CN100363328C - Trimellitic tri(C8-9 ol)ester preparation method - Google Patents

Abstract

The invention discloses a preparation method of trimellitate tri(C _8-10 alcohol) ester, which belongs to the technical field of plasticizer synthesis. The present invention relates to the synthetic method of tri(2-ethyl)hexyl trimellitate, trinonyl trimellitate and tridecyl trimellitate, using trimellitic anhydride and _C8-10 alcohol as raw materials, and using solid super Strong acid or divalent tin oxide is used as a catalyst to carry out esterification reaction, and a new synthesis process of sulfuric acid-free catalysis and solvent-free water-carrying method is adopted. The process of the present invention not only makes the product have high ester content and high volume resistivity, but also does not require Neutralized and washed with water, no large amount of waste water is generated, and there is no pollution to the environment. The products can be widely used in 105℃ grade cable materials, 125℃ grade cable materials, automobile decoration materials, high-grade textile fiber oils, impregnated oils for pulse low-voltage power capacitors, electronic chemicals and high-tech military products.

Description

A kind of preparation method of trimellitic acid tris (C8-10 alcohol) ester

technical field

The invention discloses a preparation method of trimellitate tri(C _8-10 alcohol) ester, which belongs to the technical field of plasticizer synthesis.

Background technique

Compared with general-purpose plasticizers dioctyl phthalate (DOP) and dibutyl phthalate (DBP), trimellitate tri(C _8-10 alcohol) has large molecular weight, high flash point, and low volatility. It has many advantages such as low resistance, resistance to extraction from various solvents, and small migration. In addition, this trimellitate tri(C _8-10 alcohol) plasticizer with high ester content and high volume resistivity has good compatibility with polymer materials, especially PVC materials, during polymer processing. Properties such as resistance and low temperature performance are similar to monomeric phthalates, so it has the advantages of both monomeric plasticizers and polyester plasticizers. It can not only be used as a general main plasticizer in civilian products, but also can be used more widely in 105°C cable materials, 125°C cable materials, automotive decoration materials, advanced textile oils, impregnated oils for pulse low-voltage power capacitors , electronic chemical industry and high-tech military products.

Contents of the invention

The purpose of this invention is to provide a kind of preparation method of trimellitate tris (C _8-10 alcohol) ester. The production process of the invention not only makes the product have high ester content and high volume resistivity, but also does not produce a large amount of waste water, does not pollute the environment, and achieves the purpose of clean production.

The technical scheme of the present invention: the raw material trimellitic anhydride (referred to as partial anhydride) and the corresponding monohydric _C8-10 fatty alcohol are prepared by esterification under the action of a catalyst. The preparation process is as follows: trimellitic anhydride and fatty alcohol undergo esterification reaction under the action of a catalyst, and then dealcoholize, filter and ion exchange to obtain trimellitic acid tri(C _8-10 alcohol) ester product. The reaction formula is

The first step is partial anhydride and alcohol monoesterification

The second step is the double esterification reaction

The third step is the triple esterification reaction:

R: C _n H _2n+1 , n: 8-10

In the above process, the reactants trimellitic anhydride, higher carbon (C _8-10 ) alcohol, and catalyst are added to the esterification reaction device in a certain proportion, the temperature is 180-220 ° C, stirred and refluxed for 5-6 hours, and the esterification reaction is carried out, trimellitic anhydride: The molar ratio of _C8-10 alcohol is 1:3.5-4.0, the amount of catalyst is 0.01%-0.1% of the total mass of the reaction raw materials, and the water generated by the reaction is utilized to form a binary azeotrope to quickly remove the ester through hydrogen bonding with excess alcohol The reaction system is used to continuously carry out the reaction in the forward direction. When the conversion rate of the partial anhydride of the raw material is greater than 99.5%, the esterification reaction is completed, and the acid value is below 0.05mgKOH/g. In the esterification system, vacuum is used to remove excess alcohol, the vacuum degree is 0.5-0.1MPa, and the product is filtered, and the final product is subjected to adsorption treatment through a composite bed ion exchange column to obtain the final trimellitic acid tris (C _8-10 alcohol) ester product.

