阅读说明：本技术 一种低色号偏苯三酸三(c8-10醇)酯的制备方法 (Preparation method of low-color tri (C8-10 alcohol) trimellitate ) 是由 郑铁江 蒋国强 孙百亚 周国君 赵跃 缪世军 章培伟 张晓� 陶植 于 2020-11-16 设计创作，主要内容包括：本发明公开了一种低色号偏苯三酸三(C8-10醇)酯的制备方法,它涉及有机化工生产技术领域。包括如下步骤：酯化：将原料投入反应釜中,加入带水剂、固体催化剂反应；脱醇：开启真空,抽除大部分过量的C8-10醇；过滤：趁热过滤回收固体催化剂；氧化：加入双氧水；碱洗：加入碱性试剂溶液,静止分层,去除其中的水相；脱醇：抽尽残留的水分和C8-10醇；吸附：加入吸附剂和助滤剂硅藻土；过滤：将脱色液趁热过滤,得到滤液即为成品偏苯三酸三(C8-10醇)酯。本发明的优点在于：采用固体催化剂、添加脱水剂和添加氧化剂工艺,不仅能得到低色号、低酸值、高体积电阻率的高质量产品,而且产生的废水较少,能实现催化剂的回收,达到绿色环保、清洁生产的目的。(The invention discloses a preparation method of low-color-number tri (C8-10 alcohol) trimellitate, and relates to the technical field of organic chemical production. The method comprises the following steps: esterification: putting the raw materials into a reaction kettle, adding a water-carrying agent and a solid catalyst for reaction; dealcoholizing: opening vacuum, and pumping out most of excessive C8-10 alcohol; and (3) filtering: filtering while the solution is hot to recover the solid catalyst; and (3) oxidation: adding hydrogen peroxide; alkali washing: adding an alkaline reagent solution, standing for layering, and removing a water phase in the solution; dealcoholizing: pumping out residual water and C8-10 alcohol; adsorption: adding adsorbent and filter aid diatomite; and (3) filtering: filtering the decolored solution while the decolored solution is hot to obtain a filtrate, namely the finished product of trimellitic acid tri (C8-10 alcohol). The invention has the advantages that: by adopting the solid catalyst, the dehydrating agent and the oxidant, high-quality products with low color number, low acid value and high volume resistivity can be obtained, the generated wastewater is less, the recovery of the catalyst can be realized, and the aims of green, environmental protection and clean production are fulfilled.)

1. A preparation method of low-color trimellitic acid tri (C8-10 alcohol) ester is characterized by comprising the following steps: the method comprises the following steps:

s1, esterification: the method comprises the following steps of mixing trimellitic anhydride and C8-10 alcohol according to a molar ratio of 1: 3.5-5.0, putting into a reaction kettle, putting under the protection of nitrogen, adding a water-carrying agent, heating to 120-130 ℃ under stirring until solid trimellitic anhydride is completely dissolved, starting to discharge water from the reaction liquid when the temperature is raised to 170 ℃, adding a solid catalyst after keeping the liquid discharge for 15-90 min, wherein the using amount of the solid catalyst is 0.01-0.2% of the total mass of the reaction charge, finally heating to 190-210 ℃, starting timing and heat preservation, detecting the acid value of the reaction liquid after 2 hours, sampling once every 0.5 hour or 1 hour until the acid value is less than 0.1mgKOH/g, and finishing the esterification reaction;

s2, dealcoholization: stopping heating, starting vacuum at the vacuum degree of-0.095 MPa, pumping out most of excessive C8-10 alcohol by using the residual temperature of the reaction liquid under stirring, and vacuumizing for 0.5-1.5 h;

s3, filtering: when the temperature of the reaction solution is reduced to 115-125 ℃, filtering and recovering the solid catalyst while the reaction solution is hot;

s4, oxidation: adding pre-prepared 12% hydrogen peroxide into the filtered reaction solution at 70-100 ℃, and stirring for 0.5-1.5 h;

s5, alkali washing: adding a prepared alkaline reagent solution at the temperature, stirring for 0.5-1.5 h, standing for layering, and removing a water phase in the solution;

s6, dealcoholization: slowly heating the product phase to 170-180 ℃, stirring under negative pressure, and pumping out residual water and C8-10 alcohol;

s7, adsorption: cooling the reaction liquid to 70-90 ℃, adding an adsorbent accounting for 0.1-1.0% of the product amount and filter aid diatomite into the reaction liquid, and uniformly stirring and decoloring for 0.5-3 h;

s8, filtering: filtering the decolored solution while the decolored solution is hot to obtain a filtrate, namely the finished product of trimellitic acid tri (C8-10 alcohol).

