Preparation method and application of catalyst for efficiently blocking 107 glue

Abstract

The invention provides a preparation method and application of a catalyst for efficiently blocking 107 glue, and belongs to the technical field of organic silicon materials, and the technical scheme is as follows: (1) adding phosphoric acid into alcohol ether organic matters, heating and stirring; (2) continuously dropwise adding an amino silane coupling agent; and (3) after the sufficient reaction, performing vacuum low-temperature removal to obtain the high-efficiency end-capped 107 product catalyst. The catalyst and the raw materials of the efficient terminated 107 adhesive are easy to obtain, the reaction condition is mild, the process is simple, the terminating efficiency is high, and the correspondingly prepared dealcoholized silicone adhesive has the advantages of rapid curing and excellent anti-aging performance.

Description

Technical Field

[0001] The present invention relates to the technical field of organosilicon materials, and in particular to a method for preparing a catalyst for efficiently capping 107 glue and application thereof. Background Art

[0002] As a type of silicone product, dealcoholized silicone adhesive is more environmentally friendly because it does not produce acidic substances during the curing process. It also has good weather resistance, heat resistance, adhesion and electrical insulation properties. It can maintain stable performance over a wide temperature range and can firmly bond with a variety of materials (such as metal, glass, ceramics, plastics, etc.). In recent years, it has not only been used in traditional construction fields, but also has shown great potential in high-tech fields such as electronics, automobiles, aerospace, etc.

[0003] Since the dealcoholized silicone rubber made with terminal hydroxyl polydimethylsiloxane as the base material is prone to "viscosity peak" during the preparation process, and the trace amount of small molecular alcohol substances in the system are easy to react with the silanol group under the action of the catalyst to generate a monoalkoxy-terminated polymer, which makes it inactive, making the product unable to solidify and having poor storage stability, it is very important to prepare the alkoxy-terminated base material. However, it is very difficult to prepare highly efficient alkoxy-terminated polydimethylsiloxane, which greatly affects the quality of the subsequent dealcoholized silicone rubber products and hinders its further development in the construction and other industries.

[0004] The Chinese patent document with publication number CN 110878142 A discloses a method for synthesizing alkoxy-terminated polysiloxane, which uses a platinum catalyst to terminate hydroxyl-terminated polydimethylsiloxane. The silicone adhesive prepared in this way has excellent high temperature and humidity resistance and good thixotropy, but the platinum catalyst is expensive, easily poisoned, and has relatively poor thermal stability, which is not conducive to industrial production. The Chinese patent document with publication number CN 114749210 B discloses a method for preparing and using a catalyst for room temperature terminated 107 adhesive. The catalyst achieves the termination of 107 at room temperature, but the curing effect of the silicone adhesive prepared in this way is still poor, and can only maintain the same performance as the initial performance within 3 days at 90°C, and the termination effect still has room for improvement. Summary of the invention

[0005] The present invention provides a method for preparing a catalyst for high-efficiency end-capped 107 glue and its application. The catalyst for high-efficiency end-capped 107 glue has readily available raw materials, mild reaction conditions, simple process and high end-capping efficiency. The corresponding dealcoholized silicone glue has rapid curing and excellent anti-aging performance.

[0006] The technical solution of the present invention is: In a first aspect, a method for preparing a catalyst for efficiently capping 107 glue is provided, comprising the following steps: (1) Add phosphoric acid to alcohol ether organic matter, heat and stir; (2) Continue to add aminosilane coupling agent; (3) After sufficient reaction, the product catalyst of the highly efficient end-capping 107 is obtained by vacuum degassing.

[0007] Preferably, the purity of phosphoric acid in step (1) is greater than 99.0%.

[0008] Preferably, the alcohol ether organic substance in step (1) is one or more of ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, preferably ethylene glycol methyl ether.

[0009] Preferably, in step (1), the reaction temperature is 40°C-150°C; and the reaction time is 0.5h-2h.

