Organic silica gel composition, organic silica gel and preparation method and application thereof

Abstract

The present invention provides an organic silica gel composition, organic silica gel and a preparation method and application thereof. The organic silica gel composition comprises component A and component B; the component A comprises vinyl silicone oil, inorganic filler, polyolefin particles and a catalyst; the component B comprises vinyl silicone oil, hydrogen-containing silicone oil, inorganic filler and polyolefin particles; the mass ratio of component A to component B is 1:(1-4). The organic silica gel composition provided in the present invention has anti-settling performance, and the viscosity is suitable for good spraying construction effect. The organic silica gel prepared therefrom has high breakdown voltage and good mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic silica gel, and in particular relates to an organic silica gel composition, organic silica gel and a preparation method and application thereof. Background Art

[0002] In the power transmission system, exposed power accessories such as transformers, wires, and high-voltage switches have potential risks such as leakage and fire. Usually, a layer of insulating material needs to be covered on their exposed surfaces to improve the safety of power use and transmission. Organic silicone has good weather resistance and curing properties, and has certain application potential in this field.

[0003] Power accessories are difficult to apply due to their irregular shapes. If spraying is used, if the viscosity of the organic silicone preparation liquid is low and the sag performance is poor, multiple applications are often required to achieve the appropriate thickness of the adhesive. If the viscosity or thixotropy of the organic silicone preparation liquid is high, the sag performance is improved, but the bubbles introduced during the spraying process are difficult to discharge, which reduces the insulation performance of the power accessories. In addition, the inorganic fillers added to the organic silicone composition have a large density difference and are prone to sedimentation when left standing for a long time (generally more than 3 months), which leads to uneven density during mixing, and then leads to unstable mechanical and insulation properties of the organic silicone.

[0004] CN116836682A discloses a liquid organic silicon sealant, which comprises vinyl silicone oil, MQ resin solution, hydrogen-containing silicone oil, filler and platinum catalyst; the viscosity of the sealant is 8500-12000 mPa·s, and the molar ratio of silicon hydrogen group to vinyl group is 1-1.4; the filler at least comprises nano calcium carbonate with an oil absorption value of 30-60g / 100g, and the amount of nano calcium carbonate is 15-30% by weight of the sealant; the MQ resin solution is a silicone oil solution of MQ resin, and the amount of the MQ resin is 5-15% by weight of the sealant. The liquid organic silicon sealant prepared by this technical solution can be sprayed and has good hanging property and strength performance, but the breakdown strength is still not high enough, the insulation performance needs to be improved, and the problem of inorganic filler sedimentation cannot be avoided, which affects the construction efficiency and product quality stability.

[0005] CN108795060A discloses a polymer lightweight insulating material for overhead wires and a preparation method thereof, wherein the polymer lightweight insulating material for overhead wires is a two-component curing liquid insulating material, which is composed of component A and component B; wherein component A is composed of vinyl silicone oil, nano-hydrophobic silica, lightweight silicon powder, titanium dioxide, platinum flame retardant catalyst, and inhibitor; component B is composed of hydrogen-containing silicone oil, nano-hydrophobic silica, lightweight silicon powder, and black pigment. The polymer lightweight insulating material for overhead wires provided by this technical solution has the advantages of fast curing speed, good insulation performance, strong adhesion, and long service life, but still cannot avoid the problem of inorganic filler sedimentation, which affects the construction efficiency and product quality stability.

[0006] Therefore, it is necessary to develop an organic silica gel composition with good insulation performance, anti-settling and easy construction. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide an organic silica gel composition, organic silica gel and its preparation method and application. The organic silica gel composition has anti-settling performance, suitable viscosity and good spraying construction effect, and the organic silica gel prepared therefrom has high breakdown voltage and good mechanical properties.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides an organic silicone composition, wherein the organic silicone composition comprises an A component and a B component.

[0010] The component A comprises vinyl silicone oil, inorganic filler, polyolefin particles and a catalyst.

[0011] The B component includes vinyl silicone oil, hydrogen-containing silicone oil, inorganic filler and polyolefin particles.

[0012] The mass ratio of component A to component B is 1: (1-4), for example, 1:1.3, 1:1.6, 1:1.9, 1:2.2, 1:2.5, 1:2.8, 1:3.1, 1:3.3, 1:3.5 or 1:3.8, etc.