2. The process according to claim 1 for the preparation of low color tri (C8-10 alcohol) trimellitate in the form of a mixture comprising: the weight ratio of the components in the reaction system is as follows:

。

3. according to the rightThe process for producing a low-color tri (C8-10 alcohol) trimellitate according to claim 1 or 2, wherein: the solid catalyst of S1 in the step is sodium bisulfite, stannous oxide, stannous chloride, solid super acid SO₄ ^2-/ZrO、SO₄ ^2-/ZnO、SO₄ ^2-/Fe₃O₄The water-carrying agent is one or more of toluene, xylene, pseudocumene and mesitylene.

4. The process for producing a low-color tri (C8-10 alcohol) trimellitate according to claim 1 or 2, wherein: the alkaline reagent in the step S5 is one or more of potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate.

5. The process for producing a low-color tri (C8-10 alcohol) trimellitate according to claim 1 or 2, wherein: the adsorbent in the step S7 is one or more of activated carbon, pottery clay and activated alumina.

Technical Field

The invention relates to the technical field of organic chemical production, in particular to a preparation method of low-color-number tri (C8-10 alcohol) trimellitate.

Background

The trimellitic triester plasticizer is a plastic processing aid with very excellent performance, and the esters have the advantages of small volatility, extraction resistance, migration resistance and the like of polyester plasticizers, and have the characteristics of both monomer plasticizers and polyester plasticizers because the compatibility, the processability, the low-temperature performance and the like of the esters are similar to monomer phthalate. The heat-resistant and durable plasticizer is widely used in industrial and civil applications, and has been widely used in developed countries such as the united states and germany, and the plasticizer has been used not only in the plastic industry but also in automobile manufacturing and civil entertainment and sports fields.

The tri (C8-10 alcohol) trimellitate is also called tri (n-octyl n-decyl) trimellitate, has comprehensive performance superior to that of the traditional plasticizer, and can endow the product with good light resistance, heat resistance, aging resistance and electrical insulation performance. The product produced by the product has the characteristics of good water resistance and extraction resistance, low toxicity, aging resistance and excellent electrical insulation performance, so the product is widely applied to the industrial fields of toy films, wire and cable insulation materials, automobile interior decoration materials, refrigerator sealing strips, swimming pool decoration materials and the like, and the product comprehensively meets all strict requirements of REACH detection.

At present, strong acids such as sulfuric acid and sulfonic acid are mostly adopted as catalysts in the process of synthesizing trimellitic acid tri (C8-10 alcohol) ester reported in literature, although the catalytic activity is high, the esterification temperature is low, the cost is low, the corrosion to equipment is serious, and impurities generated by side reactions during esterification are many, so that the problems of deepening the color and luster of products, higher acid value, lower volume resistivity and the like are caused, thereby affecting the product quality.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method of low-color tri (C8-10 alcohol) trimellitate, which can solve the problems of serious corrosion to equipment when strong acid is used as a catalyst, more impurities generated by side reaction during esterification, deepened product color, higher acid value, lower volume resistivity and influence on product quality.

In order to solve the technical problems, the technical scheme of the invention is as follows: the method comprises the following steps:

s1, esterification: the method comprises the following steps of mixing trimellitic anhydride and C8-10 alcohol according to a molar ratio of 1: 3.5-5.0, putting into a reaction kettle, putting under the protection of nitrogen, adding a water-carrying agent, heating to 120-130 ℃ under stirring until solid trimellitic anhydride is completely dissolved, starting to discharge water from the reaction liquid when the temperature is raised to 170 ℃, adding a solid catalyst after keeping the liquid discharge for 15-90 min, wherein the using amount of the solid catalyst is 0.01-0.2% of the total mass of the reaction charge, finally heating to 190-210 ℃, starting timing and heat preservation, detecting the acid value of the reaction liquid after 2 hours, sampling once every 0.5 hour or 1 hour until the acid value is less than 0.1mgKOH/g, and finishing the esterification reaction;

s2, dealcoholization: stopping heating, starting vacuum at the vacuum degree of-0.095 MPa, pumping out most of excessive C8-10 alcohol by using the residual temperature of the reaction liquid under stirring, and vacuumizing for 0.5-1.5 h;

s3, filtering: when the temperature of the reaction solution is reduced to 115-125 ℃, filtering and recovering the solid catalyst while the reaction solution is hot;

s4, oxidation: adding pre-prepared 12% hydrogen peroxide into the filtered reaction solution at 70-100 ℃, and stirring for 0.5-1.5 h;

s5, alkali washing: adding a prepared alkaline reagent solution at the temperature, stirring for 0.5-1.5 h, standing for layering, and removing a water phase in the solution;

s6, dealcoholization: slowly heating the product phase to 170-180 ℃, stirring under negative pressure, and pumping out residual water and C8-10 alcohol;

s7, adsorption: cooling the reaction liquid to 70-90 ℃, adding an adsorbent accounting for 0.1-1.0% of the product amount and filter aid diatomite into the reaction liquid, and uniformly stirring and decoloring for 0.5-3 h;

s8, filtering: filtering the decolored solution while the decolored solution is hot to obtain a filtrate, namely the finished product of trimellitic acid tri (C8-10 alcohol).