[0010] Preferably, the aminosilane coupling agent in step (2) is one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-aminoethyl-γ-aminopropyltriethoxysilane, 3-(2-aminoethyl)-aminopropyltrimethoxysilane, 3-(2-aminoethyl)-aminopropylmethyldimethoxysilane, and N-aminoethyl-γ-aminopropyltriethoxysilane. γ-aminopropyltrimethoxysilane is preferred.

[0011] Preferably, in step (2), the reaction temperature is 50°C-150°C; and the reaction time is 1h-3h.

[0012] Preferably, the molar ratio of phosphoric acid: alcohol ether organic matter: aminosilane coupling agent is 1: (0.5-1.5): (1-2).

[0013] The reaction mechanism is as follows: based on phosphate ester and introducing silane on the side chain, it effectively promotes its compatibility with silicone rubber, improves the reaction activity of the catalyst, and can produce 107 glue with a high alkoxy end-capping rate, so that the dealcoholized silicone rubber with it as the base material has excellent anti-aging properties. At the same time, the introduction of hydrophilic ether bonds on the side chain also improves the water vapor permeability of the colloid to a certain extent, greatly accelerating the surface drying and curing time of the dealcoholized silicone rubber with it as the base material.

[0014] On the other hand, the present invention also provides the use of the high-efficiency capping catalyst in the preparation of dealcoholized silicone rubber. The preparation steps of the dealcoholized silicone rubber include the following: (1) Weigh 100 parts of 35000 mPa·s hydroxy-terminated polydimethylsiloxane into a planetary mixer, turn on the vacuum pump to about -0.09 MPa, and stir for 0.5 h.

[0015] (2) Fill the container with nitrogen until the pressure is equal, open the lid and add 2 parts of vinyltrimethoxysilane, add 0.25 parts of the high-efficiency catalyst, open the vacuum valve and evacuate to about -0.09 MPa, close the vacuum valve, raise the temperature to 45°C under negative pressure, and stir for 2 hours to obtain modified 107 rubber.

[0016] (3) Take 100 parts of the modified 107 rubber, add 10 parts of fumed silica and 10 parts of dimethyl silicone oil, mix evenly under vacuum at about -0.05 MPa, then add 6 parts of methyltrimethoxysilane, 1.5 parts of silane coupling agent and 0.3 parts of organotin catalyst, stir under vacuum at about -0.09 MPa for 0.5 h to obtain dealcoholized silicone rubber.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method of the present invention is simple, the reaction conditions are mild, the raw material cost is low, there is no complicated reaction process, and it is convenient for large-scale industrial production.

[0018] (2) The high-efficiency catalyst described in the present invention greatly accelerates the surface drying and curing time of the corresponding dealcoholized silicone adhesive.

[0019] (3) The high-efficiency catalyst described in the present invention can produce alkoxy-terminated polydimethylsiloxane with a high end-capping rate. The corresponding dealcoholized silicone adhesive product has excellent anti-aging properties and can still be cured normally after 7 days at 100°C, and the mechanical properties are not much different from the initial ones. DETAILED DESCRIPTION

[0020] The technical scheme and advantages of the present invention are further illustrated below in conjunction with the embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods in the following embodiments without specifying specific conditions are usually carried out under normal conditions or according to the conditions recommended by the manufacturer.

[0021] Comparative Example 1 Take 100 parts of 35 000mPa·s hydroxy-terminated polydimethylsiloxane in a planetary mixer, turn on the vacuum pump to about -0.09MPa, and stir for 0.5h. Fill with nitrogen to equal pressure, open the cover and add 2 parts of vinyltrimethoxysilane, turn on the vacuum pump to about -0.09MPa, close the vacuum valve, heat to 45℃ under negative pressure, and stir for 2h to obtain modified 107 glue.

