Reactive emulsifier, silicone rubber emulsion, and preparation method and application thereof

Abstract

The present invention discloses a reactive emulsifier, a silicone rubber emulsion, and a preparation method and application thereof. 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a silane hydroaddition reaction to prepare a prepolymer; the prepolymer is subjected to a silane hydroaddition reaction with tetramethyltetravinylcyclotetrasiloxane to obtain a reactive emulsifier. The reactive emulsifier of the present invention has a stable and controllable segment structure and an adjustable HLB value, and can be used to prepare a stable and uniform ultra-high molecular weight silicone rubber emulsion. The ultra-high molecular weight silicone rubber emulsion of the present invention has a high molecular weight of the silicone rubber raw material selected and has high reactivity, an adjustable viscosity of the emulsion, a small particle size and good stability. The film-forming material of the ultra-high molecular weight silicone rubber emulsion of the present invention has excellent mechanical properties, good wear resistance, low friction coefficient, good hand feel, high flexibility in construction methods, and can be widely used in weather-resistant, stain-resistant, hand-feeling, waterproof and wear-resistant coatings.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicone rubber, and in particular relates to a reactive emulsifier, silicone rubber emulsion, and a preparation method and application thereof. Background Art

[0002] Silicone rubber is a specialized polymer with a Si—O—Si backbone, with other organic functional groups attached to the silicon atoms. It exhibits excellent high and low temperature resistance, chemical stability, physiological inertness, ozone resistance, weather resistance, electrical insulation, and resistance to oils and chemicals. The low rotational energy and large bond distance of the Si—O bond also contribute to its exceptionally flexible feel. By introducing specialized vinyl groups into the side chains of silicone rubber, it can be vulcanized via a hydrosilylation reaction, resulting in silicone products with high tensile strength, tear strength, and resilience, as well as some ultra-wear-resistant coatings. These products have widespread applications in aerospace, electronics, automotive, textiles, and chemical industries. However, because the molecular weight of the silicone rubber used to create stain-resistant, water-resistant, and wear-resistant coatings is around several hundred thousand, the addition of large amounts of solvent is required, hindering VOC control.

[0003] After research and analysis by the present inventors, the patents related to reactive silicone oil and silicone resin emulsions reported at home and abroad, such as CN108250953A and CN109504281A, have the following technical disadvantages: ① They mainly use low molecular weight silicone oil and silicone resin, resulting in low strength and toughness of the film and poor feel of the film; ② The emulsion has poor stability and requires the addition of a large amount of stabilizer and thickener; ③ The addition of a large amount of non-reactive surfactant results in poor water resistance and strength of the film. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology and provide a reactive emulsifier, a silicone rubber emulsion and a preparation method and application thereof.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] The present invention provides a reactive emulsifier, which is prepared by the following reaction:

[0007] 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a hydrosilylation reaction to prepare a prepolymer;

[0008] The prepolymer is subjected to a hydrosilylation reaction with tetramethyltetravinylcyclotetrasiloxane to prepare the reactive emulsifier.

[0009] As a further improvement, the structural formula of the allyl polyether is:

[0010] H2C=CHCH2O(C2H4O) n (C3H6O) m R1

[0011] Wherein: R1 is H or CH3 or C2H5 or C3H7 or C4H9; and / or

[0012] n:m=(1~40):1, m is an integer between 1 and 5.

[0013] The present invention also provides a method for preparing the reactive emulsifier, comprising the following steps:

[0014] 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a hydrosilylation reaction in a solvent in an inert atmosphere in the presence of a catalyst to prepare a prepolymer; wherein the molar ratio of the silicon-hydrogen bond in the 1,1,3,3-tetramethyldisiloxane to the double bond in the allyl polyether is (1.95-2.05):1;

[0015] The prepolymer is subjected to a silylation reaction with tetramethyltetravinylcyclotetrasiloxane to prepare the reactive emulsifier; wherein the molar ratio of the double bonds of the tetramethyltetravinylcyclotetrasiloxane to the silylation bonds in the prepolymer is 4:(1-3).

[0016] As a further improvement, the catalyst is a platinum catalyst; and / or

[0017] The solvent is a combination of one or more of methanol, ethanol or isopropanol.

[0018] As a further improvement, the temperature of the first step hydrosilylation reaction is controlled at 20-30°C, and the temperature of the second step hydrosilylation reaction is controlled at 20-60°C.

[0019] As a further improvement, the HLB value of the reactive emulsifier is between 4 and 15.

