The invention relates to a toner for development of electrostatic images excellent in fusing property on polypropylene films and excellent in rubfastness of printed images, and a resin composition for a toner for development of electrostatic images. The toner for development of electrostatic images and the resin composition for a toner for development of electrostatic images each contain an amorphous polyester-based resin A and a crystalline polyester-based resin C, wherein the amorphous polyester-based resin A has a constituent moiety derived from a polyester resin, and a constituent moiety derived from a reactive functional group-having modified polyolefin-based polymer A, the polyester resin-derived constituent moiety and the modified polyolefin-based polymer A-derived constituent moiety being bonded via a covalent bond, and the amount of the modified polyolefin-based polymer A-derived constituent moiety is 5% by mass or more and 30% by mass or less relative to the total amount of the resin component in the toner.

The present invention relates to a binder resin composition capable of giving a toner remarkably excellent in fusing property on polypropylene films, and to a toner for developing electrostatic images that contains the binder resin composition. [1] A binder resin composition for toners, containing an amorphous polyester resin which has a polyester resin-derived constituent moiety that is a constituent moiety derived from a polyester resin and a modified polypropylene polymer A-derived constituent moiety that is a constituent moiety derived from a modified polypropylene polymer A having a carboxylic acid group or a carboxylic anhydride group and in which the polyester resin-derived constituent moiety and the modified polypropylene polymer A-derived constituent moiety bond to each other via a covalent bond, wherein the polymer A is a polypropylene polymer terminally-modified with an unsaturated bond-having carboxylic acid compound or an anhydride thereof, and in the polyester resin, the amount of the polymer A-derived constituent unit is 8 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total of the alcohol component and the carboxylic acid component constituting the polyester resin-derived constituent moiety; and [2] a toner for developing electrostatic images, containing the binder resin composition of [1].

A toner comprising a toner particle comprising a binder resin including a polyester resin, and a polyolefin resin having a sulfonic acid group, wherein the polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin, a content ratio of a monomer unit containing a sulfonic acid group in the vinyl polymer is from 1.0 mass % to 20.0 mass %, in a FT-IR spectrum obtained through measurement of a large particle size toner and a small particle size toner resulting from dividing, on a number basis, the toner into two substantially equal parts, a ratio of an intensity of a maximum absorption peak in a range from 1130 cm.sup.−1 to 1170 cm.sup.−1 with respect to an intensity of a maximum absorption peak in a range from 1713 cm.sup.−1 to 1723 cm.sup.−1 exhibits a specific relationship.

An image forming apparatus includes an electrostatic latent image bearer, an electrostatic latent image former, a developing device, a transfer device, and a fixing device. The electrostatic latent image former forms an electrostatic latent image on the electrostatic latent image bearer. The developing device develops the electrostatic latent image with a developer to form a toner image. The transfer device transfers the toner image on a recording medium. The fixing device fixes the toner image on the recording medium. The developer contains an adhesive medium and foamable particles.

A toner includes polyolefin and has an exothermic peak in a range from 40° C. to 70° C. in a cooling process of the polyolefin by the DSC after a first heating process of the polyolefin by DSC. The polyolefin does not have an exothermic peak in the cooling process of the polyolefin by the DSC after the first heating process of the polyolefin by the DSC, and has an exothermic peak in a range from 0° C. to 30° C. in a second heating process of the polyolefin by the DSC.

An image forming method is provided. The image forming method includes: forming an electrostatic latent image on an electrostatic latent image bearer; developing the electrostatic latent image on the electrostatic latent image bearer with a toner to form a toner image; transferring the toner image from the electrostatic latent image bearer onto a continuous resin film; fixing the toner image on the continuous resin film with a heat roller or a heat belt. The toner contains a maleic-acid-modified polyolefin having a polypropylene block in a main chain.

The present invention relates to a binder resin composition capable of giving a toner remarkably excellent in fusing property on polypropylene films, and to a toner for developing electrostatic images that contains the binder resin composition. [1] A binder resin composition for toners, containing an amorphous polyester resin which has a polyester resin-derived constituent moiety that is a constituent moiety derived from a polyester resin and a modified polypropylene polymer A-derived constituent moiety that is a constituent moiety derived from a modified polypropylene polymer A having a carboxylic acid group or a carboxylic anhydride group and in which the polyester resin-derived constituent moiety and the modified polypropylene polymer A-derived constituent moiety bond to each other via a covalent bond, wherein the polymer A is a polypropylene polymer terminally-modified with an unsaturated bond-having carboxylic acid compound or an anhydride thereof, and in the polyester resin, the amount of the polymer A-derived constituent unit is 8 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total of the alcohol component and the carboxylic acid component constituting the polyester resin-derived constituent moiety; and [2] a toner for developing electrostatic images, containing the binder resin composition of [1].

Provided is a magnetic toner having a toner particle containing a binder resin and a magnetic body, wherein the binder resin contains a polymer A having a first monomer unit and a second monomer unit, the first polymerizable monomer is at least one selected from the group consisting of the (meth)acrylic acid esters having C.sub.18-36 alkyl groups, a content of the first monomer unit and a content of the second monomer unit based on the total moles of all monomer units in the polymer A are respectively 5.0 to 60.0 mol % and 20.0 to 95.0 mol %, and assuming that an SP value of the first monomer unit and the second monomer unit are taken as SP.sub.11 (J/cm.sup.3).sup.0.5 and SP.sub.21(J/cm.sup.3).sup.0.5, respectively, 3.00≤(SP.sub.21−SP.sub.11)≤25.00 is satisfied, and an oil absorption of the magnetic body is 5 to 40 ml/100 g.

A toner comprising: a toner particle containing a binder resin; and an external additive, wherein the external additive comprises an external additive A and B; the external additive A has a number-average primary particle diameter of 35 to 300 nm, a dielectric constant ε.sub.ra of not more than 3.50, and a shape factor SF-1 of not more than 114, and is an organosilicon polymer particle having a particular T3 unit structure; a proportion for an area of a peak originating from silicon having the T3 unit structure with reference to that of all silicon elements is 0.50 to 1.00; the external additive B has a number-average primary particle diameter of from 5 nm to 25 nm and a dielectric constant ε.sub.rb that satisfies formula (A): 0.50≤ε.sub.rb−ε.sub.ra (A); and a coverage ratio by the external additive B for the toner particle surface is 50% to 100%.

An electrostatic charge image developing toner includes a polar group-containing olefin resin that is a polymer of a composition containing at least one nonpolar monomer unit (X) selected from the group consisting of ethylene and -olefin having 3 to 10 carbon atoms, a polar monomer unit (Y) having at least one of a maleic acid group and a maleic anhydride group, and a monomer unit (Z) having a polymerizability to at least one of the nonpolar monomer unit (X) and the polar monomer unit (Y), in which an acid value of the toner is 10 mgKOH/g to 60 mgKOH/g.