[0022] Take 100 parts of the modified 107 rubber, add 10 parts of fumed silica and 10 parts of dimethyl silicone oil, mix evenly under vacuum at about -0.05 MPa, then add 6 parts of methyltrimethoxysilane, 1.5 parts of silane coupling agent and 0.3 parts of organic tin catalyst (dibutyltin dilaurate), stir under vacuum at about -0.09 MPa for 0.5 h to obtain dealcoholized silicone rubber.

[0023] Example 1 A method for preparing a catalyst for efficiently capping 107 rubber, the specific steps are as follows: Pour 10g of phosphoric acid into 9.3g of ethylene glycol methyl ether, heat the oil bath to 80°C, set the speed to 120r / min, react for 1.5h, then add 22g of γ-aminopropyltrimethoxysilane dropwise, react for 2h, heat to 130°C, and degas for 0.5h to obtain the product catalyst.

[0024] Take 100 parts of 35 000mPa·s hydroxy-terminated polydimethylsiloxane in a planetary mixer, turn on the vacuum pump to about -0.09MPa, and stir for 0.5h. Fill with nitrogen until the pressure is equal, open the cover and add 2 parts of vinyltrimethoxysilane and 2.5 parts of the above-mentioned high-efficiency catalyst, turn on the vacuum pump to about -0.09MPa, close the vacuum valve, heat to 45℃ under negative pressure, and stir for 2h to obtain modified 107 glue.

[0025] Take 100 parts of the modified 107 rubber, add 10 parts of fumed silica and 10 parts of dimethyl silicone oil, mix evenly under vacuum at about -0.05 MPa, then add 6 parts of methyltrimethoxysilane, 1.5 parts of silane coupling agent and 0.3 parts of organic tin catalyst (dibutyltin dilaurate), stir under vacuum at about -0.09 MPa for 0.5 h to obtain dealcoholized silicone rubber.

[0026] Example 2 A method for preparing a catalyst for efficiently capping 107 rubber, the specific steps are as follows: 10g of phosphoric acid was poured into 9.3g of ethylene glycol methyl ether, the oil bath temperature was raised to 80°C, the speed was set to 120r / min, the reaction was continued for 0.5h, and then 22g of γ-aminopropyltrimethoxysilane was added dropwise, the temperature was raised to 130°C after the reaction for 3h, and the reaction was continued for 0.5h to obtain the product catalyst. The subsequent steps were the same as those in Example 1.

[0027] Example 3 In this embodiment, the method for preparing a catalyst for efficiently capping 107 glue is different from that in Example 1 only in that 9.3 g of ethylene glycol methyl ether is replaced by 7.34 g of n-propanol, and other reaction conditions and steps are the same.

[0028] Example 4 In this embodiment, the catalyst preparation method for a highly efficient capped 107 glue is different from that in Example 1 only in that 22 g of γ-aminopropyltrimethoxysilane is replaced with 7.34 g of n-propanol, and other reaction conditions and steps are the same.

[0029] Example 5 In this embodiment, the catalyst preparation method for a high-efficiency capped 107 glue is different from that in Example 1 only in that 9.3 g of ethylene glycol methyl ether is replaced by 9.7 g of propylene glycol ethyl ether, and 22 g of γ-aminopropyltrimethoxysilane is replaced by 27 g of γ-aminopropyltriethoxysilane, and other reaction conditions and steps are the same.