[0020] The present invention also provides an ultra-high molecular weight silicone rubber emulsion, which is mainly prepared from the following raw materials in parts by weight:

[0021] 80-100 parts of ultra-high molecular weight silicone rubber;

[0022] 0-20 parts of viscosity regulator;

[0023] Emulsifier A 0-10 parts;

[0024] Emulsifier B 5-18 parts;

[0025] 10-60 parts water;

[0026] The molecular weight of the ultra-high molecular weight silicone rubber is 150,000 to 850,000 g / mol, wherein the mass fraction of vinyl groups is 0.03% to 5%;

[0027] The emulsifier A is a reactive emulsifier prepared by the above method with an HLB value of <10, and one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, sorbitan fatty acid ester, alkylphenol polyoxyethylene ether, polyether silicone oil emulsifier or polyether emulsifier;

[0028] The emulsifier B is a reactive emulsifier prepared by the above method with an HLB value of ≥10, and one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, sorbitan fatty acid ester, alkylphenol polyoxyethylene ether, polyether silicone oil emulsifier or polyether emulsifier.

[0029] The present invention also provides a method for preparing the ultra-high molecular weight silicone rubber emulsion, comprising the following steps:

[0030] The ultra-high molecular weight silicone rubber and the viscosity modifier are uniformly mixed to obtain a mixture 1;

[0031] Add emulsifier A and emulsifier B to mixture 1 and mix well to obtain mixture 2;

[0032] Add water to mixture 2 and mix thoroughly;

[0033] The mixture is homogenized to obtain an ultra-high molecular weight silicone rubber emulsion.

[0034] The present invention also provides a composition comprising the ultra-high molecular weight silicone rubber emulsion, which is mainly prepared from the following raw materials in parts by weight:

[0035] 80-100 parts of the ultra-high molecular weight silicone rubber emulsion;

[0036] 5-30 parts of hydrogenated silicone oil emulsion;

[0037] 1-10 parts of platinum catalyst emulsion;

[0038] 10-100 parts of water.

[0039] The present invention also provides a method for preparing a film-forming material from the composition, comprising the following steps:

[0040] mixing the ultra-high molecular weight silicone oil emulsion, hydrogenated silicone oil emulsion, platinum catalyst emulsion and water to obtain a composition;

[0041] The composition is coated on a silica gel substrate and baked to obtain the film-forming material.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The reactive emulsifier of the present invention incorporates siloxane and polyether segments, resulting in a stable and controllable segment structure and adjustable HLB value, making it suitable for preparing stable, uniform ultra-high molecular weight silicone rubber emulsions. The siloxane segments have a three-dimensional structure and retain reactive vinyl functional groups, which can be used to increase the crosslink density of silicone rubber emulsion particles. The polyether siloxane block structure provides self-lubrication, reducing the friction coefficient of the film-forming material.

[0044] The preparation method of the reactive emulsifier of the present invention has few by-products, high yield, specificity and high selectivity of the reaction, mild reaction conditions and high reaction rate, and can be used for large-scale production.

[0045] The ultra-high molecular weight silicone rubber emulsion of the invention uses silicone rubber raw materials with high molecular weight and high reactivity, and the viscosity of the emulsion is adjustable, and the particle size is small and the stability is good.

[0046] The method for preparing the ultra-high molecular weight silicone rubber emulsion of the present invention has a convenient preparation process, does not require complicated and expensive equipment, and the prepared emulsion has small particle size and good stability.

[0047] The ultra-high molecular weight silicone rubber emulsion composition of the present invention has high cross-linking activity, is flexible and convenient to construct, has no VOC emissions, and is green and environmentally friendly.

[0048] The film-forming material of the ultra-high molecular weight silicone rubber emulsion of the present invention has excellent mechanical properties, good wear resistance, low friction coefficient, good hand feel, and high construction flexibility, and can be widely used in weather-resistant, stain-resistant, hand-feeling, waterproof, and wear-resistant coatings. DETAILED DESCRIPTION

[0049] To facilitate understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0050] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0051] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0052] In a first aspect, the present application provides a reactive emulsifier, which is prepared by the following method:

[0053] In the first step, 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a hydrosilylation reaction in a solvent in the presence of a catalyst to prepare a prepolymer. In the second step, the prepolymer is subjected to a hydrosilylation reaction with tetramethyltetravinylcyclotetrasiloxane to obtain the final reactive emulsifier. The reaction equation is as follows:

[0054] first step:

[0055]

[0056] Step 2:

[0057]

[0058] Wherein, in the above structure, R1 is H or CH3 or C2H5 or C3H7 or C4H9;

[0059] The above R2, R3 structure is HC=CH2 or

[0060] By adopting this technical solution, the siloxane segments in the reactive emulsifier have excellent compatibility with silicone rubber, while the polyether segments are hydrophilic, making them suitable for use as emulsifiers to disperse silicone rubber particles into an emulsion. Furthermore, the siloxane segments have a three-dimensional structure and retain reactive vinyl groups, allowing them to cross-link with silicone rubber particles, increasing the crosslink density and film strength. Furthermore, the reactive emulsifier exhibits a self-lubricating effect, significantly reducing the coefficient of friction on the film surface and enhancing its smoothness.

