Tetraisononyl pyromellitic acid ester as well as preparation method and application thereof

Abstract

The invention discloses tetraisononyl pyromellitate as well as a preparation method and application thereof. The tetraisononyl pyromellitate is obtained by carrying out esterification reaction on pyromellitic acid or pyromellitic anhydride and isononyl alcohol under the action of a catalyst. The raw materials used in the synthesis process of the tetraisononyl pyromellitic acid are safe, the cost is low, the synthesis procedures and steps are simple, and the synthesis method is suitable for industrial processing and production. The trioctyl trimellitate plasticizer can be used as one of substitutes of the trioctyl trimellitate TOTM plasticizer, and even is a better improved product.

Description

Technical Field

[0001] The invention relates to the technical field of polymer chemical synthesis, and in particular to tetraisononyl pyromellitate, a preparation method and application thereof. Background Art

[0002] Trioctyl trimellitate, referred to as TOTM, also known as tri(2-ethylhexyl) trimellitate, is an excellent plasticizer with low volatility, good heat resistance, small migration, electrical insulation, durability, low toxicity, water resistance and appropriate compatibility. It is mainly used in plastic products such as polyvinyl chloride (PVC), vinyl chloride copolymers, nitrocellulose, ethyl cellulose, and is also used in heat-resistant wire and cable materials, plates, sheets and sealing gaskets.

[0003] In terms of production methods, TOTM is usually produced through esterification reaction with trimellitic anhydride (TMA) and octanol as raw materials. During the preparation process, concentrated sulfuric acid, solid acid, metal oxides, etc. are used as catalysts, and the final product is obtained through purification processes such as neutralization, washing, decolorization, and dealcoholization.

[0004] However, due to the increasing price of TMA and the inconvenience in transportation and use caused by its easy sublimation, the cost of TOTM is higher than that of traditional plasticizers, which directly affects its competitiveness in the price-sensitive market. In addition, although TMA itself is non-toxic and environmentally friendly, the byproducts and wastes that may be generated during its production process, as well as its persistence and bioaccumulation in the environment, may cause potential risks to the ecosystem and human health, and are currently restricted under REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals is a chemical management regulation of the European Union).

[0005] Therefore, developing TOTM substitutes and alternative technologies to provide an environmentally friendly, low-cost, high-performance plasticizer is a technical problem that needs to be solved urgently. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide tetraisononyl pyromellitate.

[0007] The second object of the present invention is to provide a method for preparing tetraisononyl pyromellitic acid.

[0008] The third object of the present invention is to provide an application of tetraisononyl pyromellitate in a plasticizer.

[0009] One of the purposes of the present invention is achieved by the following technical scheme: a tetraisononyl pyromellitic acid ester is obtained by esterification reaction of pyromellitic acid or pyromellitic anhydride with isononanol in the presence of a catalyst.

[0010] Optionally, the molar ratio of pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5).

[0011] Optionally, the purity of the pyromellitic acid or pyromellitic anhydride is 98.5-99.9%.

[0012] Optionally, the structural formula of the pyromellitic acid is as follows:

[0013] The structural formula of the pyromellitic anhydride is as follows:

[0014] Optionally, the catalyst is selected from a titanate catalyst, and the molar ratio of the catalyst to isononanol is 1:(2000-4000).

[0015] Optionally, after the acid value of the esterification reaction reaches 0.3 mgKOH / g, alkali is added to remove excess water and alcohol, and the product is finely purified to obtain tetraisononyl pyromellitate.

[0016] The present invention also provides a method for preparing tetraisononyl pyromellitate as described above, comprising the following steps:

[0017] (1) adding pyromellitic acid or pyromellitic anhydride and isononanol into a reactor, stirring and heating;

[0018] (2) When the temperature reaches 110-150°C, add the catalyst and continue to heat to 200-240°C with stirring to carry out esterification reaction;

[0019] (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated;

[0020] (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

[0021] Optionally, the molar ratio of pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5).

[0022] Optionally, the catalyst is selected from a titanate catalyst, and the molar ratio of the catalyst to isononanol is 1:(2000-4000).

[0023] The present invention also provides a polyvinyl chloride resin plastisol, comprising the following components in parts by weight: 100 parts of polyvinyl chloride and 1-120 parts of the above-mentioned tetraisononyl pyromellitic acid as a plasticizer.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) There are many types of plasticizers, among which trioctyl trimellitate (TOTM) is expensive and has potential risks to the ecosystem and human health, and is currently restricted under the REACH regulations. The raw materials used in the synthesis process of tetraisononyl pyromellitate of the present invention are safe and low in cost, and the synthesis process and steps are simple, which is suitable for industrial processing and production. It can be used as a substitute for trioctyl trimellitate (TOTM) plasticizer, or even a better improved product.

