Silicone rubber cold shrink tube with high expansion rate

Abstract

The invention relates to the technical field of chemical materials, and provides a high expansion rate silicone rubber cold shrink tube, which comprises the following raw materials by weight: 100 parts of organopolysiloxane, 30-40 parts of a reinforcing filler, 0.5-1.5 parts of an antioxidant, 1-3 parts of a vulcanizing agent, 5-10 parts of a plasticizer, 0.5-1.5 parts of a light stabilizer, and 1-2 parts of an anti-aging agent. The organopolysiloxane consists of methyl MQ silicon resin and vinyl MQ silicon resin, and the mass ratio of the methyl MQ silicon resin to the vinyl MQ silicon resin is (1: 10)-(10: 1). According to the technical scheme, the problems of low expansion rate and low tearing strength of the silicone rubber cold shrink tube in the related technology are solved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical materials, and in particular to a high expansion ratio silicone rubber cold shrink tube. Background Art

[0002] Silicone rubber cold shrink tube is a tubular product made of silicone rubber material. It uses the elasticity of silicone rubber to expand and cover the support core in advance during production. When installing, the support core is pulled out, and the cold shrink tube will shrink by its own elasticity and tightly wrap around the surface of the protected object (such as cables, wires, etc.), playing the role of insulation, sealing, waterproofing, and corrosion prevention. Although silicone rubber has good elasticity, the cold shrink tube may be deformed or cracked when subjected to large external impact or long-term extrusion, affecting its protection function; some cold shrink tubes also have the problem of low expansion ratio. During the installation process, they cannot be smoothly covered on thicker cables or irregularly shaped objects. They require large external force to stretch, which can easily cause the cold shrink tube to rupture or damage, increasing the difficulty and cost of installation. Cold shrink tubes with low expansion ratios cannot provide good wrapping effects, thereby reducing insulation and protection performance. Therefore, the development of a silicone rubber cold shrink tube with high expansion ratio and tear strength has broad application prospects. Summary of the invention

[0003] The invention provides a silicone rubber cold shrink tube with a high expansion ratio, which solves the problems of low expansion ratio and low tear strength of the silicone rubber cold shrink tube in the related art.

[0004] The technical scheme of the present invention is as follows: The present invention provides a high expansion ratio silicone rubber cold shrink tube, comprising the following component raw materials in parts by weight: 100 parts of organic polysiloxane, 30-40 parts of reinforcing filler, 0.5-1.5 parts of antioxidant, 1-3 parts of vulcanizer, 5-10 parts of plasticizer, 0.5-1.5 parts of light stabilizer, and 1-2 parts of antioxidant; The organopolysiloxane is composed of methyl MQ silicone resin and vinyl MQ silicone resin, and the mass ratio of the methyl MQ silicone resin to the vinyl MQ silicone resin is 1:10-10:1.

[0005] As a further technical solution, the mass ratio of the methyl MQ silicone resin to the vinyl MQ silicone resin is 3:2~3.

[0006] As a further technical solution, the raw material further comprises 10 to 20 parts of a functional filler, wherein the functional filler comprises one or both of hollow glass microspheres and ceramic microspheres. When the functional filler is hollow glass microspheres, the true density of the hollow glass microspheres is 0.38 to 0.46 g / cm 3 .

[0007] In the present invention, hollow glass microspheres with different true densities are added as functional fillers. Through the deformation of the hollow glass microspheres themselves and the interaction with the matrix, the stress distribution is made more uniform, so that the cold shrink tube can withstand greater tensile deformation, which helps to enhance the tear strength of the cold shrink tube and improve the expansion ratio of the cold shrink tube.

[0008] As a further technical solution, the reinforcing filler includes one or more of carbon black, calcium carbonate, and mica powder.

[0009] As a further technical solution, when the reinforcing filler is carbon black, the carbon black is modified carbon black, and the modifier of the modified carbon black is an aminophenyl urea compound.

[0010] In the present invention, aminophenylurea compounds are used to modify carbon black, which optimizes the surface properties of carbon black, strengthens the π-π stacking force between the modified carbon black and vinyl MQ silicone resin, enhances the bonding force between the modified carbon black and silicone resin, and improves the expansion ratio of the cold shrink tube.

[0011] As a further technical solution, the preparation method of the modified carbon black comprises the following steps: dissolving an aminophenyl urea compound in a solvent, adding the pretreated carbon black, heating and stirring to react, and filtering and drying to obtain the modified carbon black.

[0012] As a further technical solution, the mass ratio of the modifier to the carbon black is 1~2:20.

[0013] As a further technical solution, the aminophenyl urea compound includes one or more of 1-(4-aminophenyl)-3-naphthalene-1-urea, 4-phenylaminourea, and diphenylaminourea.

