Liquid organosilicon-based glue, preparation method thereof, and liquid silicone rubber

Abstract

The present invention discloses a liquid organosilicon-based glue, a preparation method thereof, and a liquid silicone rubber. The liquid organosilicon-based glue, in terms of parts by mass, includes 1 to 10 parts of an ionic liquid, 3 to 15 parts of a silane coupling agent, 10 to 20 parts of vinyl hydroxy silicone oil, 5 to 20 parts of hydroxy fluorosilicone oil, 40 to 70 parts of vinyl silicone oil, and 20 to 45 parts of fumed silica. The ionic liquid is a hydroxy-functionalized imidazole-based ionic liquid, and the hydroxy fluorosilicone oil is a methyltrifluoropropyl polysiloxane capped with a hydroxy functional group. Applying the liquid organosilicon-based glue of the present invention to the liquid silicone rubber can endow the liquid silicone rubber with excellent waterproofness, antifouling property, antistatic property, antibacterial and bactericidal characteristics, and maintain good transparency and mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone rubber, and in particular relates to a liquid organic silicon-based adhesive and a preparation method thereof, and liquid silicone rubber. Background Art

[0002] The basic structural unit of silicone products is composed of silicon-oxygen chain links, and the side chains are connected to various other organic groups through silicon atoms. This unique structure gives silicone products the characteristics of both organic and inorganic materials, such as low surface tension, small viscosity-temperature coefficient, high compressibility, high gas permeability and other basic properties, as well as excellent properties such as high and low temperature resistance, electrical insulation, oxidation stability, weather resistance, flame retardancy, hydrophobicity, corrosion resistance, non-toxicity and odorlessness, and physiological inertness. Therefore, silicone products are widely used in aerospace, electronics and electrical, construction, transportation, chemical, textile, food, light industry, medical and other industries.

[0003] Liquid silicone rubber is a common silicone product. It is a two-component system that uses a platinum complex as a catalyst and is cured by the addition reaction of vinyl-containing and hydrogen-containing polysiloxanes. However, due to its good electrical insulation, liquid silicone rubber is prone to static electricity accumulation, which attracts dust and causes the surface to become dirty easily. In order to meet the "three-proof" requirements of waterproof, oil-proof and anti-static, it is usually necessary to add conductive additives to silicone materials to improve their antistatic properties. Commonly used conductive additives include acetylene black, metal powder, graphene or carbon nanotubes, etc. However, the addition of these conductive additives may cause the product color to darken and may reduce the mechanical properties of the material.

[0004] Therefore, there is an urgent need for a liquid silicone-based adhesive and a preparation method and liquid silicone rubber to solve the deficiencies of the existing technical problems. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a liquid silicone base adhesive and a preparation method and liquid silicone rubber, wherein the liquid silicone base adhesive can enable the liquid silicone rubber to have excellent waterproofness, antifouling, antistatic, antibacterial and bactericidal properties and maintain good transparency and mechanical properties.

[0006] To achieve the above objectives, the first aspect of the present invention provides a liquid silicone-based adhesive, wherein the raw materials for preparation include, by weight, 1 to 10 parts of ionic liquid, 3 to 15 parts of silane coupling agent, 10 to 20 parts of vinyl hydroxy silicone oil, 5 to 20 parts of hydroxy fluorosilicone oil, 40 to 70 parts of vinyl silicone oil, and 20 to 45 parts of white carbon black; the ionic liquid is a hydroxyl-functionalized imidazole ionic liquid, and the hydroxyl fluorosilicone oil is a methyltrifluoropropyl polysiloxane terminated with a hydroxyl functional group.

