Modified platinum catalyst, organic silicon hot melt adhesive and preparation method of modified platinum catalyst

Abstract

The invention belongs to the technical field of hot melt adhesives, and discloses a modified platinum catalyst, an organic silicon hot melt adhesive and a preparation method of the organic silicon hot melt adhesive. The platinum-containing phenyl vinyl resin particles are obtained by reacting a platinum catalyst with phenyl vinyl silicon resin B; wherein the phenyl vinyl silicone resin A and the phenyl vinyl silicone resin B are different in melting temperature. The modified platinum catalyst can be applied to the organic silicon hot melt adhesive to improve the cross-linking curing problem of the hot melt adhesive at high temperature, so that the organic silicon hot melt adhesive can still keep the continuous bonding strength performance in the environment with the temperature higher than or equal to 150 DEG C, and metal aluminum, iron, stainless steel and base materials such as PC, PA and PCB can be rapidly bonded; and the method has the advantage of wide applicability.

Description

Technical Field

[0001] This invention belongs to the field of hot melt adhesive technology, specifically relating to a modified platinum catalyst, an organosilicon hot melt adhesive, and a method for preparing the same. Background Technology

[0002] Hot melt adhesives are single-component, high-performance adhesives that are solid at room temperature but melt at high temperatures when applied to the substrate. During cooling, they provide rapid bonding and setting. They are environmentally friendly, easy to apply, and offer fast bonding, making them widely used in intelligent assembly processes in electronics, smart homes, and apparel. Common hot melt adhesive systems include EVA, PUR, and alkane polymers; however, these materials generally suffer from poor high-temperature resistance and cannot be effectively used for extended periods at high temperatures. Silicone materials possess excellent high-temperature resistance, radiation resistance, and weather resistance. Conventional silicone sealants can be used for extended periods at high temperatures without significant performance degradation. However, there is limited literature on silicone hot melt adhesives. Existing patent application CN201811486111.2 discloses a method for preparing boric acid modified organosilicon hot melt adhesive. The hot melt adhesive obtained by this method has advantages such as high thermal stability, good bonding strength, and good solvent resistance. However, this hot melt adhesive belongs to a thermoplastic resin system with a low softening temperature. At high temperatures (especially ambient temperatures above 150°C), its bonding strength will be significantly reduced, resulting in significant limitations in the use of this hot melt adhesive. Summary of the Invention

[0003] The purpose of this invention is to provide a modified platinum catalyst for use in silicone hot melt adhesives. The application of this modified platinum catalyst can improve the performance of silicone hot melt adhesives, enabling them to maintain continuous adhesive strength in environments with temperatures above or equal to 150°C.

[0004] The following technical solutions are used to achieve the above objectives.

[0005] The first aspect of the present invention provides a modified platinum catalyst, wherein the modified platinum catalyst is obtained by reacting platinum-containing phenyl vinyl resin particles with phenyl vinyl silicone resin A, and the platinum-containing phenyl vinyl resin particles are obtained by reacting a platinum catalyst with phenyl vinyl silicone resin B.

[0006] The phenyl vinyl silicone resin A and phenyl vinyl silicone resin B have different melting temperatures.

[0007] In some embodiments, the melting temperature of the phenyl vinyl silicone resin A is lower than the melting temperature of the phenyl vinyl silicone resin B;

[0008] Preferably, the melting temperature of the phenyl vinyl silicone resin A is 85°C to 115°C, and the melting temperature of the phenyl vinyl silicone resin B is 100°C to 140°C.

[0009] And / or, the weight ratio of the phenyl vinyl silicone resin A, the phenyl vinyl silicone resin B and the platinum catalyst is 100:100~120:15~30, preferably 100:100~105:18~22;

[0010] And / or, the platinum catalyst is a Castells platinum catalyst;

[0011] And / or, the platinum catalyst contains 2500ppm to 3500ppm of platinum.

