Active controllable platinum complex and preparation method and application thereof

Abstract

The application discloses a platinum complex with controllable activity and a preparation method and application thereof, which is formed by coordination of vinyl siloxane, modified ligand and chloroplatinic acid; the modified ligand is prepared by reaction of maleic anhydride, allylamine and hydroxymethyl dimethyl phosphite. The application introduces amide groups and phosphite groups into the molecular chain of maleic anhydride, uses the groups as coordination compounds to coordinate with vinyl siloxane and platinum, and can improve the normal-temperature storage stability of the platinum catalyst while still keeping high catalytic activity of the platinum catalyst on the hydrosilylation reaction; when the platinum complex is used for catalyzing preparation of addition-type liquid silicone rubber, no inhibitor needs to be added, and the silicone rubber has good mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst, in particular to a platinum complex with controllable activity and a preparation method and application thereof. BACKGROUND

[0002] The hydrosilylation reaction has been widely studied in small molecule chemistry, and many dispersed systems of transition metals and their complexes can be used to catalyze the hydrosilylation reaction. Among these catalysts, the most effective and widely used is platinum complex. However, if the activity of platinum catalyst is too high, there is a problem that the operable time of the two-component addition type liquid silicone rubber is too short after mixing, and the single-component addition type liquid silicone rubber cannot be stored. If the activity of the catalyst is too low, the addition reaction cannot be ensured to be complete. Therefore, it is of great significance to improve the catalytic activity and storage stability of platinum catalyst for the synthesis of addition type silicone rubber.

[0003] In the prior art, a platinum complex with catalytic and inhibitory functions is generally obtained by coordinating vinyl siloxane and a compound with inhibitory function with platinum to improve the storage stability of platinum catalyst. For example, a preparation method of platinum catalyst for liquid silicone rubber is disclosed in Chinese patent document CN107189071A. The invention adopts a method of coordinating divinyltetramethyldisiloxane and maleate compound with platinum to obtain a special structure platinum catalyst with catalytic and inhibitory functions. Since the hydrosilylation reaction can be effectively inhibited at room temperature, the operable time of addition type silicone rubber and the room temperature storage time of single-component addition type liquid silicone rubber can be significantly improved.

[0004] However, after the compound with inhibitory function is coordinated with platinum in the prior art, although the room temperature storage stability can be improved, the catalytic activity of platinum catalyst and the performance of silicone rubber after curing are also affected to some extent. SUMMARY

[0005] The present application is to overcome the above-mentioned problems of platinum hydrosilylation catalyst in the prior art, and to provide a platinum complex with controllable activity and a preparation method and application thereof. By introducing amide group and phosphite group into the molecular chain of maleic anhydride and using them as coordination compounds to coordinate with vinyl siloxane and platinum, the room temperature storage stability of platinum catalyst can be improved, and the high catalytic activity of platinum catalyst for hydrosilylation reaction can be maintained. When the platinum complex is used to catalyze the preparation of addition type liquid silicone rubber, no inhibitor needs to be added, and the silicone rubber has good mechanical properties.

[0006] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a platinum complex with controllable activity, which is formed by coordination of vinyl siloxane and modified ligand with chloroplatinic acid; the modified ligand is prepared by reaction of maleic anhydride with allylamine and dimethyl hydroxymethyl phosphite.

[0008] The platinum complex in the present application is formed by coordination of vinyl siloxane and modified ligand with chloroplatinic acid, which can make the platinum complex in the present application have both catalytic and inhibitory effects on preparation of addition type liquid silicone rubber. The modified ligand contains amide group obtained by reaction of maleic anhydride with allylamine, vinyl group, and phosphite group obtained by reaction of maleic anhydride with dimethyl hydroxymethyl phosphite; introduction of each functional group in the modified ligand makes the platinum complex in the present application be able to be stably stored at room temperature, and have long operable time when used for preparation of addition type liquid silicone rubber; meanwhile, introduction of each functional group can also ensure the platinum complex to have high catalytic activity and to be able to rapidly catalyze silicon-hydrogen addition reaction at high temperature. When the platinum complex in the present application is used for preparation of addition type liquid silicone rubber, no inhibitor needs to be added, and the silicone rubber obtained after curing has good mechanical properties.