[0007] Compared with the prior art, the raw materials for preparing the liquid organosilicon-based rubber of the present invention include ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil. Among them, the silane coupling agent serves as a bridge, and through a condensation reaction, the ionic liquid, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil can be combined to form an active ionized organosilicon composition containing vinyl, trifluoropropyl, and alkoxy groups. Due to the difference in polarity, the trifluoropropyl group and the polar ionic part will drive the molecular chain migration and gradually accumulate on the material surface. The ions accumulated on the material surface form a conductive network, thereby obtaining excellent antistatic performance; while the trifluoropropyl group accumulated on the material surface endows the material with the functions of oil and stain resistance; due to the anchoring effect of the silane coupling agent, the active ionized organosilicon composition can be stable and persistent, without "sweating" or phase separation. At the same time, since no dark conductive additives are introduced, the liquid organosilicon-based rubber also has good transparency and can be adapted to products of different colors. In addition, since the cell wall of bacteria usually carries a negative charge, and the liquid organosilicon-based rubber contains a large amount of cations due to the bridging of ionic liquid and exhibits certain positive charge properties, bacteria are easily adsorbed on the material surface under the action of electrostatic attraction, resulting in the ultimate dissolution and rupture of the bacterial cell wall, thereby achieving the effects of sterilization and antibacterial. Furthermore, the active ionized organosilicon composition can also exert the effect of a structuring inhibitor. High-temperature internal mixing with fumed silica can bond the residual alkoxy groups in the active ionized organosilicon composition with the residual hydroxyl groups on the surface of fumed silica, thereby improving the dispersibility of fumed silica in the organosilicon system and thus enhancing the mechanical properties of the entire material. Therefore, applying the liquid organosilicon-based rubber of the present invention to liquid silicone rubber can endow the liquid silicone rubber with excellent waterproofness, stain resistance, antistatic property, antibacterial and bacteriostatic characteristics, and maintain good transparency and mechanical properties.

[0008] Further, the content of the ionic liquid in the present invention can specifically be, but is not limited to, 1 part, 3 parts, 6 parts, 8 parts, 10 parts; the content of the silane coupling agent can specifically be, but is not limited to, 3 parts, 8 parts, 10 parts, 12 parts, 15 parts; the content of the vinyl hydroxy silicone oil can specifically be, but is not limited to, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts; the content of the hydroxy fluorosilicone oil can specifically be, but is not limited to, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts; the content of the vinyl silicone oil can specifically be, but is not limited to, 40 parts, 45 parts, 48 parts, 55 parts, 60 parts, 65 parts, 70 parts; the content of the fumed silica can specifically be, but is not limited to, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts.

[0009] Further, the ionic liquid of the present invention includes at least one of Formula 1 and Formula 2;

[0010]

[0011] Wherein Y - is selected from BF4 - , PF 6 - , PhSO 3 - (p - toluenesulfonate) or [(CF 3 SO 2 ) 2 N] - .

[0012] Furthermore, the silane coupling agent of the present invention is a vinyl silane coupling agent. More specifically, the silane coupling agent can be, but is not limited to, at least one of vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(β - methoxyethoxy)silane.

[0013] Furthermore, the vinyl hydroxy silicone oil of the present invention has a viscosity of 20 - 100 mm 2 / s at 25°C; the molar fraction of hydroxyl groups in the vinyl hydroxy silicone oil is 1 - 7.5%, and the molar fraction of vinyl groups is 2 - 7%.

[0014] Furthermore, the hydroxy fluorosilicone oil of the present invention has a viscosity of 150 - 500000 mPa·s at 25°C. More specifically, the mass fraction of hydroxyl groups in the hydroxy fluorosilicone oil > 0.3%, and the rotational viscosity is 150 - 3000 mPa·s.

[0015] Furthermore, the vinyl silicone oil of the present invention is an end - vinyl silicone oil with a viscosity of 2000 - 23000 CP, and the mass fraction of vinyl groups in the vinyl silicone oil is 0.05 - 0.3%.

[0016] Furthermore, the fumed silica of the present invention is fumed silica prepared by the gas - phase method. Specifically, the fumed silica is a hydrophilic fumed silica with a specific surface area of 250 - 380 m 2 / g.

