Unlock instant, AI-driven research and patent intelligence for your innovation.
Catalytic hydrogenation method of cyclohexane polyfluorobenzene liquid crystal monomer
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A liquid crystal monomer, catalytic hydrogenation technology, applied in chemical instruments and methods, liquid crystal materials, physical/chemical process catalysts, etc., can solve the problems of quality influence, difficulty in separation of main products, etc., reduce production costs, and solve defluorination problems. High yield of products and the effect of suppressing the formation of hydrogenolysis defluorination products
Inactive Publication Date: 2012-09-12
SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
View PDF6 Cites 0 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
Although the use of these catalysts can reduce the amount of defluorination compared with the use of highly active rhodium carbon, platinum carbon, basic Raney Ni, etc. as catalysts, the amount of defluorination is still maintained at a relatively high level, which can still reach 0.1%. ~1%, defluorinated by-products as impurities have a serious impact on the purification work and the quality of liquid crystal monomers
When the hydrogenation reaction of cyclohexenyl polyfluorobenzene is involved, Pd / C or neutral Raney Ni is used as a catalyst, and the minimum defluorination amount of the hydrogenation reaction in a neutral solvent is above 0.1%, or even as high as about 1%, resulting in The main product is difficult to separate, and the purity of the main product decreases, which has become a major problem in improving the purity and performance of liquid crystal monomers
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0022] Add 20 ml of toluene, 40 ml of acetic anhydride, 5 ml of glacial acetic acid, 4-(trans-4-n-propyl)cyclohexyl-1-cyclohexenyl-3,4,5-tri 10 grams of fluorobenzene, 0.5 grams of 5% Pd / C (dry weight. The other embodiments are the same), the hydrogenation reaction device is installed, and after the air in the reaction flask is filled with nitrogen, catalytic hydrogenation is carried out at normal temperature and pressure for 2 hours . The gas chromatography analysis results of the reaction liquid were as follows: the conversion rate was 100%, the content of the defluorinated product was 0.02%, the trans product was 59%, and the cis product was 40%.
Embodiment 2
[0024]20 ml of ethyl acetate, 20 ml of glacial acetic acid, 4-(trans-4-n-propyl)cyclohexyl-1-cyclohexenyl-3,4,5-trifluorobenzene 10 gram, 0.5 gram of 5% Pd / C, install the hydrogenation reaction device, after filling the air in the reaction bottle with nitrogen, catalytic hydrogenation under normal temperature and pressure for 1.5 hours. The gas chromatographic analysis results of the reaction liquid are as follows: the conversion rate is 100%, the content of the defluorinated product is 0.01%, the trans product is 55%, and the cis product is 44%.
Embodiment 3
[0026] Add 3 ml of concentrated hydrochloric acid, 2 ml of concentrated sulfuric acid, 30 ml of ethyl acetate, 20 ml of absolute ethanol, 4-(trans-4-n-propyl)cyclohexyl-1-cyclohexenyl into a 500 ml single-port bottle 10 grams of -3,4,5-trifluorobenzene, 0.15 grams of 5% Pd / C, the hydrogenation reaction device was installed, and after the air in the reaction bottle was replaced with nitrogen, catalytic hydrogenation was carried out at normal temperature and pressure for 1.5 hours. The gas chromatographic analysis results of the reaction liquid are: the conversion rate is 99.8%, the content of defluorinated products is 0.006%, the trans products are 54%, and the cis products are 45%.
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
PUM
Login to View More
Abstract
The invention discloses a catalytic hydrogenation method of cyclohexane polyfluorobenzene liquid crystal monomer; catalytic hydrogenation is carried out on a cyclohexenyl polyfluorobenzene compound toobtain the cyclohexane polyfluorobenzene; wherein, by using 5% Pd / C as a catalyst in a catalytic system and adding a proper inorganic acid or an organic acid, the catalytic hydrogenation reaction ofthe cyclohexenyl polyfluorobenzene compound is carried out. The catalytic method of the invention is capable of effectively inhibiting hydrogenolysis and defluorination in the reaction and belongs tothe technical field of catalytic synthesis of fine chemical products. The invention is capable of effectively inhibiting generation of products obtained by hydrogenolysis and defluorination in the catalytic hydrogenation reaction by regulating the properties of additives and reaction medium and basically eliminating the problems of product separation and purification caused by the side reactions of hydrogenolysis and defluorination. The reaction technology has the characteristics of simple operation, high yield and high purity.
Description
technical field [0001] The invention relates to a method for catalytic hydrogenation of a fluorine-containing TFT liquid crystal monomer trans-4-(trans-4'-n-alkylcyclohexyl)cyclohexyl-3,4,5-trifluorobenzene, which is applied to electronics The invention relates to the catalytic hydrogenation reaction in the preparation process of the liquid crystal monomer in the material, and belongs to the technical field of catalytic synthesis of fine chemical products. Background technique [0002] Trans-4-(trans-4'-n-alkylcyclohexyl)cyclohexyl-3,4,5-trifluorobenzene is a cyclohexane polyfluorobenzene liquid crystal compound. Due to the characteristics of low viscosity, moderate dielectric anisotropy, high resistivity, and high charge retention rate, fluorine-containing liquid crystals are widely used, and they are also one of the main components of mixed liquid crystals for STN, TFT and other liquid crystal displays. The synthesis of 3,4-difluoro-substituted and 3,4,5-trifluoro-substit...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C17/354C09K19/08C07C25/13B01J23/44
Inventor 夏治国华瑞茂梁晓李韶辉王奎朱起明
Owner SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
Login to View More 
Login to View More