[0009] Preferably, the molar ratio of chloroplatinic acid to vinyl siloxane is 1:3-50, and the molar ratio of modified ligand to vinyl siloxane is 1:5-50.

[0010] Preferably, the vinyl siloxane is one or more of tetramethyldivinyldisiloxane, tetramethyltetra-vinylcyclotetrasiloxane, and end-vinyl silicone oil.

[0011] Preferably, the molar ratio of maleic anhydride, allylamine, and dimethyl hydroxymethyl phosphite is 1:1-1.2:1-1.2.

[0012] In a second aspect, the present application provides a preparation method of the above-mentioned platinum complex with controllable activity, which comprises the following steps:

[0013] (1) reacting maleic anhydride with allylamine, and then reacting the product with dimethyl hydroxymethyl phosphite to obtain the modified ligand; (2) dissolving sodium bicarbonate in an alcohol solvent, then adding chloroplatinic acid and vinyl siloxane to the solution, and performing heating reaction; (3) mixing the product obtained in step (2) with the modified ligand, and performing heating reaction to obtain the platinum complex with controllable activity.

[0014] Preferably, the reaction conditions of maleic anhydride and allylamine in step (1) are as follows: maleic anhydride is added to a solvent, then the solution is heated to 35-50℃, allylamine is added dropwise to the solution, and the solvent is removed after reaction for 1-2h.

[0015] As preferred, the reaction conditions of the product obtained by reacting maleic anhydride with allylamine in step (1) with dimethyl hydroxymethyl phosphite are as follows: the product and dimethyl hydroxymethyl phosphite are added into dimethylbenzene, and sodium methoxide catalyst is added, and the reaction is carried out at 120-160℃ for 3-8h, and then the solvent is removed to obtain the modified ligand.

[0016] As preferred, the alcohol solvent in step (2) is one or more of methanol, ethanol, and isopropanol; and the mass ratio of sodium bicarbonate to chloroplatinic acid added is 2-5:1.

[0017] As preferred, the reaction temperature in step (2) is 40-80℃, and the reaction time is 1-4h; and the reaction temperature in step (3) is 50-100℃, and the reaction time is 0.5-2h.

[0018] In a third aspect, the application provides a use of the above-mentioned platinum complex with controllable activity in the preparation of silicone rubber.

[0019] Therefore, the application has the following beneficial effects: the platinum complex is formed by coordinating vinyl siloxane and modified ligand with chloroplatinic acid, the functional groups such as amide group, phosphite, and vinyl are introduced into the modified ligand, which can make the platinum complex in the application have both catalytic and inhibitory effects on the preparation of addition-type liquid silicone rubber, and the platinum complex can be stably stored at room temperature in the silicone rubber, and has a long operable time when used for the preparation of addition-type liquid silicone rubber; meanwhile, the introduction of various functional groups can also ensure that the platinum complex has high catalytic activity, and can rapidly catalyze the silicon-hydrogen addition reaction at high temperature; when the platinum complex in the application is used for the preparation of addition-type liquid silicone rubber, no inhibitor needs to be added, and the silicone rubber obtained after curing has good mechanical properties. DETAILED DESCRIPTION

[0020] The application will be further described below in combination with the specific embodiments.

[0021] In the application, all the equipment and raw materials can be purchased from the market or commonly used in the industry, and the methods in the following examples are all conventional methods in the field unless otherwise specified.

[0022] General example:

[0023] A platinum complex with controllable activity is formed by coordinating vinyl siloxane and modified ligand with chloroplatinic acid; the modified ligand is obtained by reacting maleic anhydride with allylamine and dimethyl hydroxymethyl phosphite.

[0024] The above-mentioned vinyl siloxane is one or more of tetramethyldivinyl disiloxane, tetramethyltetraethenyl cyclotetrasiloxane, and end-vinyl silicone oil; preferably, it is tetramethyldivinyl disiloxane. The viscosity of the end-vinyl silicone oil is 5-50mm 2 / s.