[0017] Correspondingly, the second aspect of the present invention provides a method for preparing a liquid organosilicon - based glue, and the steps include:

[0018] (1) Adding an ionic liquid, a silane coupling agent, a vinyl hydroxy silicone oil, and a hydroxy fluorosilicone oil into a reaction kettle for mixing, stirring and heating under an inert atmosphere and then carrying out a condensation reaction, cooling and then evacuating to obtain an ionized modified silicone oil;

[0019] (2) Adding fumed silica, vinyl silicone oil, and ionized modified silicone oil into a kneader, heating and kneading under an inert atmosphere, then carrying out vacuum rubber milling, cooling and then grinding to obtain a liquid organosilicon - based glue.

[0020] Specifically, when the ionic liquid is as shown in Formula 2, the condensation reaction equation in step (1) of the present invention is as follows:

[0021]

[0022] Among them, Y - is selected from BF 4 - , PF 6 - , PhSO 3 - or [(CF 3 SO 2 ) 2 N] - ; R is methyl, ethyl or β-methoxyethoxy; a, b, and n are all integers greater than or equal to 1.

[0023] Furthermore, step (1) of the present invention includes stirring and heating to 90 - 150 °C and then carrying out a condensation reaction for 3 - 5 h; and cooling to 75 - 85 °C, and carrying out vacuum pumping under a condition of -0.09 MPa for 1.5 - 3 h.

[0024] Furthermore, step (2) of the present invention includes kneading and heating to 180 - 190 °C and then carrying out vacuum rubber refining for 3 - 6 h; and cooling to below 50 °C and then carrying out grinding. Specifically, a three-roll grinder is used for grinding.

[0025] Furthermore, the inert atmosphere in step (1) and step (2) of the present invention can be but is not limited to a nitrogen atmosphere.

[0026] Furthermore, the vinyl silicone oil of the present invention is added in small amounts and multiple times. Specifically, the vinyl silicone oil can be added in 3 - 5 times.

[0027] Correspondingly, the third aspect of the present invention also provides a liquid silicone rubber, which includes a hydrogen-containing silicone oil, an inhibitor, a catalyst, and a liquid organosilicon-based rubber. The liquid organosilicon-based rubber is the above-mentioned liquid organosilicon-based rubber or the liquid organosilicon-based rubber prepared by the above-mentioned preparation method.

[0028] Compared with the prior art, when the liquid silicone rubber of the present invention is coated on the surface of a non-woven fabric or a fiber product, after heat vulcanization, it can not only endow the product with waterproof, oil-proof, and anti-static effects, but also has an antibacterial effect. Therefore, the liquid silicone rubber of the present invention can be applied in the fields of medicine, environmental protection, textiles, etc.

[0029] Furthermore, the raw materials for preparing the liquid silicone rubber of the present invention include 1-10 parts of ionic liquid, 3-15 parts of silane coupling agent, 10-20 parts of vinyl hydroxy silicone oil, 5-20 parts of hydroxy fluorosilicone oil, 40-70 parts of vinyl silicone oil, 20-45 parts of fumed silica, 0.1-15 parts of hydrogen-containing silicone oil, 0.006-0.1 part of inhibitor, and 0.02-0.7 part of catalyst. Specifically, the content of hydrogen-containing silicone oil can be, but is not limited to, 0.1 part, 2 parts, 5 parts, 8 parts, 10 parts, 13 parts, 15 parts; the content of inhibitor can be, but is not limited to, 0.006 part, 0.01 part, 0.05 part, 0.08 part, 0.1 part; the content of catalyst can be, but is not limited to, 0.02 part, 0.07 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part.

[0030] Furthermore, the hydrogen-containing silicone oil of the present invention has a viscosity of 70-150 mm 2 / s and a hydrogen content of 0.3-0.8% (wt) of side hydrogen-containing silicone oil.

[0031] Furthermore, the inhibitor of the present invention is selected from at least one of alkynol compounds, maleic acid esters, fumaric acid esters, and tetramethyltetravinylcyclotetrasiloxane.

