Small test method for DOTP production

文档序号：1810277 发布日期：2021-11-09 浏览：12次中文

阅读说明：本技术 一种用于dotp生产的小试方法 (Small test method for DOTP production ) 是由朱敬忠梅国启国成于 2021-07-20 设计创作，主要内容包括：本发明公开了一种用于DOTP生产的小试方法,其技术方案要点是：包括以下步骤：步骤一.准备原材料：准备以下组分原材料：25-30份对甲苯二酸、50-70份辛醇以及0.1-0.3份催化剂；步骤二.处理原材料：将对甲苯二酸与辛醇转移到容量瓶内,然后将容量瓶至于冷柜中,控制冷柜的温度为-10℃至-20℃,存放时间为30-65min；步骤三.酯化反应：将冷冻后的对辛醇与对甲苯二酸从冷柜中取出后依次注入反应容器内,加注顺序为先加注辛醇；具有反应收率高、反应速率快、工艺流程简单易操作、副产品及杂质少、产品纯度高以及后处理简单的优点。(The invention discloses a pilot scale test method for DOTP production, which has the technical scheme key points that: the method comprises the following steps: step one, preparing raw materials: preparing the following raw materials: 25-30 parts of p-toluic acid, 50-70 parts of octanol and 0.1-0.3 part of catalyst; step two, processing raw materials: transferring p-toluic acid and octanol into a volumetric flask, placing the volumetric flask into a refrigerator, controlling the temperature of the refrigerator to be-10 ℃ to-20 ℃, and storing for 30-65 min; step three, esterification reaction: taking the frozen p-octanol and p-toluic acid out of the refrigerator, and then sequentially injecting the p-octanol and the p-toluic acid into the reaction container, wherein the injection sequence is that octanol is injected firstly; has the advantages of high reaction yield, high reaction rate, simple and easy operation of process flow, few by-products and impurities, high product purity and simple post-treatment.)

1. A pilot scale test method for DOTP production is characterized in that: the method comprises the following steps:

step one, preparing raw materials: preparing the following raw materials: 25-30 parts of p-toluic acid, 50-70 parts of octanol and 0.1-0.3 part of catalyst;

step two, processing raw materials: transferring p-toluic acid and octanol into a volumetric flask, placing the volumetric flask into a refrigerator, controlling the temperature of the refrigerator to be-10 ℃ to-20 ℃, and storing for 30-65 min;

step three, esterification reaction: taking the frozen p-octanol and p-toluic acid out of a refrigerator, and then sequentially injecting the p-octanol and the p-toluic acid into a reaction container, wherein the injection sequence is that firstly the octanol is injected, the p-toluic acid is injected after the octanol and the p-toluic acid are continuously stirred for 1-3min, then the reaction container is slowly heated, the catalyst is added for multiple times while the octanol and the p-toluic acid are continuously stirred for catalysis, and a primary finished product is obtained after the reaction is finished;

step four, inspection of finished products: and (3) neutralizing, degreasing, purifying and filter-pressing the primary finished product obtained in the step two to finally obtain the DOTP finished product, then inspecting the heat resistance, cold resistance, volatility and electrical insulation performance of the DOTP finished product, and if the performances in the inspection are unqualified, adjusting the ratio of the raw materials according to the performances until the performances are completely qualified.

2. A bench scale process for DOTP production according to claim 1, wherein: the specific operation of adding the catalyst for multiple times in the step two is as follows: adding catalyst accounting for one third of the total mass after adding the p-toluic acid and continuously stirring for 5-10min, then continuously stirring for 20-45min, then adding the rest catalyst accounting for one half of the total mass, and continuously stirring for 60-85min, and then completely adding the rest catalyst into the reaction container.

3. A bench scale process for DOTP production according to claim 1, wherein: the specific operation of slowly raising the temperature in the second step is as follows: firstly, heating a reaction container to 50-85 ℃ by using a heating tool, carrying out heat preservation reaction for 1h, then heating the reaction temperature in the reaction container to 230 ℃ at the heating rate of 5-8 ℃/min, and finally carrying out heat preservation reaction for 3-5 h.