[0061] In some specific embodiments, the ratio of EO segments (C2H4O) to PO segments (C3H6O) in the above structure is n:m=(1-40):1, where m is an integer between 1 and 5.

[0062] By employing this technical solution, allyl polyethers of varying structures can be selectively introduced into the siloxane structure, resulting in controlled structure, rapid reaction, and high yield. Furthermore, the HLB value (hydrophile-lipophile balance) of the reactive emulsifier can be adjusted by adjusting the number (n) and ratio (m) of EO and PO segments, as well as the molar ratio of the prepolymer to tetramethyltetravinylcyclotetrasiloxane. This allows the reactive emulsifier to disperse the silicone rubber into a more stable, smaller-particle emulsion while retaining crosslinking properties. When the EO to PO segment ratio is greater than 40, the reactivity of the allyl polyether segments with the siloxane segments decreases.

[0063] In some embodiments, the catalyst is a platinum catalyst.

[0064] By adopting the above technical solution and using the above reagent as a catalyst, the reaction activity of allyl polyether and siloxane chain segments can be greatly improved, the reaction stability and reaction rate can be improved, and at the same time, the amount of catalyst used is small, and no further catalyst needs to be added in the second step reaction.

[0065] In some specific embodiments, the solvent is a combination of one or more of methanol, ethanol, and isopropanol.

[0066] Using the above reagents as solvents can effectively inhibit the polycondensation of 1,1,3,3-tetramethyldisiloxane itself, thereby improving the specificity of the reaction between allyl polyether and siloxane and increasing the product yield. At the same time, it reduces the viscosity during the reaction, thus facilitating a better reaction.

[0067] In a second aspect, the present application also provides a method for preparing a reactive emulsifier, comprising the following steps:

[0068] Add the solvent and 1,1,3,3-tetramethyldisiloxane into a round-bottom flask, pass nitrogen for protection, slowly add the platinum catalyst under stirring, and control the temperature at 20-30°C;

[0069] Add allyl polyether dropwise (the molar ratio of silicon-hydrogen bonds in 1,1,3,3-tetramethyldisiloxane to double bonds in allyl polyether is 1.95-2.05:1) for 30-40 minutes at a reaction temperature of 20-30° C. to obtain a prepolymer;

[0070] The prepolymer prepared above is added dropwise to tetramethyltetravinylcyclotetrasiloxane under nitrogen protection, with the molar ratio of the double bond of tetramethyltetravinylcyclotetrasiloxane to the silicon-hydrogen bond in the prepolymer being 4:(1-3), the addition time being 30-40 minutes, and the reaction temperature being 20-60° C., to obtain a reactive emulsifier;

[0071] The above-mentioned reactive emulsifier was distilled under reduced pressure at 80 to 100° C. to remove the solvent.

[0072] In some specific embodiments, the mass ratio of the solvent to the allyl polyether is (0.1-0.5):1.

[0073] In some specific embodiments, the content of the platinum catalyst in the prepolymer is 50-500 ppm.

[0074] By adopting the above technical solution, the reactive emulsifier produced has an HLB value between 4 and 15, a yield of 96% to 98.5%, few byproducts, a high yield, and a moderate product viscosity of 500 to 1400 mPa·s. The polyether segment is highly selectively introduced into the siloxane segment, while the reaction conditions are mild, the reaction rate is high, and the product structure is stable.

[0075] In a third aspect, the present application provides an ultra-high molecular weight silicone rubber emulsion, which is prepared from the following raw materials in parts by weight:

[0076] 80-100 parts of ultra-high molecular weight silicone rubber;

[0077] 0-20 parts of viscosity regulator;

[0078] Emulsifier A 0-10 parts;

[0079] Emulsifier B 5-18 parts;

[0080] 10-60 parts of water.

[0081] In some embodiments, the ultra-high molecular weight silicone rubber structure is Where a and b are the number of links, 1500≤a+b≤2500.

[0082] In some specific embodiments, the molecular weight of the ultra-high molecular weight silicone rubber is 150,000 to 850,000 g / mol, wherein the mass fraction of vinyl groups is 0.03% to 5%.

[0083] In some specific embodiments, the viscosity modifier is one or more of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, DMC (dimethylsiloxane mixed ring body), tetramethyltetravinylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, kerosene, octanol, alkane, etc.

[0084] By using the above reagents as viscosity regulators, it can help to better mix the reactive emulsifier and facilitate the preparation of the emulsion.

[0085] In some specific embodiments, the emulsifier A is one or more of the reactive emulsifier prepared above with an HLB value (hydrophile-lipophile balance) <10, and fatty alcohol polyoxyethylene ethers, fatty acid polyoxyethylene esters, sorbitan fatty acid esters, alkylphenol polyoxyethylene ethers, polyether silicone oil emulsifiers, and polyether emulsifiers well known in the art.