[0013] In the present invention, the A component and the B component with specific components are matched, so that the prepared organic silicone composition has the advantages of good anti-settling performance, suitable viscosity and good spraying construction effect, and the organic silicone prepared has a high breakdown voltage and good mechanical properties. The addition of inorganic fillers helps to reduce costs and improve sagging performance. The polyolefin particles have low density and good insulation. The polyolefin particles can be suspended in the organic silicone composition, which plays a role in slowing down the Stokes sedimentation of the inorganic filler, can effectively improve the anti-settling performance of the organic silicone composition, increase the dispersion uniformity of the inorganic filler in components such as vinyl silicone oil and hydrogen-containing silicone oil, and improve the breakdown voltage.

[0014] Preferably, the vinyl content of the vinyl silicone oil in component A and component B is independently 0.08 to 0.37 mmol / g, for example, 0.11 mmol / g, 0.14 mmol / g, 0.17 mmol / g, 0.20 mmol / g, 0.23 mmol / g, 0.26 mmol / g, 0.29 mmol / g, 0.32 mmol / g or 0.35 mmol / g, etc.

[0015] Preferably, the viscosity of the vinyl silicone oil in the component A and the component B at 25° C. is independently 100-2000 cP, such as 300 cP, 600 cP, 900 cP, 1200 cP, 1500 cP or 1800 cP, and more preferably 500-2000 cP.

[0016] Preferably, the inorganic fillers in the component A and the component B independently include any one of silicon micropowder, nano-calcium carbonate, hollow glass microspheres, fumed silica or talc, or a combination of at least two of them.

[0017] Preferably, the polyolefin particles in the A component and the B component independently include any one of ultra-high molecular weight polyethylene microspheres, high-density polyethylene microspheres, linear low-density polyethylene microspheres or polypropylene microspheres, or a combination of at least two thereof.

[0018] In the present invention, the ultra-high molecular weight polyethylene in the ultra-high molecular weight polyethylene microspheres refers to linear polyethylene with a weight average molecular weight of more than 1 million; the high-density polyethylene in the high-density polyethylene microspheres refers to polyethylene with a density of 0.941-0.960 g / cm 3 The linear low-density polyethylene microspheres refer to linear low-density polyethylene with a density of 0.918 to 0.935 g / cm 3 Linear structure polyethylene.

[0019] Preferably, the average particle size of the polyolefin particles in the A component and the B component is independently 1 to 30 μm, for example, 3 μm, 6 μm, 9 μm, 12 μm, 15 μm, 18 μm, 21 μm, 24 μm or 27 μm.

[0020] In the present invention, the average particle size of the polyolefin particles is preferably 1 to 30 μm. If the average particle size of the polyolefin particles is too large, the prepared organic silicone composition has the risk of clogging the spraying equipment, and the surface of the prepared organic silicone is not smooth enough; if the average particle size of the polyolefin particles is too small, the specific surface area of ​​the polyolefin particles increases, and the same addition amount will lead to a significant increase in the viscosity of the organic silicone composition and a sharp increase in the cost of the polyolefin particles.

[0021] Preferably, the catalyst is a catalyst solution.

[0022] Preferably, the catalyst solution consists of dimethyl silicone oil and a platinum catalyst, and the mass percentage concentration of the platinum catalyst in the catalyst solution is 0.5% to 1%, for example, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9% or 0.95%, etc.

[0023] Preferably, the hydrogen-containing silicone oil includes terminal hydrogen-containing silicone oil and cross-linked hydrogen silicone oil.

[0024] Preferably, the hydrogen content of the terminal hydrogenated silicone oil is 0.03wt% to 0.2wt%, for example, 0.05wt%, 0.07wt%, 0.09wt%, 0.11wt%, 0.13wt%, 0.15wt%, 0.17wt% or 0.19wt%.

[0025] Preferably, the hydrogen content of the cross-linked hydrogen silicone oil is 0.1wt%~0.9wt%, for example, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt% or 0.8wt%.

[0026] Preferably, the molar ratio of hydrogen to vinyl (H / Vi value) in the organic silica gel composition is (1.2-1.4):1, for example, 1.22:1, 1.24:1, 1.26:1, 1.28:1, 1.3:1, 1.32:1, 1.34:1, 1.36:1 or 1.38:1, etc.

[0027] In the present invention, the molar ratio of hydrogen to vinyl in the organic silicone composition refers to the ratio of the molar amount of hydrogen in the hydrogen-containing silicone oil in the B component to the sum of the molar amounts of vinyl in the vinyl silicone oil in the A component and the B component.