[0025] The molar ratio of maleic anhydride, allylamine and hydroxymethyl dimethyl phosphite in the preparation of the modified ligand is 1:1-1.2:1-1.2; in some specific embodiments of the present application, the molar ratio of maleic anhydride, allylamine and hydroxymethyl dimethyl phosphite in the preparation of the modified ligand is 1:1:1, 1:1:1.1, 1:1:1.2, 1:1.1:1, 1:1.2:1 or 1:1.1:1.1.

[0026] In the present application, the molar ratio of chloroplatinic acid to vinyl siloxane is 1:3-50, and the molar ratio of the modified ligand to vinyl siloxane is 1:5-50; preferably, the molar ratio of chloroplatinic acid to vinyl siloxane is 1:5-30, and the molar ratio of the modified ligand to vinyl siloxane is 1:5-30; more preferably, the molar ratio of chloroplatinic acid to vinyl siloxane is 1:10-20, and the molar ratio of the modified ligand to vinyl siloxane is 1:5-10; in some specific embodiments of the present application, the molar ratio of chloroplatinic acid to vinyl siloxane is 1:5, 1:10, 1:15 or 1:20, and the molar ratio of the modified ligand to vinyl siloxane is 1:5, 1:10 or 1:15.

[0027] The preparation method of the active controllable platinum complex comprises the following steps:

[0028] (1) reacting maleic anhydride with allylamine, and then reacting the product with hydroxymethyl dimethyl phosphite to obtain a modified ligand; (2) dissolving sodium bicarbonate in an alcoholic solvent, and then adding chloroplatinic acid and vinyl siloxane to the solution to perform a heating reaction; (3) mixing the product obtained in step (2) with the modified ligand, and performing a heating reaction to obtain the active controllable platinum complex.

[0029] The reaction conditions of maleic anhydride and allylamine in step (1) are as follows: maleic anhydride is added to a solvent, and then the solution is heated to 35-50°C, allylamine is added dropwise to the solution, and the solvent is removed after 1-2h of reaction. In the present application, the solvent is water or ethanol; the method for removing the solvent is reduced pressure distillation, and the present application does not have special limitations on the mode and equipment of the reduced pressure distillation, and the mode and equipment well known to those skilled in the art can be used; the present application does not have special limitations on the heating mode, and water bath heating or oil bath heating is preferred.

[0030] The reaction conditions of the product obtained by reacting maleic anhydride with allylamine in step (1) and dimethyl hydroxymethyl phosphite are as follows: the product and dimethyl hydroxymethyl phosphite are added into xylene, and sodium methoxide catalyst is added, and the mixture is reacted at 120-160°C for 3-8h, and then the solvent is removed to obtain the modified ligand. In the present application, the amount of sodium methoxide catalyst added is 10-100ppm, preferably 30-50ppm; in the present application, the method for removing the solvent is reduced pressure distillation, and the present application does not have special limitations on the method and equipment for the reduced pressure distillation, and the method and equipment known to those skilled in the art can be used.

[0031] The alcohol solvent in step (2) is one or more of methanol, ethanol, and isopropyl alcohol; preferably, it is ethanol or isopropyl alcohol; in the present application, the mass ratio of sodium bicarbonate to chloroplatinic acid added is 2-5:1.

[0032] In the present application, the reaction temperature of step (2) is 40-80°C, preferably 45-55°C; the reaction time of step (2) is 1-4h, preferably 1-2h; in the present application, the reaction temperature of step (3) is 50-100°C, preferably 60-80°C; the reaction time of step (3) is 0.5-2h, preferably 1-1.5h; the present application does not have special limitations on the heating method, and water bath heating or oil bath heating is preferred.

[0033] In the present application, after the heating reaction of step (3), the process further includes the steps of filtering to remove solid substances in the product and removing low-boiling substances by reduced pressure distillation; the present application does not have special limitations on the method and equipment for the reduced pressure distillation, and the method and equipment known to those skilled in the art can be used.

[0034] In the present application, the reactions of step (2) and step (3) are carried out under inert gas protection, and the inert gas is preferably nitrogen.