[0012] In some embodiments, the phenyl vinyl silicone resin A and phenyl vinyl silicone resin B are prepared by reacting dialkoxysilane, trialkoxysilane and vinyl end-capping agent under the action of a catalyst;

[0013] Preferably, the dialkoxysilane is at least one selected from phenylmethyldimethoxysilane and dimethyldimethoxysilane;

[0014] And / or, the trialkoxysilane is phenyltrimethoxysilane;

[0015] And / or, the catalyst is hydrochloric acid;

[0016] And / or, the catalyst accounts for 0.5% to 2% of the total mass fraction of the system;

[0017] And / or, the vinyl end-capping agent is at least one of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane and vinyltrimethoxysilane;

[0018] And / or, the mass ratio of the trialkoxysilane, dialkoxysilane to the vinyl end-capping agent is 1:0.1~0.6:0.05~0.5, preferably 1:0.3~0.6:0.3~0.5;

[0019] And / or, the preparation method of the phenyl vinyl silicone resin A and phenyl vinyl silicone resin B includes the following steps:

[0020] Mix deionized water, solvent and catalyst, and heat to 50℃~60℃;

[0021] A mixture of dialkoxysilane, trialkoxysilane, and vinyl end-capping agent is added dropwise over 1 hour, and the mixture is stirred for 1-2 hours. The temperature is raised to 65-75°C and maintained for 2-3 hours. The oil phase is separated and washed until neutral. Anhydrous magnesium sulfate is added until a clear, transparent liquid is obtained. The transparent liquid is heated to 115-125°C and refluxed for half an hour. The mixture is then purified to obtain the phenyl vinyl silicone resin. More preferably, the solvent is a mixture of ethanol and toluene, and the volume ratio of ethanol to toluene in the solvent is 1:0.8-1.2.

[0022] A second aspect of the present invention provides a method for preparing the modified platinum catalyst as described above, comprising the following steps:

[0023] Step a: After uniformly mixing molten phenyl vinyl silicone resin B, platinum catalyst and solvent, the reaction yields platinum-containing phenyl vinyl resin particles.

[0024] Step b: After uniformly mixing platinum-containing phenyl vinyl resin particles, molten phenyl vinyl silicone resin A, and solvent, the reaction yields modified platinum catalyst particles.

[0025] In some embodiments, in step a, the volume ratio of phenyl vinyl silicone resin B to solvent is 1:1 to 2;

[0026] And / or, in steps a and b, the solvent is at least one of dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, ethylene glycol monomethyl ether, butanol, and ethylene glycol monoethyl ether;

[0027] And / or, in steps a and b, the reaction includes the following steps:

[0028] The mixture was stirred in a mixer with a speed of 1000 r / min to 3000 r / min and gradually cooled to room temperature in a cooling system of 1℃ / min to 10℃ / min to obtain particles;

[0029] The resulting particles were washed and filtered with ethanol, and then vacuum dried for 15 to 30 hours at a temperature at least 10°C lower than the melting temperature of the phenyl vinyl silicone resin A.

[0030] A third aspect of the present invention provides the application of the modified platinum catalyst as described above as a catalyst in organosilicon hot melt adhesives.

[0031] A fourth aspect of the present invention provides an organosilicon hot melt adhesive, wherein the catalyst in its raw materials is a modified platinum catalyst as described above.

[0032] In some embodiments, the silicone hot melt adhesive is prepared from raw materials comprising the following components, by weight:

[0033] Phenyl vinyl silicone resin C 100 parts

[0034] 5-6 parts of phenyl hydrosilicone resin

[0035] 1-2 parts adhesive

[0036] 1-2 parts catalyst;

[0037] And / or, the melting temperature of the phenyl vinyl silicone resin C is lower than that of the phenyl vinyl silicone resin A and the phenyl vinyl silicone resin B; preferably, the melting temperature of the phenyl vinyl silicone resin C is 65°C to 100°C.

[0038] And / or, the active hydrogen mass fraction of the phenyl hydrogen-containing silicone resin is 0.1%~2%, and the viscosity at 25°C is 50mPa.s~500mPa.s.

[0039] The fifth aspect of this invention provides a method for preparing an organosilicon hot melt adhesive, comprising the following steps:

[0040] It is prepared by uniformly mixing molten phenyl vinyl silicone resin C, phenyl hydrogen silicone resin, adhesive and modified platinum catalyst at a temperature of 80-160℃.

