초록

A polyhydroxyalkanoate (PHA) comprised of two kinds of units, a 3-hydroxybutyrate (3HB) unit and a 3-hydroxyhexanoate (3HHx) unit is used as a binder resin. This provides a binder resin which is biodegradable and can more highly contribute to the conservation of natural environment.

대표청구항 ▼

1. A binder resin composition for toners which comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2)and at least one resin selected fro

1. A binder resin composition for toners which comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2)and at least one resin selected from polycaprolactone and polylactic acid. 2. The binder resin composition for toners according to claim 1, wherein said polyhydroxyalkanoate further contains at least one unit selected from a 4-hydroxybutyrate (4HB) unit represented by the following formula (3), a 4-hydroxyvalerate (4HV) unit represented by the following formula (4), a 4-hydroxyvalerate (3HV) unit represented by the following formula (5) and a 3-hydroxypropionate (3HP) unit represented by the following formula (6): 3. The binder resin composition for toners according to claim 1, wherein said 3-hydroxybutyrate (3HB) unit is contained in an amount of 50 mol % to 95 mol %. 4. The binder resin composition for toners according to claim 1, which has a number average molecular weight of 2,000 to 300,000. 5. The binder resin composition for toners according to claim 1, which has a glass transition point of 30° C. to 80° C. and a softening point of 60° C. to 170° C. 6. A toner comprising a binder resin composition, whereinsaid binder resin composition comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2):and at least one resin selected from polycaprolactone and polylactic acid. 7. An image-forming method comprising the steps of:a charging step of applying a voltage to a charging member from its outside to charge an electrostatic-latent-image-bearing member electrostatically;a latent-image-forming step of forming an electrostatic latent image on the electrostatic-latent-image-bearing member thus charged;a developing step of developing the electrostatic latent image by the use of a toner for developing electrostatic latent images, to form a toner image on the electrostatic-latent-image-bearing member;a transfer step of transferring to a recording medium the toner image formed on the electrostatic-latent-image-bearing member; anda fixing step of fixing by heat the toner image held on the recording medium;wherein said toner comprises a binder resin composition, and the binder resin composition comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2):and at least one resin selected from polycaprolactone and polylactic acid. 8. An image forming method comprising the steps of:a charging step of applying a voltage to a charging member from its outside to charge an electrostatic-latent-image-bearing member electrostatically;a latent-image-forming step of forming an electrostatic latent image on the electrostatic-latent-image-bearing member thus charged;a developing step of developing the electrostatic latent image by the use of a toner for developing electrostatic latent images, to form a toner image on the electrostatic-latent-image-bearing member;a first transfer step of transferring to an intermediate transfer member the toner image formed on the electrostatic-latent-image-bearing member;a second transfer step of transferring to a recording medium the toner image held on the intermediate transfer member; anda fixing step of fixing by heat the toner image held on the recording medium;wherein said toner comprises a binder resin composition, and the binder resin composition comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2):and at least one resin selected from polycaprolactone an d polylactic acid. 9. An image-forming apparatus comprising:charging means for applying a voltage to a charging member from its outside to charge an electrostatic-latent-image-bearing member electrostatically;latent-image-forming means for forming an electrostatic latent image on the electrostatic-latent-image-bearing member thus charged;developing means for developing the electrostatic latent image by the use of a toner for developing electrostatic latent images, to form a toner image on the electrostatic-latent-image-bearing member;transfer means for transferring to a recording medium the toner image formed on the electrostatic-latent-image-bearing member; andfixing means for fixing by heat the toner image held on the recording medium;wherein said toner comprises a binder resin composition, and the binder resin composition comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2):and at least one resin selected from polycaprolactone and polylactic acid. 10. An image-forming further apparatus comprising:charging means for applying a voltage to a charging member from its outside to charge an electrostatic-latent-image-bearing member electrostatically;latent-image-forming means for forming an electrostatic latent image on the electrostatic-latent-image-bearing member thus charged;developing means for developing the electrostatic latent image by the use of a toner for developing electrostatic latent images, to form a toner image on the electrostatic-latent-image-bearing member;first transfer means for transferring to an intermediate transfer member the toner image formed on the electrostatic-latent-image-bearing member;second transfer means for transferring to a recording medium the toner image held on the intermediate transfer member; andfixing means for fixing by heat the toner image held on the recording medium;wherein said toner comprises a binder resin composition, and the binder resin composition comprises a polyhydroxyalkanoate having at least two kinds of units, a 3-hydroxybutyrate (3HB) unit represented by the following formula (1) and a 3-hydroxyhexanoate (3HHx) unit represented by the following formula (2):and at least one resin selected from polycaprolactone and polylactic acid.