[0035] Example 1:

[0036] A method for preparing a platinum complex with controllable activity, the steps are as follows:

[0037] (1) Maleic anhydride is dissolved in water, and then the solution is heated to 40°C, and allylamine is added dropwise into the solution, and after reacting for 2h, the solvent is removed by reduced pressure distillation; the obtained product and dimethyl hydroxymethyl phosphite are added into xylene, and 5ppm of sodium methoxide catalyst is added, and the mixture is reacted at 130°C for 5h, and then the solvent is removed by reduced pressure distillation to obtain the modified ligand; the molar ratio of maleic anhydride, allylamine, and dimethyl hydroxymethyl phosphite added is 1:1:1;

[0038] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0039] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1). The molar ratio of the modified ligand to tetramethyldivinyldisiloxane is 1:5. Heat the mixture at 70°C for 1 h, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the active controllable platinum complex.

[0040] Example 2:

[0041] A method for preparing an active controllable platinum complex, comprising the following steps:

[0042] (1) Dissolve maleic anhydride in water, and then heat the solution to 40°C. Add allylamine dropwise into the solution, and remove the solvent under reduced pressure after reacting for 2 h. Add the obtained product and hydroxymethyl dimethyl phosphite into dimethylbenzene, and add 5 ppm of sodium methoxide catalyst. React at 130°C for 5 h, remove the solvent under reduced pressure to obtain a modified ligand. The molar ratio of maleic anhydride, allylamine and hydroxymethyl dimethyl phosphite added is 1:1:1.1;

[0043] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:10, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0044] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1). The molar ratio of the modified ligand to tetramethyldivinyldisiloxane is 1:5. Heat the mixture at 70°C for 1 h, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the active controllable platinum complex.

[0045] Example 3:

[0046] A method for preparing an active controllable platinum complex, comprising the following steps:

[0047] (1) Dissolve maleic anhydride in water, and then heat the solution to 40°C. Add allylamine dropwise into the solution, and remove the solvent under reduced pressure after reacting for 2 h. Add the obtained product and hydroxymethyl dimethyl phosphite into dimethylbenzene, and add 5 ppm of sodium methoxide catalyst. React at 130°C for 5 h, remove the solvent under reduced pressure to obtain a modified ligand. The molar ratio of maleic anhydride, allylamine and hydroxymethyl dimethyl phosphite added is 1:1:1.2;

[0048] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:15, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0049] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1). The molar ratio of the modified ligand to tetramethyldivinyldisiloxane is 1:5. Heat the mixture at 70°C for 1 h, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the active controllable platinum complex.

[0050] Example 4:

[0051] A method for preparing an active controllable platinum complex, comprising the following steps:

[0052] (1) Dissolve maleic anhydride in water, and then heat the solution to 40°C. Add allylamine dropwise into the solution, and remove the solvent under reduced pressure after reacting for 2 h. Add the obtained product and hydroxymethyl dimethyl phosphite into dimethylbenzene, and add 5 ppm of sodium methoxide catalyst. React at 130°C for 5 h, remove the solvent under reduced pressure to obtain a modified ligand. The molar ratio of maleic anhydride, allylamine, and hydroxymethyl dimethyl phosphite added is 1:1.1:1;

[0053] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:20, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0054] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1). The molar ratio of the modified ligand to tetramethyldivinyldisiloxane is 1:5. Heat the mixture at 70°C for 1 h, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the active controllable platinum complex.

[0055] Example 5:

[0056] A method for preparing an active controllable platinum complex, comprising the following steps:

[0057] (1) Dissolve maleic anhydride in water, and then heat the solution to 40°C. Add allylamine dropwise into the solution, and remove the solvent under reduced pressure after reacting for 2 h. Add the obtained product and hydroxymethyl dimethyl phosphite into dimethylbenzene, and add 5 ppm of sodium methoxide catalyst. React at 130°C for 5 h, remove the solvent under reduced pressure to obtain a modified ligand. The molar ratio of maleic anhydride, allylamine, and hydroxymethyl dimethyl phosphite added is 1:1.2:1;

[0058] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0059] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1), and heat the mixture at 70°C for 1 h. Then, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the platinum complex with controllable activity.

