Multi-element catalyst for producing trioctyl trimellitate and application of multi-element catalyst

Abstract

The invention relates to a multi-element catalyst for producing trioctyl trimellitate and application of the multi-element catalyst. The multi-element catalyst comprises a main catalyst and a co-catalyst; the main catalyst is one or a mixture of several of stannate, a titanic acid compound, stannous chloride, stannous octoate and dibutyltin p-toluenesulfonate; and the cocatalyst is a quaternary ammonium salt ionic catalyst. The preparation method comprises the following steps: adding isooctyl alcohol into an esterification reaction kettle, preheating, adding trimellitic acid or trimellitic anhydride in batches, and stirring; adding a multi-element catalyst, heating to carry out primary esterification reaction, and further heating to carry out esterification reaction; and after the reaction is completed, removing the isooctanol under high vacuum to obtain the trioctyl trimellitate. The method has the advantages that when the multi-element catalyst is applied to synthesis of trioctyl trimellitate, the catalytic effect is good, the reaction is rapidly completed at a relatively low temperature, decomposition and deterioration of raw materials, a large amount of side reactions and generation of impurities, which are easily caused by high-temperature dissolution, are avoided, the reaction time is shortened, and the prepared trioctyl trimellitate is light in color, high in purity and high in yield.

Description

Technical Field

[0001] The invention relates to the technical field of plasticizer synthesis, and in particular to a multi-component catalyst for producing trioctyl trimellitate and application thereof. Background Art

[0002] Plasticizers are widely used polymer material additives in industry. Using plasticizers in plastic processing can modify or soften plastics, increase their physical properties such as plasticity, flexibility, stretchability or expansion.

[0003] Trioctyl trimellitate (TOTM) is a new type of special high-grade plasticizer with heat resistance and durability as its main features. It has the advantages of high flash point, low volatility, resistance to solvent extraction, low migration, and large molecular weight. At the same time, due to the high volume resistivity of trioctyl trimellitate and its excellent compatibility with polymers, especially polyvinyl chloride materials, it has excellent electrical properties and high resistivity, and is suitable for products with high electrical performance requirements. It can not only be used as a general plasticizer, but also be widely used in low-temperature cable materials, automotive interior materials, medical devices and polyvinyl chloride materials, as well as in vinyl chloride copolymers, cellulose nitrate, ethyl cellulose, polymethyl methacrylate and other plastics, so it has broad application prospects. It has good performance in terms of resistance to volatility, water extraction, and migration, and can maintain the stability and durability of the product. Trioctyl trimellitate is increasingly used in the plastics industry and telecommunications industry, and the demand for it is also increasing. Trioctyl trimellitate has a simple production process, is easy to prepare, and has a lower price than polyester plasticizers. It not only has the overall durability of polymeric plasticizers, but also has the good low-temperature performance of monomeric plasticizers. Therefore, trioctyl trimellitate has great development prospects and has become one of the main plasticizer varieties.

[0004] The traditional production process of trioctyl trimellitate is to mix the main raw materials, partial anhydride and isooctyl alcohol, in a certain ratio in an esterification reactor, add appropriate temperature, and keep enough time under the action of a catalyst to complete the esterification reaction and generate trioctyl trimellitate. However, due to the poor solubility of trimellitic anhydride or trimellitic acid in isooctyl alcohol, the initial esterification reaction time is long, and more excess isooctyl alcohol needs to be added for reaction, which has high energy consumption and is difficult to separate; high-temperature dissolution is easy to cause decomposition and deterioration of raw materials and a large number of side reactions and impurities; titanate or metal oxide is generally used as a catalyst in industrial production at present, although the overall reaction efficiency is high, the reaction temperature must not be kept at a high level due to its low initial esterification reaction rate, and the reaction is long, the catalyst deactivation speed is fast, the dosage is large, and the final product has more impurities. Therefore, it is necessary to further research and develop the catalyst used for the preparation of trioctyl trimellitate. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a multi-catalyst for the production of trioctyl trimellitate and its application, which can solve the problems in the prior art that the initial esterification reaction of the commonly used catalysts has a long reaction time, a large amount of excess isooctyl alcohol needs to be added, the energy consumption is high and the separation is difficult, and the high-temperature dissolution easily causes the decomposition and deterioration of the raw materials and a large number of side reactions and impurities are generated.