[0041] In this invention, a novel secondary-coated modified platinum catalyst is obtained by sequentially coating a platinum catalyst with two phenyl vinyl silicone resins of different melting temperatures. This modified platinum catalyst can be applied to silicone hot melt adhesives to improve the crosslinking and curing problem of hot melt adhesives at high temperatures. This allows the silicone hot melt adhesive to maintain continuous bonding strength in environments with temperatures above or equal to 150°C. Furthermore, it can quickly bond aluminum, iron, stainless steel, as well as substrates such as PC, PA, and PCB, and has the advantage of wide applicability. Detailed Implementation

[0042] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0043] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0044] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0045] Example 1

[0046] (1) The preparation steps of solid phenyl vinyl silicone resin are as follows:

[0047] In a 2000 mL three-necked flask equipped with a stirrer and temperature control, add 250 mL of a mixture of deionized water, anhydrous ethanol, and toluene (volume ratio 1:1) and hydrochloric acid. HCl (1.25% of the total mass fraction of the system) was heated to 55°C, and a mixture of phenylmethyldimethoxysilane (PMDMS), phenyltrimethoxysilane (PTMS), and 1,1,3,3-tetramethyl-1,3-divinyldisiloxane (TMDVS) end-capping agent was added dropwise over 1 hour. After the addition was complete, the mixture was stirred for 1 hour, and the temperature was raised to 70°C and maintained for 2 hours. The oil phase was separated while hot and washed in distilled water until neutral. Anhydrous magnesium sulfate was added until a clear and transparent liquid was obtained. The transparent liquid was then heated to 120°C and refluxed for half an hour. The temperature was then raised again and the remaining small molecules were distilled off under vacuum (-0.09 MPa) to obtain a colorless and transparent phenylvinylsilane resin (hereinafter referred to as resin). After cooling, the resin was solid. The weights of the different experimental reaction materials are shown in the table below. The melting temperatures of the different products, resin 1 to resin 3, were 136°C, 107°C, and 86°C, respectively.

[0048]

[0049] (2) The preparation steps of the modified platinum catalyst are as follows:

[0050] After 100g of resin 1 was completely melted at 140℃, 20g of Johnson Matthey (Shanghai) Castel platinum catalyst (platinum content 3000 ppm) was dissolved in it and stirred quickly and evenly. Then, 150g of 1-butanol was added, and the mixture was slowly stirred in a high-speed mixer. The speed was gradually increased to 2000 r / min, and the system was cooled to room temperature at 2℃ / min. The platinum-containing phenyl vinyl resin particles were obtained by filtration.

[0051] The obtained platinum-containing phenyl vinyl resin particles were soaked in ethanol and then filtered (this step was repeated 3 times). They were then placed in a vacuum (-0.09MPa) oven at 75℃ and dried for 24 h to obtain the dried platinum-containing phenyl vinyl resin particles.

[0052] After 100g of resin 2 was completely melted at 110℃, it was rapidly mixed with the dried platinum-containing phenyl vinyl resin particles. Then, 150g of 1-butanol was added, and the mixture was stirred and dispersed again at 2000 r / min for 2 min in a high-speed mixer. The mixture was then cooled to room temperature at a rate of 5℃ / min. The modified platinum catalyst particles were separated by filtration. The modified platinum catalyst particles were then soaked in ethanol and filtered again (this step was repeated 3 times). Finally, the mixture was placed in a vacuum (-0.09Mpa) oven at 75℃ and dried for 24 h to obtain the dried modified platinum catalyst particles (CatA).

[0053] (3) The preparation steps of the silicone hot melt adhesive (SSR1) are as follows:

[0054] 100 parts of resin 3 were completely melted at 100℃, and then mixed with 8 parts of phenyl hydrogen-containing silicone resin (Runhe, RH-SH307) with an active hydrogen mass fraction of 0.9% and a viscosity of 300 mPa·s at 25℃, 1.5 parts of adhesive (Jiangxi Lutai, Z-1501), and 2 parts of the above-prepared CatA catalyst particles. The mixture was quickly stirred until uniform to obtain a milky white organosilicon hot melt adhesive (SSR1). The adhesive was then sealed in an aluminum tube and rapidly cooled to room temperature.