[0060] Example 6:

[0061] A method for preparing a platinum complex with controllable activity, comprising the following steps:

[0062] (1) Dissolve maleic anhydride in water, and then heat the solution to 40°C. Drop allylamine into the solution, and remove the solvent under reduced pressure after reaction for 2 h. Add the obtained product and dimethyl hydroxymethyl phosphite into dimethylbenzene, and then add 5 ppm of sodium methoxide catalyst. React at 130°C for 5 h, and then remove the solvent under reduced pressure to obtain a modified ligand. The molar ratio of maleic anhydride, allylamine and dimethyl hydroxymethyl phosphite is 1:1.1:1.1;

[0063] (2) Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0064] (3) Mix the product obtained in step (2) with the modified ligand prepared in step (1), and heat the mixture at 70°C for 1 h. Then, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the platinum complex with controllable activity.

[0065] Comparative Example 1 (without adding a modified ligand):

[0066] A method for preparing a platinum complex, comprising the following steps:

[0067] Dissolve sodium bicarbonate in ethanol, and then add chloroplatinic acid and tetramethyldivinyldisiloxane into the solution after removing oxygen by nitrogen blowing. Heat the solution at 50°C for 1.5 h. Then, remove the solid substances in the product by filtration, and remove the low-boiling substances by distillation under reduced pressure to obtain the platinum complex. The molar ratio of chloroplatinic acid to tetramethyldivinyldisiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1.

[0068] Comparative Example 2 (no phosphite group introduced in the modified ligand):

[0069] A method for preparing a platinum complex, comprising the steps of:

[0070] (1) dissolving maleic anhydride in water, then heating the solution to 40°C, and adding allylamine dropwise into the solution, and then removing the solvent under reduced pressure after reacting for 2h to obtain a modified ligand; the molar ratio of maleic anhydride to allylamine added is 1:1;

[0071] (2) dissolving sodium bicarbonate in ethanol, removing oxygen from the solution by passing nitrogen gas, and then adding chloroplatinic acid and tetramethyldivinylsiloxane into the solution, and then heating the solution at 50°C for 1.5h; the molar ratio of chloroplatinic acid to tetramethyldivinylsiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0072] (3) mixing the product obtained in step (2) with the modified ligand prepared in step (1), the molar ratio of the modified ligand to tetramethyldivinylsiloxane is 1:5, and then heating the mixture at 70°C for 1h, and then removing solid substances in the product by filtration and removing low-boiling substances by distillation under reduced pressure to obtain the platinum complex.

[0073] Comparative Example 3 (no amide group introduced in the modified ligand):

[0074] A method for preparing a platinum complex, comprising the steps of:

[0075] (1) adding maleic anhydride and hydroxymethyl phosphite dimethyl ester into dimethylbenzene, and adding 5ppm of sodium methoxide catalyst, and then reacting at 130°C for 5h, and then removing the solvent under reduced pressure to obtain a modified ligand; the molar ratio of maleic anhydride to hydroxymethyl phosphite dimethyl ester added is 1:1;

[0076] (2) dissolving sodium bicarbonate in ethanol, removing oxygen from the solution by passing nitrogen gas, and then adding chloroplatinic acid and tetramethyldivinylsiloxane into the solution, and then heating the solution at 50°C for 1.5h; the molar ratio of chloroplatinic acid to tetramethyldivinylsiloxane is 1:5, and the mass ratio of sodium bicarbonate to chloroplatinic acid is 3:1;

[0077] (3) mixing the product obtained in step (2) with the modified ligand prepared in step (1), the molar ratio of the modified ligand to tetramethyldivinylsiloxane is 1:5, and then heating the mixture at 70°C for 1h, and then removing solid substances in the product by filtration and removing low-boiling substances by distillation under reduced pressure to obtain the platinum complex.

