Process for preparing oligosiloxane by hydrolysis of dimethyldichlorosilane with concentrated acid
A technology of dimethyldichlorosilane and oligosiloxane, which is applied in the field of preparation of oligosiloxane, can solve the problems of high operating cost, large amount of waste water, polysiloxane, etc., to reduce steam consumption, Reduced generation of waste acid and reduction in production cost
Active Publication Date: 2015-09-02
TANGSHAN SANYOU SILICON IND
View PDF1 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, its disadvantages are high operating cost (a large amount of refrigeration is required to cool the heat of hydrogen chloride solution; and a large amount of heat is required to decompose hydrogen chloride from concentrated acid), large amount of waste water, and more polysiloxane entrained in hydrochloric acid, etc., which are seriously restricted. Development and application of azeotropic acid hydrolysis
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0017] Describe the present invention in detail below in conjunction with accompanying drawing and embodiment
[0018] A process for preparing oligosiloxane by concentrated acid hydrolysis of dimethyldichlorosilane, using six-stage loop hydrolysis and refining, after acid washing, alkali washing and water washing, etc., one of the loop systems is the one of this embodiment core, and the rest of the loop process is consistent with the prior art.
[0019] For this example see image 3 As shown, the specific steps are as follows:
[0020] Dimethyldichlorosilane enters the first loop preheater in the loop system from the dimethyldichlorosilane mixer 1, and contacts and reacts with the concentrated acid circulating in the first loop.
[0021] Since the reaction is an endothermic reaction, the mixture enters a loop preheater 2 for heating, and the reacted material enters the hydrolysis reactor 3. When the system pressure reaches a pressure value of 2 kg, the generated hydrogen chl...
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 relates to a process for preparing oligosiloxane and in particular relates to a process for preparing oligosiloxane by virtue of hydrolyzing dimethyl dichlorosilance by concentrated acid. The process comprises the following steps that the dimethyl dichlorosilance performs contact reaction with the concentrated acid which circulates along a loop; a mixture enters a loop preheater to be heated; after the reaction, materials enter a hydrolysis reactor; HCL gas is separated out of the hydrolysis reactor; the generated oligosiloxane and concentrated sulfuric acid in a system overflow to a preseparator to be separated primarily; the concentrated acid at the bottom enters a circulating pump again to circulate; materials at the top and 7-15% of concentrated acid overflow to an acid layering device and then are settled and separated; the concentrated acid separated from the bottom returns to the circulating pump to be used continuously; and the materials at the top is conveyed to a rear loop refining system and the oligosiloxane is finally obtained. The hydrogen chloride gas is directly separated out of the hydrolysis reactor, so the hydrogen chloride gas is reduced, steam is consumed, a large quantity of waste acid is reduced, and the production cost is greatly reduced.
Description
technical field [0001] The invention relates to a process for preparing oligosiloxane, in particular to a process for preparing oligosiloxane by hydrolyzing dimethyldichlorosilane with concentrated acid. Background technique [0002] At present, the azeotropic acid loop hydrolysis process is widely used in the industry, that is, dimethyldichlorosilane and about 20% dilute acid are continuously sent in proportion to the centrifugal pump, heat exchanger, oil-water separator and pipeline. In the formed loop system, the generated HCL gas is dissolved in dilute acid and releases a large amount of heat. The hydrolysis temperature in the system is controlled at about 30°C after cooling, and the generated hydrolyzate is separated from oil and water. After removing the siloxane, the hydrochloric acid enters the desorption tower to extract HCL, which is used as a raw material for the synthesis of methyl chloride, and the dilute acid obtained by desorption is used as a raw material and...
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
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): C08G77/06
Inventor 李索海丁学志陈辉朱艳娜陈春江荣宝成孙国俊刘存泽李玉江王炳涛
Owner TANGSHAN SANYOU SILICON IND