[0086] In some specific embodiments, the emulsifier B is one or more of the reactive emulsifier prepared above with an HLB value (hydrophile-lipophile balance) ≥ 10, and fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, sorbitan fatty acid ester, alkylphenol polyoxyethylene ether, polyether silicone oil emulsifier, and polyether emulsifier.

[0087] By using the above reagents as emulsifiers, ultra-high molecular weight silicone rubber can be dispersed in water. By adjusting the type and combination of emulsifiers, the prepared emulsion particle size can be made small and the stability is good.

[0088] By adjusting the amount of water, the emulsion can be prepared to have different viscosities, which is beneficial for further dispersion and construction of the emulsion particles.

[0089] In a fourth aspect, the present application further provides a method for preparing the above-mentioned ultra-high molecular weight silicone rubber emulsion, comprising the following steps:

[0090] The ultra-high molecular weight silicone rubber and the viscosity modifier are mixed in a mixer for 30 to 90 minutes until uniform, at a temperature of 60 to 90° C., to obtain a mixture 1;

[0091] Add emulsifier A and emulsifier B to mixture 1, mix evenly at 30-70° C. to obtain mixture 2;

[0092] Add water to mixture 2, mixing thoroughly while adding. The addition time is 30 to 90 minutes, and the temperature is controlled within 40°C.

[0093] After the water is added, a homogenizer is used for homogenization at a rotation speed of 2000 to 4000 rpm for 20 to 60 minutes to obtain an ultra-high molecular weight silicone rubber emulsion.

[0094] In some specific embodiments, the mixer can be a vacuum kneader, a screw mixer, a planetary mixer, a ribbon mixer, a frame mixer, or a centrifugal mixer.

[0095] By adopting the above technical solution, ultra-high molecular weight silicone rubber can be prepared into an emulsion, using water as the diluent, significantly reducing VOC emissions during application. The preparation process is convenient and does not require complex and expensive equipment. The resulting emulsion has a small particle size, good stability, and uniform distribution.

[0096] In a fifth aspect, the present application also provides a composition of the above-mentioned ultra-high molecular weight silicone rubber emulsion, which is mainly prepared from the following raw materials in parts by weight:

[0097] 80-100 parts of ultra-high molecular weight silicone rubber emulsion;

[0098] 5-30 parts of hydrogenated silicone oil emulsion;

[0099] 1-10 parts of platinum catalyst emulsion;

[0100] 10-100 parts of water.

[0101] In some specific embodiments, the hydrogen content of the hydrogenated silicone oil emulsion is 0.1% to 1%.

[0102] In some specific embodiments, the molar ratio of vinyl double bonds to silicon-hydrogen bonds of the ultra-high molecular weight silicone rubber emulsion and the hydrogen-containing silicone oil emulsion is (0.5-4):1.

[0103] In some specific embodiments, the platinum content of the platinum catalyst emulsion is 100-1000 ppm, and the platinum catalyst emulsion is prepared by emulsifying and dispersing the Custer platinum catalyst with a non-ionic emulsifier.

[0104] The ultra-high molecular weight silicone rubber emulsion composition prepared by adopting the above components and proportions has good stability and is flexible and convenient to construct.

[0105] In a sixth aspect, the present application further provides a method for preparing a film-forming material of the ultra-high molecular weight silicone rubber emulsion, comprising the following steps:

[0106] Mixing ultra-high molecular weight silicone oil emulsion, hydrogenated silicone oil emulsion, platinum catalyst emulsion and water for 20 to 40 minutes to obtain composition A;

[0107] The composition A is coated on a silicone substrate and baked in an oven at 90-130° C. for 60-120 min to obtain an ultra-high molecular weight silicone rubber emulsion film-forming material.

[0108] In some specific embodiments, the film-forming material has a thickness of 5 to 30 μm.

[0109] In some embodiments, the coating method can be air knife coating, rod coating, spin coating, spray coating, blade coating, brush coating or roller coating.

[0110] The ultra-high molecular weight silicone rubber emulsion film produced by adopting the above technical solution has excellent mechanical properties, good wear resistance, low friction coefficient, good hand feel, and good hydrophobicity. It is easy to apply and suitable for large-scale industrial production.

[0111] Synthesis example of reactive emulsifier

[0112] Synthesis example 1

[0113] S1: Add isopropyl alcohol and 1,1,3,3-tetramethyldisiloxane to a round-bottom flask, purge with nitrogen for protection, and slowly add platinum catalyst under stirring. The specific amount of catalyst is shown in Table 1.

[0114] S2: Control the temperature to 25°C, and add allyl polyether (the molar ratio of silicon-hydrogen bonds in 1,1,3,3-tetramethyldisiloxane to double bonds in allyl polyether is 2:1, wherein R1 is H) dropwise for 30 minutes to obtain a prepolymer;

[0115] S3: adding the above-prepared prepolymer dropwise to tetramethyltetravinylcyclotetrasiloxane under nitrogen protection for 35 minutes at a reaction temperature of 40° C. to obtain a reactive emulsifier;

[0116] S4: The solvent of the reactive emulsifier is removed by distillation under reduced pressure at 90°C.