[0028] Preferably, the A component includes the following components in parts by weight: 40-60 parts (e.g., 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, etc.) of vinyl silicone oil, 30-50 parts (e.g., 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts or 48 parts, etc.) of inorganic filler, 2-20 parts (e.g., 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts or 19 parts, etc.) of polyolefin particles and 0.4-1.5 parts (e.g., 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts or 1.4 parts, etc.) of catalyst.

[0029] Preferably, the B component includes the following components in parts by weight: 40-70 parts of vinyl silicone oil (for example, 43 parts, 46 parts, 49 parts, 52 parts, 55 parts, 58 parts, 61 parts, 64 parts or 67 parts, etc.), 2-8 parts of terminal hydrogen silicone oil (for example, 3 parts, 4 parts, 5 parts, 6 parts or 7 parts, etc.), 1-3 parts of cross-linked hydrogen silicone oil (for example, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.4 parts, 2.6 parts or 2.8 parts, etc.), 30-50 parts of inorganic filler (for example, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts or 48 parts, etc.), and 2-20 parts of polyolefin particles (for example, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts or 19 parts, etc.).

[0030] Preferably, the B component further comprises an inhibitor, but does not comprise O.

[0031] Preferably, the mass content of the inhibitor in the B component is 0-120 ppm, for example, 20 ppm, 40 ppm, 60 ppm, 80 ppm or 100 ppm.

[0032] Preferably, the B component further comprises a pigment.

[0033] Preferably, the weight proportion of the pigment in the B component is 0.1 to 2 parts, for example, 0.3 parts, 0.5 parts, 0.7 parts, 0.9 parts, 1.1 parts, 1.3 parts, 1.5 parts, 1.7 parts or 1.9 parts, etc.

[0034] Preferably, in the component A, based on the total mass of the inorganic filler and the polyolefin particles as 100%, the mass percentage concentration of the polyolefin particles is 5% to 40%, for example, 10%, 15%, 20%, 25%, 30% or 35%.

[0035] Preferably, in the B component, based on the total mass of the inorganic filler and the polyolefin particles as 100%, the mass percentage concentration of the polyolefin particles is 5% to 40%, for example, 10%, 15%, 20%, 25%, 30% or 35%.

[0036] In a second aspect, the present invention provides an organic silica gel, wherein the organic silica gel is prepared using the organic silica gel composition described in the first aspect.

[0037] In a third aspect, the present invention provides a method for preparing the organic silica gel as described in the second aspect, the preparation method comprising the following steps:

[0038] (1) mixing vinyl silicone oil, inorganic filler, polyolefin particles and catalyst to obtain component A;

[0039] (2) mixing vinyl silicone oil, hydrogen-containing silicone oil, inorganic filler and polyolefin particles to obtain component B;

[0040] (3) mixing the component A obtained in step (1) and the component B obtained in step (2), and curing them to obtain the organic silica gel;

[0041] Wherein, step (1) and step (2) are performed in no particular order, or are performed simultaneously.

[0042] Preferably, the mixing in step (1) and step (2) independently comprises a first stirring mixing, a vacuuming and a second stirring mixing performed in sequence.

[0043] Preferably, the rotation speed of the first stirring and mixing is 100-200 rpm (for example, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm or 190 rpm, etc.), and the stirring time is 10-30 min (for example, 13 min, 16 min, 19 min, 22 min, 25 min or 28 min, etc.).

[0044] Preferably, the rotation speed of the second stirring and mixing is 150-300 rpm (for example, 170 rpm, 190 rpm, 210 rpm, 230 rpm, 250 rpm, 270 rpm or 290 rpm, etc.), and the stirring time is 30-60 min (for example, 33 min, 36 min, 39 min, 42 min, 45 min, 48 min, 51 min, 54 min or 57 min, etc.).

[0045] Preferably, the curing in step (3) includes heating curing or room temperature curing.

[0046] Preferably, the heating and curing temperature is 75-85°C, for example, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C or 84°C.

[0047] Preferably, the complete curing time of the heating curing is 30 to 60 min, for example, 33 min, 36 min, 39 min, 42 min, 45 min, 48 min, 51 min, 54 min or 57 min.

[0048] Preferably, the curing temperature of the room temperature curing is 20-40°C, for example, 22°C, 24°C, 26°C, 28°C, 30°C, 32°C, 34°C, 36°C or 38°C.

[0049] Preferably, the surface drying time of the room temperature curing is 15 to 20 min, for example, 15.5 min, 16 min, 16.5 min, 17 min, 17.5 min, 18 min, 18.5 min, 19 min or 19.5 min.

