CN1085541A

CN1085541A - The preparation technology of powdered benzene diformate of alkali metal

Info

Publication number: CN1085541A
Application number: CN 93109976
Authority: CN
Inventors: 许生
Original assignee: LIAOYANG CITY PETRO-CHEMICAL INST
Current assignee: LIAOYANG CITY PETRO-CHEMICAL INST
Priority date: 1993-08-24
Filing date: 1993-08-24
Publication date: 1994-04-20

Abstract

The preparation technology of powdered benzene diformate of alkali metal of the present invention is the industrial process of masking agent and linking agent in the tanning industry, it makes raw material at the bottom of utilizing the still of production of polyester, drop into mixing in the mixer (5) with technical grade soda ash (2), mixed raw materials is put into the reactor stirring reaction, at last product that reaction is finished and mixed dibasic acid (3) (fourth, penta, oneself) add mixing machine (9) mix neutralize product (4).The product that uses technology of the present invention to make can satisfy the needs of tanning industry fully, is mainly used in tanning industry and makes masking agent and linking agent.Because its cost is low, quality is good, and promotional value is high.

Description

The preparation technology of powdered benzene diformate of alkali metal

The preparation technology of powdered benzene diformate of alkali metal of the present invention is the industrial process of masking agent and linking agent in the tanning industry, belongs to the invention that leather chemistry is handled articles for use.

In tanning industry, the pollution of chromium is very big, in order to solve the pollution problem of chromium, many no chromic tannings had once been proposed both at home and abroad, but the leather of making is qualitatively far away from chrome tanned leather, so adopt any method can keep chrome-tanned advantage, can reduce the pollution of chromium again, be the current problem that needs solution, in recent years, tanning industry generally adopts sodium phthalate to make chrome tanning adjuvant, because sodium phthalate does not have product to sell, therefore, tannery uses phthalate anhydride by adopting with in the soda ash and back, use extremely inconvenience, cost is also higher.

Along with developing rapidly of petrochemical industry, the output of polyester increases considerably, produce a large amount of products of paying that contains terephthalic acid simultaneously, domestic and international many scientific workers are engaged in this pair Products Development and utilization, the technology that adopts is pressurization, high temperature, saponification hydrolysis, as United States Patent (USP) 4078143,4578520,4542239, English Patent 2123403, German Patent 3221341,206677 etc., in addition, with the alkaline purification of PET polyester fabric, generation contains the NaOH aqueous solution of a small amount of para-phthalic sodium, uses H ₂SO ₄Carry out acidifying and get terephthalic acid, as day the disclosure specially permit clear 62-212339,61-43139,60-19748,60-51145, United States Patent (USP) 4215224, day disclosure special permission 57-212318,58-21645, the products obtained therefrom terephthalic acid is mainly used in the production softening agent, and report is not used for tanning as yet, the seventies later stage, Shanghai Inst. of Leather Industry utilized above-mentioned caustic soda hydrolysis process to make the phthalic acid sodium water solution, be used for tanning industry first, but owing to can only obtain 12% the aqueous solution, concentration and evaporation, the energy consumption height, easily fouling is not promoted the use of, but its use in tanning industry has obtained fully certainly.This method is owing to use different phthalic acid isomer, and the solubleness of an alkali metal salt is also different, and it is very big to consume energy in dehydration procedure, and plant factor is low, and this is an also open question.

The preparation technology's of powdered benzene diformate of alkali metal of the present invention purpose of design is exactly the preparation technology's energy consumption height that solves powdered benzene diformate of alkali metal, the problem that plant factor is low, it adopts at the bottom of the still of production of polyester, based on phthalic acid (contain to, and adjacent), process using soda ash neutralisation, raw material and soda ash are mixed, pulverize, dry powder reaction under 120 ℃ of-150 ℃ of conditions, directly obtain more than 100 orders, content is compared with general technology greater than 80% product, flow process is short, and energy expenditure is low.

General saponification hydrolysis can only obtain 12% the aqueous solution, and (para-phthalic sodium is 12% at the water solubility of water, and do not vary with temperature and change, can not form crystallization), if expect solid phthalic acid sodium, just must concentrate, in concentration process, the easy fouling of para-phthalic sodium is because concentration is low, energy consumption is very high, be difficult to form suitability for industrialized production, utilize neutralisation to address this problem, and can directly obtain content greater than the powder-like product more than 80%.