[0117] The HLB value and viscosity of the prepared reactive emulsifier are shown in Table 9.

[0118] Synthesis example 2-6

[0119] The difference between Synthesis Example 2-6 and Synthesis Example 1 is that the prepared materials and their dosages are different, and R1 in the allyl polyether structure is H. Please refer to Table 1 for details.

[0120] Table 1 Preparation materials and mass components of reactive emulsifiers

[0121]

[0122] The difference between Synthesis Examples 7-12 and Synthesis Example 1 is that the prepared materials and their dosages are different, and R1 in the allyl polyether structure is H. Please refer to Table 2 for details.

[0123] Table 2 Preparation materials and mass components of reactive emulsifiers

[0124]

[0125]

[0126] Synthesis Example 13-16

[0127] The difference between Synthesis Examples 13-16 and Synthesis Example 2 is that the ratios of solvents and catalysts are different, and the reaction conditions of preparation steps S2-S4 are different. Please refer to Table 3 for details.

[0128] Table 3 Preparation reaction conditions of reactive emulsifier

[0129]

[0130]

[0131] Preparation Example of Ultra-High Molecular Weight Silicone Rubber Emulsion

[0132] Preparation Example 1

[0133] S1: 100 parts of ultra-high molecular weight silicone rubber (molecular weight 450,000 g / mol, vinyl mass fraction 0.5%) and 10 parts of decamethylcyclopentasiloxane were mixed in a planetary mixer at 70° C. for 60 min to obtain mixture 1;

[0134] S2. Add 10 parts of Synthesis Example 7 to mixture 1, and mix at 70°C for 60 minutes to obtain mixture 2.

[0135] S3 Add 50 parts of water to mixture 2, mixing thoroughly while adding, adding time is 60 minutes, and the temperature is controlled at 30°C;

[0136] After the addition of water in S4 is completed, a homogenizer is used for homogenization at a speed of 3000 rpm for 30 min, and an ultra-high molecular weight silicone rubber emulsion is obtained after the treatment.

[0137] The average particle size, D90 particle size, and stability of the ultra-high molecular weight silicone rubber emulsion are shown in Table 10.

[0138] The difference between Preparation Example 2-9 and Preparation Example 1 is that different emulsifiers are used. Please refer to Table 4 for details.

[0139] Table 4 Preparation materials and mass components of ultra-high molecular weight silicone rubber emulsion

[0140]

[0141] The difference between Preparation Examples 10-15 and Preparation Example 1 is that different emulsifiers are used (emulsifier A and emulsifier B are added at the same time), please refer to Table 5 for details.

[0142] Table 5 Preparation materials and mass components of ultra-high molecular weight silicone rubber emulsion

[0143]

[0144] The difference between Preparation Examples 16-20 and Preparation Example 10 is that the components and processes used are different. For details, refer to Table 6

[0145] Table 6 Preparation conditions of ultra-high molecular weight silicone rubber emulsion

[0146]

[0147]

[0148] Examples of ultra-high molecular weight silicone rubber emulsion film-forming materials

[0149] Example 1

[0150] The preparation of an ultra-high molecular weight silicone rubber emulsion film-forming material comprises the following steps:

[0151] Weigh 100 parts of the ultra-high molecular weight silicone oil emulsion obtained in Preparation Example 10, 15 parts of hydrogenated silicone oil emulsion, 5 parts of platinum catalyst emulsion, and 50 parts of water and mix them for 30 minutes to obtain composition A;

[0152] The composition A was sprayed on a silicone substrate and baked in an oven at 100° C. for 60 min to obtain an ultra-high molecular weight silicone rubber emulsion film having a film thickness of 15 μm.

[0153] The water contact angle, abrasion resistance and CoF value of the ultra-high molecular weight silicone rubber emulsion film are shown in Table 11.

[0154] Examples 2-9

[0155] The difference between Examples 2-9 and Example 1 is that the sources of the ultra-high molecular weight silicone oil emulsion are different, see Table 7 for details.

[0156] Table 7 Preparation materials and mass components of ultra-high molecular weight silicone rubber emulsion film-forming materials

[0157]

[0158] Examples 10-16

[0159] The difference between Examples 10-16 and Example 1 is that the prepared substances involved in the reaction and their dosages are different, and the reaction conditions are different. Please refer to Table 8 for details.

[0160] Table 8 Preparation conditions of ultra-high molecular weight silicone rubber emulsion film-forming materials

[0161]

[0162]

[0163] Comparative Example

[0164] Comparative Example 1

[0165] The preparation method of Comparative Example 1 is the same as that of Example 1, except that a low molecular weight silicone oil emulsion is used in Comparative Example 1, and the preparation method of the low molecular weight silicone oil emulsion is the same as that of Preparation Example 10, wherein the molecular weight of the silicone oil is 5000 g / mol and the vinyl content is 0.5%.