[0050] In a fourth aspect, the present invention provides a use of the organic silicone composition as described in the first aspect or the organic silicone as described in the second aspect in an insulating coating material for power accessories.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] In the present invention, by using component A and component B with specific components, the prepared organic silicone composition has the advantages of good anti-settling performance, suitable viscosity and good spraying construction effect, and the organic silicone prepared has a high breakdown voltage and good mechanical properties. The organic silicone has a breakdown voltage of ≥18.6 kV / mm, a tensile strength of ≥1.65 MPa, and an elongation at break of ≥128.6%. Preferably, the breakdown voltage is ≥19.0 kV / mm, the tensile strength is ≥1.80MPa, and the elongation at break is ≥130%. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0054] The sources of some raw materials in the following examples and comparative examples are as follows.

[0055] (1) Vinyl silicone oil:

[0056] The first vinyl silicone oil, brand name AB 1000Vi, viscosity at 25°C is 1000cp, vinyl content is 0.11mmol / g, manufacturer is Anbiya Special Silicone Co., Ltd.;

[0057] The second vinyl silicone oil has a brand name of AB 500Vi, a viscosity of 500 cp at 25°C, a vinyl content of 0.15 mmol / g, and is manufactured by Anbia Special Silicone Co., Ltd.

[0058] (2) Inorganic fillers:

[0059] Silica powder, brand B03-12, manufactured by Lianyungang Huawei Silica Powder Co., Ltd.

[0060] Nano calcium carbonate, brand name is Tianshichou, manufacturer is Zhejiang Tianshi Nano Technology Co., Ltd.;

[0061] Fumed silica, brand TS720, manufactured by Cabot;

[0062] Hollow glass microspheres, brand HS60, manufactured by Zhengzhou Shenglait Hollow Microsphere New Materials Co., Ltd.

[0063] (3) Catalyst solution, composed of 50cs dimethyl silicone oil and platinum catalyst, the mass percentage concentration of the platinum catalyst is 0.5%, and the manufacturer is Anbia Special Silicone Co., Ltd.

[0064] (4) Polyolefin particles:

[0065] Polyolefin particles a, brand name XM-220, average particle size 30 μm, manufacturer Mitsui Chemicals;

[0066] Polyolefin particles b, brand PM-200, average particle size 10 μm, manufactured by Mitsui Chemicals;

[0067] Polyolefin particles c, brand XM-330, average particle size 65 μm, manufactured by Mitsui Chemicals.

[0068] (5) End-hydrogenated silicone oil, brand DH07, hydrogen content 0.065wt%, manufacturer: Zhejiang Runhe Organic Silicone New Materials Co., Ltd.

[0069] (6) Cross-linked hydrogen silicone oil, brand name RH-LHC-3, hydrogen content 0.8 wt%, manufacturer: Zhejiang Runhe Silicone New Materials Co., Ltd.

[0070] (7) Pigment: Carbon black, manufactured by Shanghai Jiasheng New Materials Co., Ltd.

[0071] (8) Inhibitor, brand name MVC, manufacturer: Anbia Special Silicone Co., Ltd.

[0072] Example 1

[0073] This embodiment provides an organic silica gel composition and organic silica gel, wherein the organic silica gel composition comprises component A and component B in a mass ratio of 1:1;

[0074] The component A comprises the following components by weight: 52.5 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 41 parts of silicon powder (B03-12), 2 parts of nano calcium carbonate (Tianshichou), 4 parts of polyolefin particles (polyolefin particles a, XM-220) and 0.8 parts of catalyst solution (composed of 50cs dimethyl silicone oil and platinum catalyst, with a mass percentage concentration of the platinum catalyst of 0.5%);

[0075] The B component includes the following components in parts by weight: 45 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 6 parts of end-hydrogen silicone oil (DH07), 1.3 parts of cross-linked hydrogen silicone oil (RH-LHC-3), 39 parts of silicon micropowder (B03-12), 4 parts of nano calcium carbonate (Tianshichou), 4 parts of polyolefin particles (polyolefin particles b, PM-200), 1 part of pigment (carbon black) and an inhibitor (MVC), and the mass content of the inhibitor in the B component is 10 ppm.