[0014] As a further technical solution, the aminophenylurea compounds have different numbers of benzene rings.

[0015] As a further technical solution, the number of benzene rings in the aminophenylurea compound is 1 to 3.

[0016] As a further technical solution, the aminophenyl urea compound is preferably diphenylamino urea.

[0017] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0018] As a further technical solution, the vulcanizing agent includes one or more of benzoyl peroxide, dicumyl peroxide, and tert-butyl perbenzoate.

[0019] As a further technical solution, at least one of the following technical features is also included: The plasticizer includes one or both of dimethyl silicone oil and methylphenyl silicone oil; The light stabilizer includes one or more of UV-531, UV-327, and UV-9; The antioxidant includes one or two of antioxidant ODA and antioxidant 4010NA.

[0020] The present invention also provides a method for preparing a high expansion ratio silicone rubber cold shrink tube, comprising the following steps: S1, weighing organopolysiloxane, reinforcing filler, antioxidant, plasticizer, light stabilizer, and antioxidant, kneading, heating, evacuating, adding vulcanizing agent, mixing and cutting to obtain silicone rubber masterbatch; S2. After the silicone rubber masterbatch is extruded, passed through a drying tunnel, and cooled, an insulating and sealed cold shrink tube is obtained.

[0021] As a further technical solution, the kneading time is 1 to 3 hours, the heating temperature is 100 to 120°C, the vacuuming time is 1 to 2 hours, the vacuum degree is -0.09 to -0.1 MPa, the mixing time is 10 to 20 minutes, the extrusion temperature is 150 to 180°C, the drying tunnel temperature is 120 to 180°C, and the drying tunnel time is 10 to 30 minutes.

[0022] The working principle and beneficial effects of the present invention are: In the present invention, methyl MQ silicone resin and vinyl MQ silicone resin are added as raw materials, and their ratio is limited to exert their synergistic effect, adjust the flexibility, crosslinking density and reaction activity of the molecular chain, enhance the tear strength of the cold shrink tube, and improve the expansion ratio of the cold shrink tube. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the following examples and comparative examples: Methyl MQ silicone resin: model SK-MVR-810, manufacturer Shenzhen Tianqi New Material Technology Co., Ltd.; Vinyl MQ silicone resin: model is SK-VR-715, manufacturer is Shenzhen Tianqi New Materials Technology Co., Ltd.

[0025] Example 1 A method for preparing a high expansion ratio silicone rubber cold shrink tube comprises the following steps: S1. Weigh 100 parts of organopolysiloxane, 30 parts of carbon black, 0.5 parts of antioxidant 1010, 5 parts of dimethyl silicone oil, 0.5 parts of UV-531, and 1 part of antioxidant ODA, knead for 1 hour, heat to 120°C for vacuuming, the vacuum degree is -0.09 MPa, the vacuuming time is 1 hour, add 1 part of benzoyl peroxide, mix for 10 minutes, and cut to obtain a silicone rubber masterbatch, wherein 100 parts of organopolysiloxane are composed of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:1; S2. Put the silicone rubber masterbatch into the extruder at an extrusion temperature of 150°C. After extrusion molding, pass through a drying tunnel for 30 minutes at a drying tunnel temperature of 120°C. After cooling, a high expansion ratio silicone rubber cold shrink tube is obtained.

[0026] Example 2 A method for preparing a high expansion ratio silicone rubber cold shrink tube comprises the following steps: S1, weighing 100 parts of organopolysiloxane, 35 parts of carbon black, 1 part of antioxidant 168, 8 parts of dimethyl silicone oil, 1 part of UV-327, and 1.5 parts of antioxidant ODA, kneading for 2 hours, heating to 110°C for vacuuming, the vacuum degree is -0.095MPa, the vacuuming time is 1.5 hours, adding 2 parts of diisopropylbenzene peroxide, mixing for 15 minutes, and cutting to obtain a silicone rubber masterbatch, wherein 100 parts of the organopolysiloxane is composed of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:1; S2. Put the silicone rubber masterbatch into the extruder at an extrusion temperature of 165°C. After extrusion molding, pass through a drying tunnel for 20 minutes at a drying tunnel temperature of 150°C. After cooling, a high expansion ratio silicone rubber cold shrink tube is obtained.

