Preparation process of alkoxy-terminated polysiloxane

Abstract

The invention relates to the technical field of organic silicon materials, in particular to a preparation process of alkoxy-terminated polysiloxane. The preparation process of the alkoxy-terminated polysiloxane provided by the invention comprises the following steps: under the condition of inert gas, mixing vinyl silicone oil, a composite catalyst and alkoxy hydrogen silane, heating to 100-120 DEG C, reacting, and then carrying out variable-temperature treatment to obtain the alkoxy-terminated polysiloxane, wherein the composite catalyst comprises 3-5 parts of a platinum catalyst and 1-2 parts of a palladium catalyst. On the basis of a platinum catalyst, a palladium catalyst is introduced, so that the reaction of vinyl silicone oil and alkoxy hydrosilane is more thorough, the content of impurities in alkoxy-terminated polysiloxane is reduced, and the content of the impurities in the alkoxy-terminated polysiloxane is further reduced by carrying out variable-temperature treatment on a product obtained after the reaction, so that the content of the impurities in the alkoxy-terminated polysiloxane is further reduced. And the stability of the alkoxy-terminated polysiloxane can be improved, so that the alkoxy-terminated polysiloxane can be stored for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon materials, and in particular to a preparation process of alkoxy-terminated polysiloxane. Background Art

[0002] Alkoxy-terminated polysiloxane is a kind of organic silicon polymer with special structure and properties. The molecular structure of alkoxy-terminated polysiloxane is mainly composed of siloxane chains and end-capped alkoxy groups. The siloxane chains give the material good flexibility, heat resistance, weather resistance and electrical insulation properties, while the siloxane end-capping gives it special reactivity and compatibility with other materials.

[0003] Usually, terminal hydrogen-containing silicone oil is used as the starting material. The two ends of the terminal hydrogen-containing silicone oil molecular chain contain silicon-hydrogen bonds. Then, the terminal hydrogen-containing silicone oil is reacted with an alkoxy compound containing an unsaturated bond to undergo a hydrosilylation addition reaction, so that the alkoxy groups are connected to the two ends of the polysiloxane molecular chain, thereby obtaining an alkoxy-terminated polysiloxane.

[0004] However, the existing preparation method for preparing alkoxy-terminated polysiloxane has the problem of high impurity content and short storage time. Under long-term storage, the alkoxy-terminated polysiloxane is prone to skinning and whitening. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a preparation process of alkoxy-terminated polysiloxane, by adding a composite catalyst can reduce the impurity content in the alkoxy-terminated polysiloxane, and by subjecting the reaction product to a temperature change treatment, the impurity content of the alkoxy-terminated polysiloxane can be further reduced, and the problem of unstable storage of the alkoxy-terminated polysiloxane can also be solved.

[0006] To this end, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a process for preparing an alkoxy-terminated polysiloxane in an optional embodiment, comprising the following steps:

[0008] Under the condition of inert gas, vinyl silicone oil, composite catalyst and alkoxyhydrogensilane are mixed, heated to 100-120°C for reaction, and then subjected to temperature change treatment to obtain alkoxy-terminated polysiloxane;

[0009] Wherein, the composite catalyst is 3-5 parts of platinum catalyst and 1-2 parts of palladium catalyst.

[0010] In the present invention, the composite catalyst is a platinum catalyst and a palladium catalyst. By introducing a palladium catalyst on the basis of the platinum catalyst, the present invention can make the reaction of vinyl silicone oil and alkoxyhydrogensilane more thorough and reduce the content of impurities in the alkoxy-terminated polysiloxane.

[0011] Preferably, the temperature-variable treatment comprises: cooling the product after the reaction to (-10)-(-5)°C at a rate of 8-10°C / min, then heating it to 60-80°C at a rate of 1-2°C / min, and finally cooling it to room temperature. The product after the reaction is kept at (-10)-(-5)°C for 10-15 minutes; and / or kept at 60-80°C for 30-50 minutes.

[0012] Preferably, the temperature-variable treatment comprises: cooling the product after the reaction to 60-80°C at a rate of 3-6°C / min, then cooling to (-10)-(-5)°C at a rate of 8-10°C / min, and finally heating to room temperature. The product after the reaction is kept at 60-80°C for 30-50 minutes; and / or kept at (-10)-(-5)°C for 10-15 minutes.

[0013] In the present invention, by subjecting the product after the reaction to a temperature change treatment, the content of impurities in the alkoxy-terminated polysiloxane can be further reduced, and the stability of the alkoxy-terminated polysiloxane can be improved, so that the alkoxy-terminated polysiloxane can be stored for a long time.

[0014] Preferably, the mass ratio of the vinyl silicone oil, alkoxyhydrogen silane and the composite catalyst is 100:(1-4):(0.1-0.5). Furthermore, the mass ratio of the vinyl silicone oil, alkoxyhydrogen silane and the composite catalyst is 100:2:0.3.

[0015] Preferably, the reaction time is 60-120 min. The viscosity of the vinyl silicone oil is 2000-80000 mPa.s. The inert gas is one or more of nitrogen, argon or helium.