[0078] Comparative Example 4 (changing the type of primary amine reacted with maleic anhydride):

[0079] A method for preparing a platinum complex, comprising the steps of:

[0080] (1) Maleic anhydride was dissolved in water, and then the solution was heated to 40°C. n-Propylamine was added dropwise into the solution, and after 2h of reaction, the solvent was removed under reduced pressure. The obtained product and dimethyl hydroxymethyl phosphite were added into xylene, and 5ppm of sodium methoxide catalyst was added. After 5h of reaction at 130°C, the solvent was removed under reduced pressure to obtain the modified ligand. The molar ratio of maleic anhydride, n-propylamine and dimethyl hydroxymethyl phosphite was 1:1:1.

[0081] (2) Sodium bicarbonate was dissolved in ethanol, and after oxygen was removed by nitrogen blowing, chloroplatinic acid and tetramethyldivinylsiloxane were added into the solution. After 1.5h of reaction at 50°C, the molar ratio of chloroplatinic acid and tetramethyldivinylsiloxane was 1:5, and the mass ratio of sodium bicarbonate and chloroplatinic acid was 3:1.

[0082] (3) The product obtained in step (2) was mixed with the modified ligand prepared in step (1), and the molar ratio of the modified ligand and tetramethyldivinylsiloxane was 1:5. After 1h of reaction at 70°C, the solid substances in the product were removed by filtration, and low-boiling substances were removed by distillation under reduced pressure to obtain the platinum complex.

[0083] Vinyl silicone oil with a double bond content of 2% and hydrogen-containing silicone oil with a hydrogen content of 1% were mixed, and the platinum complexes prepared in the above examples and comparative examples were added. The mass of platinum in the platinum complex was 5ppm of the mass of the vinyl silicone oil, and the mass ratio of the vinyl silicone oil and the hydrogen-containing silicone oil was 100:5. After being mixed uniformly, the mixture was reacted at 120°C for 10min to obtain a silicone rubber. In Comparative Example 1, in addition to the platinum complex, an inhibitor ethynylcyclohexanol was also added, and the mass ratio of the inhibitor and the vinyl silicone oil was 0.3:100. No inhibitor was added in the remaining examples and comparative examples.

[0084] The sulfur vulcanization properties and mechanical properties of the silicone rubber were tested, and the results are shown in Table 1. The test method of the sulfur vulcanization properties was as follows: the prepared silicone rubber was placed in a rotorless sulfur vulcanization tester, and the sulfur vulcanization test was carried out at 120°C. The time T50 and T90 required for the rubber to reach 50% and 90% of the maximum torque were measured to evaluate the activity of the platinum complex. The shorter the time, the faster the vulcanization speed, and the higher the activity of the platinum complex. The test method of the mechanical properties of the silicone rubber was in accordance with GB / T528-2009.

[0085] Table 1: Test results of the properties of the silicone rubber.

[0086]

[0087] The vinyl silicone oil with 2% double bond content and the hydrogen-containing silicone oil with 1% hydrogen content were mixed, and the platinum complex prepared in the above examples and comparative examples was added, the mass of platinum in the platinum complex was 5 ppm of the mass of the vinyl silicone oil, the mass ratio of the vinyl silicone oil to the hydrogen-containing silicone oil was 100:5 (an inhibitor was also added in Comparative Example 1), the mixture was uniformly mixed, and then the sample was sealed and placed in an environment at 25°C, the time taken for the viscosity to increase to 2 times the initial viscosity was tested to reflect the room temperature catalytic activity of the platinum complex, and the results are shown in Table 2.

[0088] Table 2: Results of room temperature catalytic activity test.

[0089] No. Initial viscosity (mPa-s) Final viscosity (mPa-s) Time taken (days) Example 1 28100 56700 91 Example 2 27300 54800 94 Example 3 26700 53600 96 Example 4 25900 52300 105 Example 5 27800 55900 93 Example 6 27700 55500 96 Comparative Example 1 27800 56000 4 Comparative Example 2 28200 56600 33 Comparative Example 3 27900 55900 126 Comparative Example 4 28000 56300 117

[0090] As can be seen from Tables 1 and 2, the platinum complexes prepared in Examples 1-6 using the method of the present application have low catalytic activity at room temperature, can be stably stored in silicone rubber, do not need to add an inhibitor when catalyzing the preparation of silicone rubber, and have a long operable time; and at high temperature, they can quickly catalyze the silicon-hydrogen addition reaction and have high catalytic activity, and the silicone rubber prepared by catalysis has good mechanical properties.

