34 results about "4-Butyrolactone" patented technology

The invention discloses dielectric paste for a metal aluminum substrate thick film circuit and a preparation method thereof. The invention aims to prepare the dielectric paste matched with a metal aluminum substrate. The dielectric paste is characterized in that SiO2, Na2O, B2O3, K2O, BaO, CaO, Co2O3, TiO2, P2O5, V2O5, Sb2O3 and Cr2O3 are combined to prepare microcrystalline glass powder; and themicrocrystalline glass powder and an organic binder which consists of terpinol, butyl carbitol, butyl carbitol acetate, tirbutyl citrate, 1,4-butyrolactone, nitroncellulose, ethyecellulose, hydrogenated castor oil and lecithin are put in a vessel for stirring and rolling by a three-roll roller mill in a weight ratio of the microcrystalline glass powder to the organic binder of 70-90 parts: 30-10 parts so as to prepare the finished product dielectric paste. The dielectric paste is mainly used as the dielectric paste of the thick film circuit formed by being printed on the metal aluminum substrate.

The invention discloses a dielectric paste used for a high-power thick film circuit and a preparation method thereof. The invention aims at preparing a dielectric paste matched with a 304 or a 316 stainless steel base plate. The dielectric paste is characterized in that neoceramic glass powder consisting of SiO2, B2O3, Al2O3, BaO, CaO, MgO, ZrO2, Co2O3 and TiO2, and organic binder consisting of tributyl citrate, 1, 4-butyrolactone, nitroncellulose, hydrogenated castor oil and lecithin are put into a container according to the weight proportion that the ratio of the neoceramic glass powder andthe organic binder is 70-90 parts by weight to 30-10 parts by weight to be stirred, and then are milled by a three-high mill, so that the finished product dielectric paste is obtained. The invention is mainly used as the dielectric paste which forms the high-power thick film circuit on the 304 or the 316 stainless steel base plate.

The invention relates to a method for biocatalytically synthesizing optically active alkyl lactones. The method comprises the following steps: (1) using a biocatalyst to catalyze the asymmetric reduction of oxoacids to synthesize optically active hydroxyacids; (2) in an acidic environment, using The optically active hydroxy acid is cyclized to form an optically active lactone compound. Use freshly cultured Candida parapsilosis cells or cell-free extracts as biocatalysts to catalyze the stereoselective reduction of 4-oxodecanoic acid and 5-oxodecanoic acid, followed by cyclization into lactone compounds in an acidic environment, with high efficiency Preparation of (R)‑(+)‑4‑hexyl‑4‑butyrolactone and (R)‑(+)‑5‑pentyl‑5‑valerolactone. Compared with the prior art, the cells and extracts thereof of the strain of the present invention are easy to prepare, have strong stereoselectivity, and catalyze the preparation of (R)-(+)-4-hexyl-4-butyrolactone and (R )‑(+)‑5‑pentyl‑5‑valerolactone has a simple process, is environmentally friendly, and has good industrial application prospects.

The invention provides YBCO thick film resistance paste based on a stainless steel base board and a preparation method thereof, belonging to electronic material. The paste comprises solid phase component and organic carrier component, wherein the organic carrier component comprises the following components based on the parts by percentage of: 50-90% of terpinol, 1-20% of ethocel, 0-30% of tirbutyl citrate, 0-10% of 1, 4-butyrolactone, 0-9% of nitro cellulose, 0-8% of hydrogenated castor oil and 0-10% of lecithin; the weight ratio of the solid phase component to the organic carrier is equal to(60-85):(40-15); according to the weight ratio, the component of the solid phase component is as follows: YBCO ceramic powder: glass powder=(60-9.9):(40-0.1); the YBCO ceramic powder comprises Y2O3, BaO and CuO; according to the mole ratio, Y2O3: BaO: CuO=(1-2): (1-8): (1-8); the glass is SiO2-B2O3-Na2O-Al2O3-BaO-Li2O-ZnO series glass; and the weight percentage of each component of the glass is as follows: 20-50% of SiO2, 5-40% of B2O3, 10-50% of Na2O, 0-20% of Al2O3, 0-20% of BaO, 0-30% of Li2O and 0-20% of ZnO. The invention has the characteristics of low cost, large power and good stability, etc.

The invention belongs to the technical field of food safety detection, and in particular relates to a method for identifying vegetable oil and waste table oil by using SIFT / MS. The present invention measures furan, acrylamide, furfural, 2-pentylfuran, acrolein, exogenous pollutants citral, limonene, diallyl sulfide, m-cresol, 4-isopropyl Toluene, methyl piperonol, oxidative decomposition products: aldehydes such as heptanal, octanal, 2-heptenal, 3-hexenal, 2-octenal, (E, E)-2-decadienal , acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, other oxidative decomposition products such as acetone, butanone, 2-heptanone, 1,3-propylene glycol, 1,4-butyrolactone, propionate Esters 28 components, and then identify vegetable oil and waste cooking oil. The method not only saves the cost of reagents, but also has no pre-concentration, no column separation, no need for standard products, and has the advantages of high sensitivity, simplicity, speed, accuracy and the like.

The invention belongs to the field of fine chemistry, and particularly relates to a synthetic method of 4-methyl-4-(cis-3-hexenyl)-4-butyrolactone. The method comprises the following steps: taking leaf alcohol as a starting material, enabling the leaf alcohol to react with thionyl chloride to generate cis-1-chloro-3-hexene, first reacting with metal magnesium to obtain a cis-3-hexenyl Grignard reagent, then reacting with acetyl chloride to generate cis-5-hexene-2-ketone, and then reacting with methyl propiolate in the presence of n-butyllithium to obtain cis-4-methy-4-hydroxyl-7-decene-2-acetylenic acid methyl ester, and finally directly performing the reaction cyclization with NaBH4 under the catalysis of CuCl to obtain the 4-methyl-4-(cis-3-hexenyl)-4-butyrolactone. The method is environment-friendly, low in cost and suitable for the industrialization production.