Organosilicon pressure-sensitive adhesive and lining-free insulating self-adhesive tape formed by same

Abstract

The organic silicon pressure-sensitive adhesive is prepared from the following raw materials: 30 to 50 parts of vinyl silicone oil, 20 to 40 parts of vinyl MQ silicon resin, 1 to 10 parts of modified silicon resin, 0.1 to 5 parts of hydrogen-containing silicone oil, 0.03 to 0.3 part of an inhibitor, 0.03 to 1.0 part of a catalyst and 20 to 50 parts of a diluent, the vinyl silicone oil is vinyl-terminated polydimethylsiloxane, the solid content of the vinyl MQ silicon resin is 30-70%, and the modified silicon resin is acrylic acid modified silicon resin. The organic silicon pressure-sensitive adhesive serves as an adhesive layer and an ethylene propylene rubber base layer to form a lining-free insulating self-adhesive tape, a release film is not needed, a base material cannot be self-melted and can be repaired, meanwhile, the adhesion of the organic silicon pressure-sensitive adhesive layer and the base material is effectively improved, and the problem of degumming is avoided; the high-temperature resistance of the product is effectively improved; and the problem that the joint is easy to tilt during use is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and particularly relates to a silicone pressure-sensitive adhesive for a non-liner insulating self-adhesive tape and a non-liner insulating self-adhesive tape containing the pressure-sensitive adhesive. Background Art

[0002] The non-liner insulating self-adhesive tape has excellent adhesive properties and electrical insulation properties. In the power industry, it can be used as the main insulating adhesive material for solid dielectric insulated cables with various voltages up to 69 kV, the main insulating material for making stress cones on solid dielectric insulated cables with a voltage up to 35 kV, the secondary insulating material for high-voltage joints and terminals, as well as materials for moisture-proof sealing, electrical connection, busbar insulation, terminal tying of high-voltage cables, engine lead-out wires, bushing maintenance, etc. In the automotive industry, this product can be used for insulating wrapping of electrical joints such as automotive engines and various electrical equipment to protect the terminal high-voltage cables from arc attacks and prevent the appearance of tracking. At the same time, in the aerospace industry, this product can be used for insulating wrapping of electrical joints such as sensors and aircraft engines and various electrical equipment.

[0003] Common self-adhesive tape products on the market are covered with a release film to prevent the tapes from self-adhering to each other during storage, making them unusable, and the residual release film after peeling is not friendly to the environment. In addition, in the prior art, acrylic pressure-sensitive adhesives are often used as the release layer for non-liner self-adhesive tapes, which are extremely easy to mutually melt with the substrate itself, affecting the high-temperature resistance performance and operability of the product. Summary of the Invention

[0004] In order to improve the above technical problems, the present invention provides a silicone pressure-sensitive adhesive for a non-liner insulating self-adhesive tape and a non-liner insulating self-adhesive tape containing the pressure-sensitive adhesive. The technical solution of the present invention is as follows:

[0005] A silicone pressure-sensitive adhesive, comprising the following raw materials: 30 - 50 parts of vinyl silicone oil, 20 - 40 parts of vinyl MQ silicone resin, 1 - 10 parts of modified silicone resin, 0.1 - 5 parts of hydrogen-containing silicone oil, 0.03 - 0.3 parts of inhibitor, 0.03 - 1.0 parts of catalyst, and 20 - 50 parts of diluent.

[0006] According to an embodiment of the present invention, it comprises the following raw materials: 35 - 45 parts of vinyl silicone oil, 25 - 35 parts of vinyl MQ silicone resin, 4 - 8 parts of modified silicone resin, 2 - 4 parts of hydrogen-containing silicone oil, 0.08 - 0.13 parts of inhibitor, 0.3 - 0.7 of catalyst, and 35 - 45 parts of diluent.

[0007] According to an embodiment of the present invention, the vinyl silicone oil is a terminal vinyl polydimethylsiloxane, with a viscosity range of 2500 - 15000 mPa·s and a vinyl content of 5% - 10%; preferably, its viscosity range is 2500 - 3500 mPa·s.

[0008] According to an embodiment of the present invention, the vinyl MQ silicone resin has a solid content of 30 - 70%, a viscosity range of 20000 - 60000 mPa·s, and a vinyl content of 0.1% - 2%; preferably, its solid content is 45 - 55%, its viscosity range is 35000 - 45000 mPa·s, and its vinyl content is 1 - 1.5%.