[0026] (2) In addition, the tetraisononyl pyromellitic acid ester of the present invention is compared with several commonly used plasticizers in terms of performance. The tetraisononyl pyromellitic acid ester of the present invention has excellent heat resistance and electrical conductivity. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0028] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0029] The tetraisononyl pyromellitic acid provided by the present invention is obtained by esterification reaction of pyromellitic acid or pyromellitic anhydride with isononanol under the action of a catalyst.

[0030] As a further embodiment, the isononanol used in the present invention has multiple isomers, that is, an isononanol composition containing multiple isomers can be selected, or a single isononanol can be selected, which includes but is not limited to the following single isononanol structures: 7-methyl-1-octanol, 3,5,5-trimethylhexanol, etc. Among them, the isononanol is purchased from multiple raw material suppliers such as Maoming BASF, Shandong Qixiang Tengda Chemical Co., Ltd., Shanghai Jizhi Biochemical Technology Co., Ltd., Shanghai Aladdin Biochemical Technology Co., Ltd., Shanghai Chuangsai Technology Co., Ltd., German BASF, Degussa, etc.

[0031] The structural formula of 7-methyl-1-octanol is as follows:

[0032] The structural formula of 3,5,5-trimethylhexanol is as follows:

[0033] As a further embodiment, the molar ratio of pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5). Pyromellitic acid and pyromellitic anhydride are selected from pyromellitic acid (anhydride) provided by Puyang Longdeyang New Materials Co., Ltd., Jiangsu Hualun Chemical Co., Ltd., Puyang Hengfeng Electronic Insulation Materials Co., Ltd., and Sigma-Aldrich Company.

[0034] As a further embodiment, the purity of the pyromellitic acid or pyromellitic anhydride is 98.5-99.9%. In the present application, pyromellitic acid or pyromellitic anhydride of different purities as raw materials for esterification reaction have an impact on the product purity, by-products and production cost of the reaction process. In terms of raw material price, pyromellitic anhydride with a purity of 99.5%> pyromellitic anhydride with a purity of 98.5%> pyromellitic acid with a purity of 99.5%> pyromellitic acid with a purity of 98.5%.

[0035] As a further embodiment, the structural formula of the pyromellitic acid is as follows:

[0036] The structural formula of the pyromellitic anhydride is as follows:

[0037] As a further embodiment, the catalyst is selected from titanate catalysts, and the molar ratio of the catalyst to isononanol is 1:(2000-4000).

[0038] As a further embodiment, after the acid value of the esterification reaction reaches 0.3 mgKOH / g, alkali is added to remove excess water and alcohol, and the product is finely purified to obtain tetraisononyl pyromellitate.

[0039] The present invention also provides a method for preparing tetraisononyl pyromellitate as described above, comprising the following steps:

[0040] (1) adding pyromellitic acid or pyromellitic anhydride and isononanol into a reactor, stirring and heating;

[0041] (2) When the temperature reaches 110-150°C, add the catalyst and continue to heat to 200-240°C with stirring to carry out the esterification reaction.

[0042] (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated;

[0043] (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

[0044] As a further embodiment, the isononyl alcohol used in the present invention is a mixture of isononyl alcohols containing multiple isomers or a mixture of one or two of the following single compounds 7-methyl-1-octanol and 3,5,5-trimethylhexanol. The above-mentioned isononyl alcohol is purchased from multiple raw material suppliers such as Maoming BASF, Shandong Qixiang Tengda Chemical Co., Ltd., Shanghai Jizhi Biochemical Technology Co., Ltd., Shanghai Aladdin Biochemical Technology Co., Ltd., Shanghai Chuangsai Technology Co., Ltd., German BASF, Degussa, etc.

[0045] The molar ratio of pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5);

[0046] The catalyst is selected from titanate catalysts, and the molar ratio of the catalyst to isononyl alcohol is 1:(2000-4000).

[0047] In this scheme, isononyl alcohol has multiple isomers. According to the different isomeric structures of isononyl alcohol, tetraisononyl pyromellitic acid is obtained by including but not limited to the following reaction process:

[0048]

[0049] The present invention also provides a polyvinyl chloride resin plastisol, comprising the following components in parts by weight: 100 parts of polyvinyl chloride and 1-120 parts of the above-mentioned tetraisononyl pyromellitic acid as a plasticizer.