[0076] The preparation method of the organic silica gel is as follows:

[0077] (1) Vinyl silicone oil, silicon powder, nano calcium carbonate, polyolefin particles and catalyst solution were added into a reactor according to the stoichiometric ratio, mixed for 10 min at a stirring speed of 120 rpm, the powder on the stirring paddle and the reactor wall was cleaned with a scraper, vacuum was drawn, and then the mixture was continued to be mixed for 60 min at a stirring speed of 200 rpm to obtain component A;

[0078] (2) Vinyl silicone oil, end-hydrogen silicone oil, cross-linked hydrogen silicone oil, silicon powder, nano calcium carbonate, polyolefin particles, pigment and inhibitor were added into the reactor according to the stoichiometric ratio, mixed for 10 min at a stirring speed of 120 rpm, and the powder on the stirring paddle and the reactor wall was cleaned with a scraper. Finally, after vacuuming, the mixture was mixed for 60 min at a stirring speed of 200 rpm to obtain component B;

[0079] (3) Component A obtained in step (1) and component B obtained in step (2) were mixed in a mass ratio of 1:1, and heated in an oven at 80° C. for 30 min for curing to obtain the organic silica gel.

[0080] Example 2

[0081] This embodiment provides an organic silica gel composition and organic silica gel, wherein the organic silica gel composition comprises component A and component B in a mass ratio of 1:2;

[0082] The component A comprises the following components by weight: 48.6 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 44.3 parts of silicon powder (B03-12), 2 parts of nano calcium carbonate (Tianshichou), 5 parts of polyolefin particles (polyolefin particles a, XM-220) and 0.8 parts of catalyst solution (composed of 50cs dimethyl silicone oil and platinum catalyst, with a mass percentage concentration of the platinum catalyst of 0.5%);

[0083] The B component includes the following components in parts by weight: 40 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 2.5 parts of terminal hydrogen silicone oil (DH07), 1 part of cross-linked hydrogen silicone oil (RH-LHC-3), 42.3 parts of silicon micropowder (B03-12), 4 parts of nano calcium carbonate (Tianshichou) and 5 parts of polyolefin particles (polyolefin particles b, PM-200).

[0084] The preparation method of the organic silica gel is as follows:

[0085] (1) Vinyl silicone oil, silicon powder, nano calcium carbonate, polyolefin particles and catalyst solution were added into a reactor according to the stoichiometric ratio, mixed for 30 min under stirring conditions at a speed of 100 rpm, the powder on the stirring paddle and the reactor wall was cleaned with a scraper, vacuum was drawn, and then the mixture was continued to be mixed for 30 min under stirring conditions at a speed of 300 rpm to obtain component A;

[0086] (2) Vinyl silicone oil, end-hydrogen silicone oil, cross-linked hydrogen silicone oil, silicon powder, nano calcium carbonate and polyolefin particles were added into a reactor according to the stoichiometric ratio, mixed at a stirring speed of 100 rpm for 30 min, and the powder on the stirring paddle and the reactor wall was cleaned with a scraper. Finally, after vacuuming, the mixture was continued to be mixed at a stirring speed of 300 rpm for 30 min to obtain component B;

[0087] (3) Component A obtained in step (1) and component B obtained in step (2) were mixed in a mass ratio of 1:1, and heated in an oven at 80° C. for 30 min for curing to obtain the organic silica gel.

[0088] Example 3

[0089] This embodiment provides an organic silica gel composition and organic silica gel, wherein the organic silica gel composition comprises component A and component B in a mass ratio of 1:4;

[0090] The component A comprises the following components by weight: 60 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 34.1 parts of silicon powder (B03-12), 1 part of nano calcium carbonate (Tianshichou), 4 parts of polyolefin particles (polyolefin particles a, XM-220) and 1.5 parts of catalyst solution (composed of 50cs dimethyl silicone oil and platinum catalyst, with a mass percentage concentration of the platinum catalyst of 0.5%);

[0091] The B component includes the following components in parts by weight: 58 parts of vinyl silicone oil (first vinyl silicone oil, AB1000Vi), 2 parts of end-hydrogen silicone oil (DH07), 1.2 parts of cross-linked hydrogen silicone oil (RH-LHC-3), 30.3 parts of silicon micropowder (B03-12), 1 part of nano calcium carbonate (Tianshichou), 4 parts of polyolefin particles (polyolefin particles b, PM-200), 2 parts of pigment (carbon black) and an inhibitor (MVC), and the mass content of the inhibitor in the B component is 15 ppm.