[0032] Furthermore, the catalyst of the present invention is a Karstedt platinum catalyst with an effective platinum content of 2800-3200 ppm.

[0033] Furthermore, the preparation of the liquid silicone rubber of the present invention includes: placing the liquid organosilicon base gum, hydrogen-containing silicone oil, and inhibitor in a planetary mixer, stirring evenly, adding the catalyst, and then dispersing evenly to obtain the liquid silicone rubber. Coating the liquid silicone rubber of the present invention on the surface of PP non-woven fabric, due to the "bridging" effect of the ionized and coupling agent in the active ionized organosilicon composition, the interface between the liquid silicone rubber and the non-woven fabric surface can be combined more firmly. Specifically, the temperature inside the planetary mixer is below 50°C, the stirring time of the planetary mixer is 30-45 min; the stirring time after adding the catalyst is 20-30 min. Detailed Embodiments

[0034] To better illustrate the purpose, technical solution, and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the methods described in the following embodiments are further explanatory descriptions of the present invention and should not be regarded as limitations of the present invention.

[0035] The structural formulas of the ionic liquids in Examples 1-5 and Comparative Examples 1-4 are as follows:

[0036]

[0037] In Examples 1 to 5 and Comparative Examples 1 to 5, the silane coupling agent was vinyltriethoxysilane; in the vinyl hydroxy silicone oil, the molar fraction of hydroxyl groups was 6%, the molar fraction of vinyl groups was 5.5%, and the viscosity was 25 mm 2 / s; the hydroxy fluorosilicone oil was a hydroxy fluorosilicone oil with a hydroxy content of 0.35% and a viscosity of 1500 mPa·s produced by Zhejiang Huanxin Fluorine Materials Co., Ltd.; the vinyl silicone oil was an end vinyl silicone oil with a viscosity of 20000 mPa·s and a vinyl content of 0.095% produced by Hubei Zheng'an New Materials Co., Ltd.; the white carbon black was a hydrophilic fumed white carbon black with a specific surface area of 260 m 2 / g; the hydrogen-containing silicone oil was H-075t-120 produced by Zhejiang Haiduo Organosilicon Materials Co., Ltd., with a viscosity of 120 mm 2 / s and a hydrogen content of 0.75%; the inhibitor was 1-ethynylcyclohexanol; the catalyst was a Karstedt catalyst with a platinum effective content of 3000 ppm.

[0038] Example 1

[0039] This example provides a liquid silicone rubber. By mass, the preparation raw materials include 3 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of white carbon black, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0040] This example provides a preparation method of a liquid silicone rubber. The steps include:

[0041] (1) Add the ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil into a reaction kettle for mixing, stir and heat up to 135°C under a nitrogen atmosphere for a condensation reaction for 3.5 h, then cool down to 80°C and evacuate under a condition of -0.09 MPa for 3 h to obtain an ionized modified silicone oil;

[0042] (2) Add the white carbon black, vinyl silicone oil, and ionized modified silicone oil into a kneader, knead and heat up to 185°C under a nitrogen atmosphere, then carry out vacuum rubber mixing for 6 h, cool down to 48°C, and grind with a three-roll grinder to obtain a liquid organosilicon base rubber, where the vinyl silicone oil is added in three portions;

[0043] (3) Place the liquid organosilicon base rubber, hydrogen-containing silicone oil, and inhibitor in a planetary stirrer, stir at 48°C for 45 min, then add the catalyst and stir again for 30 min to obtain a liquid silicone rubber.