[0027] Example 3 A method for preparing a high expansion ratio silicone rubber cold shrink tube comprises the following steps: S1. Weigh 100 parts of organopolysiloxane, 40 parts of carbon black, 1.5 parts of antioxidant 1076, 10 parts of methylphenyl silicone oil, 1.5 parts of UV-9, and 2 parts of antioxidant 4010NA, knead for 3 hours, heat to 100°C for vacuuming, the vacuum degree is -0.1MPa, the vacuuming time is 2 hours, add 3 parts of tert-butyl peroxybenzoate, mix for 20 minutes, and cut to obtain a silicone rubber masterbatch, wherein 100 parts of the organopolysiloxane is composed of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:1; S2. Put the silicone rubber masterbatch into the extruder at an extrusion temperature of 180°C. After extrusion molding, pass through a drying tunnel for 10 minutes at a drying tunnel temperature of 180°C. After cooling, a high expansion ratio silicone rubber cold shrink tube is obtained.

[0028] Example 4 Compared with Example 3, the difference of Example 4 is that 100 parts of the organopolysiloxane consists of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:2.

[0029] Example 5 Compared with Example 3, the difference of Example 5 is that 100 parts of the organopolysiloxane consists of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:3.

[0030] Example 6 Compared with Example 3, the difference of Example 6 is that 100 parts of the organopolysiloxane consists of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:4.

[0031] Example 7 S1, weigh 100 parts of organopolysiloxane, 40 parts of carbon black, 1.5 parts of antioxidant 1076, 10 parts of methylphenyl silicone oil, 1.5 parts of UV-9, 2 parts of antioxidant 4010NA, 10 parts of hollow glass microspheres (true density 0.38g / cm 3 ), kneading for 3 hours, heating to 100°C for vacuuming, the vacuum degree is -0.1MPa, the vacuuming time is 1 hour, 3 parts of tert-butyl perbenzoate are added, and after mixing for 20 minutes, the silicone rubber masterbatch is cut to obtain, wherein 100 parts of the organopolysiloxane is composed of methyl MQ silicone resin and vinyl MQ silicone resin in a mass ratio of 3:1; S2. Put the silicone rubber masterbatch into a cold feed extruder at an extrusion temperature of 30°C. After extrusion molding, pass through a drying tunnel for 10 minutes at a drying tunnel temperature of 180°C. After cooling, a high expansion ratio silicone rubber cold shrink tube is obtained.

[0032] Example 8 Compared with Example 7, the difference of Example 8 is that hollow glass microspheres (true density of 0.38 g / cm 3 ) was replaced with an equal amount of hollow glass microspheres (true density 0.46 g / cm 3 ).

[0033] Example 9 Preparation method of modified carbon black: dissolve 1 part of 1-(4-aminophenyl)-3-naphthalene-1-urea in 500 parts of dimethyl sulfoxide, dry 40 parts of carbon black in an oven at 120°C for 3 hours to obtain pretreated carbon black, disperse the pretreated carbon black in a dimethyl sulfoxide solution of 1-(4-aminophenyl)-3-naphthalene-1-urea, heat to 70°C, stir at 500r / min for 3 hours, filter and dry at 120°C for 4 hours to obtain modified carbon black.

[0034] Compared with Example 8, the difference of Example 9 is that the carbon black is replaced by an equal amount of modified carbon black obtained by the above preparation method.

[0035] Example 10 Compared with Example 9, the difference in Example 10 is that the amount of 1-(4-aminophenyl)-3-naphthalene-1-urea added is 2 parts.

[0036] Embodiment 11 Compared with Example 9, Example 11 is different in that the added amount of 1-(4-aminophenyl)-3-naphthalene-1-urea is 4 parts.

[0037] Example 12 Compared with Example 9, the difference in Example 12 is that the added amount of 1-(4-aminophenyl)-3-naphthalene-1-urea is 5 parts.

[0038] Embodiment 13 Compared with Example 11, Example 13 is different in that 1-(4-aminophenyl)-3-naphthalene-1-urea is replaced by an equal amount of diphenylaminourea.

[0039] Embodiment 14 Compared with Example 11, Example 14 is different in that 1-(4-aminophenyl)-3-naphthalene-1-urea is replaced with an equal amount of 4-phenylsemicarbazide.

[0040] Comparative Example 1 Compared with Example 3, the difference in Comparative Example 1 is that 100 parts of the organopolysiloxane is methyl MQ silicone resin.

[0041] Comparative Example 2 Compared with Example 3, the difference in Comparative Example 2 is that 100 parts of the organopolysiloxane is vinyl MQ silicone resin.

[0042] The high expansion ratio silicone rubber cold shrink tubes prepared in Examples 1 to 14 and Comparative Examples 1 to 2 were tested according to the following method: 1. Tear strength: Test the tear strength of the sample according to the test method specified in GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped test specimens)".

[0043] 2. Expansion ratio: Measure the inner diameter of the cold shrink tube to obtain the original inner diameter value, expand the cold shrink tube to the corresponding ratio, place it in a 90℃ oven for aging for 30 days, and if no cracking occurs, it is determined that the expansion ratio requirement can be met. Measure the inner diameter of the cold shrink tube after expansion and record it as the inner diameter value after expansion. Calculate the expansion ratio, expansion ratio = inner diameter value after expansion / original inner diameter value.