[0092] The preparation method of the organic silica gel is as follows:

[0093] (1) Vinyl silicone oil, silicon powder, nano calcium carbonate, polyolefin particles and catalyst solution were added into a reactor according to the stoichiometric ratio, mixed for 20 min under stirring conditions at a speed of 200 rpm, the powder on the stirring paddle and the reactor wall was cleaned with a scraper, vacuum was drawn, and then the mixture was continued to be mixed for 40 min under stirring conditions at a speed of 150 rpm to obtain component A;

[0094] (2) Vinyl silicone oil, end-hydrogen silicone oil, cross-linked hydrogen silicone oil, silicon powder, nano calcium carbonate, polyolefin particles, pigment and inhibitor were added into a reactor according to the stoichiometric ratio, mixed for 20 min at a stirring speed of 200 rpm, and the powder on the stirring paddle and the reactor wall was cleaned with a scraper. Finally, after vacuuming, the mixture was mixed for 40 min at a stirring speed of 150 rpm to obtain component B;

[0095] (3) Component A obtained in step (1) and component B obtained in step (2) were mixed in a mass ratio of 1:1, and heated in an oven at 80° C. for 30 min for curing to obtain the organic silica gel.

[0096] Example 4

[0097] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component A is adjusted to 2 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are increased proportionally, with a total increase of 2 parts by weight; the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component B is adjusted to 2 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are increased proportionally, with a total increase of 2 parts by weight, and other conditions are the same as in Embodiment 1.

[0098] Example 5

[0099] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component A is adjusted to 10 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 6 parts by weight; the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component B is adjusted to 10 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 6 parts by weight, and other conditions are the same as in Embodiment 1.

[0100] Example 6

[0101] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component A is adjusted to 15 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 11 parts by weight; the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component B is adjusted to 15 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 11 parts by weight, and other conditions are the same as in Embodiment 1.

[0102] Example 7

[0103] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component A is adjusted to 20 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 16 parts by weight; the weight fraction of polyolefin particles (polyolefin particles a, XM-220) in component B is adjusted to 20 parts, and the weight fractions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) are reduced proportionally, a total reduction of 16 parts by weight, and other conditions are the same as in Embodiment 1.

[0104] Example 8

[0105] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the polyolefin particles (polyolefin particles a, XM-220) are replaced with polyolefin particles of the same mass (polyolefin particles c, XM-330), and other conditions are the same as those in Embodiment 1.

[0106] Example 9

[0107] This embodiment provides an organic silicone composition and an organic silicone, which differ from Embodiment 1 only in that the vinyl silicone oil (first vinyl silicone oil, AB 1000Vi) in component A and component B is replaced with a vinyl silicone oil (second vinyl silicone oil, AB 500Vi) of the same mass; at the same time, in order to ensure the same H / Vi value, the mid-range hydrogen silicone oil (DH07) in component B is adjusted to 5.3 parts and the cross-linked hydrogen silicone oil (RH-LHC-3) is adjusted to 2 parts, and other conditions are the same as in Embodiment 1.

[0108] Example 10

[0109] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the nano calcium carbonate (Tianshichou) in component A is replaced by the same mass of fumed silica (TS720), and the nano calcium carbonate (Tianshichou) in component B is replaced by the same mass of fumed silica (TS720), and other conditions are the same as those in Embodiment 1.

[0110] Embodiment 11

[0111] This embodiment provides an organic silica gel composition and an organic silica gel, which differ from Embodiment 1 only in that the nano calcium carbonate (Tianshichou) in component A is replaced by hollow glass microspheres (HS60) of the same mass, and the nano calcium carbonate (Tianshichou) in component B is replaced by hollow glass microspheres (HS60) of the same mass, and other conditions are the same as those in Embodiment 1.

[0112] Comparative Example 1

[0113] This comparative example provides an organic silica gel composition and an organic silica gel, which differ from Example 1 only in that no polyolefin particles are added to component A and component B, the weight portions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) in component A are increased proportionally, and a total increase of 4 weight portions; the weight portions of silicon micropowder (B03-12) and nano-calcium carbonate (Tianshichou) in component B are increased proportionally, and a total increase of 4 weight portions, and other conditions are the same as in Example 1.

[0114] Comparative Example 2

[0115] This comparative example provides an organic silica gel composition and an organic silica gel, which differ from Example 1 only in that the polyolefin particles (polyolefin particles a, XM-220) in component A are replaced with the same mass of fumed silica (TS720); the polyolefin particles (polyolefin particles b, PM-200) in component B are replaced with the same mass of fumed silica (TS720), and other conditions are the same as in Example 1.

[0116] Comparative Example 3

[0117] This comparative example provides an organic silica gel composition and an organic silica gel, which differ from Example 1 only in that the polyolefin particles (polyolefin particles a, XM-220) in component A are replaced with hollow glass microspheres (HS60) of the same mass; the polyolefin particles (polyolefin particles b, PM-200) in component B are replaced with hollow glass microspheres (HS60) of the same mass, and other conditions are the same as in Example 1.