[0055] Example 2

[0056] (1) The preparation steps of solid phenyl vinyl silicone resin are as follows:

[0057] In a 2000 mL three-necked flask equipped with a stirrer and temperature control, 250 mL of a mixture of deionized water, anhydrous ethanol, and toluene (volume ratio 1:1), and hydrochloric acid (HCl accounting for 0.8% of the total mass fraction of the system) were added in one step. The temperature was raised to 55 °C, and a mixture of phenylmethyldimethoxysilane (PMDMS), phenyltrimethoxysilane (PTMS), and vinyltrimethoxysilane (ETM) end-capping agent was added dropwise over 1 hour. After the addition was complete, the mixture was stirred for 1 hour, and the temperature was raised to 70 °C and maintained for 2 hours. The oil phase was then separated while hot, washed in distilled water until neutral, and anhydrous magnesium sulfate was added until a clear and transparent liquid was obtained. The transparent liquid was then heated to 115 °C and refluxed for half an hour. The remaining small molecules were then distilled off under vacuum (-0.09 MPa) to obtain a colorless and transparent phenyl vinyl silicone resin (hereinafter referred to as resin). After cooling, it was solid. The weights of different experimental reactants are shown in the table below. The melting temperatures of resins 1 to 3, which yielded different products, were 98℃, 112℃, and 132℃, respectively.

[0058]

[0059] (2) The preparation steps of the modified platinum catalyst are as follows:

[0060] After 100g of resin 3 was completely melted at 135℃, 20g of Johnson Matthey (Shanghai) Castel platinum catalyst (platinum content 3000 ppm) was dissolved in it and stirred quickly and evenly. Then, 150g of ethylene glycol monoethyl ether was added, and the mixture was slowly stirred in a high-speed mixer. The speed was gradually increased to 2000 r / min, and the system was cooled to room temperature at 2℃ / min. The platinum-containing phenyl vinyl resin particles were obtained by filtration.

[0061] The obtained platinum-containing phenyl vinyl resin particles were soaked in ethanol and then filtered (this step was repeated 3 times). They were then placed in a vacuum (-0.09MPa) oven at 75℃ and dried for 24 h to obtain the dried platinum-containing phenyl vinyl resin particles.

[0062] After 100g of resin 2 was completely melted at 120℃, it was rapidly mixed with dried platinum-containing phenyl vinyl resin particles. Then, 150g of ethylene glycol monoethyl ether was added, and the mixture was stirred and dispersed again at 2000 r / min for 2 min in a high-speed mixer. The mixture was then cooled to room temperature at a rate of 5℃ / min, and the modified platinum catalyst particles were obtained by filtration. The modified platinum catalyst particles were then soaked in ethanol and filtered again (this step was repeated 3 times). Finally, the mixture was placed in a vacuum oven at 75℃ and dried for 24 h to obtain the dried modified platinum catalyst particles (CatB).

[0063] (3) The preparation steps of silicone hot melt adhesive (SSR2) are as follows:

[0064] 100 parts of resin 1 were completely melted at 105°C, and then mixed with 10 parts of phenyl hydrogen-containing silicone resin (Runhe, RH-SH-305) with an active hydrogen mass fraction of 0.6% and a viscosity of 300 mPa·s at 25°C, 1.5 parts of adhesive (Guangzhou Tianjiang, TJ-340), and 2 parts of the CatB catalyst particles prepared above. The mixture was quickly stirred until uniform to obtain a milky white organosilicon hot melt adhesive (SSR2). The adhesive was then sealed in an aluminum tube and rapidly cooled to room temperature.

