A process for the preparation of a tris(3-trialkoxysilylpropyl) isocyanurate

Abstract

The application provides a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, which comprises the following steps: step one, placing a mixture of a precursor and a catalyst in a waterless and oxygenless reaction container under a nitrogen atmosphere; step two, heating the mixture in the step one to a reaction temperature to start a reaction; and step three, after the reaction is completed, cooling to room temperature, filtering out the catalyst, and obtaining a product tris(3-trialkoxysilylpropyl) isocyanurate. The preparation method has the advantages that: 1. the preparation method adopts bulk ring-closing polycondensation and does not need the participation of a solvent, thus avoiding the need for a reaction solvent and a complicated post-processing process in the prior art; 2. the preparation method uses cesium fluoride as a catalyst, the reaction rate and conversion rate are improved, the product is incompatible with the catalyst, the catalyst can be filtered out through suction filtration or pressure filtration, the process difficulty is reduced, and the product has high purity; and 3. the preparation method is simple, easy to operate, and mild in reaction, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of silane coupling agent OR flame retardant OR organic silicon synthesis, in particular to a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate. BACKGROUND

[0002] Tris(3-trialkoxysilylpropyl) isocyanurate can form multiple chemical bonds after hydrolysis, and various effects can be achieved through this strong crosslinking. Meanwhile, tris(3-trialkoxysilylpropyl) isocyanurate has a stable six-membered ring structure and good high-temperature resistance, and can be used in high-temperature environments. Therefore, in the fields of coatings, adhesives, metal powders and the like, tris(3-trialkoxysilylpropyl) isocyanurate can significantly improve the temperature resistance, solvent resistance and adhesion of the composite material.

[0003] Silicon-based flame retardants have always had the advantages of low smoke, non-toxicity and good carbon formation. During combustion, a dense silicon carbon layer is formed on the surface of the material, which can effectively prevent dripping after the polymer melts. It is an environmentally friendly flame retardant with good development prospects. Nitrogen-based flame retardants mainly release non-combustible gases during combustion to dilute combustible gases and isolate the contact between the polymer material and air. Achieve flame retardant effect. Tris(3-trialkoxysilylpropyl) isocyanurate contains both nitrogen and silicon elements, and has a stable six-membered ring, greatly improving its flame retardant efficiency in polymer materials.

[0004] The preparation method of tris(3-trialkoxysilylpropyl) isocyanurate is also recorded in the prior art. For example: CN 101805366 describes that tris(3-trimethoxysilylpropyl) isocyanurate is prepared by cyclization condensation of 3-isocyanate propyl trimethoxysilane in a solvent. After filtration, concentration and molecular distillation, high-purity tris(3-trimethoxysilylpropyl) isocyanurate is obtained. Solvent is used, and the overall process is complex. CN115403609 describes that tris(3-trimethoxysilylpropyl) isocyanurate is prepared by cyclization condensation of 3-isocyanate propyl trimethoxysilane. Organic tin is used as a catalyst, and adsorption filtration is required. The purity of the product is low. CN108570069 describes a method for preparing tris(3-trialkoxysilylpropyl) isocyanurate by hydrogenating alkoxysilane under Pt-catalyst using 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione. The catalyst is not easy to separate out, and the process is difficult.

[0005] Therefore, it is necessary to provide a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate to solve the above technical problems. SUMMARY

[0006] The application aims to disclose a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, which adopts bulk ring-closing polycondensation without the participation of solvents, avoids the need for reaction solvents and complicated post-processing technology in the prior art, improves the reaction rate and conversion rate by using cesium fluoride as a catalyst, is incompatible with the product, can be filtered out through suction filtration or pressure filtration, reduces the process difficulty, and has high product purity.

[0007] To achieve the above-mentioned purpose, the application provides a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, which comprises the following steps:

[0008] Step one: placing a mixture of precursors and a catalyst in an anhydrous and oxygen-free reaction container under a nitrogen atmosphere;

[0009] Step two: heating the mixture in step one to a reaction temperature to start the reaction;

[0010] Step three: after the reaction is completed, cooling to room temperature, filtering out the catalyst, and obtaining the product tris(3-trialkoxysilylpropyl) isocyanurate.

[0011] In some embodiments, in step one, the structure of the precursor is: wherein R1, R2 and R3 are all alkoxy groups or one of them is an alkyl group.

[0012] In some embodiments, the alkoxy group includes but is not limited to a methoxy group and an ethoxy group, and the alkyl group includes but is not limited to a methyl group and an ethyl group.

[0013] In some embodiments, the precursor is one or more of propyltrimethoxysilane isocyanate, propyltriethoxysilane isocyanate and propylmethyldimethoxysilane isocyanate.

[0014] In some embodiments, in step one, the mass ratio of the precursor to the catalyst is 100:0.1-1.

[0015] In some embodiments, in step one, the catalyst is one or more of cesium fluoride, tetrabutylammonium fluoride, sodium methoxide and sodium p-toluenesulfonate.

[0016] In some embodiments, in step two, the reaction temperature is 120-200 DEG C, and the reaction time is 1-8 h.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] I. bulk ring-closing polycondensation is adopted without the participation of solvents, which avoids the need for reaction solvents and complicated post-processing technology in the prior art;

[0019] II. By using cesium fluoride as catalyst, the reaction rate and conversion rate are improved, and the product is incompatible, which can be filtered by suction filtration or pressure filtration, reducing the process difficulty and improving the product purity.

