CN108794424A

CN108794424A - A kind of method for refining solvent of BIT

Info

Publication number: CN108794424A
Application number: CN201810774669.4A
Authority: CN
Inventors: 刘桂权
Original assignee: LIANYUNGANG SUNLION CHEMICAL CO Ltd
Current assignee: LIANYUNGANG SUNLION CHEMICAL CO Ltd
Priority date: 2018-07-16
Filing date: 2018-07-16
Publication date: 2018-11-13

Abstract

The invention discloses a kind of method for refining solvent of BIT, include the following steps：（1）Primary dissolving：Addition BIT crude products in methyl alcohol, are warming up to 50~59 DEG C, keep BIT entirely molten, cooling, crystallization, and BIT, centrifugal exsolution agent is precipitated, and gained primary crystallization BIT waits that carrying out secondary dissolving refines, and gained methanol mother liquor goes rectifying；（2）Secondary dissolving, decoloration：Primary crystallization BIT is added in methyl alcohol, is warming up to 50~56 DEG C, keeps BIT entirely molten, activated carbon is added, removal activated carbon is filtered in heat preservation decoloration, and BIT is precipitated in cooling, crystallization, and centrifugal exsolution agent obtains BIT finished products.The crude product of BIT is dissolved using solvent, is decolourized, decrease temperature crystalline obtains finished product.Sodium hydroxide is not consumed, non-sodium chloride generates, solvent recycled after rectifying and dewatering, does not increase production cost, and the quality of product is better than acid-base method, and no waste water generates.Subtractive process is closed cycle, to material free of losses.It can guarantee that entirety yield, comprehensive production cost are less than acid-base method.

Description

A kind of method for refining solvent of BIT

Technical field

The present invention relates to BIT purification techniques fields.

Background technology

Antimildew disinfectant BIT chemical names are 1.2- benzisothiazole-3-ketones, are that a kind of novel environmental protective broad spectrum kills Bacterium preservative, is particularly suitable for hot environment and alkaline system, is widely used in coating, adhesive, Polymer Synthesizing lotion The sterilization and anticorrosion of equal water, oleaginous system, performance characteristics have：One, have high-efficiency broad spectrum, can effectively kill various bacteria, The various bacterium such as bacterium, iron rust bacterium, bacillus occur for fungi, mould, saccharomycete, anaerobic bacteria, pseudomonad, Legionella, hydrogen sulfide Class kills planktonic organism and algae, and bactericidal mould proof effect broad-spectrum long-acting does not develop immunity to drugs, and can reach using concentration 0.1% good Good fungistatic effect.Two, good with various emulsifiers, surfactant and other composition compatibilities, alcohol that can be in any proportion and Water etc. mixes, and stablizes to aminated compounds.Three, applicable pH ranges are wider compared with similar product, and pH2-14 can be used.Four, steady It is qualitative strong：Stored at -2 DEG C to 50 DEG C 1 year it is unchanged, effective ingredient is also stablized at 150 DEG C.Five, formaldehyde is free of, smell is low, VOC free, toxicity is low, is free of heavy metal and halogen compounds.To sum up, BIT is the important environment-friendly type commercial sterilization preservative of a new generation.

Domestic common production method：O-chloro benzonitrile carries out condensation reaction in solvent Benzene Chloride with sodium methyl mercaptide, obtains Methylmercapto cyanophenyl；Methylmercapto cyanophenyl is passed through chlorine, carries out chlorination, closed loop, BIT crude products are obtained by filtration.The purifying of BIT crude products Currently used method is acid-base method, and detailed process is：The crude product of BIT is added in the solution of NaOH, is warming up to 60-80 DEG C, Keep BIT entirely molten, activated carbon, heat preservation decoloration is added, filtering removes activated carbon, and filtrate adds hydrochloric acid to pH value 3.5-4.5, and centrifugation is de- Water obtains BIT finished products.A large amount of sodium hydroxide is consumed during purifying, while generating sodium chloride waste water, and waste water needs to carry out De-salting operation, biochemical treatment so that the production cost of BIT greatly increases.

Invention content

In view of the drawbacks of the prior art, the present invention provides a kind of method for refining solvent of BIT, are produced in the process without waste water It is raw, do not increase the production cost of BIT.