[0118] The organic silica gel provided in the above-mentioned Examples 1 to 11 and Comparative Examples 1 to 3 was tested as follows:

[0119] (1) Hardness: Measured in accordance with GB / T 531.1-2008.

[0120] (2) Tensile strength and elongation at break: measured in accordance with GB / T 528-2009.

[0121] (3) Breakdown voltage: measured in accordance with GB / T 1695-2005.

[0122] The organic silica gel compositions provided in the above-mentioned Examples 1 to 11 and Comparative Examples 1 to 3 were tested as follows:

[0123] (1) Powder sedimentation assessment: After testing the initial viscosity of component A and component B of the silicone composition, store them in sealed bottles and let them stand for 3 months. Re-test the viscosity of component A and component B. If the absolute value of the viscosity change rate is less than 15%, it can be considered that there is basically no sedimentation; if the absolute value of the viscosity change rate is 15%≤≤35%, there is slight sedimentation; if the absolute value of the viscosity change rate is greater than 35%, there is severe sedimentation.

[0124] (2) Evaluation of spraying effect: After mixing component A and component B of the organic silicone composition, immediately scoop up the mixture with a spatula and turn it upside down until the mixture stops flowing. At this time, if the thickness of the mixture hanging on the spatula is 1-2 mm, the sag performance is good and the sizing efficiency is high during spraying. The bubble discharge rate is moderate and will not reduce the insulation performance. It is evaluated as "excellent". If the thickness of the mixture hanging on the spatula is less than 1 mm, the construction efficiency is low and the mixture is easy to flow and drip, causing waste. It is evaluated as "good". If the thickness of the mixture hanging on the spatula is greater than 2 mm, the bubbles are not easy to be discharged, which will reduce the insulation performance. At the same time, the viscosity is large and it is difficult to apply the glue. It is evaluated as "poor".

[0125] The test results are shown in Table 1 below:

[0126] Table 1

[0127]

[0128] It can be seen from the content of Table 1 that the organic silica gel provided in Examples 1-11 has a breakdown voltage of ≥18.6 kV / mm, a tensile strength of ≥1.65 MPa, and an elongation at break of ≥128.6%.

[0129] Compared with Example 1 and Examples 4 to 7, as the content of polyolefin particles increases, the breakdown voltage and mechanical properties of the prepared organic silica gel first increase and then decrease. If the content of polyolefin particles is low, the breakdown voltage and mechanical properties are low; if the content of polyolefin particles is high, the breakdown voltage is also low. This is because the density of polyolefin particles is lower than that of silicon powder. At the same mass ratio, the filling volume of polyolefin particles is larger, resulting in an increase in the "liquid / solid" interface of the organic silica gel composition system, which is not conducive to improving the insulation properties of organic silica gel. It can be seen that by controlling the total mass of inorganic fillers and polyolefin particles in component A to 100%, the mass of polyolefin particles is 5% to 40%; in component B, the total mass of inorganic fillers and polyolefin particles is 100%, the mass of polyolefin particles is 5% to 40%, and the prepared organic silica gel has better performance.

[0130] Compared with Example 1, if the polyolefin particles a (XM-220) in component A are replaced with polyolefin particles c (XM-330) (Example 8), the breakdown voltage and elongation at break are significantly reduced. This is because the average particle size of the polyolefin particles is too large and the specific surface area is reduced, resulting in poor interface bonding and compatibility between the polyolefin particles and other components. It can be seen that better performance of organic silica gel can be prepared by controlling the average particle size of the polyolefin particles within a specific range.

[0131] Compared with Example 1, if polyolefin particles are not added (Comparative Example 1), both component A and component B of the organic silicone composition are severely precipitated, and the tensile strength and breakdown voltage of the prepared organic silicone are reduced.

[0132] Compared with Example 1, if the polyolefin particles are replaced with fumed silica (TS720) (Comparative Example 2), although components A and B of the organic silicone composition are slightly precipitated, the breakdown voltage of the prepared organic silicone is significantly reduced. This is because fumed silica, as a thixotropic agent, can increase the viscosity of the organic silicone composition in a static state, thereby slowing down the powder sedimentation rate. However, during the spraying construction process, a large number of bubbles are difficult to escape, resulting in an increase in internal defects of the organic silicone formed by curing, a decrease in the actual thickness of the adhesive layer, and a decrease in the breakdown voltage.