[0020] III. The preparation method is simple, easy to operate, and mild in reaction, and is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Reaction diagram for the preparation of tris(3-trimethoxysilylpropyl) isocyanurate according to the present application;

[0022] Figure 2 FT-IR diagram of tris(3-trimethoxysilylpropyl) isocyanurate prepared according to the present application;

[0023] Figure 3 GC purity test diagram of tris(3-trimethoxysilylpropyl) isocyanurate prepared according to the present application. DETAILED DESCRIPTION

[0024] The present application will be described in detail below with reference to the embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limiting to the present application, and equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are within the scope of protection of the present application.

[0025] Example 1

[0026] The present embodiment discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically: 3-isocyanate propyl trimethoxysilane 500 g and cesium fluoride 1.5 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is purged, the temperature is raised to 180℃, and kept for 3 h, then cooled to 20℃, and the insoluble substances are removed by vacuum filtration to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 92.96%.

[0027] Example 2

[0028] The present embodiment discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically: 3-isocyanate propyl trimethoxysilane 500 g and cesium fluoride 3 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is purged, the temperature is raised to 150℃, and kept for 6 h, then cooled to 20℃, and the insoluble substances are removed by vacuum filtration to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 96.4%.

[0029] As Figure 3The GC purity test chart of the tris(3-trimethoxysilylpropyl) isocyanurate prepared in this example is shown as follows: Figure 2 The FT-IR chart of the tris(3-trimethoxysilylpropyl) isocyanurate prepared in this example is shown as follows.

[0030] Example 3

[0031] This example discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanatepropyltrimethoxysilane 500 g and cesium fluoride 3 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is blown, the temperature is raised to 150°C, and the temperature is kept for 6 h, the temperature is lowered to 20°C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 93.26%.

[0032] Example 4

[0033] This example discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanatepropyltrimethoxysilane 500 g and cesium fluoride 3 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is blown, the temperature is raised to 150°C, and the temperature is kept for 6 h, the temperature is lowered to 20°C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 93.26%.

[0034] Example 5

[0035] This example discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanatepropyltrimethoxysilane 500 g and cesium fluoride 3 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is blown, the temperature is raised to 150°C, and the temperature is kept for 6 h, the temperature is lowered to 20°C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 93.26%.

[0036] Comparative Example 1

[0037] This comparative example discloses a preparation method of tris(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanatepropyltrimethoxysilane 500 g and sodium methoxide 3 g are put into a waterless and oxygenless reactor, stirring is started and nitrogen is blown, the temperature is raised to 150°C, and the temperature is kept for 6 h, the temperature is lowered to 20°C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl) isocyanurate with a content of 93.26%.

[0038] Comparative Example 2

[0039] The comparative example discloses a preparation method of tri(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanate propyl trimethoxysilane 500 g and sodium methoxide 3 g are put into a waterless and oxygenless reactor, stirring and nitrogen purging are started, the temperature is raised to 180 DEG C, and the temperature is kept for 3 h, the temperature is lowered to 20 DEG C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tri(3-trialkoxysilylpropyl) isocyanurate with a content of 83.47%.

[0040] Comparative example 3

[0041] The comparative example discloses a preparation method of tri(3-trialkoxysilylpropyl) isocyanurate, specifically, 3-isocyanate propyl trimethoxysilane 500 g and sodium methoxide 3 g are put into a waterless and oxygenless reactor, stirring and nitrogen purging are started, the temperature is raised to 180 DEG C, and the temperature is kept for 3 h, the temperature is lowered to 20 DEG C, and the insoluble substances are removed by filtration under reduced pressure to obtain the product tri(3-trialkoxysilylpropyl) isocyanurate with a content of 83.47%.

[0042] It is found through the comparative example and the comparative example that the tri(3-trialkoxysilylpropyl) isocyanurate obtained by the preparation method provided by the application has the following beneficial effects: 1. The bulk cyclization polycondensation is adopted without the participation of a solvent, and the reaction solvent and the complicated post-processing process in the prior art are avoided; 2. The reaction rate and the conversion rate are improved by using cesium fluoride as the catalyst, and the catalyst is incompatible with the product and can be filtered out by suction filtration or pressure filtration, thereby reducing the process difficulty and the product purity is high; 3. The preparation method is simple, easy to operate, and mild in reaction, and is suitable for industrial production.

[0043] The series of detailed descriptions listed above are only specific descriptions of the feasible implementation manners of the application, and are not used to limit the protection scope of the application, and equivalent implementation manners or changes made without departing from the spirit of the application should be included in the protection scope of the application.

[0044] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A process for the preparation of tris(3-trialkoxysilylpropyl)isocyanurate, characterized in that, The method comprises the following steps: Step 1: placing a mixture of a precursor and a catalyst in a reaction container under anhydrous and oxygen-free conditions in a nitrogen atmosphere; Step 2: heating the mixture in step 1 to a reaction temperature to start the reaction; Step 3: after the reaction is completed, cooling to room temperature, filtering out the catalyst to obtain a product tris(3-trialkoxysilylpropyl) isocyanurate; The structural formula of the precursor is: wherein R1, R2, R3 are all alkoxy or one of them is alkyl; the alkoxy is methoxy or ethoxy, and the alkyl is methyl or ethyl; The catalyst is one or more of cesium fluoride and tetrabutylammonium fluoride.

2. A process for the preparation of tris(3-trialkoxysilylpropyl) isocyanurate according to claim 1, characterized in that, The precursor is one or more of propyltrimethoxysilane isocyanate, propyltriethoxysilane isocyanate, and propylmethyldimethoxysilane isocyanate.

3. A process for the preparation of tris (3-trialkoxysilylpropyl) isocyanurate according to claim 1, characterized in that, In step 1, the mass ratio of the precursor to the catalyst is 100:0.1-1.

4. A process for the preparation of tris (3-trialkoxysilylpropyl) isocyanurate according to claim 1, characterized in that, In step 2, the reaction temperature is 120-200 DEG C, and the reaction time is 1-8 h.

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