Abstract: A toner to develop electrostatic latent images which uses an appropriate combination of a high molecular weight binder resin and a low molecular weight binder resin, an appropriate amount of a releasing agent, and a combination of silica particles and iron oxide particles as external additives, and thus has the following effects: the toner may reduce a generation amount of ultra-fine particles (UFPs) and have enhanced fluidity, charging uniformity, charging stability, transfer efficiency, fixability, durability and a cleaning ability.

Abstract: The present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefor, and polylactide resin compositions including the same.

Abstract: The present invention relates to a polylactide resin having excellent heat resistance, a preparation method thereof, and a polylactide resin composition including the same. The polylactide resin is characterized by high polymerization activity owing to an organic coordinated metal catalyst even though it has a low catalyst content, and a molecular weight reduction due to thermal decomposition at high temperature and a rate of thermal decomposition including depolymerization are greatly suppressed by a low catalyst content and a low resin acidity, and thus provided is the polylactide resin having superior heat resistance.

Abstract: This disclosure relates to a method for preparing alkyl lactate with high yield and high selectivity, comprising the step of reacting glycerol with water or alcohol in the presence of a catalyst. In addition, the present invention provides a method for efficiently preparing lactamide using the alkyl lactate.

Abstract: A toner to develop electrostatic latent images which uses an appropriate combination of a high molecular weight binder resin and a low molecular weight binder resin, an appropriate amount of a releasing agent, and a combination of silica particles and iron oxide particles as external additives, and thus has the following effects: the toner may reduce a generation amount of ultra-fine particles (UFPs) and have enhanced fluidity, charging uniformity, charging stability, transfer efficiency, fixability, durability and a cleaning ability.

Abstract: The present invention relates to an organotin compound represented by R1O—Sn—OR2 (where R1 and R2 are independently a primary, secondary, or tertiary alkyl group having 5 to 30 carbon atoms), a preparation method thereof, and a preparation method for polylactide using the organotin compound. The organotin compound of the present invention is easy to prepare and is used to prepare a polylactide resin having a high molecular weight at a high yield without using a separate initiator.

Abstract: The present invention relates to a polylactide resin having excellent heat resistance, a preparation method thereof, and a polylactide resin composition including the same. The polylactide resin is characterized by high polymerization activity owing to an organic coordinated metal catalyst even though it has a low catalyst content, and a molecular weight reduction due to thermal decomposition at high temperature and a rate of thermal decomposition including depolymerization are greatly suppressed by a low catalyst content and a low resin acidity, and thus provided is the polylactide resin having superior heat resistance.

Abstract: Disclosed are polylactide resin that may exhibit and maintain excellent mechanical properties, exhibit excellent heat resistance, and thus can be used for a semi-permanent use, a method for preparing the same, and a polylactide resin composition comprising the same. The polylactide resin has a low hydrolysis rate constant of 0.1 day?1 or less and a weight average molecular weight of 100,000˜1,000,000, under specific conditions.

Abstract: The present invention relates to a polysiloxane-polylactide block copolymer and a preparation method thereof, in which the polysiloxane-polylactide block copolymer has improved impact resistance and flexibility, compared to the conventional polylactide resins and can be prepared by ring-opening polymerization of lactide monomers in the presence of a polymerization initiator of polysiloxane.

Abstract: The present invention relates to a polylactide resin having excellent heat resistance, a preparation method thereof, and a polylactide resin composition including the same. The polylactide resin is characterized by high polymerization activity owing to an organic coordinated metal catalyst even though it has a low catalyst content, and a molecular weight reduction due to thermal decomposition at high temperature and a rate of thermal decomposition including depolymerization are greatly suppressed by a low catalyst content and a low resin acidity, and thus provided is the polylactide resin having superior heat resistance.

Abstract: The present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefor, and polylactide resin compositions including the same.

Abstract: The present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefor, and polylactide resin compositions including the same.

Abstract: The present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefore, and polylactide resin compositions including the same.

Abstract: The present invention relates to a polysiloxane-polylactide block copolymer and a preparation method thereof, in which the polysiloxane-polylactide block copolymer has improved impact resistance and flexibility, compared to the conventional polylactide resins and can be prepared by ring-opening polymerization of lactide monomers in the presence of a polymerization initiator of polysiloxane.

Abstract: The present invention relates to a polylactide resin having excellent heat resistance, a preparation method thereof, and a polylactide resin composition including the same. The polylactide resin is characterized by high polymerization activity owing to an organic coordinated metal catalyst even though it has a low catalyst content, and a molecular weight reduction due to thermal decomposition at high temperature and a rate of thermal decomposition including depolymerization are greatly suppressed by a low catalyst content and a low resin acidity, and thus provided is the polylactide resin having superior heat resistance.

Abstract: This disclosure relates to a method for preparing alkyl lactate with high yield and high selectivity, comprising the step of reacting glycerol with water or alcohol in the presence of a catalyst. In addition, the present invention provides a method for efficiently preparing lactamide using the alkyl lactate.

Abstract: The present invention relates to a polysiloxane-polylactide block copolymer and a preparation method thereof, in which the polysiloxane-polylactide block copolymer has improved impact resistance and flexibility, compared to the conventional polylactide resins and can be prepared by ring-opening polymerization of lactide monomers in the presence of a polymerization initiator of polysiloxane.

Abstract: Disclosed are polylactide resin that may exhibit and maintain excellent mechanical properties, exhibit excellent heat resistance, and thus can be used for a semi-permanent use, a method for preparing the same, and a polylactide resin composition comprising the same. The polylactide resin has a low hydrolysis rate constant of 0.1 day?1 or less and a weight average molecular weight of 100,000˜1,000,000, under specific conditions.

Abstract: The present invention relates to an organotin compound represented by R1O—Sn—OR2 (where R1 and R2 are independently a primary, secondary, or tertiary alkyl group having 5 to 30 carbon atoms), a preparation method thereof, and a preparation method for polylactide using the organotin compound. The organotin compound of the present invention is easy to prepare and is used to prepare a polylactide resin having a high molecular weight at a high yield without using a separate initiator.

Abstract: The present invention is directed to an organometallic complex and a catalyst composition capable of producing polylactide resins with improved properties at a higher conversion rate, a method of producing the organometallic complex, polylactide resins having enhanced hydrolysis resistance and heat resistance together with superior mechanical properties, a preparation process therefor, and polylactide resin compositions including the same.