[0016] In a second aspect, the present invention provides an alkoxy-terminated polysiloxane in an optional embodiment, which is prepared using the above-mentioned preparation process.

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

[0018] 1. The present invention introduces a palladium catalyst on the basis of a platinum catalyst, so as to make the reaction between vinyl silicone oil and alkoxyhydrogensilane more thorough and reduce the content of impurities in the alkoxy-terminated polysiloxane.

[0019] 2. The present invention further reduces the content of impurities in the alkoxy-terminated polysiloxane by subjecting the product after the reaction to temperature change treatment, and can improve the stability of the alkoxy-terminated polysiloxane so that it can be stored for a long time.

[0020] 3. The raw materials of the present invention are easily available, the operation is simple, the reaction conditions are mild, and large-scale industrial promotion can be carried out. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the following examples and comparative examples, the vinyl silicone oil is a vinyl-terminated silicone oil purchased from Ningbo Runhe High-tech Materials Technology Co., Ltd., with a product model of RH-Vi302. Trimethoxyhydrosilane is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a product number of T107289. The platinum catalyst is a chloroplatinic acid solution purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a product number of C139933. The palladium catalyst is palladium carbon purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a product number of P476057.

[0023] The technical solution of the present invention will be described below in conjunction with embodiments.

[0024] Example 1

[0025] This embodiment provides a preparation process of alkoxy-terminated polysiloxane, comprising the following steps:

[0026] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0027] (2) The reaction kettle was cooled to -10°C at a rate of 10°C / min and maintained at that temperature for 10 min, and then heated to 80°C at a rate of 2°C / min and maintained at that temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0028] The reaction formula is as follows:

[0029] CH2=CH-Si(CH3)2O((CH3)2SiO) n (CH3)2Si-CH=CH2+HSi(OCH3)3→CH2=CH-Si(CH3)2O((CH3)2SiO) n (CHx)2Si-CH2-CH2-Si(OCH3)3.

[0030] Example 2

[0031] This embodiment provides a preparation process of alkoxy-terminated polysiloxane, comprising the following steps:

[0032] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0033] (2) The reaction kettle was cooled to -10°C at a rate of 8°C / min and maintained at that temperature for 10 min, and then heated to 80°C at a rate of 1°C / min and maintained at that temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0034] Example 3

[0035] This embodiment provides a preparation process of alkoxy-terminated polysiloxane, comprising the following steps:

[0036] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0037] (2) The reaction kettle was cooled to -5°C at a rate of 8°C / min and maintained at this temperature for 15 min, and then heated to 60°C at a rate of 1°C / min and maintained at this temperature for 50 min to obtain an alkoxy-terminated polysiloxane.

[0038] Example 4

[0039] This embodiment provides a preparation process of alkoxy-terminated polysiloxane, comprising the following steps:

[0040] (1) In a nitrogen atmosphere, 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.4 kg of chloroplatinic acid), palladium carbon (containing 0.1 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) were added to a reaction kettle, stirred evenly, and heated to 110° C. for reaction for 80 min;

[0041] (2) The reaction kettle was cooled to -10°C at a rate of 10°C / min and maintained at that temperature for 10 min, and then heated to 80°C at a rate of 2°C / min and maintained at that temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0042] Example 5

[0043] This embodiment provides a preparation process of alkoxy-terminated polysiloxane, comprising the following steps:

[0044] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0045] (2) The reaction kettle was cooled to 80° C. at a rate of 5° C. / min and maintained for 40 min, and then cooled to −10° C. at a rate of 10° C. / min and maintained for 10 min to obtain an alkoxy-terminated polysiloxane.

[0046] Comparative Example 1

[0047] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0048] (1) In a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.3 kg of chloroplatinic acid) and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 minutes;

[0049] (2) The reaction kettle was cooled to -10°C at a rate of 10°C / min and maintained at that temperature for 10 min, and then heated to 80°C at a rate of 2°C / min and maintained at that temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0050] Comparative Example 2

[0051] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0052] (1) In a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, palladium carbon (containing 0.3 kg of palladium) and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0053] (2) The reaction kettle was cooled to -10°C at a rate of 10°C / min and maintained at that temperature for 10 min, and then heated to 80°C at a rate of 2°C / min and maintained at that temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0054] Comparative Example 3

[0055] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0056] Under a nitrogen atmosphere, 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium) and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) were added to the reactor, stirred evenly, and the temperature was raised to 110°C for reaction for 80 minutes to obtain alkoxy-terminated polysiloxane.

[0057] Comparative Example 4

[0058] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0059] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0060] (2) The reaction kettle was cooled to -10°C at a rate of 5°C / min and maintained at this temperature for 10 min, and then heated to 80°C at a rate of 5°C / min and maintained at this temperature for 35 min to obtain an alkoxy-terminated polysiloxane.

[0061] Comparative Example 5

[0062] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0063] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0064] (2) The reaction kettle was cooled to 80° C. at a rate of 10° C. / min and maintained at that temperature for 40 min, and then cooled to −10° C. at a rate of 5° C. / min and maintained at that temperature for 10 min to obtain an alkoxy-terminated polysiloxane.

