Preparation method of tris (3-trialkoxysilylpropyl) isocyanurate

Abstract

The invention provides a preparation method of tris (3-trialkoxysilylpropyl) isocyanurate, which comprises the following steps: step 1, in a nitrogen atmosphere, putting a mixture of a precursor and a catalyst into a water-free and oxygen-free reaction container; 2, heating the mixture in the step 1 to a reaction temperature, and starting a reaction; and step 3, after the reaction is finished, cooling to room temperature, and filtering out the catalyst to obtain the product tris (3-trialkoxysilylpropyl) isocyanurate. The preparation method comprises the following steps: 1, body cyclization polycondensation is adopted without participation of a solvent, so that the need of a reaction solvent and a tedious post-treatment process in the prior art are avoided; 2, cesium fluoride and the like are adopted as catalysts, so that the reaction rate and the conversion rate are improved, the catalyst is incompatible with the product and can be filtered out through suction filtration or filter pressing, the process difficulty is reduced, and the product purity is high; and thirdly, the preparation method is simple, simple and convenient to operate, mild in reaction and suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of silane coupling agent OR flame retardant OR organosilicon synthesis, and in particular to a preparation method of tris(3-trialkoxysilylpropyl)isocyanurate. Background Art

[0002] Tris(3-trialkoxysilylpropyl)isocyanurate can form multiple chemical bonds after hydrolysis, and various effects can be achieved through this strong cross-linking; at the same time, it has a stable six-membered ring structure and good high temperature tolerance, and can be used in high temperature environments. Therefore, in the fields of coatings, adhesives, metal powders, etc., tris(3-trialkoxysilylpropyl)isocyanurate can significantly improve the heat resistance, solvent resistance, and bonding properties of composite materials.

[0003] Silicon flame retardants have always had the advantages of low smoke, non-toxicity, and good carbonization. During the combustion process, a dense silicon carbon layer will form on the surface of the material, which can effectively inhibit the dripping of polymers after melting. It is an environmentally friendly flame retardant with good development prospects. Nitrogen flame retardants mainly decompose and release non-flammable gases during the combustion process to dilute the flammable gases and isolate the polymer materials from the air. To achieve a flame retardant effect. Tris (3-trialkoxysilylpropyl) isocyanurate contains both nitrogen and silicon elements and has a stable six-membered ring, which greatly improves its flame retardant performance in polymer materials.

[0004] The preparation method of tris(3-trialkoxysilylpropyl)isocyanurate is also recorded in the prior art. For example, CN 101805366 describes the preparation of tris(3-trimethoxysilylpropyl)isocyanurate by cyclocondensation with 3-isocyanatepropyltrimethoxysilane 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 complicated. CN115403609 describes the preparation of tris(3-trimethoxysilylpropyl)isocyanurate by cyclocondensation with 3-isocyanatepropyltrimethoxysilane. 3-trimethoxysilylpropyl) isocyanurate, using organic tin as a catalyst, requires adsorption filtration, and the product purity is low; CN108570069 describes a method for preparing tris(3-trialkoxysilylpropyl) isocyanurate by hydrosilylation of 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione with hydrogen alkoxysilane under Pt-catalyst, the catalyst is not easy to separate, and the process is difficult.

[0005] In view of this, it is necessary to propose a preparation method of tris(3-trialkoxysilylpropyl)isocyanurate to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to disclose a preparation method of tris(3-trialkoxysilylpropyl)isocyanurate, which adopts bulk cyclocondensation without the participation of solvent, thus avoiding the need for reaction solvent and cumbersome post-treatment process in the prior art; by adopting cesium fluoride or the like as a catalyst, the reaction rate and conversion rate are improved, and the isocyanurate is incompatible with the product and can be filtered out by suction filtration or pressure filtration, thus reducing the process difficulty and achieving high product purity; the preparation method is simple, easy to operate, mild in reaction, and suitable for industrial production.

[0007] To achieve the above object, the present invention provides a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, comprising the following steps:

[0008] Step 1: Place a mixture of the precursor and the catalyst in a water-free and oxygen-free reaction vessel under a nitrogen atmosphere;

[0009] Step 2: heating the mixture in step 1 to the reaction temperature to start the reaction;

[0010] Step 3: After the reaction is completed, cool to room temperature, filter out the catalyst, and obtain the product tris(3-trialkoxysilylpropyl)isocyanurate.

[0011] In some embodiments, in step 1, the structural formula of the precursor is: Among them, R1, R2, and R3 are all alkoxy groups or one of them is an alkyl group.

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

[0013] In some embodiments, the precursor is one or more of isocyanatepropyltrimethoxysilane, isocyanatepropyltriethoxysilane, and isocyanatepropylmethyldimethoxysilane.

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

[0015] In some embodiments, in step 1, the catalyst is one or more of cesium fluoride, tetrabutylammonium fluoride, sodium methoxide, and sodium p-toluenesulfonate.

[0016] In some embodiments, in step 2, the reaction temperature is 120-200° C., and the reaction time is 1-8 h.