[0009] According to an embodiment of the present invention, the modified silicone resin is an acrylic modified silicone resin, with a solid content of 30 - 70% and a viscosity range of 5000 - 30000 mPa·s; preferably, its viscosity range is 9000 - 11000 mPa·s and its solid content is 45 - 55%.

[0010] According to an embodiment of the present invention, the hydrogen-containing silicone oil is a terminal hydrogen-containing silicone oil, with a hydrogen content of 0.04 - 0.4% and a viscosity of 50 - 300 mPa·s; preferably, its hydrogen content is 0.2 - 0.3% and its viscosity range is 80 - 120 mPa·s.

[0011] According to an embodiment of the present invention, the inhibitor is one or a mixture of more than one of methyl butynol, ethynyl cyclohexanol or phenyl butynol. Specifically, for example, 3 - methyl - 1 - butynol, ethynyl cyclohexanol or 3 - phenyl - 1 - butyn - 3 - ol and / or 2 - phenyl - 1 - butyn - 2 - ol.

[0012] According to an embodiment of the present invention, the catalyst is a platinum - vinyl siloxane complex, wherein the platinum content is 0.2% - 1%.

[0013] According to an embodiment of the present invention, the diluent is one or a mixture of more than one of toluene, xylene and ethyl acetate.

[0014] According to an embodiment of the present invention, the silicone pressure - sensitive adhesive is formed by mixing the above - mentioned raw materials.

[0015] All the contents mentioned in the present invention are in mass percentage.

[0016] According to an embodiment of the present invention, after the raw materials are mixed evenly, they are further filtered.

[0017] The present invention also provides a preparation method of the above - mentioned silicone pressure - sensitive adhesive, which includes the following steps:

[0018] (1) Weigh vinyl silicone oil, vinyl MQ silicone resin, and modified silicone resin by weight parts, mix them evenly to obtain Component A;

[0019] (3) Weigh hydrogen-containing silicone oil and inhibitor by weight parts, mix them evenly to obtain Component B;

[0020] (4) Mix Component A, Component B, catalyst, and diluent evenly, and filter.

[0021] The present invention also provides a non-liner insulating self-adhesive tape, which includes a substrate layer and an adhesive layer, and the adhesive layer is formed by the above-mentioned silicone pressure-sensitive adhesive.

[0022] According to the embodiment of the present invention, the non-liner insulating self-adhesive tape is only composed of the substrate layer and the adhesive layer.

[0023] According to the embodiment of the present invention, the substrate is ethylene-propylene rubber. Any ethylene-propylene rubber known to those skilled in the art can be used for the ethylene-propylene rubber. In one embodiment of the present invention, the ethylene-propylene rubber adopts the formulation in the patent document CN112251154B, for example, the ethylene-propylene rubber base layer disclosed in Examples 1-4 thereof.

[0024] According to the embodiment of the present invention, the thickness of the adhesive layer is 10-50 μm, and the thickness of the substrate layer is 0.5-3 mm.

[0025] The present invention also provides a preparation method of the above-mentioned non-liner insulating self-adhesive tape, which includes the following steps:

[0026] (1) Prepare the substrate layer;

[0027] (2) Prepare the silicone pressure-sensitive adhesive according to the method for preparing the silicone pressure-sensitive adhesive as described above in the present invention;

[0028] (3) Coat the silicone pressure-sensitive adhesive obtained in step (2) on the substrate layer, dry it, cure it at high temperature, and cool and wind it up.

[0029] According to the embodiment of the present invention, the preparation of the substrate layer is carried out according to the scheme disclosed in the patent document CN112251154B. For example, ethylene-propylene rubber, polyisobutylene, stearic acid, and anti-aging agent are kneaded into a masterbatch in a kneader; a plasticizer and a filler are added to the masterbatch for mixing to obtain a uniform rubber compound, and the rubber compound is sheeted and wound up.