[0006] In order to solve the above technical problems, the technical scheme of the present invention is: comprising a main catalyst and a co-catalyst; the main catalyst is one or a mixture of several of stannate, titanate compound, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate; the co-catalyst is a quaternary ammonium salt ion catalyst; wherein the weight content of the main catalyst is 90-98% of the total amount of the multi-catalyst, and the weight content of the co-catalyst is 2-10% of the total amount of the multi-catalyst.

[0007] Furthermore, the stannate is one or more of tin hydroxymethane sulfonate, 2-hydroxybutyl-1-tin sulfonate, 2-hydroxyethyl-1-tin sulfonate, 2-butane sulfonate and modified stannates thereof; the titanate compound is one or more of hydroxymethane titanate, tributyl titanate and titanium toluene sulfonate.

[0008] The invention discloses an application of a multi-component catalyst for producing trioctyl trimellitate in synthesizing trioctyl trimellitate, characterized in that the application comprises the following steps: S1. Add isooctyl alcohol into the esterification reaction kettle, preheat to 130-140°C, add trimellitic acid or trimellitic anhydride in batches and stir for 10-15 minutes; S2, adding a multi-catalyst, first adding a titanate compound, then adding a co-catalyst quaternary ammonium salt ion catalyst, and finally adding a stannate compound, i.e., a mixture of one or more of stannate, stannous chloride, stannous octoate, and dibutyltin p-toluenesulfonate, heating to 160-180° C. and keeping warm for 1-1.5 hours to carry out a primary esterification reaction, and after the primary esterification reaction is completed, further heating to 180-200° C. and keeping warm for 1-2 hours to carry out an esterification reaction, the water and a small amount of isooctyl alcohol generated during the esterification process are evaporated out of the system and separated in a stratification tank, and the isooctyl alcohol is refluxed to the esterification kettle for reuse to reduce material loss; The interaction between the main catalyst and the co-catalyst accelerates the primary esterification reaction to generate monooctyl trimellitate and dioctyl trimellitate. Since the solubility of monooctyl trimellitate and dioctyl trimellitate in octanol is higher than that of trimellitic anhydride and trimellitic acid, it is beneficial for the full contact of the reactants and guides the reaction to diester and triester, ensuring that the reaction is completed quickly at a relatively low temperature and reducing the generation of side reactions and impurities. S3. After the reaction is completed, isooctyl alcohol is removed under a high vacuum of -0.090 to -0.095 MPa to obtain trioctyl trimellitate.

[0009] Furthermore, the molar ratio of trimellitic anhydride or trimellitic acid to isooctyl alcohol is 1:3.1-3.3, and the amount of the multi-catalyst is 0.03-0.06% of the total mass of the reaction raw materials.

[0010] Furthermore, in step S2, the reaction is carried out under normal pressure.

[0011] The invention has the advantages that: the main catalyst-modified metal salt of the multi-catalyst interacts with the co-catalyst, the co-catalyst effectively strengthens the interphase ion migration, accelerates the primary esterification reaction to generate monooctyl trimellitate and dioctyl trimellitate, and dissolves them in isooctyl alcohol solution; since the solubility of monooctyl trimellitate and dioctyl trimellitate in octanol is higher than that of trimellitic anhydride and trimellitic acid, sufficient contact of reactants is ensured and the reaction is guided to diester and triester; at the same time, due to the good reaction selectivity, the use amount of the raw material isooctyl alcohol is greatly reduced, and the material loss in the reaction process and the heat loss required for reflux dealcoholization are reduced; The multi-catalyst is applied in the synthesis of trioctyl trimellitate, and has a good catalytic effect. The reaction is completed quickly at a relatively low temperature, and high-temperature dissolution is avoided to easily cause the decomposition and deterioration of the raw materials and the generation of a large number of side reactions and impurities, and the reaction time is reduced. The prepared trioctyl trimellitate has a light color, a high-quality trioctyl trimellitate content of ≥99.5%, an acid value of ≤0.15 mgKOH / g, high purity, high yield, and high volume resistivity, which provides the possibility for further production of ultra-high purity trioctyl trimellitate. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific implementation methods. The following examples can enable technicians in this field to understand the present invention more comprehensively, but the present invention is not limited to the scope of the embodiments.