[0044] Example 2

[0045] This embodiment provides a liquid silicone rubber. In terms of parts by mass, the raw materials for preparation include 5 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0046] This embodiment provides a method for preparing a liquid silicone rubber. The steps include:

[0047] (1) Add the ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil into a reaction kettle for mixing. Stir and heat up to 120 °C under a nitrogen atmosphere for a condensation reaction for 4.5 h, then cool down to 75 °C and evacuate under the condition of -0.09 MPa for 3 h to obtain ionized modified silicone oil;

[0048] (2) Add the fumed silica, vinyl silicone oil, and ionized modified silicone oil into a kneader. Knead and heat up to 190 °C under a nitrogen atmosphere, then carry out vacuum rubber refining for 5 h, cool down to 45 °C, and use a three-roll mill for grinding to obtain a liquid organosilicon base rubber, where the vinyl silicone oil is added in four portions;

[0049] (3) Place the liquid organosilicon base rubber, hydrogen-containing silicone oil, and inhibitor in a planetary stirrer, stir at 48 °C for 43 min, then add the catalyst and stir for another 20 min to obtain the liquid silicone rubber.

[0050] Example 3

[0051] This embodiment provides a liquid silicone rubber. In terms of parts by mass, the raw materials for preparation include 10 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0052] This embodiment provides a method for preparing a liquid silicone rubber. The steps include:

[0053] (1) Add the ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil into a reaction kettle for mixing. Stir and heat up to 100 °C under a nitrogen atmosphere for a condensation reaction for 5 h, then cool down to 85 °C and evacuate under the condition of -0.09 MPa for 3 h to obtain ionized modified silicone oil;

[0054] (2) Add the fumed silica, vinyl silicone oil, and ionized modified silicone oil into a kneader. Knead and heat up to 180 °C under a nitrogen atmosphere, then carry out vacuum rubber refining for 6 h, cool down to 40 °C, and use a three-roll mill for grinding to obtain a liquid organosilicon base rubber, where the vinyl silicone oil is added in five portions;

[0055] (3) Place the liquid silicone-based glue, hydrogen-containing silicone oil, and inhibitor in a planetary mixer, stir at 48 °C for 35 min, then add the catalyst and stir for another 25 min to obtain liquid silicone rubber.

[0056] Example 4

[0057] This example provides a liquid silicone rubber. By mass, the raw materials for preparation include 5 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 9 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0058] This example provides a method for preparing a liquid silicone rubber. The steps include:

[0059] (1) Add the ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil to a reaction kettle for mixing, stir and heat up to 135 °C under a nitrogen atmosphere for a condensation reaction for 3.5 h, then cool down to 80 °C and evacuate under a condition of -0.09 MPa for 3 h to obtain ionized modified silicone oil;

[0060] (2) Add the fumed silica, vinyl silicone oil, and ionized modified silicone oil to a kneader, knead and heat up to 185 °C under a nitrogen atmosphere, then carry out vacuum rubber refining for 6 h, cool down to 48 °C, and grind with a three-roll grinder to obtain a liquid silicone-based glue, where the vinyl silicone oil is added in three portions;

[0061] (3) Place the liquid silicone-based glue, hydrogen-containing silicone oil, and inhibitor in a planetary mixer, stir at 48 °C for 45 min, then add the catalyst and stir for another 30 min to obtain liquid silicone rubber.

[0062] Example 5

[0063] This example provides a liquid silicone rubber. By mass, the raw materials for preparation include 5 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 12 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0064] This example provides a method for preparing a liquid silicone rubber. The steps include:

[0065] (1) Add the ionic liquid, silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil to a reaction kettle for mixing, stir and heat up to 135 °C under a nitrogen atmosphere for a condensation reaction for 3.5 h, then cool down to 80 °C and evacuate under a condition of -0.09 MPa for 3 h to obtain ionized modified silicone oil;

[0066] (2) Add fumed silica, vinyl silicone oil, and ionized modified silicone oil into a kneader. Under a nitrogen atmosphere, knead and heat up to 185 °C, then conduct vacuum rubber refining for 6 h, cool down to 48 °C, and use a three-roll grinder for grinding to obtain a liquid silicone-based rubber, where the vinyl silicone oil is added in three portions.

[0067] (3) Place the liquid silicone-based rubber, hydrogen-containing silicone oil, and inhibitor in a planetary mixer, stir at 48 °C for 45 min, then add a catalyst and stir again for 30 min to obtain a liquid silicone rubber.