[0065] Example 3

[0066] (1) The preparation steps of solid phenyl vinyl silicone resin are as follows:

[0067] In a 2000 mL three-necked flask equipped with a stirrer and temperature control, 250 mL of a mixed solvent of deionized water, anhydrous ethanol, and toluene (volume ratio 1:1) and hydrochloric acid (HCl content of 0.8% of the total system mass) were added at once. The temperature was raised to 55 °C, and the mixture was kept at 1... A mixture of phenylmethyldimethoxysilane (PMDMS), phenyltrimethoxysilane (PTMS), and vinyltrimethoxysilane (ETM) end-capping agent was added dropwise over a period of time. After the addition was complete, the mixture was stirred for 1 hour. The temperature was then raised to 70°C and maintained for 2 hours. The oil phase was then separated while hot and washed in distilled water until neutral. Anhydrous magnesium sulfate was added until a clear and transparent liquid was obtained. The transparent liquid was then heated to 115°C and refluxed for half an hour. The temperature was then raised again and the remaining small molecules were distilled off under vacuum (-0.09 MPa) to obtain a colorless and transparent phenyl vinyl silicone resin (hereinafter referred to as resin). After cooling, the resin was solid. The weights of the different experimental reaction materials are shown in the table below. The melting temperatures of the different products, resin 1 to resin 3, were 76°C, 90°C, and 108°C, respectively.

[0068]

[0069] (2) The preparation steps of the modified platinum catalyst are as follows:

[0070] After 100g of resin 3 was completely melted at 120℃, 20g of Johnson Matthey (Shanghai) Castel platinum catalyst (platinum content 3000 ppm) was dissolved in it and stirred quickly and evenly. Then, 150g of 1-butanol was added, and the mixture was slowly stirred in a high-speed mixer. The speed was gradually increased to 2000 r / min, and the system was cooled to room temperature at 2℃ / min. The platinum-containing phenyl vinyl resin particles were obtained by filtration.

[0071] The obtained platinum-containing phenyl vinyl resin particles were soaked in ethanol and then filtered (this step was repeated 3 times). They were then placed in a vacuum (-0.09Mpa) oven at 75℃ and dried for 24 h to obtain the dried platinum-containing phenyl vinyl resin particles.

[0072] 100g of resin 2 was completely melted at 95℃ and rapidly mixed with dried platinum-containing phenyl vinyl resin particles. 150g of 1-butanol was then added, and the mixture was stirred again at 2000 r / min for 2 min in a high-speed mixer. The mixture was then cooled to room temperature at 5℃ / min. The modified platinum catalyst particles were separated by filtration, then immersed in ethanol and filtered again (this step was repeated 3 times). The particles were then dried in a 75℃ vacuum (-0.09 MPa) oven for 24 h to obtain the dried modified platinum catalyst particles (CatC).

[0073] (3) The preparation steps of silicone hot melt adhesive (SSR3) are as follows:

[0074] 100 parts of resin 1 were completely melted at 90°C, and then mixed with 6 parts of phenyl hydrogen-containing silicone resin (Runhe, RH-SH-309) with an active hydrogen mass fraction of 1.2% and a viscosity of 500 mPa·s at 25°C, 1.5 parts of adhesive (Guangzhou Tianjiang, TJ-328), and 2 parts of the CatC catalyst particles prepared above. The mixture was quickly stirred until uniform to obtain a milky white organosilicon hot melt adhesive (SSR3). The adhesive was then sealed in an aluminum tube and rapidly cooled to room temperature.

[0075] Comparative Example 1

[0076] The difference between this comparative example and Example 1 is that in the preparation steps of the modified platinum catalyst, only resin 1 is used to perform a single coating modification treatment on the platinum catalyst, omitting the further coating treatment of the platinum catalyst with resin 2. The resulting modified platinum catalyst is thus obtained.

[0077] The other steps are the same as in Example 1.

[0078] A milky white silicone hot melt adhesive (SSR4) was prepared.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 1 is that in the preparation step of the modified platinum catalyst, resin 1 is used to modify the platinum catalyst to obtain platinum-containing phenyl vinyl resin particles, and then resin 1 is used to modify the platinum-containing phenyl vinyl resin particles again. This yields modified platinum catalyst particles.

[0081] The other steps are the same as in Example 1.

[0082] A milky white organosilicon hot melt adhesive (SSR5) was prepared.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 1 is that in the preparation step of the modified platinum catalyst, resin 2 is used to modify the platinum catalyst to obtain platinum-containing phenyl vinyl resin particles, and then resin 1 is used to modify the platinum-containing phenyl vinyl resin particles to obtain modified platinum catalyst particles.