[0013] This specific implementation adopts the following technical scheme: a multi-catalyst for the production of trioctyl trimellitate, including a main catalyst and a co-catalyst; the main catalyst is a mixture of one or more of stannate, titanate, stannous chloride, stannous octoate, and dibutyltin p-toluenesulfonate; the co-catalyst is a quaternary ammonium salt ion catalyst; wherein the weight content of the main catalyst is 90-98% of the total weight of the multi-catalyst, and the weight content of the co-catalyst is 2-10% of the total weight of the multi-catalyst.

[0014] The stannate is one or more of tin hydroxymethane sulfonate, 2-hydroxybutyl-1-tin sulfonate, 2-hydroxyethyl-1-tin sulfonate, 2-butane sulfonate and modified stannates thereof; the titanate compound is one or more of hydroxymethane titanate, tributyl titanate and titanium toluene sulfonate.

[0015] Application of a multi-component catalyst for producing trioctyl trimellitate in synthesizing trioctyl trimellitate comprises the following steps: S1. Add isooctyl alcohol into the esterification reaction kettle, preheat to 130-140°C, add trimellitic acid or trimellitic anhydride in batches and stir for 10-15 minutes. The molar ratio of trimellitic anhydride or trimellitic acid to isooctyl alcohol is 1:3.1-3.3.

[0016] S2, adding a multi-catalyst, first adding a titanate compound, then adding a co-catalyst quaternary ammonium salt ion catalyst, and finally adding a stannate compound, i.e., a mixture of one or more of stannate, stannous chloride, stannous octoate, and dibutyltin p-toluenesulfonate, the amount of the multi-catalyst is 0.03-0.06% of the total mass of the reaction raw materials, heating to 160-180°C and keeping warm for 1-1.5 hours to carry out a primary esterification reaction, and after the primary esterification reaction is completed, further heating to 180-200°C and keeping warm for 1-2 hours to carry out an esterification reaction, the reaction is carried out under normal pressure, the water and a small amount of isooctyl alcohol generated during the esterification process are evaporated out of the system and separated in a stratification tank, and the isooctyl alcohol is refluxed to the esterification kettle for reuse, thereby reducing material loss; The interaction between the main catalyst and the co-catalyst accelerates the primary esterification reaction to generate monooctyl trimellitate and dioctyl trimellitate. Since the solubility of monooctyl trimellitate and dioctyl trimellitate in octanol is higher than that of trimellitic anhydride and trimellitic acid, it is beneficial for the full contact of the reactants and guides the reaction to diester and triester, ensuring that the reaction is completed quickly at a relatively low temperature and reducing the generation of side reactions and impurities. S3. After the reaction is completed, isooctyl alcohol is removed under a high vacuum of -0.090 to -0.095 MPa to obtain trioctyl trimellitate.

[0017] Embodiment 1: First, add isooctyl alcohol to the esterification reaction kettle, preheat to 130-135°C, then add trimellitic anhydride in batches and stir for 10 minutes, the molar ratio of trimellitic anhydride to isooctyl alcohol is 1:3.1; then add multiple catalysts, first add titanate compound, then add co-catalyst quaternary ammonium salt ion catalyst, and finally add stannic acid compound, i.e., one or a mixture of stannate, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate, control the initial reaction temperature at 160-180°C, stir and reflux for 1 minute, and then add stannic acid compound, i.e., stannate, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate, and stannic acid compound, and then add stannic acid compound, i.e., stannate, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate, and stannic acid compound, and then add stannic acid compound, i.e., stannate, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate, and stannic acid compound, and then add stannic acid compound, i.e., stannic acid compound ...stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid compound, stannic acid hours, and the amount of multi-catalyst is 0.04% of the total mass of the reaction raw materials. Among them, the main catalysts are titanate compounds and stannate compounds, and hydroxymethane titanate, tributyl titanate, dibutyltin p-toluenesulfonate and stannous chloride are selected respectively. The mass ratio of hydroxymethane titanate, tributyl titanate, dibutyltin p-toluenesulfonate and stannous chloride is 1:1:2:2. The total amount of main catalysts is 0.036% of the total mass of the reaction raw materials, and the amount of co-catalyst is 0.004% of the total mass of the reaction raw materials.