[0166] Comparative Example 2

[0167] The preparation method of Comparative Example 2 is the same as that of Example 1, except that a low molecular weight silicone oil emulsion is used in Comparative Example 2. The preparation method of the low molecular weight silicone oil emulsion is the same as that of Preparation Example 10, wherein the molecular weight of the silicone oil is 5000 g / mol and the vinyl content is 1.5%.

[0168] Comparative Example 3

[0169] The preparation method of Comparative Example 3 is the same as that of Example 1, except that a low molecular weight silicone oil emulsion is used in Comparative Example 3. The preparation method of the low molecular weight silicone oil emulsion is the same as that of Preparation Example 10, wherein the molecular weight of the silicone oil is 15,000 g / mol and the vinyl content is 0.5%.

[0170] Comparative Example 4

[0171] The preparation method of Comparative Example 4 is the same as that of Example 1, except that a low molecular weight silicone oil emulsion is used in Comparative Example 4. The preparation method of the low molecular weight silicone oil emulsion is the same as that of Preparation Example 10, wherein the molecular weight of the silicone oil is 15,000 g / mol and the vinyl content is 1.5%.

[0172] Comparative Example 5

[0173] The preparation method of Comparative Example 5 is the same as that of Example 1, except that the hydroxy silicone rubber emulsion used in Comparative Example 5 has a molecular weight of 450,000 g / mol.

[0174] Comparative Example 6

[0175] The preparation method of Comparative Example 6 is the same as that of Example 5, except that a low molecular weight silicone oil emulsion is used in Comparative Example 6. The preparation method of the low molecular weight silicone oil emulsion is the same as that of Preparation Example 14, wherein the molecular weight of the silicone oil is 15,000 g / mol and the vinyl content is 0.5%.

[0176] Performance testing experiment

[0177] The viscosity of the reactive emulsifier was determined according to GB / T 11175-2021 using a Brookfield DV-11+Pro viscometer.

[0178] The HLB value of reactive emulsifier is determined by the water number method. For specific operation, please refer to the reference: Chen Pinghua, Jiang Hualin, Shu Hongying. Determination of HLB value of low hydrogen silicone oil by water number method [J]. Jiangxi Chemical Industry, 2007(3):72-73.

[0179] The particle size of the ultra-high molecular weight silicone rubber emulsion was measured according to GB / T 11175-2021 using a Nicomp380N3000 laser particle size analyzer.

[0180] The stability of ultra-high molecular weight silicone rubber emulsion is tested by centrifugation according to HG / T 3314-1999. Grade 1: fine emulsion without any stratification; Grade 2: fine emulsion with an oil layer of less than 2%; Grade 3: coarse emulsion with an oil layer of less than 2%; Grade 4: sedimentation layer, sub-emulsion layer and gel appear.

[0181] Water contact angle, deionized water was used as the reagent, and the fixed volume for each measurement was 2 μL;

[0182] The abrasion times were measured using a Taber abrasion tester with a CS-10 rubber and a load of 1 kg.

[0183] The friction coefficient was measured according to GB / T 10006-2021 with a load of 300 g and a pulling speed of 100 mm / min.

[0184] Table 9 Yield, viscosity and HLB value of Synthesis Examples 1-16

[0185]

[0186] Table 10 Average particle size, D90 particle size and stability of Preparation Examples 1-20

[0187]

[0188]

[0189] Table 11 Water contact angle, abrasion resistance times, CoF of Examples 1-16 and Comparative Examples 1-6

[0190]

[0191] Combining Synthesis Examples 1-16 with Table 9 demonstrates that the reactive emulsifier preparation method of this application achieves high yields, exceeding 95%. This is due to the specificity and selectivity of the addition reaction, the low number of byproducts, and the mild reaction conditions, which prevent product gelation. The structural design of the allyl polyether segment results in a moderate product viscosity, facilitating mixing with ultra-high molecular weight silicone rubber. Furthermore, by adjusting the ratio of the components, reactive emulsifiers with varying HLB values ​​can be produced.

[0192] Combined with Preparation Example 1 and Preparation Example 2-9, the difference is that the emulsifiers used are different. As can be seen from Table 10, the emulsion stability of Preparation Example 2-7 and Preparation Example 1 is secondary, and the average particle size and D90 particle size fluctuate with the change of the HLB value of the emulsifier, but the overall range of variation is narrow. Preparation Examples 8 and Preparation Examples 9 use commercially available emulsifiers, and their particle sizes have increased compared to Preparation Examples 1-7. This is because the reactive emulsifier introduces a siloxane segment and has good compatibility with ultra-high molecular weight silicone rubber, which improves the stability of the emulsion to a certain extent. Overall, after the centrifugal test, the emulsion did not show sedimentation or demulsification using the preparation process of the ultra-high molecular weight silicone oil emulsion.