[0044] The test results are shown in the following table: Table 1 Performance test results of high expansion ratio silicone rubber cold shrink tubes prepared in Examples 1 to 14 and Comparative Examples 1 to 2

[0045] Compared with Example 3, Comparative Example 1 only adds methyl MQ silicone resin, and Comparative Example 2 only adds vinyl MQ silicone resin. As a result, the tear strength and expansion ratio of Example 3 are greater than those of Comparative Examples 1 and 2, indicating that the methyl MQ silicone resin and the vinyl MQ silicone resin play a synergistic role, which can enhance the tear strength of the cold shrink tube and improve the expansion ratio of the cold shrink tube. In Examples 3 to 6, methyl MQ silicone resin and vinyl MQ silicone resin in different mass ratios are added. As a result, the tear strength and expansion ratio of Examples 4 and 5 are greater than those of Examples 3 and 6, indicating that when the mass ratio of methyl MQ silicone resin to vinyl MQ silicone resin is 3:2 to 3, the tear strength and expansion ratio of the obtained cold shrink tube are better.

[0046] Compared with Example 5, Examples 7-8 added hollow glass microspheres. As a result, the tear strength and expansion ratio of Examples 7-8 were greater than those of Example 5, indicating that the addition of hollow glass microspheres can further enhance the tear strength of the cold shrink tube and improve the expansion ratio of the cold shrink tube.

[0047] Compared with Example 8, Examples 9 to 12 added modified carbon black, and the tear strength and expansion ratio of Examples 9 to 12 were greater than those of Example 8, indicating that the addition of modified carbon black can enhance the tear strength of the cold shrink tube and improve the expansion ratio of the cold shrink tube. In Examples 9 to 12, different masses of the modifier 1-(4-aminophenyl)-3-naphthalene-1-urea were added, and the tear strength and expansion ratio of Examples 10 and 11 were greater than those of Examples 9 and 12, indicating that when the mass ratio of the modifier to carbon black was 1 to 2:20, the tear strength and expansion ratio of the obtained cold shrink tube were better.

[0048] Compared with Example 11, Examples 13 and 14 added modifiers with different numbers of benzene rings. As a result, the tear strength and expansion ratio of Example 13 were greater than those of Examples 11 and 14, indicating that when the added modifier was diphenylamino urea, the tear strength and expansion ratio of the obtained cold shrink tube were better.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high expansion ratio silicone rubber cold shrink tube, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of organopolysiloxane, 30-40 parts of reinforcing filler, 0.5-1.5 parts of antioxidant, 1-3 parts of vulcanizer, 5-10 parts of plasticizer, 0.5-1.5 parts of light stabilizer and 1-2 parts of antioxidant; the organopolysiloxane is composed of methyl MQ silicone resin and vinyl MQ silicone resin, and the mass ratio of the methyl MQ silicone resin to the vinyl MQ silicone resin is 1:10-10:

1.

2. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: The mass ratio of the methyl MQ silicone resin to the vinyl MQ silicone resin is 3:2-3.

3. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: The raw materials also include 10-20 parts of functional fillers, wherein the functional fillers include one or two of hollow glass microspheres and ceramic microspheres. When the functional fillers are hollow glass microspheres, the true density of the hollow glass microspheres is 0.38-0.46 g / cm 3 .

4. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: The reinforcing filler includes one or more of carbon black, calcium carbonate and mica powder.

5. The high expansion ratio silicone rubber cold shrink tube according to claim 4, characterized in that: When the reinforcing filler is carbon black, the carbon black is modified carbon black, and the modifier of the modified carbon black is an aminophenyl urea compound.

6. The high expansion ratio silicone rubber cold shrink tube according to claim 5, characterized in that: The mass ratio of the modifier to the carbon black is 1-2:

20.

7. The high expansion ratio silicone rubber cold shrink tube according to claim 5, characterized in that: The aminophenyl urea compound includes one or more of 1-(4-aminophenyl)-3-naphthalene-1-urea, 4-phenylaminourea, and diphenylaminourea.

8. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010 , antioxidant 168 , and antioxidant 1076 .

9. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: The vulcanizing agent includes one or more of benzoyl peroxide, dicumyl peroxide, and tert-butyl perbenzoate.

10. The high expansion ratio silicone rubber cold shrink tube according to claim 1, characterized in that: Also includes at least one of the following technical features: The plasticizer includes one or both of dimethyl silicone oil and methylphenyl silicone oil; The light stabilizer includes one or more of UV-531, UV-327, and UV-9; The antioxidant includes one or two of antioxidant ODA and antioxidant 4010NA.

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