The catalyst is solid superacid or divalent tin oxide, and the solid superacid is SO ₄ ^2- /ZrO ₂ , SO ₄ ^2- /TiO ₂ or SO ₄ ^2- /Fe ₃ O ₄ . Solid superacid is obtained by impregnating carrier (such as zirconia ZrO ₂ , titanium oxide TiO ₂ or ferric iron tetroxide Fe ₃ O ₄ ) in sulfuric acid solution to absorb SO ₄ ^2- and then calcining. a supported catalyst.

The ion exchange resin in the composite bed ion exchange column is composed of macroporous anion resin and macroporous cation resin. The kind of plasticizer produced by the invention is: tri(2-ethyl)hexyl trimellitate, trinonyl trimellitate or tridecyl trimellitate. The raw material organic alcohol is a C _8-10 fatty alcohol, which can be a straight chain or a branched C _8-10 fatty alcohol. The catalyst is a solid acid, and the solid acid can be a solid superacid or divalent tin oxide. The product prepared by the invention can be widely used in 105°C polyvinyl chloride wire and cable materials and other PVC plastic products.

Beneficial effects of the present invention: the present invention adopts a new advanced sulfuric acid-free catalytic synthesis process, instead of traditional sulfuric acid catalysis, solid superacid or divalent tin oxide is used as a catalyst, which has better catalytic effect and no pollution.

The trimellitic acid tris (C _8-10 alcohol) ester reaction is a reversible reaction. For the benefit of the reaction, the product water must be continuously removed from the reaction system to destroy the balance of the esterification reaction. The solvent-carrying water method uses the hydrogen bond between alcohol and water to quickly form a binary azeotrope to remove the generated water from the reaction system and shorten the reaction time. Therefore, the process is short, the investment is small, and the production cost is low.

Since the reactivity of the three carboxyl groups in the molecular structure of trimellitic anhydride is unequal, after partial anhydride generates mono- and di-esters, the reactivity, electronic effect, and steric hindrance of the reactive group carboxyl group on the benzene ring will be greater. The change of the esterification reaction increases the reversibility of the esterification reaction, so that some mono- and di-esters exist in different degrees in the crude ester; the use of solid acid catalyst and ion exchange adsorption treatment can effectively reduce the by-products of the product and purify the product.

Detailed ways

Example 1

In the esterification reaction device, it is trimellitic anhydride and 2-ethylhexanol that the molar ratio of the reactants is 1: 3.5, and the solid acid SO ₄ ^2- /Fe ₃ O ₄ catalyst of 0.1% of the total mass of the reaction raw materials is added, at 180 After stirring and refluxing for 5 hours at ~220°C, the acid value of the esterified crude ester was determined to be 0.05mgKOH/g by neutralization titration, and the excess alcohol was removed under vacuum at 0.5-0.1MPa. After exchange column treatment, a finished product with a flash point of 245°C, an ester content of 99.5%, an acid value of 0.15 mgKOH/g, a color of 60 (APHA) and a volume resistivity of 1×10 ¹² Ω·CM was obtained. APHA is the platinum-cobalt colorimetric color unit.

Example 2

Add trimellitic anhydride and nonanol with a reactant molar ratio of 1:3.8 in the same esterification reaction device as in Example 1, and add 0.05% of the total mass of the reaction raw materials as a solid acid SO ₄ ^2- /TiO ₂ Catalyst, the catalyst is divided into two 75% solid acid of the total amount of catalyst is added as a reaction catalyst for the first time, and after stirring and reflux reaction for 4 hours under the condition of 180-220°C, the remaining 25% of solid acid catalyst is added to the reaction system, and then stirred and refluxed After reacting for 2 hours, the acid value of the esterified crude ester was determined to be 0.04mgKOH/g by neutralization titration, and the excess alcohol was removed under the condition of a vacuum of 0.5-0.1MPa, filtered, and then treated with a composite bed ion exchange column to obtain The flash point is 245°C, the ester content is 99%, the acid value of the finished product is 0.1mgKOH/g, the color is 60 (APHA), and the volume resistivity is 6×10 ¹¹ Ω·CM finished product

Example 3

Add the trimellitic anhydride and decanol that reactant mol ratio is 1: 4.0 in the esterification reaction device of embodiment 1, and add the solid acid SO of 0.01% of reaction raw material gross mass ₄ ^2- /ZrO ₂ Catalyst, at 180 After stirring and refluxing for 5 hours at ~220°C, the acid value of the esterified crude ester was determined to be 0.05mgKOH/g by neutralization titration, and the excess alcohol was removed under vacuum at 0.5-0.1MPa. After exchange column treatment, a finished product with a flash point of 245°C, an ester content of 99%, an acid value of 0.2 mgKOH/g, a color of 60 (APHA) and a volume resistivity of 1.5×10 ¹² Ω·CM was obtained.

