Preparation method of high-stability inhibitor modified white carbon black and application thereof in platinum-gold catalytic system

Abstract

The application discloses to the technical field of silicon rubber silicon hydrogen addition reaction catalysis, and particularly relates to a high-stability inhibitor modified white carbon black preparation method and application thereof in a platinum gold catalytic system, which comprises the following specific steps: firstly, an alkynol intermediate 2 is prepared by adding o-propenyl oxybenzaldehyde 1 and ethynyl Grignard reagent; then, the alkynol intermediate 2 is subjected to secondary addition with trialkoxy hydrogen siloxane to prepare an intermediate 3; finally, the intermediate 3 is used to modify white carbon black to prepare SG-0. The complex can be used as a high-stability and high-dispersion inhibitor, and can be used in combination with a platinum gold catalyst; the obtained platinum gold catalytic system has good stability and high catalytic activity. When the complex is applied to the field of silicone rubber, the silicone rubber has excellent storage stability without adding additional inhibitors.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon rubber hydrosilylation reaction catalyst, in particular to a high-stability inhibitor modified white carbon black preparation method and its application in platinum gold catalytic system. BACKGROUND

[0002] Silicone rubber has excellent properties such as high and low temperature resistance, oxygen resistance, weather resistance, and heat insulation, so it has very wide application in automobiles, food, medical treatment and other fields. Two types of catalysts are mainly used in the molding process of silicone rubber, namely peroxide catalyst and platinum gold catalyst. The platinum gold catalyst system can effectively catalyze the silicon hydrogen addition reaction between the silicon hydrogen bond and the unsaturated bond, has high catalytic activity, high processing efficiency, no by-product generation, environmental friendliness and many other advantages, and is generally favored by the industry.

[0003] However, due to the high activity of platinum gold catalyst, it can catalyze the silicone rubber to occur latent curing at room temperature. In order to improve its operable time, the platinum gold catalyst must be used with an inhibitor during use. Alkynol compounds, maleate compounds, phosphite compounds and carbazole compounds are all commonly used reaction inhibitors. Among them, ethynylcyclohexanol is a commonly used alkynol inhibitor, which has many advantages such as low price, excellent inhibition performance and good compatibility with silicone rubber system, so it is widely used in the industry.

[0004] However, ethynylcyclohexanol still has the following disadvantages:

[0005] First, it is volatile at room temperature, which can seriously affect the long-term storage stability of silicone rubber.

[0006] Second, direct mixing of ethynylcyclohexanol and Karstedt catalyst can easily lead to the precipitation of platinum black, reducing the catalytic efficiency of the catalyst.

[0007] Therefore, the present application provides a high-stability inhibitor modified white carbon black preparation method and its application in platinum gold catalytic system. SUMMARY

[0008] To solve the above technical problems, according to one aspect of the present application, the present application provides the following technical scheme:

[0009] A high-stability inhibitor modified white carbon black preparation method, which comprises the following specific steps:

[0010] Step one, synthesis of intermediate 2: dissolve substrate 1 in solvent THF, slowly add ethynyl Grignard reagent at zero degrees, stir at zero degrees for 30 min, then react at room temperature, after monitoring that the raw materials have been completely reacted, quench with water, extract, and purify by column to obtain intermediate 2, whose specific structural formula is shown as follows:

[0011]

[0012] Step two, synthesis of intermediate 3: intermediate 2 and alkoxy hydrogen silane are added to an organic solvent, then a cast catalyst is added, and the reaction is heated for two hours. After monitoring the reaction of the raw materials is complete, after cooling, filtering, and alcohol washing, intermediate 3 is obtained.

[0013] Step three, synthesis of SG-0: fumed white carbon black is taken and added to dry toluene, intermediate 3 is added dropwise, and then the reaction is heated for four hours. After cooling to room temperature, filtering, washing, and drying, the product SG-0 is obtained.

[0014] As a preferred scheme of the preparation method of the high-stability inhibitor modified white carbon black, the alkoxy hydrogen silane is one or a mixture of multiple of trimethoxy hydrogen silane and triethoxy hydrogen silane.

[0015] As a preferred scheme of the preparation method of the high-stability inhibitor modified white carbon black, the organic solvent is one or a mixture of multiple of toluene, dichloromethane, petroleum ether, tetrahydrofuran, and N,N-dimethylformamide.