[0065] Comparative Example 6

[0066] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0067] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0068] (2) The reaction kettle was cooled to 10° C. at a rate of 10° C. / min and maintained at 10° C. for 10 min, and then heated to 80° C. at a rate of 2° C. / min and maintained at 80° C. for 35 min to obtain an alkoxy-terminated polysiloxane.

[0069] Comparative Example 7

[0070] This comparative example provides a preparation process of an alkoxy-terminated polysiloxane, comprising the following steps:

[0071] (1) Under a nitrogen atmosphere, add 100 kg of vinyl-terminated silicone oil, chloroplatinic acid solution (containing 0.18 kg of chloroplatinic acid), palladium carbon (containing 0.12 kg of palladium), and 2 kg of alkoxyhydrogensilane (trimethoxyhydrogensilane) into a reaction kettle, stir evenly, and heat to 110° C. to react for 80 min;

[0072] (2) The reaction kettle was cooled to 80° C. at a rate of 5° C. / min and maintained at that temperature for 40 min, and then cooled to 10° C. at a rate of 10° C. / min and maintained at that temperature for 10 min to obtain an alkoxy-terminated polysiloxane.

[0073] Experimental example

[0074] The purity of the alkoxy-terminated polysiloxane prepared in Examples 1-5 and Comparative Examples 1-7 was detected by infrared spectroscopy, and the impurity content was calculated, impurity content = 1-purity of the alkoxy-terminated polysiloxane. The alkoxy-terminated polysiloxane was placed in an open space, and the time for the appearance of skinning and whitening was observed. The results are shown in Table 1.

[0075] Table 1 Impurity content and storage time of alkoxy-terminated polysiloxane

[0076]

[0077]

[0078] Note: If the impurity content exceeds 2%, it is unqualified, otherwise it is qualified; the storage time is the time when the alkoxy-terminated polysiloxane begins to crust and turn white.

[0079] Conclusion: By comparing the data of Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that the alkoxy-terminated polysiloxane produced by using only palladium catalyst or platinum catalyst has a high impurity content, is unqualified, and has a short storage time; By comparing the data of Example 1 and Comparative Example 3, it can be seen that if the product after the reaction is not subjected to temperature change treatment, even if only palladium and platinum catalysts are used for production, the alkoxy-terminated polysiloxane has a high impurity content and is still unqualified. The storage time has been improved to a certain extent compared with Comparative Examples 1 and 2, but the storage time is also relatively short. By comparing the data of Example 1, Example 5, Comparative Example 4 and Comparative Example 5, it can be seen that when the temperature change treatment is carried out, if the rate is not strictly implemented according to the production process, although the impurity content is qualified, the storage time will be greatly shortened compared to the strict implementation of the production process. By comparing the data of Example 1, Example 5, Comparative Example 6 and Comparative Example 7, it can be seen that during the temperature change treatment process, when the temperature is lowered to less than sub-zero temperature, the impurity content is unqualified and the storage time is not very ideal.

[0080] Although the principles of the present invention are described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above embodiments are merely explanations of the exemplary implementations of the present invention, and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute limitations on the scope of the present invention, and any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, fall within the protection scope of the present invention.

Claims

1. A process for preparing an alkoxy-terminated polysiloxane, characterized in that: The following steps are involved: Under the condition of inert gas, vinyl silicone oil, composite catalyst and alkoxyhydrogensilane are mixed, heated to 100-120°C for reaction, and then subjected to temperature change treatment to obtain alkoxy-terminated polysiloxane; Wherein, the composite catalyst is 3-5 parts of platinum catalyst and 1-2 parts of palladium catalyst.

2. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The temperature change treatment method includes: The product after the reaction is cooled to (-10)-(-5)°C at a rate of 8-10°C / min, then heated to 60-80°C at a rate of 1-2°C / min, and finally cooled to room temperature.

3. The process for preparing the alkoxy-terminated polysiloxane according to claim 2, characterized in that: The product after the reaction is kept at (-10)-(-5)°C for 10-15 minutes; and / or, Keep at 60-80℃ for 30-50min.

4. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The temperature change treatment method includes: The product after the reaction is cooled to 60-80°C at a rate of 3-6°C / min, then cooled to (-10)-(-5)°C at a rate of 8-10°C / min, and finally heated to room temperature.

5. The process for preparing the alkoxy-terminated polysiloxane according to claim 4, characterized in that: The product after the reaction is kept at 60-80° C. for 30-50 min; and / or, Keep at (-10)-(-5)℃ for 10-15min.

6. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The mass ratio of the vinyl silicone oil, alkoxyhydrogensilane and the composite catalyst is 100:(1-4):(0.1-0.5).

7. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The mass ratio of the vinyl silicone oil, alkoxyhydrogensilane and the composite catalyst is 100:2:0.

3.

8. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The reaction time is 60-120 min.

9. The process for preparing the alkoxy-terminated polysiloxane according to claim 1, characterized in that: The viscosity of the vinyl silicone oil is 2000-80000 mPa.s.

10. An alkoxy-terminated polysiloxane, characterized in that: The preparation is obtained by the preparation process described in any one of claims 1 to 9.

Images