[0050] The tetraisononyl pyromellitic acid of the present invention can be used as a plasticizer, especially for polyvinyl chloride (PVC). The tetraisononyl pyromellitic acid of the present invention can be used alone as a plasticizer for PVC, or it can be used together with conventional plasticizers in the art. For example, polyvinyl chloride resin plastisol can be processed according to the following components, specifically containing 50g of plasticizer and 3g of stabilizer in every 100 grams of PVC. Wherein, the plasticizer is the tetraisononyl pyromellitic acid obtained by the present invention, and the stabilizer (or "stabilizer") can be lead salt or lead-free calcium zinc, organic tin, rare earth and other types. It can be understood by those skilled in the art that the above-mentioned components and their contents are only used as an exemplary embodiment, and those skilled in the art can make adaptive adjustments to the above-mentioned components and / or contents according to actual conditions to achieve better plasticizing effects.

[0051] The following are specific embodiments of the present invention. Unless otherwise specified, the raw materials, equipment, etc. used in the following embodiments can be obtained by purchase.

[0052] Example 1

[0053] Tetraisononyl pyromellitic acid is prepared by the following preparation method, comprising the following steps:

[0054] (1) Add pyromellitic acid and isononyl alcohol into a reactor, stir and heat; the molar ratio of pyromellitic acid to isononyl alcohol is 1:4. The purity of the pyromellitic acid is 99.5%. In this example, pyromellitic acid is purchased from Puyang Longdeyang New Materials Co., Ltd., and isononyl alcohol is isononyl alcohol containing multiple isomers, which is purchased from Maoming BASF.

[0055] (2) When the temperature reaches 110-150° C., add titanate catalyst TPT tetraisopropyl titanate, continue to heat to 225° C. and stir to carry out esterification reaction; the molar ratio of the catalyst to isononyl alcohol is 1:2000.

[0056] (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated;

[0057] (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

[0058] Example 2

[0059] Tetraisononyl pyromellitic acid is prepared by the following preparation method, comprising the following steps:

[0060] (1) Add pyromellitic acid and isononyl alcohol into a reactor, stir and heat; the molar ratio of pyromellitic acid to isononyl alcohol is 1:4. The purity of the pyromellitic acid is 99.5%. In this example, pyromellitic acid is purchased from Puyang Longdeyang New Materials Co., Ltd., and isononyl alcohol is isononyl alcohol containing multiple isomers, which is purchased from Maoming BASF.

[0061] (2) When the temperature reaches 110-150° C., add a titanate catalyst, tetraisopropyl titanate (TPT), and continue to heat to 230° C. with stirring to carry out an esterification reaction; the molar ratio of the catalyst to isononyl alcohol is 1:1450.

[0062] (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated;

[0063] (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

[0064] Example 3

[0065] Tetraisononyl pyromellitic acid is prepared by the following preparation method, comprising the following steps:

[0066] (1) Add pyromellitic acid and isononyl alcohol into a reactor, stir and heat; the molar ratio of pyromellitic acid to isononyl alcohol is 1:5. The purity of the pyromellitic acid is 99.5%. In this example, pyromellitic acid is purchased from Puyang Longdeyang New Materials Co., Ltd., and isononyl alcohol is isononyl alcohol containing multiple isomers, which is purchased from Maoming BASF.

[0067] (2) When the temperature reaches 110-150° C., add a titanate catalyst, tetraisopropyl titanate (TPT), and continue to heat to 240° C. with stirring to carry out an esterification reaction; the molar ratio of the catalyst to isononyl alcohol is 1:1850.

[0068] (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated;

[0069] (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

[0070] Example 4

[0071] Compared with the preparation method of Example 2, the difference of Example 4 is that the isononyl ester is 7-methyl-1-octanol purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.

[0072] The reaction formula of tetraisononyl pyromellitic acid is as follows:

[0073]

[0074] Example 5

[0075] Compared with the preparation method of Example 2, the difference of Example 5 is that the isononyl ester is 3,5,5-trimethylhexanol purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.

[0076] The reaction formula of tetraisononyl pyromellitic acid is as follows:

[0077]

[0078] Example 6

[0079] Compared with the preparation method of Example 2, the difference is that pyromellitic anhydride replaces pyromellitic acid and is purchased from Puyang Longdeyang New Materials Co., Ltd., and the other process conditions are the same as those of Example 2.