[0133] Compared with Example 1, if the polyolefin particles are replaced with hollow glass microspheres (HS60) (Comparative Example 3), both component A and component B of the organic silica gel composition are severely precipitated, and the breakdown voltage of the prepared organic silica gel is significantly reduced. This is because the hollow glass microspheres have low density, general insulation properties, and a large density difference with components such as vinyl silicone oil, hydrogenated silicone oil, and nano-calcium carbonate, which easily causes stratification.

[0134] In summary, the organic silica gel composition of the present invention has good anti-settling performance, and the organic silica gel prepared by combining component A and component B with specific components has a high breakdown voltage and good mechanical properties.

[0135] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate an organic silica gel composition, organic silica gel and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic silica gel composition, characterized in that: The organic silica gel composition comprises component A and component B; The component A comprises vinyl silicone oil, inorganic filler, polyolefin particles and a catalyst; The B component includes vinyl silicone oil, hydrogen-containing silicone oil, inorganic filler and polyolefin particles; The mass ratio of component A to component B is 1:(1-4); In the component A, the mass percentage concentration of the polyolefin particles is 15% to 40%, based on the total mass of the inorganic filler and the polyolefin particles being 100%; In the B component, the mass percentage concentration of the polyolefin particles is 15% to 40%, based on the total mass of the inorganic filler and the polyolefin particles being 100%; The average particle size of the polyolefin particles in the A component and the B component is independently 1 to 30 μm.

2. The organic silica gel composition according to claim 1, characterized in that: The vinyl content of the vinyl silicone oil in the A component and the B component is independently 0.08 to 0.37 mmol / g; The viscosity of the vinyl silicone oil in the A component and the B component at 25° C. is independently 100 to 2000 cP; The inorganic fillers in the A component and the B component independently include any one of silicon powder, nano calcium carbonate, hollow glass microspheres, fumed silica or talc, or a combination of at least two thereof; The polyolefin particles in the A component and the B component independently include any one of ultra-high molecular weight polyethylene microspheres, high-density polyethylene microspheres, linear low-density polyethylene microspheres or polypropylene microspheres, or a combination of at least two thereof.

3. The organic silica gel composition according to claim 1, characterized in that: The catalyst is a catalyst solution; The catalyst solution is composed of dimethyl silicone oil and a platinum catalyst, and the mass percentage concentration of the platinum catalyst in the catalyst solution is 0.5% to 1%; The hydrogen-containing silicone oil includes terminal hydrogen-containing silicone oil and cross-linked hydrogen silicone oil; The hydrogen content of the hydrogen-terminated silicone oil is 0.03 wt% to 0.2 wt%; The hydrogen content of the cross-linked hydrogen silicone oil is 0.1 wt% to 0.9 wt%.

4. The organic silica gel composition according to claim 1, characterized in that: The component A comprises the following components by weight: 40-60 parts of vinyl silicone oil, 30-50 parts of inorganic filler, 2-20 parts of polyolefin particles and 0.4-1.5 parts of catalyst; The component B comprises the following components by weight: 40-70 parts of vinyl silicone oil, 2-8 parts of terminal hydrogen silicone oil, 1-3 parts of cross-linked hydrogen silicone oil, 30-50 parts of inorganic filler, and 2-20 parts of polyolefin particles.

5. The organic silica gel composition according to claim 1, characterized in that: The B component also includes an inhibitor; The mass content of the inhibitor in the B component is 0 to 120 ppm, but excluding 0; The B component also includes a pigment; The weight proportion of the pigment in the B component is 0.1 to 2 parts.

6. An organic silica gel, characterized in that: The organic silica gel is prepared using the organic silica gel composition according to any one of claims 1 to 5.

7. A method for preparing organic silica gel as claimed in claim 6, characterized in that: The preparation method comprises the following steps: (1) mixing vinyl silicone oil, inorganic filler, polyolefin particles and catalyst to obtain component A; (2) mixing vinyl silicone oil, hydrogen-containing silicone oil, inorganic filler and polyolefin particles to obtain component B; (3) mixing the component A obtained in step (1) and the component B obtained in step (2), and curing them to obtain the organic silica gel; Wherein, step (1) and step (2) are performed in no particular order, or are performed simultaneously.

8. The preparation method according to claim 7, characterized in that: The mixing in step (1) and step (2) independently comprises a first stirring and mixing, a vacuuming and a second stirring and mixing performed in sequence; The first stirring and mixing has a rotation speed of 100-200 rpm and a stirring time of 10-30 min; The second stirring and mixing has a rotation speed of 150-300 rpm and a stirring time of 30-60 min.

9. Use of the organic silica gel composition according to any one of claims 1 to 5 or the organic silica gel according to claim 6 in insulating coating materials for power accessories.

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