[0018] The binary azeotrope formed by the water and a small amount of isooctyl alcohol generated in the esterification process is removed from the esterification reaction system, and the reaction temperature is further adjusted to 185-195°C, and the reaction is stirred and refluxed for 1.5 hours. The reaction is carried out under normal pressure, so that the esterification reaction continues to proceed in the positive direction. The isooctyl alcohol is removed from the esterification product under vacuum, and the vacuum degree is -0.090 to -0.095 MPa to obtain trioctyl trimellitate. The chromaticity of the product is 10 platinum-cobalt color number, the acid value is 0.025 mgKOH / g, and the volume resistivity is 15×10 11 (Ω.cm), the ester content is 99.7%, and the system acid value is 0.05mgKOH / g, which meets the requirements of the product standard for superior products.

[0019] Embodiment 2: First add isooctyl alcohol into the esterification reaction kettle, preheat to 130-135°C, then add trimellitic anhydride in batches and stir for 10 minutes, the molar ratio of trimellitic anhydride: isooctyl alcohol is 1:3.2; then add a multi-catalyst, control the initial reaction temperature at 160-170°C, stir and reflux for 1.2 hours, the amount of the multi-catalyst is 0.05% of the total mass of the reaction raw materials, wherein the main catalyst is a titanate compound and a stannic acid compound, tributyl titanate, titanium toluenesulfonate and stannous chloride, stannous octoate are selected respectively, the mass ratio of tributyl titanate, titanium toluenesulfonate and stannous chloride, stannous octoate is 2:3:4:4, the total amount of the main catalyst is 0.048% of the total mass of the reaction raw materials, and the amount of the co-catalyst is 0.002% of the total mass of the reaction raw materials.

[0020] The binary azeotrope formed by the water and a small amount of isooctyl alcohol generated in the esterification process is removed from the esterification reaction system, and the reaction temperature is further adjusted to 180-190°C, and the reaction is stirred and refluxed for 1.5 hours. The reaction is carried out under normal pressure, so that the esterification reaction continues to proceed in the positive direction. The isooctyl alcohol is removed from the esterification product under vacuum, and the vacuum degree is -0.090 to -0.095 MPa to obtain trioctyl trimellitate. The chromaticity of the product is 15 platinum-cobalt color number, the acid value is 0.022 mgKOH / g, and the volume resistivity is 12×10 11 (Ω.cm), the ester content is 99.8%, and the system acid value is 0.04mgKOH / g, which meets the requirements of the product standard for superior products.

[0021] Embodiment 3: First, add isooctanol into the esterification reaction kettle, preheat to 135-140°C, then add trimellitic anhydride in batches and stir for 15 minutes, the molar ratio of trimellitic anhydride: isooctanol is 1:3.3; then add a multi-catalyst, control the initial reaction temperature at 165-170°C, stir and reflux for 1.5 hours, the amount of the multi-catalyst is 0.06% of the total mass of the reaction raw materials, wherein the main catalyst is a titanate compound and a stannic acid compound, hydroxymethane titanate, tributyl titanate and stannous octoate, dibutyl tin p-toluenesulfonate are selected respectively, the mass ratio of hydroxymethane titanate, tributyl titanate and stannous octoate, dibutyl tin p-toluenesulfonate is 1:1:3:2, the total amount of the main catalyst is 0.055% of the total mass of the reaction raw materials, and the amount of the co-catalyst is 0.005% of the total mass of the reaction raw materials.

[0022] The binary azeotrope formed by the water and a small amount of isooctyl alcohol generated in the esterification process is removed from the esterification reaction system, and the reaction temperature is further adjusted to 190-195°C, and the reaction is stirred and refluxed for 2 hours. The reaction is carried out under normal pressure, so that the esterification reaction continues to proceed in the positive direction. The isooctyl alcohol is removed from the esterification product under vacuum, and the vacuum degree is -0.090--0.095MPa to obtain trioctyl trimellitate. The chromaticity of the product is 10 platinum-cobalt color number, the acid value is 0.020mgKOH / g, and the volume resistivity is 20×10 11 (Ω.cm), the ester content is 99.7%, and the system acid value is 0.06mgKOH / g, which meets the requirements of the product standard for superior products.

[0023] Embodiment 4: First add isooctanol into the esterification reaction kettle, preheat to 135-140°C, then add trimellitic anhydride in batches and stir for 15 minutes, the molar ratio of trimellitic anhydride: isooctanol is 1:3.2; then add a multi-catalyst, control the initial reaction temperature at 170-175°C, stir and reflux for 1.5 hours, the amount of the multi-catalyst is 0.03% of the total mass of the reaction raw materials, among which the main catalysts are titanate compounds and stannic acid compounds, titanium toluenesulfonate and stannous chloride, stannous octoate are selected respectively, the mass ratio of titanium toluenesulfonate and stannous chloride, stannous octoate is 1:3:3, the total amount of the main catalyst is 0.028% of the total mass of the reaction raw materials, and the amount of the co-catalyst is 0.002% of the total mass of the reaction raw materials.