The present invention makes raw material at the bottom of utilizing the still of production of polyester, it mainly is phthalic acid, contain contraposition, the three kinds of isomer in an ortho position and a position, start mixer (5), raw material (1) and technical grade soda ash (2) are dropped in the mixer (5), the ratio of raw material (1) and soda ash (2) should add in the ratio of neutralization reaction, the amount of soda ash should be more, till being mixed to evenly, generally need 15-30 minute, it generally also plays certain crushing effect.Then mixed raw materials is put into material logical sequence (6), entering before the reactor (8), add equably in the pulverizer (7) earlier, be crushed to granularity and more than 100 orders, can add stirring reaction in the reactor (8), reactor is equipped with agitator and thermometer, temperature of reaction is controlled at 120 ℃ to 150 ℃, optimum point is 135 ℃, reaction and drying are carried out simultaneously, reaction times is generally at 20-40 minute, water-soluble pH value was between 7-8 when reaction was finished, the phthalic acid sodium content is greater than 80%, and free alkali is not more than 3%, at last product that reaction is finished and mixed dibasic acid (3) (fourth, penta, oneself) add mixing machine (9) mix neutralize product (4), adding mixed dibasic acid is for the free alkali in the neutralized product, and the water-soluble pH value that makes the finished product (4) is 7.

The product that uses technology of the present invention to make can satisfy the needs of tanning industry fully, is mainly used in tanning industry and makes masking agent and linking agent, because its cost is low, quality is good, and promotional value is high.

Enumerate embodiments of the invention below, see Fig. 1.

With (1) 100 kilogram of raw material, be to utilize (phthalic acid at the bottom of the still of production of polyester, contain contraposition, an ortho position and a position) make raw material, (2) 86 kilograms of technical grade soda ash, drop into mixer (5), mixed 20 minutes, pulverize after reactor (8) reacts under 135 ℃ of conditions through pulverizer (7), reaction times is 30 minutes, gets 152 kilograms of intermediates, and its water-soluble pH value is 7.5, free alkali is 2%, the phthalic acid sodium content is 85%, again with mix in intermediate product and (3) the 10 kilograms of adding mixing machines of mixed dibasic acid (9) neutralize (4) 162 kilograms of products, water-soluble pH value is 7.

Claims

1, a kind of preparation technology who is used for the powdered benzene diformate of alkali metal of tanning industry masking agent and linking agent adopts phthalic acid is neutralized with soda ash, the invention is characterized in:

(a) make raw material at the bottom of utilizing the still of production of polyester, it mainly is phthalic acid, contain contraposition, the three kinds of isomer in an ortho position and a position, start mixer (5), raw material (1) and technical grade soda ash (2) are dropped in the mixer (5), and the ratio of raw material (1) and soda ash (2) should add in the ratio of neutralization reaction, and the amount of soda ash should be more, till being mixed to evenly, generally need 15-30 minute;

(b) then mixed raw materials is put into material logical sequence (6), entering before the reactor (8), add equably in the pulverizer (7) earlier, be crushed to granularity and can add stirring reaction in the reactor (8) more than 100 orders, reactor is equipped with agitator and thermometer, temperature of reaction is controlled at 120 ℃ to 150 ℃, reaction and drying are carried out simultaneously, and the reaction times, water-soluble pH value was between 7-8 when reaction was finished generally at 20-40 minute, the phthalic acid sodium content is greater than 80%, and free alkali is not more than 3%;

(c) product that reaction is finished and mixed dibasic acid (3) (fourth, penta, oneself) add mixing machine (9) mix neutralize product (4), adding mixed dibasic acid is for the free alkali in the neutralized product, the water-soluble pH value that makes the finished product (4) is 7.

2, the preparation technology of powdered benzene diformate of alkali metal according to claim 1, it is characterized in that: the temperature of reaction optimum point of raw material in reactor (8) is 135 ℃, reaction times is 30 minutes, and the water-soluble pH value that the back intermediate product is finished in reaction is 7.5 to be good.