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

[0018] 1. It adopts bulk cyclocondensation, which does not require the participation of solvents, avoiding the need for reaction solvents and cumbersome post-treatment processes in the prior art;

[0019] Second, by using cesium fluoride as a catalyst, the reaction rate and conversion rate are improved, and it is incompatible with the product and can be filtered out by suction or pressure filtration, which reduces the process difficulty and the product purity is high;

[0020] 3. The preparation method is simple, easy to operate, mild in reaction, and suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a reaction diagram of the preparation process of tris(3-trialkoxysilylpropyl)isocyanurate shown in the present invention;

[0022] Figure 2 FT-IR graph of tris(3-trimethoxysilylpropyl)isocyanurate prepared in the present invention;

[0023] Figure 3 This is a GC purity test chart of tris(3-trimethoxysilylpropyl)isocyanurate prepared in the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0025] Example 1

[0026] The present embodiment discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which is specifically as follows: 500 g of 3-isocyanatepropyltrimethoxysilane and 1.5 g of cesium fluoride are added into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 180° C., the temperature is kept for 3 hours, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 92.96%.

[0027] Example 2

[0028] The present embodiment discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which is specifically as follows: 500 g of 3-isocyanatepropyltrimethoxysilane and 3 g of cesium fluoride are added into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 hours, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 96.4%.

[0029] like Figure 3The GC purity test chart of tris(3-trimethoxysilylpropyl)isocyanurate prepared in this example is shown in FIG. Figure 2 Shown is the FT-IR graph of tris(3-trimethoxysilylpropyl)isocyanurate prepared in this example.

[0030] Example 3

[0031] The present embodiment discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which is specifically as follows: 500 g of 3-isocyanatepropyltriethoxysilane and 3 g of cesium fluoride are added into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 hours, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 93.26%.

[0032] Example 4

[0033] The present embodiment discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which is specifically as follows: 500 g of 3-isocyanatepropylmethyldimethoxysilane and 3 g of cesium fluoride are added into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 hours, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 94.87%.

[0034] Example 5

[0035] This embodiment discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which is specifically as follows: 500 g of 3-isocyanatepropyltrimethoxysilane and 3 g of tetrabutylammonium fluoride are added into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 hours, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate, with a content of 91.15%.

[0036] Comparative Example 1

[0037] The present comparative example discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which comprises the following steps: adding 500 g of 3-isocyanatepropyltrimethoxysilane and 3 g of sodium methoxide into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 h, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 86.37%.

[0038] Comparative Example 2

[0039] The present comparative example discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which comprises the following steps: adding 500 g of 3-isocyanatepropyltrimethoxysilane and 3 g of sodium methoxide into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 180° C., the temperature is kept for 3 h, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 83.47%.

[0040] Comparative Example 3

[0041] The present comparative example discloses a method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, which comprises the following steps: adding 500 g of 3-isocyanatepropyltrimethoxysilane and 3 g of sodium p-toluenesulfonate into an anhydrous and oxygen-free reactor, stirring and nitrogen purging are started, the temperature is raised to 150° C., the temperature is kept for 6 h, the temperature is lowered to 20° C., and the insoluble matter is removed by filtration under reduced pressure to obtain the product tris(3-trimethoxysilylpropyl)isocyanurate with a content of 89.11%.

[0042] By comparing the examples and comparative examples, it is found that the tris(3-trialkoxysilylpropyl)isocyanurate obtained by the preparation method provided by the present invention has the following beneficial effects: First, it adopts bulk cyclocondensation without the participation of solvent, thereby avoiding the need for reaction solvent and cumbersome post-treatment process in the prior art; Second, by using cesium fluoride or the like as a catalyst, the reaction rate and conversion rate are improved, and it 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; Third, the preparation method is simple, easy to operate, mild in reaction, and suitable for industrial production.

[0043] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0044] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing tris(3-trialkoxysilylpropyl)isocyanurate, characterized in that: The steps include: Step 1: Place a mixture of the precursor and the catalyst in a water-free and oxygen-free reaction vessel under a nitrogen atmosphere; Step 2: heating the mixture in step 1 to the reaction temperature to start the reaction; Step 3: After the reaction is completed, cool to room temperature, filter out the catalyst, and obtain the product tris(3-trialkoxysilylpropyl)isocyanurate.

2. The method for preparing tris(3-trialkoxysilylpropyl)isocyanurate according to claim 1, characterized in that: In step 1, the structural formula of the precursor is: Among them, R1, R2, and R3 are all alkoxy groups or one of them is an alkyl group.

3. The method for preparing tris(3-trialkoxysilylpropyl)isocyanurate according to claim 2, characterized in that: Alkoxy groups include, but are not limited to, methoxy and ethoxy groups, and alkyl groups include, but are not limited to, methyl and ethyl groups.

4. The method for preparing tris(3-trialkoxysilylpropyl)isocyanurate according to claim 2, characterized in that: The precursor is one or more of isocyanate propyl trimethoxy silane, isocyanate propyl triethoxy silane, and isocyanate propyl methyl dimethoxy silane.

5. The method for preparing 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.

6. The method for preparing tris(3-trialkoxysilylpropyl)isocyanurate according to claim 1, characterized in that: In step 1, the catalyst is one or more of cesium fluoride, tetrabutylammonium fluoride, sodium methoxide, and sodium p-toluenesulfonate.

7. The method for preparing tris(3-trialkoxysilylpropyl)isocyanurate according to claim 1, characterized in that: In step 2, the reaction temperature is 120-200°C and the reaction time is 1-8h.

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