[0024] The binary azeotrope formed by the water and a small amount of octanol generated in the esterification process was removed from the esterification reaction system, and the reaction temperature was further adjusted to 190-200°C, and the reaction was stirred and refluxed for 2 hours. The reaction was carried out under normal pressure, so that the esterification reaction continued to proceed in the positive direction. The isooctyl alcohol was removed from the esterification product under vacuum, and the vacuum degree was -0.090 to -0.095 MPa to obtain trioctyl trimellitate. The chromaticity of the product was 12 platinum-cobalt color numbers, the acid value was 0.023 mgKOH / g, and the volume resistivity was 25×10 11 (Ω.cm), the ester content is 99.8%, and the system acid value is 0.06mgKOH / g, which meets the requirements of the product standard for superior products.

[0025] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A multi-component catalyst for the production of trioctyl trimellitate, characterized in that: The invention comprises a main catalyst and a co-catalyst; the main catalyst is one or a mixture of stannate, stannous chloride, stannous octoate, dibutyltin p-toluenesulfonate and titanate compounds; the co-catalyst is a quaternary ammonium salt ion catalyst; wherein the weight content of the main catalyst is 90-98% of the total amount of the multi-catalyst, and the weight content of the co-catalyst is 2-10% of the total amount of the multi-catalyst.

2. The multi-component catalyst for producing trioctyl trimellitate according to claim 1, characterized in that: The stannate is one or more of tin hydroxymethane sulfonate, 2-hydroxybutyl-1-tin sulfonate, 2-hydroxyethyl-1-tin sulfonate, 2-butane sulfonate and modified stannates thereof; the titanate compound is one or more of hydroxymethane titanate, tributyl titanate and titanium toluene sulfonate.

3. Use of the multi-component catalyst for producing trioctyl trimellitate according to claim 1 in synthesizing trioctyl trimellitate, characterized in that: The following steps are involved: S1. Add isooctyl alcohol into the esterification reaction kettle, preheat to 130-140°C, add trimellitic acid or trimellitic anhydride in batches and stir for 10-15 minutes; S2, adding a multi-catalyst, first adding a titanate compound, then adding a co-catalyst quaternary ammonium salt ion catalyst, and finally adding a stannate compound, i.e., a mixture of one or more of stannate, stannous chloride, stannous octoate, and dibutyltin p-toluenesulfonate, heating to 160-180° C. and keeping warm for 1-1.5 hours to carry out a primary esterification reaction, and after the primary esterification reaction is completed, further heating to 180-200° C. and keeping warm for 1-2 hours to carry out an esterification reaction, the water and a small amount of isooctyl alcohol generated during the esterification process are evaporated out of the system and separated in a stratification tank, and the isooctyl alcohol is refluxed to the esterification kettle for reuse to reduce material loss; The interaction between the main catalyst and the co-catalyst accelerates the primary esterification reaction to generate monooctyl trimellitate and dioctyl trimellitate. Since the solubility of monooctyl trimellitate and dioctyl trimellitate in octanol is higher than that of trimellitic anhydride and trimellitic acid, it is beneficial for the full contact of the reactants and guides the reaction to diester and triester, ensuring that the reaction is completed quickly at a relatively low temperature and reducing the generation of side reactions and impurities. S3. After the reaction is completed, isooctyl alcohol is removed under a vacuum of -0.090 to -0.095 MPa to obtain trioctyl trimellitate.

4. The use of a multi-component catalyst for producing trioctyl trimellitate according to claim 3 in synthesizing trioctyl trimellitate, characterized in that: The molar ratio of trimellitic anhydride or trimellitic acid to isooctyl alcohol is 1:3.1-3.3, and the amount of the multi-catalyst is 0.03-0.06% of the total mass of the reaction raw materials.

5. The use of a multi-component catalyst for producing trioctyl trimellitate according to claim 3 in synthesizing trioctyl trimellitate, characterized in that: In the step S2, the reaction is carried out under normal pressure.