The weight ratio of the components in the reaction system is as follows:

further, the solid catalyst of S1 in the step is sodium bisulfite, stannous oxide, stannous chloride, solid super acid SO₄ ^2-/ZrO、SO₄ ^2-/ZnO、SO₄ ^2-/Fe₃O₄The water-carrying agent is one or more of toluene, xylene, pseudocumene and mesitylene.

Further, the alkaline agent in step S5 is one or more of potassium carbonate, potassium bicarbonate, sodium carbonate, and sodium bicarbonate.

Further, the adsorbent in step S7 is one or more of activated carbon, clay, and activated alumina.

The invention has the advantages that: the catalyst replaces the traditional concentrated sulfuric acid and sulfonic acid catalysts with solid catalysts, so that side reactions can be reduced, the solid catalysts can be directly recycled in the subsequent treatment process, less waste water is generated, and the aims of environmental protection and clean production are fulfilled;

because the molecular weight of the raw material C8-10 alcohol is larger, the boiling point is higher, the esterification can be completed at lower temperature under the action of a small amount of water-carrying agent, the reaction time is shortened, the energy is saved, and the acid value and the color number of the product are reduced;

hydrogen peroxide is added in the post-treatment step, and the color of the product can be further reduced to No. 15-20 mainly by virtue of the oxidation and decoloration effects of the hydrogen peroxide, so that the product quality is improved;

and (3) extracting and layering the water phase obtained by alkali washing in the post-treatment step to remove salts dissolved in the water phase, so that the product has the characteristic of high volume resistivity, and the product quality is improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments. The following examples are presented to enable one of ordinary skill in the art to more fully understand the present invention and are not intended to limit the scope of the embodiments described herein.

Example one

(1) Esterification: putting 115.3g of trimellitic anhydride and 389.44g of C8-10 alcohol as raw materials into a reaction kettle, putting under the protection of nitrogen, adding 50g of dimethylbenzene as a water-carrying agent, heating to 120 ℃ under stirring to completely dissolve solid trimellitic anhydride, heating to 170 ℃ to enable reaction liquid to begin to produce water, keeping the reaction liquid for 30min, adding 0.5g of stannous oxide, finally heating to 195 ℃, keeping the temperature for 3h at the beginning of timing, and measuring the acid value of the reaction liquid to be 0.056 mgKOH/g;

(2) dealcoholizing: stopping heating, starting vacuum at the vacuum degree of-0.095 MPa, pumping out most of excessive C8-10 alcohol by using the residual temperature of the reaction solution under stirring, and vacuumizing for 1 h;

(3) and (3) filtering: when the temperature of the reaction solution is reduced to about 120 ℃, filtering and recovering the solid catalyst while the reaction solution is hot;

(4) and (3) oxidation: adding 20.0g of pre-prepared 12% hydrogen peroxide into the filtered reaction solution at the temperature of 80 ℃, and stirring for 0.5 h;

(5) alkali washing: adding 20.0g of prepared sodium bicarbonate solution with the mass fraction of 2% at the temperature, stirring for 0.5h, standing for layering, and removing a water phase in the solution;

(6) dealcoholizing: slowly heating the product phase to 180 ℃, stirring under negative pressure and pumping out residual water and C8-10 alcohol;

(7) adsorption: cooling the reaction liquid to 80 ℃, adding 3.5g of argil and 3.5g of diatomite into the reaction liquid, and uniformly stirring the mixture for decoloring for 0.5 h;

(8) and (3) filtering: filtering the decolored solution while the decolored solution is hot to obtain filtrate, namely the finished product of trimellitic acid tri (C8-10 alcohol) ester, wherein the acid value is 0.028mgKOH/g (the acid value detection method is determined according to the method of GB/T1668-⁹Omega m (detection according to GB/T1672-1988).

