A coated platinum catalyst for the curing of one-component silicone resins and a method of preparation

Abstract

The application relates to a coated platinum gold catalyst for single-component silicone resin curing and a preparation method, and relates to a coated platinum gold catalyst and a preparation method. The application is used for solving the problem that a traditional two-component polysiloxane curing system needs to be strictly mixed according to a proportion, and the use of the two-component polysiloxane curing system is limited in direct application to human bodies and in environment-friendly products. The coated platinum gold catalyst comprises siloxane monomers, a platinum gold catalyst, an emulsifier, deionized water, an organic solvent, an alkali catalyst, polyvinyl alcohol and ethyl cellulose; the mass fractions of the components are as follows: the deionized water is 50-100 parts, the emulsifier is 0.5-1 part, the polyvinyl alcohol is 0.5-1 part, the alkali catalyst is 0.5-1 part, the silane monomers are 1-2 parts, the platinum gold catalyst is 1-2 parts, the organic solvent is 25-50 parts, and the ethyl cellulose is 1-2 parts. The application belongs to the technical field of hydrosilylation type silicone rubber and hydrosilylation type silicone resin preparation.

Description

Technical Field

[0001] This invention relates to a coated platinum catalyst and its preparation method, belonging to the technical field of preparation of hydrosilicone addition-type silicone rubber and hydrosilicone addition-type silicone resin. Background Technology

[0002] Among synthetic materials, silicone rubber is widely used in life sciences, aerospace, and electronic information fields due to its excellent properties, including low toxicity, good biocompatibility, physiological inertness, excellent thermal and oxidative stability, and unique aesthetic properties.

[0003] Currently, two-component addition curing systems based on platinum catalysts still dominate the industrial market. Traditional two-component polysiloxane curing systems consist of a vinyl-containing polysiloxane (component A) and a hydrogen-containing silicone oil and platinum catalyst (component B), requiring strict mixing in precise proportions. This system has significant limitations: firstly, unreacted Si-H groups contacting the platinum catalyst lead to pre-crosslinking, resulting in a working life of only a few hours after mixing; secondly, the mixing process easily introduces air bubbles, affecting the mechanical properties and appearance of the final material; moreover, precise metering and uniform mixing require highly skilled operators, making it inconvenient for delicate applications; finally, some systems require heating (60-100℃) or the use of organic solvents to achieve full curing, limiting their use in direct human application and environmentally friendly products. These problems necessitate the development of single-component controllable curing systems, and coated catalyst technology is one of the most promising solutions. Summary of the Invention

[0004] This invention addresses the problem that traditional two-component polysiloxane curing systems require strict mixing according to a specific ratio, limiting their use in direct human applications and environmentally friendly products. Therefore, it proposes a coated platinum catalyst for curing single-component silicone resins and its preparation method.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: The coated platinum catalyst for curing single-component organosilicon resin of the present invention includes siloxane monomer, platinum catalyst, emulsifier, deionized water, organic solvent, alkaline catalyst, polyvinyl alcohol and ethyl cellulose;

[0006] The mass fractions of each component are as follows: 50-100 parts deionized water, 0.5-1 part emulsifier, 0.5-1 part polyvinyl alcohol, 0.5-1 part alkaline catalyst, 1-2 parts silane monomer, 1-2 parts platinum catalyst, 25-50 parts organic solvent, and 1-2 parts ethyl cellulose.

[0007] Furthermore, the siloxane-containing monomer is one or more of methyltrimethoxysilane, methyltriethoxysilane, and ethyltriethoxysilane.

[0008] Furthermore, the platinum catalyst is a platinum(O)-divinyltetramethyldisiloxane complex.

[0009] Furthermore, the emulsifier is sodium dodecyl sulfate, one of Tween 20.

[0010] Furthermore, the organic solvent is one or more of toluene, xylene, dichloromethane, and ethyl acetate.

[0011] Furthermore, the alkaline catalyst is one of sodium carbonate, sodium hydroxide, sodium bicarbonate, tetramethylammonium hydroxide, and the corresponding silanol salt.

[0012] Furthermore, the platinum catalyst is a Kaestedt catalyst.