[0068] Comparative Example 1

[0069] This comparative example provides a liquid silicone rubber. By mass, the preparation raw materials include 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0070] The preparation method of the liquid silicone rubber in this comparative example is exactly the same as that of Example 2.

[0071] Comparative Example 2

[0072] This comparative example provides a liquid silicone rubber. By mass, the preparation raw materials include 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0073] The preparation method of the liquid silicone rubber in this comparative example is exactly the same as that of Example 2.

[0074] Comparative Example 3

[0075] This comparative example provides a liquid silicone rubber. By mass, the preparation raw materials include 5 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0076] The preparation method of the liquid silicone rubber in this comparative example is exactly the same as that of Example 2.

[0077] Comparative Example 4

[0078] This comparative example provides a liquid silicone rubber. By mass, the preparation raw materials include 5 parts of ionic liquid, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst.

[0079] The preparation method of the liquid silicone rubber in this comparative example is exactly the same as that of Example 2.

[0080] Comparative Example 5

[0081] This comparative example provides a liquid silicone rubber. By mass, the preparation raw materials include 5 parts of ionic liquid, 8 parts of silane coupling agent, 12 parts of vinyl hydroxy silicone oil, 7 parts of hydroxy fluorosilicone oil, 60 parts of vinyl silicone oil, 35 parts of fumed silica, 8.5 parts of hydrogen-containing silicone oil, 0.07 part of inhibitor, and 0.22 part of catalyst; the ionic liquid is 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (cas: 350493-08-2). The preparation method of the liquid silicone rubber in this comparative example is exactly the same as that of Example 2.

[0082] The liquid silicone rubbers prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were coated on non-woven fabrics using a coater. Then, they were laminated and hot-pressed at 110°C for 120 s for vulcanization molding. The appearance of the obtained adhesive layer was observed, and it was found that all the adhesive layers were transparent. At the same time, surface resistance testing, bond strength testing, antibacterial testing, and anti-oil stain testing were carried out according to the following testing methods, and the test results are shown in Table 1.

[0083] Surface resistance testing: Three base fabrics with a length of 150 mm × 30 mm were taken, and silicone rubber was coated at a mass of 40 mg / cm 2 After hot-pressing and vulcanization molding, it was placed in a constant temperature and humidity environment of 25°C and 50% RH for 3 h, and then the surface resistivity was tested.

[0084] Surface resistance testing after wiping: After being placed in a constant temperature and humidity environment of 25°C and 50% RH for 3 h after hot-pressing and vulcanization molding, the surface of the sample was wiped 3 times with ethyl acetate, and after standing for 1 min, the surface resistivity was directly tested.

[0085] Antibacterial testing: Staphylococcus aureus and Escherichia coli were used, and the antibacterial rate was tested according to the standard of GB / T 20944.3-2008.

[0086] Bond strength testing: Two base fabrics with a length of 150 mm × 30 mm were taken, and silicone rubber was coated at a mass of 40 g / m 2 For the material specimen bonded with liquid glue, manual peeling was carried out to separate the coating of the upper and lower fabrics from the base fabric by 50 mm. Then, the separated two ends were respectively clamped on the fixtures of a tensile testing machine, and peeled at 180° at a speed of 200 mm / min, and the maximum load of specimen peeling was recorded.

[0087] Anti-oil stain testing: The liquid silicone rubber was placed in a 50 mm × 50 mm mold and hot-pressed at 110°C for 120 s for vulcanization molding. After standing at room temperature for 3 h, an oil-based marker pen was used to draw lines on the surface. If the oil-based marker pen could not draw lines, it indicated good anti-oil stain property. If the drawn lines were discontinuous, it indicated general anti-stain property. If clear lines could be drawn, it indicated poor anti-stain performance.