[0030] Beneficial effects:

[0031] The silicone pressure-sensitive adhesive provided by the present invention improves the bonding strength between the silicone pressure-sensitive adhesive and the EPDM rubber substrate by selecting a suitable modified silicone resin, eliminating the process of surface treatment for the EPDM rubber substrate. While ensuring product quality, the process is simplified and costs are reduced. By selecting suitable vinyl silicone oil, vinyl MQ silicone resin, and modified silicone resin, and using a blend of high molecular weight vinyl silicone rubber and low molecular weight vinyl silicone oil, the vinyl content is increased, the crosslinking density is increased, and the body strength is increased, so that it will not easily loosen and warp. Moreover, the viscosity is reduced, and the operability is improved. In addition, the dosages of these three components are controlled in this application to ensure that the product has excellent initial tack and holding tack. The addition-type silicone pressure-sensitive adhesive of the present invention is coated on the surface of the EPDM rubber substrate, without a release film, which is convenient and simple to use, environmentally friendly, and greatly improves the high-temperature resistance and reparability of the product, expanding the application field of the EPDM rubber self-adhesive tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 FIG. is a schematic structural diagram of the linerless insulating self-adhesive tape of the present invention.

[0033] Reference numeral 1 is the silicone pressure-sensitive adhesive layer, and reference numeral 2 is the EPDM rubber substrate layer DETAILED DESCRIPTION OF THE INVENTION

[0034] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] Example 1 A linerless insulating self-adhesive tape material was prepared as follows:

[0036] (1) Preparation of the EPDM rubber tape substrate: The formulation and process refer to Example 1 of Patent CN112251154B;

[0037] (2) Preparation of the linerless insulating self-adhesive tape:

[0038] Weigh 40 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 3000 ± 300 mPa·s and a vinyl content of 10%, 30 parts of vinyl-terminated MQ silicone resin with a viscosity of 40000 ± 4000 mPa·s, a vinyl content of 1.3%, and a solid content of 50%, and 5 parts of acrylic acid-modified silicone resin with a viscosity of 10000 ± 1000 mPa·s and a solid content of 50%, and mix them evenly to obtain Component A;

[0039] Weigh 3 parts of hydrogen-containing silicone oil with a viscosity of 100 mPa·s and a hydrogen content of 0.3% and 0.1 part of ethynylcyclohexanol, and mix them evenly to obtain Component B;

[0040] Mix the obtained Component A, Component B, 0.5 part of a platinum-cyclohexenylmethylsiloxane complex with a platinum content of 0.4%, 5.5 parts of xylene, and 34.5 parts of ethyl acetate uniformly, filter, coat it on an ethylene propylene diene monomer (EPDM) rubber substrate, dry it in a drying tunnel, cure it at a high temperature, and then cool and wind it up. The thickness of the adhesive layer is 30 μm.

[0041] Comparative Example 1 A non-lined insulating self-adhesive tape material, and its preparation method is as follows:

[0042] (1) Preparation of the EPDM rubber tape substrate: The formula and process refer to Example 1 of Patent CN112251154B;

[0043] (2) Preparation of the non-lined insulating self-adhesive tape:

[0044] Weigh 40 parts of a vinyl-terminated polydimethylsiloxane with a viscosity of 3000 ± 300 mPa·s and a vinyl content of 10%, and 30 parts of a vinyl-terminated MQ silicone resin with a viscosity of 50000 ± 5000 mPa·s, a vinyl content of 0.8%, and a solid content of 50%, mix them uniformly to obtain Component A;

[0045] Weigh 3 parts of a hydrogen-containing silicone oil with a viscosity of 100 mPa·s and a hydrogen content of 0.3%, and 0.1 part of ethynylcyclohexanol, mix them uniformly to obtain Component B;

[0046] Mix the obtained Component A, Component B, 0.5 part of a platinum-cyclohexenylmethylsiloxane complex with a platinum content of 0.4%, 5 parts of xylene, and 34 parts of ethyl acetate uniformly, filter, coat it on an EPDM rubber substrate, dry it in a drying tunnel, cure it at a high temperature, and then cool and wind it up. The thickness of the adhesive layer is 30 μm.