[0091] In Comparative Example 1, no modified ligand was added to coordinate with chloroplatinic acid, and the prepared platinum complex did not have inhibitory properties, was difficult to be stably stored in silicone rubber at room temperature, and needed to add an inhibitor when preparing silicone rubber, and the operation time was short. In Comparative Example 2, no phosphate group was introduced into the modified ligand, and the storage stability of the platinum complex was significantly lower than that in the examples. In Comparative Example 3, no vinyl group was introduced into the modified ligand and the allylamine, and the high-temperature catalytic activity of the catalyst was significantly lower than that in the examples, resulting in a decrease in the mechanical properties of the finally prepared silicone rubber. In Comparative Example 4, n-propylamine was used instead of allylamine, and the introduction of the vinyl group was lacking, and the high-temperature catalytic activity of the catalyst and the mechanical properties of the silicone rubber also decreased.

Claims

1. Use of an active controllable platinum complex for the preparation of silicone rubber, characterized in that The active controllable platinum complex is formed by coordination of vinyl siloxane and modified ligand with chloroplatinic acid; the modified ligand is prepared by reaction of maleic anhydride with allyl amine and hydroxymethyl dimethyl phosphite.

2. Use of the active-controllable platinum complex according to claim 1 for the production of silicone rubber, characterized in that, The molar ratio of chloroplatinic acid to vinyl siloxane is 1:3-50, and the molar ratio of modified ligand to vinyl siloxane is 1:5-50.

3. Use of the active-controllable platinum complex according to claim 1 or 2 for the production of silicone rubber, characterized in that, The vinyl siloxane is one or more of tetramethyl divinyl disiloxane, tetramethyl tetra-vinyl cyclosiloxane, and end-vinyl silicone oil.

4. Use of the active-controllable platinum complex according to claim 1 for the production of silicone rubber, characterized in that, The molar ratio of maleic anhydride, allyl amine and hydroxymethyl dimethyl phosphite is 1:1-1.2:1-1.

2.

5. Use of the active controllable platinum complex according to claim 1 for the production of silicone rubber, characterized in that The preparation method of the active controllable platinum complex comprises the following steps: (1) reacting maleic anhydride with allyl amine, and then reacting the product with hydroxymethyl dimethyl phosphite to obtain a modified ligand; (2) dissolving sodium bicarbonate in an alcohol solvent, then adding chloroplatinic acid and vinyl siloxane to the solution, and heating to react; (3) mixing the product obtained in step (2) with the modified ligand, and heating to react to obtain the active controllable platinum complex.

6. Use of the active controllable platinum complex according to claim 5 for the production of silicone rubber, characterized in that In step (1), the reaction conditions of maleic anhydride with allyl amine are as follows: maleic anhydride is added to a solvent, then the solution is heated to 35-50℃, allyl amine is added dropwise to the solution, and the solvent is removed after 1-2h of reaction.

7. Use of an active controllable platinum complex according to claim 5 or 6 for the preparation of silicone rubber, characterized in that, In step (1), the reaction conditions of the product obtained by reaction of maleic anhydride with allyl amine with hydroxymethyl dimethyl phosphite are as follows: the product and hydroxymethyl dimethyl phosphite are added to xylene, and sodium methoxide catalyst is added, and the reaction is carried out at 120-160℃ for 3-8h, and the solvent is removed to obtain the modified ligand.

8. Use of the active controllable platinum complex according to claim 5 for the production of silicone rubber, characterized in that, In step (2), the alcohol solvent is one or more of methanol, ethanol, and isopropanol; the mass ratio of sodium bicarbonate to chloroplatinic acid added is 2-5:

1.

9. Use of the active-controllable platinum complex according to claim 5 or 8 for the production of silicone rubber, characterized in that, The reaction temperature of step (2) is 40-80℃, and the reaction temperature of step (3) is 50-100℃.

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