4. A bench scale process for DOTP production according to claim 1, wherein: the heat resistance, the cold resistance, the volatility and the electrical insulation performance are respectively tested as follows:

and (3) testing heat resistance: dividing the DOTP finished product into 20 equal parts and injecting the 20 equal parts into a glass container, taking 40 ℃ as the lowest grade, then taking 10 ℃ as one grade to respectively correspond to 20 components of DOTP finished products, then sequentially putting the 20 groups of DOTP finished products into an oven respectively and setting corresponding temperatures, taking out the DOTP finished products after testing for 5min to detect active ingredients in the DOTP finished products, and obtaining the highest heat-resistant temperature of the DOTP finished products on the premise of not influencing the active ingredients according to test data;

cold resistance test the same heat resistance test, the experimental equipment is changed from an oven to a freezer, the temperature of 10 ℃ is set as the lowest grade, and then the test is carried out by taking the temperature of-5 ℃ as the first grade, so as to obtain the lowest cold resistance temperature of the DOTP finished product on the premise of not influencing the effective components;

testing the volatilization performance: placing the DOTP finished product in a normal-temperature normal-pressure windless open container, measuring the weight before the experiment as weight A, standing for 24h, weighing to obtain weight B, comparing the difference value of the weight B and the weight A, and finally calculating the volatilization rate of the DOTP finished product;

testing the electrical insulation performance: and (3) placing the DOTP finished product in a glass container, and then measuring by using an insulation resistance tester to obtain an electrical insulation performance numerical value.

5. A bench scale process for DOTP production according to claim 1, wherein: the catalyst comprises a first component and a second component, wherein the first component comprises a dibutyltin p-toluenesulfonate catalyst, the second component comprises a B-Ti catalyst, and the catalyst is formed by fully mixing dibutyltin p-toluenesulfonate and the B-Ti catalyst.

6. A bench scale method for DOTP production according to claim 5, wherein: the mass ratio of the first component to the second component is 1: 1.25.

7. A bench scale process for DOTP production according to claim 1, wherein: the second step comprises the following chemical reaction equation:

the method comprises the following steps:

the second formula:

the first formula is that terephthalic acid and octanol react to generate monoester;

and the second formula is that the monoester reacts with the residual octanol to obtain DOTP.

8. A bench scale process for DOTP production according to claim 1, wherein: the neutralization operation in the fourth step specifically comprises the following steps: and putting the primary finished product into a neutralization kettle, then putting alkali liquor into the neutralization kettle to mix, continuously stirring the mixture for 40min, finally standing the mixture in the neutralization kettle for 1 to 2 hours, and keeping the temperature in the neutralization kettle between 50 and 75 ℃ when standing the mixture.

9. A bench scale method for DOTP production according to claim 8, wherein: the temperature of the alkali liquor is controlled to be 50-60 ℃, the concentration of the alkali liquor is 5%, the alkali liquor comprises a sodium hydroxide solution, and the end point of the neutralization acidity is controlled to be 0.03mgKOH/g-0.05 mgKOH/g.

10. A bench scale process for DOTP production according to claim 1, wherein: and the degreasing operation in the fourth step is to fill the neutralized mixed solution into a dealcoholization kettle for reaction, and simultaneously control the acid value of the mixed solution to be below 0.1mgKOH/g, control the flash point of the mixed solution to be above 180 ℃, and control the color of the mixed solution to be below 25 APHA.

Technical Field

The invention belongs to the field of plasticizer production, and particularly relates to a pilot plant test method for DOTP production.

Background

DOTP (dioctyl terephthalate) is a main plasticizer with excellent performance for polyvinyl chloride (PVC) plastics. Compared with the dioctyl phthalate (DOP) which is commonly used at present, the dioctyl phthalate has the advantages of heat resistance, cold resistance, difficult volatilization, extraction resistance, good flexibility, good electric insulation performance and the like, and shows excellent durability, soap water resistance and low-temperature flexibility in products. Because of low volatility, DOTP can completely meet the requirement of temperature resistance grade of wires and cables, and can be widely applied to 70 ℃ resistant cable materials (International electrotechnical Commission IEC standard) and other various PVC soft products. The DOTP can be used for producing artificial leather films besides a large amount of plasticizers used for cable materials and PVC. In addition, the plasticizer has excellent compatibility, and can be used for plasticizers such as acrylonitrile derivatives, polyvinyl butyral, nitrile rubber, and cellulose nitrate. It can also be used as plasticizer, coating additive, lubricant for precision instruments, lubricant additive for synthetic rubber, and softener for paper.