[0016] As a preferred scheme of the preparation method of the high-stability inhibitor modified white carbon black, the heating temperature in step two is 50-110 DEG C, and the heating temperature in step three is 50-110 DEG C.

[0017] As a preferred scheme of the preparation method of the high-stability inhibitor modified white carbon black, the alcohol is one or a mixture of multiple of methanol, ethanol, and isopropanol.

[0018] The preparation method of the high-stability inhibitor modified white carbon black and its application as an inhibitor in a platinum-gold catalytic system are provided.

[0019] The preparation method provided by the application is that an alkyne alcohol intermediate is prepared by addition of o-propenyl oxybenzaldehyde and ethynyl Grignard reagent, then a new silane coupling agent is prepared by secondary addition of trialkoxy hydrogen siloxane, and finally SG-0 is prepared by modification of the white carbon black.

[0020] Compared with the prior art, the preparation method provided by the application has the following advantages:

[0021] 1. The preparation method provided by the application is easy to operate and has high reaction yield, so that the industrial production efficiency is high, and the industrial production is easy to realize.

[0022] 2.The SG-0 prepared by the preparation method has good stability at room temperature and high temperature, in addition, due to the formation of a monolayer of silane on the surface of the white carbon black, the dispersibility is better, and the problem of oxidation of platinum after mixing with platinum can be avoided, so that the catalytic efficiency is high when applied to the platinum catalysis of silicon hydrogen addition. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The preparation flowchart of the platinum gold flame retardant for the silicone rubber. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below.

[0025] Example 1:

[0026] The present application provides a high stability inhibitor modified white carbon black preparation method, comprising the following specific steps:

[0027] Step one: 16.2g of substrate 1 is dissolved in 160mL of THF, 400mL of 0.5M ethynyl magnesium bromide is slowly added at zero degrees, stirred at zero degrees for 30min, then raised to room temperature for reaction, after monitoring the completion of the reaction of the raw material, first add 20mL of saturated ammonium chloride to quench, then extract the aqueous phase with ethyl acetate three times, then dry the obtained organic phase with anhydrous sodium sulfate, concentrate under reduced pressure, purify by column to obtain 17g of intermediate 2;

[0028] Step two: 5.6g of intermediate 2 and 4.9g of triethoxysilane are added to 50mL of toluene, then 2 drops of 0.1M Kast catalyst are added, and the reaction is carried out at 90℃ for two hours, after monitoring the completion of the reaction of the raw material, cooling, filtering, and methanol washing, the target product 10g of 3-A is obtained;

[0029] Step three: take 30g of fumed white carbon black, add it to 250mL of dry toluene, drop in 2g of intermediate 3-A, then react at 110℃ for four hours, cool to room temperature, filter, wash, concentrate and dry to obtain 32g of product SG-0A.

[0030] Example 2:

[0031] The present application provides a high stability inhibitor modified white carbon black preparation method, comprising the following specific steps:

[0032] Step one: same as step (1) in example 1;

[0033] Step two: 5.6g of intermediate 2 and 3.6g of trimethoxysilane were added to 50mL of toluene, then 2 drops of 0.1M Kastle catalyst were added, and the reaction was carried out at 90°C for two hours. After monitoring the reaction until the raw materials were completely reacted, the target product 9g 3-B was obtained after cooling, filtering, and washing with methanol.

[0034] Step three: 30g of fumed white carbon black was added to 250mL of dry toluene, 2g of intermediate 3-B was added dropwise, and then the reaction was carried out at 110°C for four hours. After cooling to room temperature, filtering, washing, and drying, 32g of product SG-0B was obtained.

[0035] Comparative Example 1:

[0036] Intermediate 2 was used as the inhibitor.

[0037] Comparative Example 2:

[0038] Ethynylcyclohexanol was used as the inhibitor.

[0039] a. Test of high-temperature vulcanization performance

[0040] Take 100g of liquid silicone rubber (Dongguan Betley New Materials Co., Ltd.), then add 4.8% SG-0A, 4.8% SG-0B, 0.3% intermediate 2, and 0.3% ethynylcyclohexanol inhibitor, respectively, and stir evenly for 5-10min. Then add Kastle catalyst (10ppm), stir for five minutes, and vulcanize at a temperature of 160°C for 5min to form silicone rubber samples A, B, C, and D.

[0041] The following Table 1 shows the vulcanization results of silicone rubber samples A, B, C, and D prepared in Examples and Comparative Examples.