[0080] Comparative Example 1

[0081] Compared with the preparation method of Example 2, the difference is that in step (2), the temperature when adding the titanate catalyst is less than 110°C, that is, 90°C, and the remaining formula composition and reaction conditions are the same as those of Example 2.

[0082] Comparative Example 2

[0083] Compared with the preparation method of Example 2, the difference is that in step (2), the temperature when adding the titanate catalyst is greater than 150°C, i.e. 155°C, and the remaining formulation composition and reaction conditions are the same as those of Example 2.

[0084] Comparative Example 3

[0085] Compared with the preparation method of Example 2, the difference is that in step (1), the molar ratio of 2-hydroxy-1-nitropropionic acid to 2-isononyl alcohol is 1:3, and the remaining formula composition and reaction conditions are the same as those of Example 2.

[0086] Comparative Example 4

[0087] Compared with the preparation method of Example 2, the difference is that in step (1), the molar ratio of 2-hydroxy-1-nitropropionic acid to 2-isononyl alcohol is 1:6, and the remaining formula composition and reaction conditions are the same as those of Example 2.

[0088] Application Example 1

[0089] A polyvinyl chloride resin plastisol can be prepared according to the following weight parts: 30g of plasticizer and 3g of stabilizer per 100g of PVC, wherein the plasticizer is tetraisononyl pyromellitic acid prepared in Example 2 of the present invention, and the stabilizer is lead-free calcium zinc salt.

[0090] Application Example 2

[0091] A polyvinyl chloride resin plastisol can be composed of the following components by weight: 80g of plasticizer and 3g of stabilizer per 100g of PVC, wherein the plasticizer is tetraisononyl pyromellitic acid prepared in Example 2 of the present invention, and the stabilizer is lead-free calcium zinc salt.

[0092] Application Example 3

[0093] A polyvinyl chloride resin plastisol can be composed of the following components by weight: 120g of plasticizer and 3g of stabilizer per 100g of PVC, wherein the plasticizer is tetraisononyl pyromellitic acid prepared in Example 2 of the present invention, and the stabilizer is lead-free calcium zinc salt.

[0094] Application Comparative Example 1

[0095] Compared with Application Example 2, the difference between the polyvinyl chloride resin plastisol in Application Comparative Example 1 is that the type of plasticizer is different. The plasticizer selected in this example is diisononyl phthalate (DINP), whose English name is Bis-(3,5,5-trimethylhexyl)phthalate, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The rest of the formula and conditions are the same as those in Example 2.

[0096] Application Comparative Example 2

[0097] Compared with Application Example 2, the difference of the polyvinyl chloride resin plastisol in Application Comparative Example 2 is that the type of plasticizer is different. The plasticizer selected in this example is trinonyl trimellitate, also known as triisononyl 1,2,4-benzenetricarboxylate, purchased from Shanghai Huayuan Century Trading Co., Ltd. The rest of the formula and conditions are the same as those in Example 2.

[0098] Application Comparative Example 3

[0099] Compared with Application Example 2, the difference of the polyvinyl chloride resin plastisol in Application Comparative Example 3 is that the type of plasticizer is different. The plasticizer selected in this example is tetraoctyl pyromellitic acid (TOPM), which is purchased from Shanghai Huayuan Century Trading Co., Ltd. The rest of the formula and conditions are the same as those in Example 2.

[0100] Application Comparative Example 4

[0101] Compared with Application Example 2, the difference of the polyvinyl chloride resin plastisol in Application Comparative Example 4 is that the type of plasticizer is different. The plasticizer selected in this example is tetra(isodecyl)pyromellitic acid (TOP-TM), and its preparation method can be found in Patent ZL202410937636.2. The rest of the formula and conditions are the same as those in Example 2.

[0102] Application Comparative Example 5

[0103] Compared with Application Example 2, the difference of the polyvinyl chloride resin plastisol in Application Comparative Example 5 is that the type of plasticizer is different. The plasticizer selected in this example is trioctyl trimellitate (TOTM), Shanghai Huayuan Century Trading Co., Ltd., and the other formulas and conditions are the same as those in Example 2.

[0104] Effect evaluation and performance testing

[0105] According to the testing regulations for ester content, density, volume resistivity, heat resistance level and other properties under HG / T 4889-2016 and UL standards, the properties of tetraisononyl pyromellitic acid in Examples 1-6 and Comparative Examples 1-4 were tested. The test items and results are shown in Tables 1-3.

