Electrophotographic toner, and image forming apparatus and image forming method using the same

An electrophotographic toner comprising a resinous composition for toner and a colorant wherein

• the resinous composition comprises a copolymer including a lower molecular weight component having a peak at molecular weight of 3,000 to 50,000 and a higher molecular weight component having a peak at molecular weight of 100,000 to 5,000.000, the copolymer comprising a vinyl based copolymer comprised of a styrene based monomer and and acrylic or methacrylic acid ester based monomer as structural units, and
• the toner comprises a fatty acid ester represented by at least one of the general formulas (1-1) through (1-4), and a carboxylic acid represented by the general formula (2),
• R1COOOR2 General Formula (1-1)
• in the formula, one or both of R1 and R2 represent an aliphatic group having not less than 14 carbon atoms and when either R1 or R2 represents an aliphatic group having not less than 14 carbon atoms, the other group represents an alkyl group having not more than 14 carbon atoms, a cycloalkyl group, an alkenyl group, or an aralkyl group,
• [R1COO—(CH2)n]n—C—[(CH2)m—OCOR2]b General Formula (1-2)
• in the formula, a and b each represents an integer of 0 to 4;
• a+b is 4;
• R1 and R2 each represents an organic group having from 1 to 40 carbon atoms;
• the difference in the number or carbon atoms between R1 and R2 is to be at least 3;
• m and n each represents an integer of 0 to 25;
• and m and n are not 0 a the same time,
• [R1COO—(CH2)n]a—C—[(CH2)m—OH]h General Formula (1-3)
• in the formula, a represents an integer of 1 to 3;
• b represents an integer of 1 to 3;
• a +b is 4;
• R1 represents an organic group having from 1 to 40 carbon atoms;
• m and n each represents an integer of 0 to 25;
• and m and n are not 0 at the same time,
• [R1COO—(CH3)n]a—C(R3)k—[CH2]m—OCOR2]b General Formula (1-4)
• in the formula, a and b each represents an integer of 0 to 3;
• a+b is 1 to 3;
• R1 and R2 each represents an organic group having from 1 of 40 carbon atoms;
• the difference in the number of atoms between R1 and R2 is at least 3;
• R3 represents a hydrogen atom or an organic group having at least 1 carbon atom with proviso, when a+b is 2, either one of R3 represents an organic group having at least 1 carbon atom;
• k represents an integer of 1 to 3;
• m and n each represents an integer of 0 to 25;
• and m and n are not 0 at the same time,
• R4—COOH General Formula (2)
• in the formula, R4 represents a saturated or unsaturated aliphatic group having at least 13 carbon atoms, and wherein a content ratio of the fatty acid ester represented by the general formulas (1-1) through (1-4) is 80.0 to 99.9 percent by weight, acid of the carboxylic acid represented by the general formula (2) is 0.1 to 20 percent by weight.

An electrophotographic toner comprising a resinous composition for toner and a colorant wherein

• the resinous composition comprises a copolymer including a lower molecular weight component having a peak at molecular weight of 3,000 to 50,000 and a higher molecular weight component having a peak at molecular weight of 100,000 to 5,000,000, the copolymer comprising a vinyl based copolymer comprised of a styrene base monomer and an acrylic or metacrylic acid ester based monomer as structural units, and
• the toner comprises a fatty acid ester represented by at least one of the general formulas (1-1) through (1-4), and a carboxylic acid represented by the general formula (2),
• R1COOR2 General Formula (1-1)
• in the formula, one or both of R1 and R2 represent an aliphatic group having not less than 14 carbon atoms and when either R1 or R2 represents an aliphatic group having not less than 14 carbon atoms, the other group represents an alkyl group having not more than 14 carbon atoms, a cycloalkyl group, an alkenyl group, or an aralkyl group,
• [R1COO—(CH2)n]a—C—[(CH2)m—OCOR2]b General Formula (1-2)
• in the formula, a and b each represents an integer of 0 to 4;
• a+b is 4;
• R1 and R2 each represents an organic group having form 1 to 40 carbon atoms;
• to difference in the number of carbon atoms between R1 and R2 is to be at least 3;
• m and n each represents an integer of 0 to 25;
• and m and in are not 0 at the same time,
• [R1COO—(CH2)n]a—C—[(CH2)m—OH]b General Formula (1-3)
• in the formula, a represents an integer of 1 to 3;
• b represents an integer of 1 to 3;
• a+b is 4;
• R1 represents an organic group having from 1 to 40 carbon atoms;
• in and n each represents an integer of 0 to 25;
• and m and n are not 0 at the same time,
• [R1COO—(CH2)n]a—C(R3)k—[CH2]m—OCOR2]b General Formula (1-4)
• in the formula, a and b each represents an integer of 0 to 3;
• a+b is 1 to 3;
• R1 and R2 each represents an organic group having from 1 to 40 carbon atoms;
• the difference in the number of atoms between R1 and R2 is at least 3;
• R3 represents a hydrogen atom or an organic group having at least 1 carbon atom with proviso, when a+b is 2, either one of R3 represents an organic group having al least 1 carbon atom;
• k represents an integer of 1 to 3;
• m and n each represents an integer of 0 to 25;
• and m and n are not 0 at the same time,
• R4—COOH General Formula (2)
• in the formula, R4 represents a saturated or unsaturated aliphatic group having at least 13 carbon atoms, and wherein the toner further comprises a crystalline compound having a terminal polar group.