[0085] The other steps are the same as in Example 1.

[0086] A milky white silicone hot melt adhesive (SSR6) was prepared.

[0087] Comparative Example 4

[0088] The difference between this comparative example and Example 1 is that in the preparation step of the silicone hot melt adhesive, resin 3 is replaced with resin 1.

[0089] The other steps are the same as in Example 1.

[0090] A milky white silicone hot melt adhesive (SSR7) was prepared.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 1 is that in the preparation step of the modified platinum catalyst, TPE resin with a melting temperature of 120°C is used to replace phenyl vinyl resin 1 and phenyl vinyl resin 2 to perform secondary coating modification treatment on the platinum catalyst.

[0093] A modified platinum catalyst was obtained.

[0094] The other steps are the same as in Example 1.

[0095] A milky white silicone hot melt adhesive (SSR8) was prepared.

[0096] The silicone hot melt adhesives prepared in the above examples and comparative examples were subjected to lap shear bonding tensile tests on anodized aluminum oxide, PA, and PCB materials, and compared with commercially available polyurethane hot melt adhesives in high-temperature tests. Shear specimens were prepared and tested according to GB / T 7124. The melting temperature of the silicone hot melt adhesives prepared in the above examples and comparative examples was also measured. Specific experimental data are shown in Tables 1 and 2 below:

[0097] Table 1 Test Results of Organosilicon Hot Melt Adhesive

[0098]

[0099] Table 2 Melting Temperature of Silicone Hot Melt Adhesives

[0100]

[0101] As shown in Table 1-2, the silicone hot melt adhesives prepared in Examples 1-3 have good adhesion to three substrates: anodized aluminum oxide, PA, and PCB. The adhesion performance did not show significant decay at 150°C, and the adhesion strength even improved after long-term aging at 150°C. In contrast, although PUR has high adhesion strength at room temperature, its adhesion strength decayed significantly at 150°C, and the adhesion failed after long-term high-temperature aging.

[0102] The results from Example 1 and Comparative Examples 1-5 show that the coating effect of platinum catalyst particles is crucial. Single coating, a second coating resin melting temperature not lower than the first coating temperature, and non-silicone coating all lead to decreased shear bond strength, higher final product melting temperature (and even the appearance of insoluble substances, such as SSR8), and poor workability. Non-silicone coating also results in decreased system transparency, increased melt viscosity, and severely reduced adhesion. Furthermore, excessively high melting temperatures of the phenylvinyl silicone resin in the raw materials for preparing the silicone resin also lead to decreased shear bond strength and higher final product melting temperatures.

[0103] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A modified platinum catalyst, characterized in that, The modified platinum catalyst is obtained by reacting platinum-containing phenyl vinyl resin particles with phenyl vinyl silicone resin A, and the platinum-containing phenyl vinyl resin particles are obtained by reacting platinum catalyst with phenyl vinyl silicone resin B. The phenyl vinyl silicone resin A and phenyl vinyl silicone resin B have different melting temperatures.

2. The modified platinum catalyst as described in claim 1, characterized in that, The melting temperature of the phenyl vinyl silicone resin A is lower than that of the phenyl vinyl silicone resin B; Preferably, the melting temperature of the phenyl vinyl silicone resin A is 85°C to 115°C, and the melting temperature of the phenyl vinyl silicone resin B is 100°C to 140°C. And / or, the weight ratio of the phenyl vinyl silicone resin A, the phenyl vinyl silicone resin B and the platinum catalyst is 100:100~120:15~30, preferably 100:100~105:18~22; And / or, the platinum catalyst is a Castells platinum catalyst; And / or, the platinum catalyst contains 2500ppm to 3500ppm of platinum.