The present invention is achieved by the following technical solutions：

A kind of method for refining solvent of BIT, includes the following steps：

Step 1: primary dissolving

BIT crude products are added in methyl alcohol, is warming up to 50~59 DEG C, keeps BIT entirely molten, BIT, centrifugal exsolution is precipitated in cooling, crystallization Agent, gained primary crystallization BIT wait that carrying out secondary dissolving refines, and gained methanol mother liquor goes rectifying；

Step 2: secondary dissolving, decoloration

Primary crystallization BIT is added in methyl alcohol, is warming up to 50~56 DEG C, keeps BIT entirely molten, activated carbon, heat preservation decoloration, filtering is added Activated carbon is removed, BIT is precipitated in cooling, crystallization, and centrifugal exsolution agent obtains BIT finished products.

Further improvement of the present invention scheme is：

Methanol set in step 1 after rectifying is used for step 2；Step 2 centrifugation gained solvent mother liquor set is used for step 1.

The mass ratio of BIT crude products and methanol is 1 in step 1:4.2~4.6.

Beneficial effects of the present invention are：

The present invention carries out secondary refining operation using solvent methanol method to BIT crude products, and whole process is physical process, that is, uses molten Agent dissolves the crude product of BIT, is decolourized, decrease temperature crystalline obtains finished product.Sodium hydroxide is not consumed, non-sodium chloride generates, solvent warp Recycled after rectifying and dewatering is crossed, production cost is not increased, the quality of product is better than acid-base method, and no waste water generates.Subtractive process For closed cycle, to material free of losses.It can guarantee that entirety yield, comprehensive production cost are less than acid-base method.

Description of the drawings

Attached drawing 1 is subtractive process flow chart.

Specific implementation mode

Embodiment 1

Step 1：240gBIT crude products are added in 1050g methanol, are warming up to 49 DEG C, Quan Rong；24 DEG C, crystallization are cooled to, filtering obtains Primary crystallization product.Methanol mother liquor recycles rectifying and dewatering, obtains the methanol 975g of proportion 0.80, abbreviation solvent A.Rectifying residual is through simple Primary crystallization product are incorporated to after processing.

Step 2：Primary crystallization product are added in 900g methanol, are warming up to 48 DEG C, Quan Rong；Activated carbon 2g is added, keeps the temperature 30 points Clock, filtering, a small amount of methanol wash activated carbon；Filtrate cools to 16 DEG C, crystallization, and filtering obtains BIT finished products 181g.Methanol mother liquor is referred to as Solvent B.

BIT finished products are analyzed through HPLC, purity 99.36%, turbidity 5.30.

Embodiment 2

Step 1：240gBIT crude products are added in solvent B, are warming up to 51 DEG C, Quan Rong；22 DEG C, crystallization are cooled to, filtering obtains once Crystallization product.Methanol mother liquor recycles rectifying and dewatering, obtains the methanol 925g of proportion 0.80.Abbreviation solvent C.Rectifying is remained through simple process After be incorporated to primary crystallization product.

Step 2：Primary crystallization product are added in solvent A, are warming up to 52 DEG C, Quan Rong；Activated carbon 2g is added, keeps the temperature 30 minutes, Filtering, 50g methanol wash activated carbon；Filtrate cools to 15 DEG C, crystallization, and filtering obtains BIT finished products 202g.Methanol mother liquor abbreviation solvent D。

BIT finished products are analyzed through HPLC, purity 99.29%, turbidity 4.50.

Embodiment 3

Step 1：240gBIT crude products are added in solvent D, 50 DEG C are warming up to, Quan Rong；23 DEG C, crystallization are cooled to, filtering obtains one Secondary crystallization product.Methanol mother liquor recycles rectifying and dewatering, obtains the methanol 980g of proportion 0.80.Rectifying residual is incorporated to one after simple process Secondary crystallization product.

Step 2：Primary crystallization product are added in solvent C, are warming up to 51 DEG C, Quan Rong；Activated carbon 2g is added, keeps the temperature 30 minutes, Filtering, 30g methanol wash activated carbon；Filtrate cools to 15 DEG C, crystallization, and filtering obtains BIT finished products 202g.

BIT finished products are analyzed through HPLC, purity 99.40%, turbidity 4.40.

Claims

1. a kind of method for refining solvent of BIT, it is characterised in that include the following steps：

Step 1: primary dissolving

Step 2: secondary dissolving, decoloration

2. the method for refining solvent of BIT according to claim 1 a kind of, it is characterised in that：First in step 1 after rectifying Alcohol set is used for step 2；Step 2 centrifugation gained solvent mother liquor set is used for step 1.

3. the method for refining solvent of BIT according to claim 1 a kind of, it is characterised in that：BIT crude products and first in step 1 The mass ratio of alcohol is 1:4.2~4.6.