[0013] The steps of the method for preparing a coated platinum catalyst for curing single-component organosilicon resin according to the present invention include: Step 1: Prepare the aqueous phase. The specific process is as follows: Step 101: Weigh 50-100 parts of deionized water and 0.5-1 part of emulsifier, and stir at 50℃ for 20-30 minutes; Step 102: Add 0.5-1 part of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours; Step 103: After the solution becomes clear, add 0.5-1 part of alkaline catalyst until the pH is 9-10; Step 2: Prepare the oil phase. The specific process is as follows: Step 201: Weigh 25-50 parts of organic solvent and 1-2 parts of ethyl cellulose, and stir at 40-50℃ for 1-2 hours; Step 202: Add 1-2 parts of siloxane monomer and 1-2 parts of platinum catalyst, and stir for 30 minutes; Step 3: Preparation of coated platinum catalyst, the specific process is as follows: Step 301: Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and after the addition is complete, continue stirring at high speed at room temperature for 10 minutes. Step 302: Remove the organic solvent using a rotary evaporator under vacuum, and separate the resulting capsules by centrifugation at 10,000 rpm for 20 min to obtain the coated platinum catalyst.

[0014] Furthermore, the stirring speed in step 1 is 300-400 rpm, the stirring speed in step 2 is 500 rpm, and the stirring speed in step 3 is 1000 rpm.

[0015] Furthermore, in step 3, the oil phase is added dropwise to the aqueous phase through a dropping funnel over a period of 30 minutes.

[0016] The beneficial effects of this invention are: this invention achieves room temperature curing of single-component polysiloxane, simplifies the application process, and is particularly suitable for in-situ curing scenarios.

[0017] First, the coating structure effectively isolates external sulfur (S) and nitrogen (N), solving the problem of poisoning in traditional platinum catalysts. Second, this coating structure delays the premature reaction between platinum and silanol groups, significantly improving the storage stability of single-component silicone without the use of inhibitors. Finally, the coating layer can regulate the platinum release rate, maintaining stable catalytic activity within a certain temperature range and improving curing efficiency at low temperatures. This invention enables room temperature curing of single-component polysiloxanes, simplifying the application process and making it particularly suitable for in-situ curing scenarios. Attached Figure Description

[0018] Figure 1 This is the infrared spectrum of the coated catalyst.

[0019] Example Example 1 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g sodium dodecyl sulfate, 0.5g polyvinyl alcohol, 1g methyltrimethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g toluene, and 0.5g sodium carbonate.

[0020] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of sodium dodecyl sulfate, and stir at 50℃ for 20-30 minutes.

[0021] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0022] 1.3 After the solution becomes clear, add sodium carbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of toluene, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0023] 2.2 Add 1g of methyltrimethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0024] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0025] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0026] Example 2 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g sodium dodecyl sulfate, 0.5g polyvinyl alcohol, 1g methyltriethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g ethyl acetate, and 0.5g sodium bicarbonate.

[0027] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of sodium dodecyl sulfate, and stir at 50℃ for 20-30 minutes.

[0028] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0029] 1.3 After the solution becomes clear, add sodium bicarbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of ethyl acetate, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0030] 2.2 Add 1g of methyltriethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0031] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0032] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0033] Example 3 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g sodium dodecyl sulfate, 0.5g polyvinyl alcohol, 0.5g methyltrimethoxysilane, 0.5g methyltriethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g toluene, and 0.5g sodium bicarbonate.

[0034] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of sodium dodecyl sulfate, and stir at 50℃ for 20-30 minutes.

[0035] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0036] 1.3 After the solution becomes clear, add sodium bicarbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of toluene, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0037] 2.2 Add 0.5g of methyltrimethoxysilane, 0.5g of methyltriethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0038] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0039] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0040] Example 4 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g Tween 20, 0.5g polyvinyl alcohol, 1g methyltrimethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g toluene, and 0.5g sodium bicarbonate.

[0041] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of Tween 20, and stir at 50℃ for 20-30 minutes.

[0042] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0043] 1.3 After the solution becomes clear, add sodium bicarbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of toluene, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0044] 2.2 Add 1g of methyltrimethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0045] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0046] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0047] Example 5 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g Tween 20, 0.5g polyvinyl alcohol, 1g methyltriethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g ethyl acetate, and 0.5g sodium bicarbonate.

[0048] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of Tween 20, and stir at 50℃ for 20-30 minutes.

[0049] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0050] 1.3 After the solution becomes clear, add sodium bicarbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of ethyl acetate, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0051] 2.2 Add 1g of methyltrimethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0052] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0053] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0054] Example 6 This embodiment discloses a method for preparing a coated platinum catalyst for curing single-component organosilicon resin. The coated platinum catalyst is composed of the following components by weight: 50g deionized water, 0.5g Tween 20, 0.5g polyvinyl alcohol, 0.5g methyltrimethoxysilane, 0.5g methyltriethoxysilane, 1g Karstedt catalyst, 1g ethyl cellulose, 12.5g dichloromethane, 12.5g ethyl acetate, and 0.5g sodium bicarbonate.