Example two

(1) Esterification: putting 115.3g of trimellitic anhydride and 346.2g of C8-10 alcohol into a reaction kettle, putting under the protection of nitrogen, adding 60g of trimellitic anhydride as a water-carrying agent, heating to about 120 ℃ under stirring to completely dissolve solid trimellitic anhydride, discharging reaction liquid at about 170 ℃, keeping the liquid discharged for 60min, and then adding solid super acid SO₄ ^2-1.0g of ZrO, finally heating to 200 ℃, and measuring the acid value of the reaction solution to be 0.045mgKOH/g when the time and the heat preservation are started for 4 hours;

(2) dealcoholizing: stopping heating, starting vacuum at a vacuum degree of-0.095 MPa, pumping out most of excessive C8-10 alcohol by using the residual temperature of the reaction solution under stirring, and vacuumizing for 0.5 h;

(3) and (3) filtering: when the temperature of the reaction solution is reduced to about 120 ℃, filtering and recovering the solid catalyst while the reaction solution is hot;

(4) and (3) oxidation: adding 15.0g of pre-prepared 12% hydrogen peroxide into the filtered reaction solution at 90 ℃, and stirring for 0.5 h;

(5) alkali washing: at the temperature, 20.0g of prepared sodium carbonate solution with the mass fraction of 1 percent is added, stirred for 0.5h, stood for demixing, and the water phase in the mixture is removed;

(6) dealcoholizing: slowly heating the product phase to 180 ℃, and pumping out residual water and C8-10 alcohol under the condition of negative pressure stirring;

(7) adsorption: cooling the reaction liquid to 90 ℃, adding 3.0g of activated carbon and 3.0g of diatomite into the reaction liquid, and uniformly stirring the mixture for decoloring for 0.5 h;

(8) and (3) filtering: filtering the decolored solution while the decolored solution is hot to obtain filtrate, namely the finished product of trimellitic acid tri (C8-10 alcohol) ester, the acid value is 0.020mgKOH/g (the acid value detection method is determined according to the method of GB/T1668-⁹Omega m (detection according to GB/T1672-1988).

EXAMPLE III

(1) Esterification: putting 115.3g of raw material trimellitic anhydride and 302.9g of C8-10 alcohol into a reaction kettle, putting under the protection of nitrogen, adding 70g of mesitylene as a water-carrying agent, heating to about 120 ℃ under stirring to completely dissolve the solid trimellitic anhydride, starting to discharge water from reaction liquid at about 170 ℃, keeping the liquid for 45min, then adding 0.8g of solid stannous chloride, finally heating to 205 ℃, starting to time and preserve heat for 3.5h, and measuring the acid value of the reaction liquid to be 0.062 mgKOH/g;

(2) dealcoholizing: stopping heating, starting vacuum at a vacuum degree of-0.095 MPa, pumping out most of excessive C8-10 alcohol by using the residual temperature of the reaction solution under stirring, and vacuumizing for 0.5 h;

(3) and (3) filtering: when the temperature of the reaction solution is reduced to about 120 ℃, filtering and recovering the solid catalyst while the reaction solution is hot;

(4) and (3) oxidation: adding 10.0g of pre-prepared 12% hydrogen peroxide into the filtered reaction solution at 85 ℃, and stirring for 0.5 h;

(5) alkali washing: at the temperature, 20.0g of prepared potassium bicarbonate solution with the mass fraction of 2 percent is added, stirred for 1 hour, stood for demixing, and the water phase in the solution is removed;

(6) dealcoholizing: slowly heating the product phase to 180 ℃, and pumping out residual water and C8-10 alcohol under the condition of negative pressure stirring;

(7) adsorption: cooling the reaction liquid to 85 ℃, adding 3.5g of activated alumina and 3.5g of diatomite into the reaction liquid, and uniformly stirring the mixture for decoloring for 0.5 h;

(8) and (3) filtering: filtering the decolorized solution while it is hot to obtain filtrate (trimellitic acid)Acid tri (C8-10 alcohol) ester, acid value of 0.030mgKOH/g (the acid value detection method is determined according to the method of GB/T1668-2008), color number of 20 (determined according to the regulation of GB/T1664-1995), volume resistivity of 14.3 x 10⁹Omega m (detection according to GB/T1672-1988).

TABLE 1 comparison of the masses of the components of examples 1 to 3

To compare the properties of the tri (C8-10 alcohol) trimellitate prepared using the above formulation, it was subjected to the relevant tests, and the test results are shown in Table 2.

TABLE 2 test results of tri (C8-10 alcohol) trimellitate prepared in examples 1 to 3

Item	Example 1	Example 2	Example 3
				Acid value in the reaction	0.056mgKOH/g	0.045mgKOH/g	0.062mgKOH/g
Acid value of the finished product	0.028mgKOH/g	0.020mgKOH/g	0.030mgKOH/g
				Color number	Number 15	Number 15	No. 20
Volume resistivity	15.2×109Ωm	17.2××109Ωm	14.3××109Ωm

As can be seen from the table above, the prepared trimellitic acid tri (C8-10 alcohol) ester has low color number and acid value, high volume resistivity and high product quality, and in addition, compared with examples 1 to 3, the performances of example 2 are better than those of the other two examples, so that example 2 is the best example.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.