3. The modified platinum catalyst as described in claim 1, characterized in that, The phenyl vinyl silicone resin A and phenyl vinyl silicone resin B are prepared by reacting dialkoxysilane, trialkoxysilane and vinyl end-capping agent under the action of a catalyst; Preferably, the dialkoxysilane is at least one selected from phenylmethyldimethoxysilane and dimethyldimethoxysilane; And / or, the trialkoxysilane is phenyltrimethoxysilane; And / or, the catalyst is hydrochloric acid; And / or, the catalyst accounts for 0.5% to 2% of the total mass fraction of the system; And / or, the vinyl end-capping agent is at least one of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane and vinyltrimethoxysilane; And / or, the mass ratio of the trialkoxysilane, dialkoxysilane to the vinyl end-capping agent is 1:0.1~0.6:0.05~0.5, preferably 1:0.3~0.6:0.3~0.5; And / or, the preparation method of the phenyl vinyl silicone resin A and phenyl vinyl silicone resin B includes the following steps: Mix deionized water, solvent and catalyst, and heat to 50℃~60℃; A mixture of dialkoxysilane, trialkoxysilane, and vinyl end-capping agent is added dropwise over 1 hour, and the mixture is stirred for 1-2 hours. The temperature is raised to 65-75°C and maintained for 2-3 hours. The oil phase is separated and washed until neutral. Anhydrous magnesium sulfate is added until a clear, transparent liquid is obtained. The transparent liquid is heated to 115-125°C and refluxed for half an hour. The mixture is then purified to obtain the phenyl vinyl silicone resin. More preferably, the solvent is a mixture of ethanol and toluene, and the volume ratio of ethanol to toluene in the solvent is 1:0.8-1.

2.

4. A method for preparing the modified platinum catalyst according to any one of claims 1-3, characterized in that, Includes the following steps: Step a: After uniformly mixing molten phenyl vinyl silicone resin B, platinum catalyst and solvent, the reaction yields platinum-containing phenyl vinyl resin particles. Step b: After uniformly mixing platinum-containing phenyl vinyl resin particles, molten phenyl vinyl silicone resin A, and solvent, the reaction yields modified platinum catalyst particles.

5. The preparation method according to claim 4, characterized in that, In step a, the volume ratio of phenyl vinyl silicone resin B to solvent is 1:1 to 2; And / or, in steps a and b, the solvent is at least one of dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, ethylene glycol monomethyl ether, butanol, and ethylene glycol monoethyl ether; And / or, in steps a and b, the reaction includes the following steps: The mixture was stirred in a mixer with a speed of 1000 r / min to 3000 r / min and gradually cooled to room temperature in a cooling system of 1℃ / min to 10℃ / min to obtain particles; The resulting particles were washed and filtered with ethanol, and then vacuum dried for 15 to 30 hours at a temperature at least 10°C lower than the melting temperature of the phenyl vinyl silicone resin A.

6. The use of the modified platinum catalyst according to any one of claims 1-3 as a catalyst in organosilicon hot melt adhesives.

7. An organosilicon hot melt adhesive, characterized in that, The catalyst in its raw materials is the modified platinum catalyst as described in any one of claims 1-3.

8. The silicone hot melt adhesive as described in claim 7, characterized in that, The silicone hot melt adhesive, by weight, is prepared from raw materials comprising the following components: Phenyl vinyl silicone resin C 100 parts 5-15 parts of phenyl-containing hydrosilicone resin 1-5 parts adhesive Catalyst 1-5 parts.

9. The silicone hot melt adhesive as described in claim 8, characterized in that, The silicone hot melt adhesive, by weight, is prepared from raw materials comprising the following components: Phenyl vinyl silicone resin C 100 parts 5-6 parts of phenyl-containing hydrosilicone resin 1-2 parts adhesive 1-2 parts catalyst; And / or, the melting temperature of the phenyl vinyl silicone resin C is lower than that of the phenyl vinyl silicone resin A and the phenyl vinyl silicone resin B; preferably, the melting temperature of the phenyl vinyl silicone resin C is 65°C to 100°C. And / or, the active hydrogen mass fraction of the phenyl hydrogen-containing silicone resin is 0.1%~2%, and the viscosity at 25°C is 50mPa.s~500mPa.s.

10. A method for preparing an organosilicon hot melt adhesive, characterized in that, Includes the following steps: It is prepared by uniformly mixing molten phenyl vinyl silicone resin C, phenyl hydrogen silicone resin, adhesive and modified platinum catalyst at a temperature of 80-160℃.

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