00001## in Formula (1), nd represents an integer of 0 or greater and 4 or less, nd number of Rd's each independently represent a hydrocarbon group having 1 or more and 4 or less carbon atoms, L represents an ether bond or a —O—C(═O)— group, and * represent a bonding portion.

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a polyester resin having a structure represented by Formula (1) at a terminal and a charge transport material, and in a case where a weight-average molecular weight Mw of the polyester resin is defined as A (×10,000), a value of a ratio M1/M2 of a mass M1 of the charge transport material to a mass M2 of an entire charge transport layer is defined as Cs, and an average thickness of the charge transport layer is defined as Ds (μm), expressions of 7≤A≤40, 0.28≤Cs≤0.55, 27≤Ds≤50, and 5.0≤(A×Ds)/(Cs×100)≤70 are satisfied,

##STR00001## in Formula (1), nd represents an integer of 0 or greater and 4 or less, nd number of Rd's each independently represent a hydrocarbon group having 1 or more and 4 or less carbon atoms, L represents an ether bond or a —O—C(═O)— group, and * represent a bonding portion.

A polyester pressure-sensitive adhesive composition is provided including a polyester resin having a predetermined amount of a structural unit derived from a hydrogenated polybutadiene structure-containing compound, or a polyester resin having a structural unit derived from a hydrogenated polybutadiene structure-containing compound and a predetermined amount of a structural unit derived from an aromatic ring structure-containing compound. The polyester pressure-sensitive adhesive composition has superior adhesion to a polyolefin base material and is highly transparency.

A polyester pressure-sensitive adhesive composition is provided including a polyester resin having a predetermined amount of a structural unit derived from a hydrogenated polybutadiene structure-containing compound, or a polyester resin having a structural unit derived from a hydrogenated polybutadiene structure-containing compound and a predetermined amount of a structural unit derived from an aromatic ring structure-containing compound. The polyester pressure-sensitive adhesive composition has superior adhesion to a polyolefin base material and is highly transparency.

Resin particles include resin base particles and silica particles on surfaces of the resin base particles. The silica particles contain a quaternary ammonium salt and have hydrophobized surfaces. A difference (detection temperature A−detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.