[0193] Combining Preparation Example 1 with Preparation Examples 10-15, the difference lies in the emulsifiers used. Preparation Examples 10-15 employ a combination of an emulsifier with an HLB value <10 and an emulsifier with an HLB value >10. Table 10 shows that the ultra-high molecular weight silicone rubber emulsions prepared using mixed emulsifiers have smaller particle sizes and better emulsion stability. This is because the film formed by the mixed emulsifier on the emulsion particles has a higher strength, effectively preventing aggregation between the emulsion particles. The ultra-high molecular weight silicone rubber emulsions prepared using mixed reactive emulsifiers can achieve Class 1 stability, which is largely due to the compatibility of the concentrated siloxane segments in the emulsifier and the complementarity of the polyether segments with different configurations.

[0194] Combining Preparation Example 10 with Preparation Examples 16-20, the differences lie in the molecular weight, vinyl content, and emulsification process of the ultra-high molecular weight silicone rubber used. As can be seen from Table 10, the ultra-high molecular weight silicone oil emulsions obtained in Preparation Examples 16-20 exhibit excellent emulsion stability and fine particles. Emulsions prepared from ultra-high molecular weight silicone rubbers with different vinyl contents showed no significant differences, allowing for the content to be adjusted according to the actual application, providing high flexibility.

[0195] Example 1 and Example 2-9, the difference is that the sources of ultra-high molecular weight silicone oil emulsion are different. In conjunction with Table 11, it can be seen that the ultra-high molecular weight silicone oil emulsion film-forming material prepared has good wear resistance, this is because the silicone rubber adopted is ultra-high molecular weight, and with reactive vinyl functional groups, the film-forming material formed has good cross-linking density, and cooperates with hydrogen-containing silicone oil emulsion and platinum catalyst emulsion to use and has very high reaction rate. Due to the hydrophobicity and self-lubricating property of the siloxane segment, the film-forming material has very low friction coefficient, and good hydrophobicity. The ultra-high molecular weight silicone oil emulsion prepared by the non-reactive emulsifier adopted in Examples 5 and 6 has reduced wear resistance.

[0196] The difference between Examples 10-16 and Example 1 lies in the different prepared substances involved in the reaction and their dosages, as well as the different reaction conditions. As can be seen from Table 11, there is no significant difference in the hydrophobicity and friction coefficient between Examples 10-16 and Example 1. While the crosslinking density varies to some extent with changes in the amounts of the hydrogenated silicone oil crosslinker and platinum catalyst used, as well as in the reaction conditions, the overall wear resistance remains at a high level.

[0197] From Example 1 and Comparative Example 1, and from Table 11, it can be seen that the film-forming material prepared using ultra-high molecular weight silicone rubber emulsion has significantly improved wear resistance and hydrophobicity than the film-forming material using low molecular weight silicone oil emulsion. This is because the ultra-high molecular weight silicone rubber emulsion can form good cohesive strength and has higher elasticity and toughness, so its overall performance is significantly improved.

[0198] From Example 1 and Comparative Example 2, and from Table 11, it can be seen that the film-forming material prepared using the ultra-high molecular weight silicone rubber emulsion has significantly improved wear resistance and hydrophobicity than the film-forming material using the low molecular weight silicone oil emulsion with a higher vinyl content. This is because although the vinyl content of the low molecular weight silicone oil emulsion is increased, it still cannot achieve the cohesive strength, elasticity and toughness that the ultra-high molecular weight silicone rubber emulsion can form.

[0199] From Example 1 and Comparative Example 3, and in combination with Table 11, it can be seen that the wear resistance and hydrophobicity of the low molecular weight silicone oil emulsion film-forming material prepared using 15,000 g / mol silicone oil are significantly lower than those of the ultra-high molecular weight silicone rubber emulsion film-forming material. This is because the ultra-high molecular weight silicone rubber emulsion can form good cohesive strength and has higher elasticity and toughness, so its overall performance is significantly improved.

[0200] From Example 1 and Comparative Example 4, and from Table 11, it can be seen that the wear resistance and hydrophobicity of the low molecular weight silicone oil emulsion film-forming material prepared using silicone oil with a vinyl content of 15,000 g / mol and 1.5% are significantly lower than those of the ultra-high molecular weight silicone rubber emulsion film-forming material. This is because although the vinyl content of the low molecular weight silicone oil emulsion is increased, the cohesive strength, elasticity and toughness that can be formed by the ultra-high molecular weight silicone rubber emulsion cannot be achieved.

[0201] From Example 1 and Comparative Example 5, and from Table 11, it can be seen that the wear resistance and hydrophobicity of the emulsion film-forming material prepared using hydroxyl silicone rubber of the same molecular weight are significantly lower than those of the ultra-high molecular weight silicone rubber emulsion film-forming material, and the friction coefficient is also higher. This is because the hydroxyl silicone rubber emulsion does not contain vinyl and has poor reaction activity, and the film-forming material formed has a low crosslinking density and poor cohesive strength.