[0047] Comparative Example 2 A non-lined insulating self-adhesive tape material, and its preparation method is as follows:

[0048] (1) Preparation of the EPDM rubber tape substrate: The formula and process refer to Example 1 of Patent CN112251154B;

[0049] (2) Preparation of the non-lined insulating self-adhesive tape:

[0050] Weigh 50 parts of a vinyl-terminated polydimethylsiloxane with a viscosity of 10000 ± 1000 mPa·s and a vinyl content of 8%, and 5 parts of an acrylic acid-modified silicone resin with a viscosity of 10000 ± 1000 mPa·s and a solid content of 50%, mix them uniformly to obtain Component A;

[0051] Weigh 3 parts of a hydrogen-containing silicone oil with a viscosity of 100 mPa·s and a hydrogen content of 0.3%, and 0.1 part of ethynylcyclohexanol, mix them uniformly to obtain Component B;

[0052] Mix the obtained Component A, Component B, 0.5 part of a platinum-cyclohexenylmethylsiloxane complex with a platinum content of 0.4%, 18.5 parts of xylene, and 31.5 parts of ethyl acetate evenly, filter, coat them on an ethylene propylene diene monomer (EPDM) rubber substrate, dry them in a drying tunnel, cure them at a high temperature, and then cool and wind them up. The thickness of the adhesive layer is 30 μm.

[0053] Comparative Example 3 A non-liner insulating self-adhesive tape material, and its preparation method is as follows:

[0054] (1) Preparation of the EPDM rubber tape substrate: The formulation and process refer to Example 1 of Patent CN112251154B;

[0055] (2) Preparation of the non-liner insulating self-adhesive tape:

[0056] Weigh 40 parts of a vinyl-terminated MQ silicone resin with a viscosity of 30000 ± 3000 mPa·s, a vinyl content of 1.5%, and a solid content of 50%, and 5 parts of an acrylic acid-modified silicone resin with a viscosity of 10000 ± 1000 mPa·s and a solid content of 50%, mix them evenly to obtain Component A;

[0057] Weigh 3 parts of a hydrogen-containing silicone oil with a viscosity of 100 mPa·s and a hydrogen content of 0.3%, and 0.1 part of ethynylcyclohexanol, mix them evenly to obtain Component B;

[0058] Mix the obtained Component A, Component B, 0.5 part of a platinum-cyclohexenylmethylsiloxane complex with a platinum content of 0.4%, 18.5 parts of xylene, and 31.5 parts of ethyl acetate evenly, filter, coat them on an EPDM rubber substrate, dry them in a drying tunnel, cure them at a high temperature, and then cool and wind them up. The thickness of the adhesive layer is 30 μm.

[0059] Test Example

[0060] The performance tests were carried out on the unlined insulating self-adhesive tapes described in Example 1 and Comparative Examples 1-3, and the results are shown in Table 1 below. Among them, (1) Peel strength: Refer to ASTM D1000; (2) High-temperature resistance test method: Cut 3 specimens with a length of 150 mm ± 10 mm from the finished tape roll, stretch them to 200% - 300%, and wrap them around a metal round bar with a diameter of Φ10 ± 0.2 mm in a half-lap manner for a total of three layers. The wrapping length is 50 ± 5 mm, and place them at 130 °C for 168 h; (3) Peelability after high-temperature resistance test method: Cool the sample after high-temperature resistance test and peel it from the outermost joint; (4) Processing self-adhesiveness test method: Cut 3 specimens with a length of 150 mm ± 10 mm from the finished tape roll, stretch them to 200% - 300%, and wrap them around a metal round bar with a diameter of Φ10 ± 0.2 mm in a half-lap manner for a total of three layers. The wrapping length is 50 ± 5 mm, and park them at room temperature for 24 H; (5) Tensile strength: Refer to the test standard GB / T 528-2009; (6) Elongation at break: Refer to the test standard GB / T 528-2009; (7) Volume resistivity: Refer to the test standard GB / T 1410-2006.

[0061] Table 1

[0062]

[0063] From the data in the table, it can be seen that when the silicone pressure-sensitive adhesive is coated on the EPDM rubber substrate, the influence on the tensile strength, elongation at break and volume resistivity of the substrate is small, meeting the product use requirements.

[0064] In Example 1 of CN112251154B, the tape structure consists of a layer of EPDM rubber layer and a layer of release film. From the test data of Example 1 of CN112251154B in Table 1, it can be seen that the EPDM rubber substrate itself has very little adhesion to the steel plate. Its working principle is to use the self-fusion property of the EPDM rubber substrate to play a waterproof protection role. Before use, it needs to be isolated by a release film. When using, remove the release film, stretch it to more than 200% of its own length and wrap it around the steel plate to make the substrate self-fuse, and it cannot be repaired.