[0055] The production method includes the following steps: Step 1: Prepare the aqueous phase 1.1 Weigh 50g of deionized water and 0.5g of Tween 20, and stir at 50℃ for 20-30 minutes.

[0056] 1.2 Add 0.5g of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours.

[0057] 1.3 After the solution becomes clear, add sodium bicarbonate until the pH reaches 9-10. Step 2: Preparation of the oil phase 2.1 Weigh 12.5g of dichloromethane, 12.5g of ethyl acetate, and 1g of ethyl cellulose, and stir at 40-50℃ for 1-2 hours.

[0058] 2.2 Add 0.5g of methyltrimethoxysilane, 0.5g of methyltriethoxysilane and 1g of Karstedt catalyst, and stir for 30min.

[0059] Step 3: Preparation of coated platinum catalyst 3.1 Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and continue stirring at high speed for 10 minutes at room temperature after the addition is complete.

[0060] 3.2 The organic solvent was removed by vacuum using a rotary evaporator, and the resulting capsules were separated by centrifugation at 10,000 rpm for 20 min to prepare the coated platinum catalyst.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A coated platinum catalyst for curing single-component organosilicon resins, characterized in that, Including siloxane monomers, platinum catalysts, emulsifiers, deionized water, organic solvents, alkaline catalysts, polyvinyl alcohol, and ethyl cellulose; The mass fractions of each component are as follows: 50-100 parts deionized water, 0.5-1 part emulsifier, 0.5-1 part polyvinyl alcohol, 0.5-1 part alkaline catalyst, 1-2 parts silane monomer, 1-2 parts platinum catalyst, 25-50 parts organic solvent, and 1-2 parts ethyl cellulose.

2. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The siloxane monomer is one or more of methyltrimethoxysilane, methyltriethoxysilane, and ethyltriethoxysilane.

3. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The platinum catalyst is a platinum(O)-divinyltetramethyldisiloxane complex.

4. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The emulsifier is sodium dodecyl sulfate, one of the ingredients in Tween 20.

5. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The organic solvent is one or more of toluene, xylene, dichloromethane, and ethyl acetate.

6. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The alkaline catalyst is one of sodium carbonate, sodium hydroxide, sodium bicarbonate, tetramethylammonium hydroxide, and the corresponding silanol salt.

7. The coated platinum catalyst for curing single-component organosilicon resin according to claim 1, characterized in that, The platinum catalyst is a Kaestedt catalyst.

8. A method for preparing the coated platinum catalyst according to any one of claims 1 to 7, characterized in that, The specific steps include: Step 1: Prepare the aqueous phase. The specific process is as follows: Step 101: Weigh 50-100 parts of deionized water and 0.5-1 part of emulsifier, and stir at 50℃ for 20-30 minutes; Step 102: Add 0.5-1 part of polyvinyl alcohol and stir at 80-90℃ for 1-2 hours; Step 103: After the solution becomes clear, add 0.5-1 part of alkaline catalyst until the pH is 9-10; Step 2: Prepare the oil phase. The specific process is as follows: Step 201: Weigh 25-50 parts of organic solvent and 1-2 parts of ethyl cellulose, and stir at 40-50℃ for 1-2 hours; Step 202: Add 1-2 parts of siloxane monomer and 1-2 parts of platinum catalyst, and stir for 30 minutes; Step 3: Preparation of coated platinum catalyst, the specific process is as follows: Step 301: Use a dropping funnel to drop the oil phase prepared in step 2 into the aqueous phase prepared in step 1, stir rapidly, and after the addition is complete, continue stirring at high speed at room temperature for 10 minutes. Step 302: Remove the organic solvent using a rotary evaporator under vacuum, and separate the resulting capsules by centrifugation at 10,000 rpm for 20 min to obtain the coated platinum catalyst.

9. The method for preparing a coated platinum catalyst for curing single-component organosilicon resin according to claim 8, characterized in that, The stirring speed is 300-400 rpm in step 1, 500 rpm in step 2, and 1000 rpm in step 3.

10. The method for preparing a coated platinum catalyst for curing a single-component organosilicon resin according to claim 8, characterized in that, In step 3, the oil phase is added dropwise to the aqueous phase through a dropping funnel over a period of 30 minutes.

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