[0042] Table 1 High-temperature catalytic results of Examples and Comparative Examples

[0043]

[0044] As shown in Table 1, the inhibitors SG-0A and SG-0B prepared in Examples 1 and 2 have similar vulcanization effects on high-temperature catalytic silicone rubber compositions as the inhibitors 2 and ethynylcyclohexanol in Comparative Examples 1 and 2, and do not affect the catalytic activity and sulfurization performance of platinum catalysts.

[0045] b. Test of room temperature stability

[0046] Take 100 g liquid silicone rubber (Dongguan Betley New Material Co., Ltd.), then add 4.8% SG-0A, 4.8% SG-0B, 0.3% intermediate 2 and 0.3% ethynylcyclohexanol inhibitor respectively, stir for 5-10 min, then add Kist catalyst (10 ppm), stir for five minutes, and mark as samples A1, B1, C1 and D1 respectively. All samples are sealed and placed in an environment at 25°C, and the viscosity of the composition is measured with a rotary viscometer (Shanghai Changji Geological Instrument Co., Ltd., Model: NDJ-8S) at regular intervals.

[0047] The viscosity of the above samples is measured at room temperature, as shown in Table 2.

[0048] Table 2 below shows the viscosity changes of the silicone rubber samples A1, B1, C1 and D1 prepared in the examples and comparative examples.

[0049]

[0050]

[0051] As can be seen from Table 2, under the same molar ratio, 4.8% SG-0A, 4.8% SG-0B, 0.3% intermediate 2 and 0.3% ethynylcyclohexanol are added to liquid silicone rubber, and the viscosity of silicone rubber samples C1 and D1 increases rapidly and cannot be applied to industrial production. It is found by comparison that the inhibitor SG-0A and SG-0B prepared by the method of the present application can make the liquid silicone rubber have an operable time of more than 60 days after being added to the liquid silicone rubber, and has high stability.

[0052] As can be seen from Table 1 and Table 2, the inhibitor SG-0A and SG-0B prepared by the method of the present application can be applied to the platinum catalyst for hydrosilylation, and can well inhibit the platinum catalyst at room temperature, without the need to add additional inhibitors, and has good room temperature stability; in addition, the crosslinking reaction can be rapidly realized under high temperature conditions; therefore, this type of inhibitor can be conveniently applied to the field of silicone rubber.

[0053] Although the present application has been described with reference to the embodiments above, various modifications can be made thereto and equivalents can be substituted for elements thereof without departing from the scope of the present application. In particular, features of the disclosed embodiments can be combined together in any manner, provided that there is no structural conflict. The combinations of features are not exhaustively described in the specification only for the purpose of saving space and resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a high-stability inhibitor-modified white carbon black, characterized by, The specific steps are as follows: Step one, synthesis of intermediate 2: dissolve substrate 1 in solvent THF, slowly add ethynyl Grignard reagent at zero degrees, stir for 30 min at zero degrees, then react at room temperature, after monitoring the completion of the reaction of raw materials, quench with water, extract, and purify by column to obtain intermediate 2, whose specific structural formula is shown as follows: ； Step two, synthesis of intermediate 3: add intermediate 2 and alkoxy hydrosilane to an organic solvent, then add Karstedt catalyst, and react for two hours at elevated temperature, after monitoring the completion of the reaction of raw materials, cool, filter, and wash with alcohol to obtain intermediate 3. Step three, synthesis of SG-0: take fumed white carbon black, add it to dry toluene, drop in intermediate 3, then react for four hours at elevated temperature, cool to room temperature, filter, wash, concentrate and dry to obtain product SG-0.

2. The method for preparing highly stable inhibitor-modified silica according to claim 1, characterized in that, The alkoxy hydrosilane is one or a mixture of more than one of trimethoxysilane and triethoxysilane.

3. The method for preparing highly stable inhibitor-modified silica according to claim 1, characterized in that, The organic solvent is one or a mixture of more than one of toluene, dichloromethane, petroleum ether, tetrahydrofuran, and N,N-dimethylformamide.

4. The method for preparing highly stable inhibitor-modified silica according to claim 1, characterized in that, The heating temperature in step two is 50-110°C, and the heating temperature in step three is 50-110°C.

5. The method for preparing highly stable inhibitor-modified silica according to claim 1, characterized in that, The alcohol is one or a mixture of more than one of methanol, ethanol, and isopropanol.

6. The application of the modified white carbon black prepared by the method of any one of claims 1-5 as an inhibitor in a platinum-gold catalytic system.

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