Reference can be made to a Chinese patent with publication number CN105130804B, which relates to the technical field of plasticizer production, in particular to a production method and a production system of an environment-friendly plasticizer DOTP. The method comprises the following steps: feeding the wet material into a double-helix meter, adding octanol, mixing, pre-soaking, feeding into an esterification kettle, adding an alkali solution, stirring, washing, controlling the pH value to be neutral, and heating to evaporate water; continuously feeding materials by utilizing the vacuum action; a decoloring agent is added to improve the decoloring effect; heating under the action of vacuum, adding diatomite and kaolin into the filter, and filtering to obtain the product. The invention realizes the feeding of two raw materials in a metering ratio, the neutralization and water washing reduce the corrosion of equipment, and the esterification and dealcoholization of the reaction kettle are completed in one kettle.

Above-mentioned patent realizes continuous production, realizes changeing material and reinforced continuous production under the vacuum effect, and the residue passes through treatment facility recycle, has realized the resourceization, has practiced thrift the cost, has improved the environment, but it also has the defect, if: the method has the advantages of long reaction steps, low yield and more reaction impurities.

Disclosure of Invention

The invention aims to provide a pilot plant method for DOTP production, which solves the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a pilot plant method for DOTP production, comprising the steps of:

step one, preparing raw materials: preparing the following raw materials: 25-30 parts of p-toluic acid, 50-70 parts of octanol and 0.1-0.3 part of catalyst;

Preferably, the specific operations of adding the catalyst for multiple times in the second step are as follows: adding catalyst accounting for one third of the total mass after adding the p-toluic acid and continuously stirring for 5-10min, then continuously stirring for 20-45min, then adding the rest catalyst accounting for one half of the total mass, and continuously stirring for 60-85min, and then completely adding the rest catalyst into the reaction container.

Preferably, the specific operation of slowly raising the temperature in the second step is as follows: firstly, heating a reaction container to 50-85 ℃ by using a heating tool, carrying out heat preservation reaction for 1h, then heating the reaction temperature in the reaction container to 230 ℃ at the heating rate of 5-8 ℃/min, and finally carrying out heat preservation reaction for 3-5 h.

Preferably, the heat resistance, the cold resistance, the volatility and the electrical insulation performance are respectively tested as follows:

Preferably, the catalyst comprises a first component and a second component, the first component comprises a dibutyltin p-toluenesulfonate catalyst, the second component comprises a B-Ti catalyst, and the catalyst is formed by fully mixing dibutyltin p-toluenesulfonate and the B-Ti catalyst.

Preferably, the mass ratio of the first component to the second component is 1: 1.25.

Preferably, the second step includes the following chemical reaction equation:

the method comprises the following steps:

the second formula:

the first formula is that terephthalic acid and octanol react to generate monoester;

and the second formula is that the monoester reacts with the residual octanol to obtain DOTP.

Preferably, the neutralization operation in the fourth step specifically comprises: and putting the primary finished product into a neutralization kettle, then putting alkali liquor into the neutralization kettle to mix, continuously stirring the mixture for 40min, finally standing the mixture in the neutralization kettle for 1 to 2 hours, and keeping the temperature in the neutralization kettle between 50 and 75 ℃ when standing the mixture.

Preferably, the temperature of the alkali liquor is controlled to be 50-60 ℃, the concentration of the alkali liquor is 5%, the alkali liquor comprises a sodium hydroxide solution, and the end point of the neutralization acidity is controlled to be 0.03mgKOH/g-0.05 mgKOH/g.

Preferably, the degreasing operation in the fourth step is to fill the neutralized mixed solution into a dealcoholization kettle for reaction, and simultaneously control the acid value of the mixed solution to be below 0.1mgKOH/g, control the flash point of the mixed solution to be above 180 ℃, and control the color of the mixed solution to be below 25 APHA.

Compared with the prior art, the invention has the beneficial effects that:

the small test method for DOTP production greatly shortens the reaction preparation time, the prior art needs 8-12 hours to ensure the esterification reaction to be complete, and the method ensures that the reaction time is shortened to 3-5 hours by optimizing the filling sequence and the filling times of octanol and p-toluic acid and performing freezing treatment, has the advantage of high reaction rate, simultaneously has simple and easily realized process flow, does not generate harmful substances in the reaction, has less impurities in the reaction, and has better color of the prepared DOTP and higher purity, so that the method has the advantages of high reaction yield, high reaction rate, simple and easily operated process flow, less byproducts and impurities, high product purity and simple post-treatment.

Drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Please refer to FIG. 1

Example 1

A pilot plant method for DOTP production, comprising the steps of:

step one, preparing raw materials: preparing the following raw materials: 25 parts of p-toluic acid, 50 parts of octanol and 0.1 part of catalyst;

step three, esterification reaction: taking the frozen p-octanol and p-toluic acid out of a refrigerator, and then sequentially injecting the p-octanol and the p-toluic acid into a reaction container, wherein the injection sequence is that firstly the octanol is injected, the p-toluic acid is injected after the octanol and the p-toluic acid are continuously stirred for 1min, then the reaction container is slowly heated, the octanol and the p-toluic acid are continuously stirred and simultaneously added with a catalyst for multiple times for catalysis, and a primary finished product is obtained after the reaction is finished;

In this embodiment, preferably, the specific operations of adding the catalyst in multiple times in step two are as follows: adding the catalyst accounting for one third of the total mass after adding the p-toluic acid and continuously stirring for 5min, then continuously stirring for 20min, then adding the catalyst accounting for one half of the rest amount, and continuously stirring for 60min, and then completely adding the rest catalyst into the reaction container.

In this embodiment, preferably, the specific operation of slowly raising the temperature in the step two is as follows: firstly, heating a reaction container to 50 ℃ by using a heating tool, carrying out heat preservation reaction for 1h, then heating the reaction temperature in the reaction container to 180 ℃ at the heating rate of 5 ℃/min, and finally carrying out heat preservation reaction for 3 h.

In this embodiment, preferably, the tests of heat resistance, cold resistance, volatility and electrical insulation performance are respectively as follows:

In this embodiment, preferably, the catalyst includes a first component and a second component, the first component includes a dibutyltin p-toluenesulfonate catalyst, the second component includes a B-Ti catalyst, and the catalyst is formed by fully mixing dibutyltin p-toluenesulfonate and the B-Ti catalyst.

In this embodiment, the mass ratio of the first component to the second component is preferably 1: 1.25.

In this embodiment, preferably, the following chemical reaction equation is included in the second step:

the method comprises the following steps:

the second formula:

the first formula is that terephthalic acid and octanol react to generate monoester;

and the second formula is that the monoester reacts with the residual octanol to obtain DOTP.

In this embodiment, preferably, the neutralization operation in the fourth step specifically includes: and putting the primary finished product into a neutralization kettle, then putting alkali liquor into the neutralization kettle to mix, continuously stirring the mixture for 40min, finally standing the mixture in the neutralization kettle for 1h, and keeping the temperature in the neutralization kettle at 50 ℃ when standing the mixture.

In this embodiment, it is preferable that the temperature of the alkali solution is controlled to 50 ℃, the concentration of the alkali solution is 5%, the alkali solution includes a sodium hydroxide solution, and the end point of the neutralization acidity is controlled to be 0.03 mgKOH/g.

In this embodiment, preferably, the degreasing operation in the fourth step is to fill the neutralized mixed solution into a dealcoholization kettle to perform a reaction, and simultaneously control the acid value of the mixed solution to be 0.06mgKOH/g, the flash point of the mixed solution to be 190 ℃, and the color of the mixed solution to be 22 APHA.

Example 2

A pilot plant method for DOTP production, comprising the steps of:

step one, preparing raw materials: preparing the following raw materials: 30 parts of p-toluenedioic acid, 70 parts of octanol and 0.3 part of catalyst;

step three, esterification reaction: taking the frozen p-octanol and p-toluic acid out of a refrigerator, and then sequentially injecting the p-octanol and the p-toluic acid into a reaction container, wherein the injection sequence is that firstly the octanol is injected, the p-toluic acid is injected after continuously stirring for 3min, then the reaction container is slowly heated, the octanol and the p-toluic acid are continuously stirred and simultaneously added with a catalyst for multiple times for catalysis, and a primary finished product is obtained after the reaction is finished;

In this embodiment, preferably, the specific operations of adding the catalyst in multiple times in step two are as follows: adding the catalyst accounting for one third of the total mass after adding the p-toluic acid and continuously stirring for 10min, then continuously stirring for 45min, then adding the catalyst accounting for one half of the rest amount, and continuously stirring for 85min, and then completely adding the rest catalyst into the reaction container.

In this embodiment, preferably, the specific operation of slowly raising the temperature in the step two is as follows: firstly, heating a reaction container to 85 ℃ by using a heating tool, carrying out heat preservation reaction for 1h, then heating the reaction temperature in the reaction container to 230 ℃ at the heating rate of 8 ℃/min, and finally carrying out heat preservation reaction for 5 h.

In this embodiment, preferably, the tests of heat resistance, cold resistance, volatility and electrical insulation performance are respectively as follows:

In this embodiment, the mass ratio of the first component to the second component is preferably 1: 1.25.

