摘要:
An aliphatic copolyester having a plurality of first: ester units of the formula: —CO—[R1]t—CO—O—R2—O— wherein R1 represents a divalent aliphatic group, R2 represents a divalent aliphatic and t is an integer of 0 or 1, and a plurality of second ester units of the formula: wherein R1 and t are as defined above and R3 represents an aliphatic group. The molar ratio of the first ester unit to the second ester unit is 90:10 to 99.9:0.1. The copolyester is produced by reacting an aliphatic diester with an aliphatic glycol and with a monoacylated glycerin under ester exchanging conditions.
摘要翻译:具有多个下式的第一酯单元的脂族共聚酯:其中R1表示二价脂族基团,R2表示二价脂族基,t表示0或1的整数,以及多个下式的第二酯单元:其中 R 1和t如上所定义,R 3表示脂族基团。 第一酯单元与第二酯单元的摩尔比为90:10至99.9:0.1。 共聚多酯是通过脂肪族二酯与酯交换条件下的单酰化甘油反应制备的。
摘要:
A process of producing a polyester or copolyester, wherein at least one cyclic lactone of the following formula (I): wherein n is an integer of 1-4 provided that n is not 2 when only one cyclic lactone is used, is polymerized under a pressure of at least 200 MPa in the absence of any catalyst or in the presence of a metal-free polyesterification catalyst.
摘要:
Disclosed is a novel, high molecular weight aliphatic polyester having excellent mechanical strengths such as breaking strain and containing a copolymer structure with 3-alkoxy-1,2-propane diol and a method of producing the aliphatic polyester in an industrially advantageous manner. The aliphatic polyester is a biodegradable high molecular weight aliphatic polyester having an ester structure derived from 3-alkoxy-1,2-propane diol.
摘要:
Disclosed is a novel .beta.-lactam compound, a 7-substituted-2-oxa-7-azabicyclo�3.2.0!heptan-6-one represented by the general formula ##STR1## in which R is an alkyl, cycloalkyl, aryl, halogen-substituted aryl or alkaryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isocyanate compound RNCO, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher.
摘要:
A simple and efficient method is proposed for the preparation of a &bgr;-lactam compound such as 1-phenyl-4-ethoxy-2-azetidinone which can be produced by mixing an isocyanate compound such as phenyl isocyanate and a vinyl ether compound such as ethyl vinyl ether and heating the mixture at a moderate temperature under a superatmospheric pressure of up to 12000 atmospheres.
摘要:
Disclosed is a novel .beta.-lactam compound, a 7-substituted-2-oxa-7-azabicyclo[3.2.0]heptan-6-one represented by the general formula ##STR1## in which R is an alkyl, cycloalkyl, aryl, halogen-substituted aryl or alkaryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isocyanate compound RNCO, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher.
摘要:
A novel and simple method is proposed for the synthetic preparation of an N,N-disubstituted .beta.-ketothioamide compound represented by the general formula R.sup.1 R.sup.2 N--CS--CH.sub.2 --CO--R.sup.3, in which R.sup.1 and R.sup.2 are each a monovalent hydrocarbon group or each a divalent hydrocarbon group jointly forming a cyclic structure together with the nitrogen atom and R.sup.3 is a hydrogen atom, a monovalent hydrocarbon group or a divalent hydrocarbon group forming a cyclic structure jointly with R.sup.1, R.sup.1 being a divalent hydrocarbon group and R.sup.2 being a monovalent hydrocarbon group. The method comprises:(a) mixing an N,N-disubstituted amide compound represented by the general formula R.sup.1 R.sup.2 N--CO--R.sup.3, and a bis(trialkylsilyl)thioketene compound represented by the general formula (R.sub.3 Si).sub.2 C.dbd.C.dbd.S, in which each R is an alkyl group, to effect an addition reaction therebetween forming an intermediate compound; and (b) dissolving the intermediate compound obtained in step (a) in an alcohol.
摘要翻译:提出了一种简单的方法,用于合成制备由通式R 1 R 2 N-CS-CH 2 -CO-R 3表示的N,N-二取代的β-酮硫代酰胺化合物,其中R 1和R 2各自是一价烃基, 二价烃基与氮原子一起形成环状结构,R 3为氢原子,一价烃基或二价烃基,与R 1一起形成环状结构,R 1为二价烃基,R 2为一价烃基 。 该方法包括:(a)将由通式R 1 R 2 N -CO-R 3表示的N,N-二取代酰胺化合物和由通式(R3Si)2C = C = S表示的双(三烷基甲硅烷基)硫代烯酮化合物混合,其中 每个R是烷基,以形成中间体化合物之间的加成反应; 和(b)将步骤(a)中获得的中间体化合物溶解在醇中。
摘要:
Disclosed is a method for the preparation of a .beta.-thiolactam compound, i.e. a 7-substituted-2-oxa-7-azabicyclo [3.2.0]-heptan-6-thione, represented by the general formula ##STR1## in which R is an alkyl or aryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isothiocyanate compound R--NCS, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher at an elevated temperature.
摘要:
At least one exemplary embodiment is directed to an image coding apparatus configured to encode moving image data including: a coding unit configured to encode each picture in the moving image data in a unit of a first block; a luminance change detection unit configured to divide the moving image data into a plurality of second blocks and to detect a luminance change block in which a luminance change occurred from the plurality of the second blocks in one picture; and a code amount adjustment unit configured to increase an amount of code allocated to the first block if the first block corresponds to the luminance change block detected by the luminance change detection unit.
摘要:
An image signal processing apparatus for quantizing an inputted moving image signal according to a quantization step so that a code amount of one frame becomes a target code amount, and for variable-length-coding the quantized moving image signal, in which a minimum value of the quantization step is determined for each frame, and the quantization step is determined so as not to be less than the minimum value.