[0202] From Example 1 and Comparative Example 6, and from Table 11, it can be seen that the wear resistance of the low molecular weight silicone oil emulsion film-forming material prepared using low molecular weight silicone oil and a traditional non-reactive emulsifier is significantly lower than that of the ultra-high molecular weight silicone rubber emulsion film-forming material. This is because the ultra-high molecular weight silicone rubber emulsion film-forming material has excellent strength, toughness and cross-linking properties. In addition, the hydrophobicity and friction coefficient of Example 1 are significantly better than those of Comparative Example 6. This is because Example 1 further uses a reactive emulsifier with self-lubrication and a siloxane chain segment, which can improve the cohesive strength of Example 1 and reduce the friction coefficient.

[0203] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical solution of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A reactive emulsifier, characterized in that The reactive emulsifier is prepared by the following reaction: 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a hydrosilylation reaction to prepare a prepolymer; The prepolymer is subjected to a hydrosilylation reaction with tetramethyltetravinylcyclotetrasiloxane to prepare the reactive emulsifier.

2. The reactive emulsifier according to claim 1, characterized in that The allyl polyether structural formula is: Wherein: R1 is H or CH3 or C2H5 or C3H7 or C4H9; n:m = (1~40):1, m is an integer between 1 and 5.

3. A method for preparing the reactive emulsifier according to claim 1 or 2, characterized in that: The following steps are included: 1,1,3,3-tetramethyldisiloxane and allyl polyether are subjected to a hydrosilylation reaction in a solvent in an inert atmosphere in the presence of a catalyst to prepare a prepolymer; wherein the molar ratio of the silicon-hydrogen bond in the 1,1,3,3-tetramethyldisiloxane to the double bond in the allyl polyether is (1.95-2.05):1; The prepolymer is subjected to a silylation reaction with tetramethyltetravinylcyclotetrasiloxane to prepare the reactive emulsifier; wherein the molar ratio of the double bond of the tetramethyltetravinylcyclotetrasiloxane to the silylation bond in the prepolymer is 4:(1-3).

4. The preparation method according to claim 3, characterized in that The catalyst is a platinum catalyst; and / or The solvent is a combination of one or more of methanol, ethanol or isopropanol.

5. The preparation method according to claim 3, characterized in that The temperature of the first step hydrosilylation reaction is controlled at 20-30°C, and the temperature of the second step hydrosilylation reaction is controlled at 20-60°C.

6. The preparation method according to claim 3, characterized in that The HLB value of the reactive emulsifier is between 4 and 15.

7. An ultra-high molecular weight silicone rubber emulsion, characterized in that: It is mainly made from the following raw materials in parts by weight: 80-100 parts of ultra-high molecular weight silicone rubber; 0-20 parts of viscosity regulator; Emulsifier A 0-10 parts; Emulsifier B 5-18 parts; 10-60 parts water; The molecular weight of the ultra-high molecular weight silicone rubber is 150,000 to 850,000 g / mol, wherein the mass fraction of vinyl is 0.03% to 5%; The emulsifier A is a reactive emulsifier prepared by the method according to any one of claims 3 to 6 with an HLB value of less than 10, and one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, sorbitan fatty acid ester, alkylphenol polyoxyethylene ether or polyether silicone oil emulsifier; The emulsifier B is a reactive emulsifier prepared by the method according to any one of claims 3 to 6 with an HLB value ≥ 10, and one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, sorbitan fatty acid ester, alkylphenol polyoxyethylene ether or polyether silicone oil emulsifier.

8. A method for preparing the ultra-high molecular weight silicone rubber emulsion according to claim 7, characterized in that: The following steps are involved: The ultra-high molecular weight silicone rubber and the viscosity modifier are uniformly mixed to obtain a mixture 1; Add emulsifier A and emulsifier B to mixture 1 and mix well to obtain mixture 2; Add water to mixture 2 and mix thoroughly; The mixture is homogenized to obtain an ultra-high molecular weight silicone rubber emulsion.

9. A composition comprising the ultra-high molecular weight silicone rubber emulsion according to claim 7, characterized in that: It is mainly prepared from the following raw materials in parts by weight: 80-100 parts of the ultra-high molecular weight silicone rubber emulsion; 5-30 parts of hydrogenated silicone oil emulsion; 1-10 parts of platinum catalyst emulsion; 10~100 parts of water.

10. A method for preparing a film-forming material from the composition according to claim 9, characterized in that: The following steps are involved: mixing the ultra-high molecular weight silicone rubber emulsion, hydrogenated silicone oil emulsion, platinum catalyst emulsion and water to obtain a composition; The composition is coated on a silica gel substrate and baked to obtain the film-forming material.

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