[0106] 1. Comparison of ester content of tetraisononyl pyromellitic acid

[0107] Table 1 is the performance test data of tetraisononyl pyromellitic acid in each embodiment

[0108]

[0109]

[0110] The raw materials used in the synthesis process of tetraisononyl pyromellitic acid of the present invention are safe and low in cost, and the synthesis process and steps are simple, so the product is suitable for industrial processing and production. In addition, the reaction raw materials replace the expensive trimellitic anhydride TMA with high environmental risk, and the prepared tetraisononyl pyromellitic acid has high ester content, is environmentally friendly, and has stable basic performance.

[0111] 2. Comparison of physical properties and costs of tetraisononyl pyromellitic acid and other commonly used plasticizers

[0112] Table 2 Comparison of tetraisononyl pyromellitic acid of the present invention and commonly used plasticizers

[0113]

[0114]

[0115] 3. Comparison of application performance of polyvinyl chloride resin plastisol

[0116] Table 3 Heat resistance of the processed products of tetraisononyl pyromellitic acid of the present invention and common plasticizers

[0117]

[0118]

[0119] As can be seen from Table 1-3, tetraisononyl pyromellitic acid is a specific organic compound used as a plasticizer, especially in PVC (polyvinyl chloride) plastic products. Tetraisononyl pyromellitic acid has a high molecular weight, a low density ratio, and a high flash point; among them, the higher the molecular weight, the more stable the compound is, the more resistant to migration, the higher the flash point, the higher the safety of the chemical, and the lower the density ratio. The advantage of its volume cost can reduce the total cost of the finished product. In the preparation process of PVC, the sheet is highly flexible. In addition, the viscosity of the banburying is moderate, which improves the processing efficiency of the sheet.

[0120] Compared with existing plasticizers, tetraisononyl pyromellitic acid has excellent heat resistance and can reach UL125 heat resistance level, which is better than tetraoctyl pyromellitic acid. It has outstanding advantages in the use environment with strict or harsh requirements on heat resistance such as aviation wires. In addition, tetraisononyl pyromellitic acid of the present invention has high volume resistivity and is more suitable for the field of high-temperature wire technology.

[0121] In summary, the tetraisononyl pyromellitic acid of the present invention has excellent heat resistance, high environmental performance and low cost, and can be used as another substitute for TOTM plasticizer, or even a better improved product.

[0122] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A tetraisononyl pyromellitic acid, characterized in that: It is obtained by esterification reaction of pyromellitic acid or pyromellitic anhydride with isononanol in the presence of a catalyst.

2. Tetraisononyl pyromellitate according to claim 1, characterized in that The molar ratio of the pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5).

3. The tetraisononyl pyromellitate according to claim 1, characterized in that: The purity of the pyromellitic acid or pyromellitic anhydride is 98.5-99.9%.

4. Tetraisononyl pyromellitate according to claim 1, characterized in that The structural formula of the pyromellitic acid is as follows: The structural formula of the pyromellitic anhydride is as follows:

5. Tetraisononyl pyromellitate according to claim 1, characterized in that The catalyst is selected from titanate catalysts, and the molar ratio of the catalyst to isononyl alcohol is 1:(2000-4000).

6. Tetraisononyl pyromellitate according to claim 1, characterized in that After the acid value of the esterification reaction reaches 0.3 mgKOH / g, alkali is added to remove excess water and alcohol, and the product is finely purified to obtain tetraisononyl pyromellitate.

7. A method for preparing tetraisononyl pyromellitate according to any one of claims 1 to 6, characterized in that: The steps include: (1) adding pyromellitic acid or pyromellitic anhydride and isononanol into a reactor, stirring and heating; (2) When the temperature reaches 110-150°C, add the catalyst and continue to heat to 200-240°C with stirring to carry out esterification reaction; (3) When the acid value of the esterification reaction reaches 0.3 mgKOH / g, the reaction is terminated; (4) adding alkali, removing excess water and excess alcohol, and fine purification to obtain tetraisononyl pyromellitate.

8. The method for preparing tetraisononyl pyromellitate according to claim 7, wherein: The molar ratio of the pyromellitic acid or pyromellitic anhydride to isononanol is 1:(4-5).

9. The method for preparing tetraisononyl pyromellitate according to claim 7, wherein: The catalyst is selected from titanate catalysts, and the molar ratio of the catalyst to isononyl alcohol is 1:(2000-4000).

10. A polyvinyl chloride resin plastisol, characterized in that: The invention comprises the following components in parts by weight: 100 parts of polyvinyl chloride and 1-120 parts of tetraisononyl pyromellitic acid as claimed in any one of claims 1-9 as a plasticizer.

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