摘要:
A toner for developing an electrostatic image is disclosed which has at least one endothermic peak in the temperature region of 120.degree. C. or below in differential thermal analysis and contains, in its particles having particle diameters of 3 .mu.m or larger, not less than 93% by number of particles having a circularity of at least 0.90 and less than 30% by number of particles having a circularity of at least 0.98. The toner does not cause the re-transfer under high transfer current conditions and can realize the formation of good images with high image density. Also, an image forming method using the toner is disclosed.
摘要:
A magnetic black toner for electrophotography, includes: (a) magnetic black toner particles containing a binder resin, a magnetic material in 30-200 wt. parts per 100 wt. parts of the binder resin, and a first solid wax, and (b) first inorganic fine powder. The first solid wax (ii) provides a DSC heat-absorption main peak in a range of 60.degree.-120.degree. C., and (iii) shows a molecular weight distribution factor Mw/Mn of 1.0-2.0. The binder resin (iv) has a THF (tetrahydrofuran)-insoluble content of at most 5 wt. %, and (v) contains a THF-soluble content showing a GPC molecular weight distribution including a content (M1) of 40-70% in molecular weights of below 5.times.10.sup.4, a content (M2.ltoreq.M1) of 20-45% in molecular weights of 5.times.10.sup.4 -5.times.10.sup.5, and a content (M3
摘要:
A toner is constituted by at least a binder resin, a colorant and a wax. The binder resin has been formed from monomers including a vinyl monomer and polyester-forming monomers containing at least a polybasic carboxylic acid having three or more carboxyl groups or its anhydride, and comprises at least a hybrid resin comprising a vinyl polymer unit and a polyester unit.
摘要:
A toner is principally constituted by a binder resin, a colorant and a wax. The toner has a maximum heat-absorption peak of 60-135° C. as measured by differential scanning calorimetry (DSC). The toner further has a viscoelastic characteristic measured at an angular frequency of the toner of 6.28 rad/sec including: a temperature giving a loss molecules G″ of 3×104 Pa of 90-115° C., a temperature giving a loss modulus G″ of 2×104 Pa of 95-120° C., a temperature giving a loss modulus G″ of 1×104 Pa of 105-135° C., a tan &dgr; (loss modulus G″/storage modulus G′) when G″=1×104-3×104 Pa of 0.6-2.0, a storage modulus at 170° C. (G′ (170° C.)) of 1×102-1×104 Pa, a loss modulus at 170° C. (G″ (170° C.)) of 1×102-1×104 Pa, and a ratio of a tan &dgr; at 170° C. (tan &dgr;170) to a tan &dgr; at 150° C. (tan &dgr;150) (tan &dgr;170/tan &dgr;150) of 1.05-1.6. The toner contains a tetrahydrofuran (THF)-soluble content exhibiting a molecular weight distribution according to gel permeation chromatography (GPC) chromatogram providing a main peak in a molecular weight region of 2,000-30,000 and a ratio (Mw/Mn) of above 100 between weight-average molecular weight (Mw) and number-average molecular weight (Mn). The resultant toner is effective in improving a low-temperature fixability and a high-temperature anti-offset characteristic while retaining an appropriate gloss of a fixed image in a broader temperature range.
摘要:
A toner for forming an image has toner particles containing at least a colorant, a binder resin and a wax. The toner has (i) a circularity distribution in which the toner has an average circularity of 0.900 to less than 0.965, contains 20 to 60% by number of particles with a circularity of less than 0.95 and has a mode circularity of 0.90 or more; and (ii) a particle size distribution in which the toner has a circle-equivalent average diameter of 2.0 to 10.0 .mu.m and has at least one peak of frequency by number in the region of a circle-equivalent diameter of 0.6 to 3.0 .mu.m and at least one peak of frequency by number in the region of a circle-equivalent diameter of from more than 3.0 .mu.m to 10.0 .mu.m. The wax has an endothermic main peak as measured by DSC of 60 to 120.degree. C. The binder resin contains THF soluble matter and 0 to 5.0% by weight of THF insoluble matter. The THF soluble matter having a molecular-weight distribution as measured by GPC in which the THF soluble matter has a content (M1) of 5% or less of a component with a molecular weight of less than 50,000, a content (M2) of 20 to 45% of a component with a molecular weight of 50,000 to 500,000, and a content (M3) of 2 to 25% of a component with a molecular weight exceeding 500,000 and the following condition (1) is satisfied:M1.gtoreq.M2>M3 (1)
摘要:
An image forming method has a developing step of developing an electrostatic latent image by the use of a developer to form a toner image on an electrostatic latent image bearing member, a primary transfer step of transferring the toner image onto an intermediate transfer member to which a voltage is applied, and a secondary transfer step of transferring onto a transfer medium the toner image held on the intermediate transfer member, while a transfer means to which a voltage is applied is pressed against the transfer medium. The developer has a toner. The toner is a black toner having at least i) black toner particles formed of a binder resin with a colorant dispersed therein and ii) an inorganic fine powder. The black toner has the value of shape factor SF-1 of 110
摘要:
The objects of the present invention are to provide a toner excellent in transferability, little remaining on the photosensitive member and causing no defective image in roll-aided transfer (or at least such a phenomenon is well-controlled), and also to provide an image forming method using the same toner. The above objects are achieved when the toner contains a binder resin and colorant, inorganic fine particles, and a hydrotalcite compound shown by the formula: M1y12+M2y22+ . . . Mjyj2+L1x13+L2x23+ . . . Lkxk3+(OH)2.(X/n)An−.mH2O (1) wherein 0