[0088] Table 1 Test Results

[0089]

[0090]

[0091] Comparing Example 2 with Comparative Examples 1-2, it can be seen that after adding the ionic liquid, the surface resistance of the liquid silicone rubber can be significantly reduced and the antibacterial effect can be improved, and at the same time, the antistatic effect of the liquid silicone rubber can be maintained at 10 5 .

[0092] Comparing Example 2 with Comparative Example 1 and Comparative Example 3, it can be seen that after adding hydroxyfluorosilicone oil, the oil-proof effect of the liquid silicone rubber can be significantly improved.

[0093] Comparing Example 2 with Comparative Example 1 and Comparative Example 4, it can be seen that introducing a vinyl-containing coupling agent into the liquid silicone rubber significantly improves the adhesion strength between the liquid silicone rubber and the non-woven fabric and the persistence of the antistatic property of the system.

[0094] Comparing Example 2 with Comparative Example 5, it can be seen that compared with imidazole-based ionic liquids, the selection of hydroxy-functionalized imidazole-based ionic liquids can improve the adhesion strength between the liquid silicone rubber and the non-woven fabric and the persistence of the antistatic property of the system.

[0095] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it is not limited only to the examples listed. Those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a liquid silicone-based adhesive, characterized in that the steps include: (1) adding an ionic liquid, a silane coupling agent, vinyl hydroxy silicone oil, and hydroxy fluorosilicone oil into a reaction kettle and mixing them, stirring and heating them under an inert atmosphere to carry out a condensation reaction, cooling them and then evacuating the mixture to obtain an ionized modified silicone oil; (2) adding white carbon black, vinyl silicone oil, and the ionized modified silicone oil into a kneader, heating and kneading under an inert atmosphere, and then vacuum mixing, cooling and then grinding to obtain a liquid silicone-based rubber; The raw materials for preparation include, by weight, 1 to 10 parts of ionic liquid, 3 to 15 parts of silane coupling agent, 10 to 20 parts of vinyl hydroxy silicone oil, 5 to 20 parts of hydroxy fluorosilicone oil, 40 to 70 parts of vinyl silicone oil, and 20 to 45 parts of white carbon black; the ionic liquid is a hydroxyl functionalized imidazole ionic liquid, and the hydroxyl fluorosilicone oil is a methyltrifluoropropyl polysiloxane terminated with a hydroxyl functional group.

2. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: The ionic liquid comprises at least one of Formula 1 and Formula 2; where Y - Selected from BF4 - PF6 - 、PhSO3 - or [(CF3SO2)2N] - .

3. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: The silane coupling agent is a vinyl silane coupling agent.

4. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: The vinyl hydroxy silicone oil has a viscosity of 20 to 100 mm at 25°C. 2 / s; the molar fraction of hydroxyl groups in the vinyl hydroxy silicone oil is 1 to 7.5%, and the molar fraction of vinyl groups is 2 to 7%.

5. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: The viscosity of the hydroxy fluorosilicone oil at 25° C. is 150 to 500,000 mPa·s.

6. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: The vinyl silicone oil is a vinyl-terminated silicone oil with a viscosity of 2000-23000 CP. The mass fraction of vinyl in the vinyl silicone oil is 0.05-0.3%.

7. The method for preparing a liquid silicone-based adhesive according to claim 1, characterized in that: Step (1) comprises stirring and heating to 90-150° C. and then carrying out a condensation reaction for 3-5 hours; step (2) comprises kneading and heating to 180-190° C. and then carrying out vacuum mixing for 3-6 hours.

8. A liquid silicone rubber, characterized in that: The invention comprises hydrogen-containing silicone oil, an inhibitor, a catalyst and a liquid silicone-based adhesive, wherein the liquid silicone-based adhesive is prepared by the preparation method of the liquid silicone-based adhesive as claimed in any one of claims 1 to 7.

9. The liquid silicone rubber according to claim 8, characterized in that In parts by mass, the hydrogen-containing silicone oil is 0.1 to 15 parts, the inhibitor is 0.006 to 0.1 parts, and the catalyst is 0.02 to 0.7 parts.

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