Patent application number | Description | Published |
20090190235 | ZOOM LENS AND IMAGE PICKUP APPARATUS INCLUDING THE SAME - A zoom lens includes first to fourth lens units which respectively have negative, positive, negative, and positive refractive powers in order from the object side to the image side. Distances between the first and second lens units, the second and third lens units, and the third and fourth lens units at the telephoto end are respectively smaller, larger, and smaller than those at the wide-angle end. An Abbe number v | 07-30-2009 |
20100128360 | ZOOM LENS AND IMAGE PICKUP APPARATUS HAVING THE SAME - A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. In the zoom lens, an interval between the first and second lens units becomes smaller at a telephoto end than at a wide-angle end during zooming. The first lens unit includes, in order from the object side to the image side, a first lens having a negative refractive power, a second lens having a negative refractive power, which is made of a plastic and has an aspheric lens surface, and a third lens unit having a positive refractive power. In the zoom lens, a refractive index and an Abbe number of the plastic (Nd, νd), a focal length of the second lens (fn), and a focal length of the first lens unit (f | 05-27-2010 |
20140022442 | ZOOM LENS AND IMAGE PICKUP APPARATUS HAVING THE SAME - A zoom lens includes a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power, in order from an object side to an image side, each lens unit moving during zooming, and the third lens unit moving toward the object side during focusing from an infinitely-distant object to a nearby object. A focal length f | 01-23-2014 |
Patent application number | Description | Published |
20140288329 | PROCESS FOR PREPARING -MERCAPTOCARBOXYLIC ACID - There is provided a process for preparing β-mercaptocarboxylic acid represented by the following General Formula (3) comprising step of reacting hydrogen sulfide, alkali hydroxide represented by a formula: XOH (X represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) under atmospheric pressure to obtain a reaction solution including a compound represented by the following General Formula (2) and step of neutralizing the reaction solution in an acid. An amount of the alkali hydroxide is equal to or greater than total moles of the unsaturated carboxylic acid and the hydrogen sulfide. | 09-25-2014 |
20140323761 | PROCESS FOR PREPARING -MERCAPTOCARBOXYLIC ACID - A process for preparing β-mercaptocarboxylic acid is provided with Step a for reacting a compound represented by a formula: X | 10-30-2014 |
20150094443 | POLYTHIOL COMPOSITION, POLYMERIZABLE COMPOSITION FOR OPTICAL MATERIAL AND USE THEREOF - A polythiol composition according to the present invention includes a polythiol compound (A) having three or more mercapto groups and a nitrogen-containing compound (B) in which one of a mercapto group of the polythiol compound (A) is replaced with a group represented by the following formula (a) and other one of a mercapto group of the polythiol compound (A) is replaced with a hydroxyl group, in which the peak area of the nitrogen-containing compound (B) is equal to or less than 3.0 with respect to the peak area of 100 of the polythiol compound (A) in a high performance liquid chromatography measurement. | 04-02-2015 |
20150126781 | METHOD FOR PRODUCING POLYTHIOL COMPOUND, POLYMERIZABLE COMPOSITION FOR OPTICAL MATERIAL, AND USES THEREOF - Provided is a method for producing a polythiol compound, comprising: a step for reacting a polyalcohol compound represented by the following formula (4) with thiourea in the presence of hydrogen chloride to obtain an isothiuronium salt; a step for adding, while maintaining a reaction solution containing the isothiuronium salt thus obtained at a temperature of 20° C. to 60° C., aqueous ammonia to the reaction solution within 80 minutes, thereby hydrolyzing the isothiuronium salt to obtain a polythiol compound containing, as a main component, one kind or two or more kinds selected from the group consisting of compounds represented by the following formulae (6) to (8); and a step for adding hydrochloric acid which is a concentration of 30% to 36% to the solution containing the polythiol compound thus obtained, washing the solution at a temperature of 30° C. to 55° C. to purify the polythiol compound. | 05-07-2015 |
20150133692 | METHOD FOR PRODUCING POLYTHIOL COMPOUND, POLYMERIZABLE COMPOSITION FOR OPTICAL MATERIAL, AND USES THEREOF - Provided is a method for producing a polythiol compound, comprising: a step for reacting 2-mercaptoethanol with a defined epihalohydrin compound at a temperature of 10° C. to 50° C. to obtain a defined polyalcohol compound; a step for reacting the polyalcohol compound thus obtained with thiourea in the presence of hydrogen chloride to obtain an isothiuronium salt; a step for adding, while maintaining a reaction solution containing the isothiuronium salt thus obtained at a temperature of 15° C. to 60° C., aqueous ammonia to the reaction solution within 80 minutes, thereby hydrolyzing the isothiuronium salt to obtain a defined polythiol compound; and a step for adding hydrochloric acid which is a concentration of 25% to 36% to the solution containing the polythiol compound thus obtained, washing the solution at a temperature of 10° C. to 50° C. to purify the polythiol compound. | 05-14-2015 |
20160024242 | METHOD FOR PRODUCING POLYTHIOL COMPOUND, POLYMERIZABLE COMPOSITION FOR OPTICAL MATERIAL, AND USES THEREOF - Provided is a method for producing a molded product comprising a step for preparing a polymerizable composition for optical materials and a step for curing the polymerizable composition for optical materials to produce the molded product. The step for preparing the polymerizable composition for optical materials comprises a step for preparing a defined polythiol compound and a step for preparing the polymerizable composition for optical materials from the polythiol compound. The step for preparing the defined polythiol compound comprises reacting 2-mercaptoethanol with a defined epihalohydrin compound at a temperature of 10° C. to 50° C. to obtain a defined polyalcohol compound, reacting the polyalcohol compound with thiourea in the presence of hydrogen chloride to obtain an isothiuronium salt, hydrolyzing the isothiuronium salt to obtain the polythiol compound, adding hydrochloric acid at a defined concentration to a solution of the polythiol compound, and washing the solution to purify the polythiol compound. | 01-28-2016 |