Example 4

Add trimellitic anhydride and 2-ethylhexanol with a molar ratio of reactants of 1:3.5 in the esterification reaction device, add 0.1% SnO of the total mass of the reaction raw materials as a reaction catalyst, stir and reflux at 180-220°C for 6 hours , the acid value of the esterified crude ester was determined to be 0.04mgKOH/g by the neutralization method, and the excess alcohol was removed under the condition of vacuum 0.5-0.1MPa. , the ester content is 99%, the acid value of the finished product is 0.15 mgKOH/g, the color is 60 (APHA), and the volume resistivity is 8×10 ¹¹ Ω·CM.

Comparative Example 1

Add trimellitic anhydride and 2-ethylhexanol in a 3.5M ³ esterification reaction device with a molar ratio of reactants of 1:3.5. After stirring and refluxing under the conditions for 6 hours, the acid value of the esterified crude ester was determined to be 0.15mgKOH/g, and then the crude ester product was neutralized with 500GK of 5% sodium carbonate solution, and the alkali water layer was removed after static separation, and then 500GK of water was used to Carry out washing with water, remove excess alcohol under vacuum condition after separating the water layer, after filtering, the flash point obtained is 240°C, the ester content is 98%, the acid value of the finished product is 0.3mgKOH/g, the color and luster is 110 (APHA), the volume The resistivity is 1×10 ¹¹ Ω·CM finished product.

Applications

The properties of tris(2-ethyl)hexyl trimellitate (TOTM) after being used in the formulation of polyvinyl chloride products in automobiles are as follows.

TOTM is used in the formulation of polyvinyl chloride products in automobiles

Chemical composition formula accounts for the weight in the formula

Polyvinyl chloride 100.0

Filler 8.0

Stabilizer 8.0

Lubricant 0.5

TOTM 50.0

Trimellitic acid triester plasticizer used in the performance of polyvinyl chloride products in automobiles

  Trimellitate   Phthalates TOTM 9-11P 11P Anti-fog starting photometric reflectance % 1 hour recovery 3616 hours recovery 88 27 3471 100 Begin weight deposition, mg 4.8 4.6 9.8 Brittle temperature, ℃ -19 -28 -34 After 100 hours at 85°C; elongation retention % 99 94 87 After 100 hours at 85°C; tensile strength retention% 104 69 91

Claims (3)

1. tri trimellitate C _8-10The preparation method of alcohol ester is characterized in that by raw material trimellitic acid 1,2-anhydride and corresponding monobasic C _8-10Alcohol by esterification preparation, after the esterification, makes through dealcoholysis, filtration, ion-exchange process under the effect of catalyzer again; Reactant trimellitic acid 1,2-anhydride, high-carbon C _8-10Alcohol, catalyzer add esterification device with certain proportioning, and temperature stirring and refluxing 5-6 hour, is carried out esterification, trimellitic acid 1,2-anhydride: C at 180-220 ℃ _8-10The alcohol mol ratio is 1: 3.5-4.0, catalyst levels is the 0.01%-0.1% of reaction raw materials total mass, catalyzer is solid super-strong acid or Bivalent Tin oxide compound, when the transformation efficiency of the inclined to one side acid anhydride of raw material greater than 99.5% the time, finish esterification, acid number is to 0.05mgKOH/g, slough excessive alcohol with vacuum in esterification system, vacuum tightness is 0.5-0.1MPa, filtering product, final product carries out adsorption treatment through the multiple-hearth ion exchange column, obtains final tri trimellitate C _8-10The alcohol ester product.

2. preparation method according to claim 1 is characterized in that solid super acid catalyst is SO ₄ ^2-/ ZrO ₂, SO ₄ ^2-/ TiO ₂Or SO ₄ ^2-/ Fe ₃O ₄

3. preparation method according to claim 1 is characterized in that the ion exchange resin in the multiple-hearth ion exchange column is to be composited by the resin anion(R.A) of macropore and the resin cation (R.C.) of macropore.