[0030] In order to verify the effectiveness of the end-capping, 2 parts of tetraisopropyl titanate were added to 100 parts of the modified 107 rubber of the above examples and comparative examples, and the viscosity peak phenomenon of rapid viscosity increase was observed during the rapid stirring process to determine whether there were unreacted hydroxyl groups in the rubber. In order to verify whether the dealcoholized silicone rubber based on the alkoxy-terminated polydimethylsiloxane prepared under the action of the efficient catalyst can be quickly cured, the silicone rubber of the above examples and comparative examples was tested for its surface drying and tack-free time under standard conditions (temperature (23±2)℃, relative humidity (50±5)%) according to the requirements of the GB16776-2005 test. In order to verify the anti-aging performance of the dealcoholized silicone rubber based on the alkoxy-terminated polydimethylsiloxane prepared under the action of the efficient catalyst, the above examples and comparative examples were placed at 100℃ for 7 days for accelerated aging, and their surface drying and tack-free time were tested. Table 1 compares the end-capping effects of the embodiments and the comparative examples, and Table 2 compares the initial performance and the performance after aging of the embodiments and the comparative examples.

[0031] Table 1 Comparison of end-capping effects of Examples 1-3 and Comparative Example 1

[0032] Table 2 Comparison of initial performance and performance after aging of Examples 1-3 and Comparative Example 1

[0033] The end-capping effects of the alkoxy-terminated 107 glue prepared in Comparative Example 1 and Examples 1-5 are shown in Table 1. The results show that compared with the examples, the modified 107 prepared in the comparative example has a viscosity peak, while the examples 1-5 do not have a viscosity peak, indicating that the modified 107 glue prepared in Examples 1-5 is successful.

[0034] The comparison of the initial and aging curing effects of the dealcoholized silicone adhesives obtained in Comparative Example 1 and Examples 1-5 is shown in Table 2. The results show that the initial surface drying and detackification of the comparative example are much slower than those of Examples 1-5, and the surface drying and detackification cannot be normal after aging, while the surface drying and detackification of Examples 1-5 after aging are still close to the initial level, which is due to the alkoxy groups in the efficient catalyst improving the compatibility of the catalyst and the silicone adhesive and increasing the reaction activity between the catalyst and the silicone adhesive. It is also due to the ether bonds in the efficient catalyst enhancing the ability of the silicone adhesive to absorb moisture during the curing process.

[0035] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a catalyst for efficiently capping 107 rubber, characterized in that: The following steps are involved: (1) Add phosphoric acid to alcohol ether organic matter, heat and stir; (2) Continue to add aminosilane coupling agent; (3) After sufficient reaction, the mixture is vacuum degassing to obtain the highly efficient end-capped 107 glue product catalyst.

2. The method for preparing a catalyst for high-efficiency end-capped 107 glue according to claim 1, characterized in that: The purity of phosphoric acid is greater than 99.0%.

3. The method for preparing a catalyst of a highly efficient end-capped 107 rubber according to claim 1, characterized in that: The alcohol ether organic compound is one or more of ethylene glycol methyl ether, propylene glycol methyl ether and propylene glycol ethyl ether.

4. The method for preparing a catalyst of a highly efficient end-capped 107 rubber according to claim 1, characterized in that: In step (1), the reaction temperature is 40°C-150°C; and the reaction time is 0.5h-2h.

5. The method for preparing a catalyst of a highly efficient end-capped 107 rubber according to claim 1, characterized in that: The aminosilane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-aminoethyl-γ-aminopropyltriethoxysilane, 3-(2-aminoethyl)-aminopropyltrimethoxysilane, 3-(2-aminoethyl)-aminopropylmethyldimethoxysilane, and N-aminoethyl-γ-aminopropyltriethoxysilane.

6. The method for preparing a catalyst of a highly efficient end-capped 107 rubber according to claim 5, characterized in that: The molar ratio of phosphoric acid: alcohol ether organic matter: aminosilane coupling agent is 1: (0.5-1.5): (1-2).

7. The method for preparing a catalyst for high-efficiency end-capped 107 glue according to claim 1, characterized in that: In step (2), the reaction temperature is 50°C-150°C; and the reaction time is 1h-3h.

8. Use of the catalyst prepared by the method for preparing a high-efficiency end-capped 107 rubber catalyst according to any one of claims 1 to 7 in preparing alkoxy-end-capped 107 rubber and as a base rubber for dealcoholized silicone rubber.

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