In this embodiment, preferably, the following chemical reaction equation is included in the second step:

the method comprises the following steps:

the second formula:

the first formula is that terephthalic acid and octanol react to generate monoester;

and the second formula is that the monoester reacts with the residual octanol to obtain DOTP.

In this embodiment, preferably, the neutralization operation in the fourth step specifically includes: and putting the primary finished product into a neutralization kettle, then putting alkali liquor into the neutralization kettle to mix, continuously stirring the mixture for 40min, finally standing the mixture in the neutralization kettle for 2h, and keeping the temperature in the neutralization kettle at 75 ℃ when standing the mixture.

In this embodiment, it is preferable that the temperature of the alkali solution is controlled to 50-60 ℃, the concentration of the alkali solution is 5%, the alkali solution comprises sodium hydroxide solution, and the end point of the neutralization acidity is controlled to be 0.05 mgKOH/g.

In this embodiment, preferably, the degreasing operation in the fourth step is to fill the neutralized mixed solution into a dealcoholization kettle to perform a reaction, and simultaneously control the acid value of the mixed solution to be 0.06mgKOH/g, the flash point of the mixed solution to be 200 ℃, and the color of the mixed solution to be 20 APHA.

Example 3

A pilot plant method for DOTP production, comprising the steps of:

step one, preparing raw materials: preparing the following raw materials: 28 parts of p-toluic acid, 65 parts of octanol and 0.1 part of catalyst;

step three, esterification reaction: taking the frozen p-octanol and p-toluic acid out of a refrigerator, and then sequentially injecting the p-octanol and the p-toluic acid into a reaction container, wherein the injection sequence is that firstly the octanol is injected, the p-toluic acid is injected after continuously stirring for 3min, then the reaction container is slowly heated, the octanol and the p-toluic acid are continuously stirred and simultaneously added with a catalyst for multiple times for catalysis, and a primary finished product is obtained after the reaction is finished;

In this embodiment, preferably, the specific operations of adding the catalyst in multiple times in step two are as follows: adding the catalyst accounting for one third of the total mass after adding the p-toluic acid and continuously stirring for 10min, then continuously stirring for 40min, then adding the catalyst accounting for one half of the rest amount, and continuously stirring for 80min, and then completely adding the rest catalyst into the reaction container.

In this embodiment, preferably, the specific operation of slowly raising the temperature in the step two is as follows: firstly, heating a reaction container to 85 ℃ by using a heating tool, carrying out heat preservation reaction for 1h, then heating the reaction temperature in the reaction container to 220 ℃ at the heating rate of 6 ℃/min, and finally carrying out heat preservation reaction for 5 h.

In this embodiment, preferably, the tests of heat resistance, cold resistance, volatility and electrical insulation performance are respectively as follows:

In this embodiment, the mass ratio of the first component to the second component is preferably 1: 1.25.

In this embodiment, preferably, the following chemical reaction equation is included in the second step:

the method comprises the following steps:

the second formula:

the first formula is that terephthalic acid and octanol react to generate monoester;

and the second formula is that the monoester reacts with the residual octanol to obtain DOTP.

In this embodiment, preferably, the neutralization operation in the fourth step specifically includes: and putting the primary finished product into a neutralization kettle, then putting alkali liquor into the neutralization kettle to mix, continuously stirring the mixture for 40min, finally standing the mixture in the neutralization kettle for 2h, and keeping the temperature in the neutralization kettle at 70 ℃ when standing the mixture.

In this embodiment, it is preferable that the temperature of the alkali solution is controlled to 55 ℃, the concentration of the alkali solution is 5%, the alkali solution comprises sodium hydroxide solution, and the end point of the neutralization acidity is controlled to be 0.04 mgKOH/g.

In this embodiment, preferably, the degreasing operation in the fourth step is to fill the neutralized mixed solution into a dealcoholization kettle to perform a reaction, and simultaneously control the acid value of the mixed solution to be 0.06mgKOH/g, the flash point of the mixed solution to be 200 ℃, and the color of the mixed solution to be 22 APHA.

The working principle and the using process of the invention are as follows:

when the small test method for DOTP production is used, the small test method for DOTP production greatly shortens the reaction preparation time, the prior art needs 8-12 hours to ensure complete esterification reaction, and the method shortens the reaction time to 3-5 hours by optimizing the filling sequence, the filling times and the freezing treatment of octanol and p-toluic acid, and has the advantage of high reaction rate.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

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