[0065] From the test data of Example 1 and Comparative Examples 1-3 of the present invention, it can be seen that the addition of the modified silicone resin can effectively improve the adhesion between the silicone pressure-sensitive adhesive layer and the substrate, avoiding the problem of degumming; at the same time, the combined use of a suitable vinyl silicone oil, vinyl MQ silicone resin and modified silicone resin can effectively improve the high-temperature resistance of the product and the problem of easy warping of the joint during use, and the product of the present invention will not have the problem of substrate self-fusion. Therefore, the self-adhesive tape can be easily peeled off for repair.

[0066] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An organosilicon pressure-sensitive adhesive, comprising the following raw materials: 30-50 parts of vinyl silicone oil, 20-40 parts of vinyl MQ silicone resin, 1-10 parts of modified silicone resin, 0.1-5 parts of hydrogen-containing silicone oil, 0.03-0.3 parts of inhibitor, 0.03-1.0 parts of catalyst, and 20-50 parts of diluent; Preferably, it comprises the following raw materials: 35-45 parts of vinyl silicone oil, 25-35 parts of vinyl MQ silicone resin, 4-8 parts of modified silicone resin, 2-4 parts of hydrogen-containing silicone oil, 0.08-0.13 parts of inhibitor, 0.3-0.7 parts of catalyst, and 35-45 parts of diluent.

2. The organosilicon pressure-sensitive adhesive according to claim 1, wherein the vinyl silicone oil is terminal vinyl polydimethylsiloxane, with a viscosity range of 2500-15000 mPa·s and a vinyl content of 5%-10%; preferably, its viscosity range is 2500-3500 mPa·s; and / or, the vinyl MQ silicone resin has a solid content of 30-70%, a viscosity range of 20000-60000 mPa·s, and a vinyl content of 0.1%-2%; preferably, its solid content is 45-55%, its viscosity range is 35000-45000 mPa·s, and its vinyl content is 1-1.5%; and / or, the modified silicone resin is acrylic-modified silicone resin, with a solid content of 30-70% and a viscosity range of 5000-30000 mPa·s; preferably, its viscosity range is 9000-11000 mPa·s and its solid content is 45-55%; and / or, the hydrogen-containing silicone oil is terminal hydrogen-containing silicone oil, with a hydrogen content of 0.04-0.4% and a viscosity of 50-300 mPa·s; preferably, its hydrogen content is 0.2-0.3% and its viscosity range is 80-120 mPa·s.

3. The organosilicon pressure-sensitive adhesive according to claim 1, wherein the inhibitor is one or a mixture of methyl butynol, ethynyl cyclohexanol, or phenyl butynol. Specifically, for example, 3-methyl-1-butynol, ethynyl cyclohexanol, or 3-phenyl-1-butyn-3-ol and / or 2-phenyl-1-butyn-2-ol; and / or, the catalyst is a platinum-vinyl siloxane complex, wherein the platinum content is 0.2%-1%. and / or, the diluent is one or a mixture of toluene, xylene, and ethyl acetate.

4. The preparation method of the organosilicon pressure-sensitive adhesive according to claim 1, which comprises the following steps: (1) Weigh vinyl silicone oil, vinyl MQ silicone resin, and modified silicone resin by weight parts, mix them evenly to obtain component A; (2) Weigh hydrogen-containing silicone oil and inhibitor by weight parts, mix them evenly to obtain component B; (3) Mix component A, component B, catalyst, and diluent evenly and filter.

5. A non-liner insulating self-adhesive tape, which comprises a base material layer and an adhesive layer, and the adhesive layer is formed by the organosilicon pressure-sensitive adhesive according to claim 1.

6. The non-liner insulating self-adhesive tape according to claim 5, wherein the non-liner insulating self-adhesive tape is only composed of the base material layer and the adhesive layer.

7. The non-liner insulating self-adhesive tape according to claim 5, wherein the substrate layer is an ethylene-propylene rubber substrate layer.

8. The non-liner insulating self-adhesive tape according to claim 5, wherein the thickness of the adhesive layer is 10-50 μm, and the thickness of the substrate layer is 0.5-3 mm.

9. The preparation method of the non-liner insulating self-adhesive tape according to claim 5, which comprises the following steps: (1) Prepare the substrate layer; (2) Prepare the silicone pressure-sensitive adhesive according to the preparation method of the silicone pressure-sensitive adhesive described in claim 4; (3) Coat the silicone pressure-sensitive adhesive obtained in step (2) onto the substrate layer, dry it, cure it at high temperature, and cool and wind it up.

Images