Silicone rubber with high tear resistance and low pressure change for new energy cable and preparation method thereof

Abstract

The invention discloses high-tear-resistance and low-voltage-change silicone rubber for a new energy cable and a preparation method of the silicone rubber, and relates to the technical field of silicone rubber material manufacturing. The silicone rubber comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 2-10 parts of hydroxyl silicone oil, 1-5 parts of silazane, 20-100 parts of fumed silica, 0.1-1 part of low-hydrogen silicone oil, 2-10 parts of a vulcanizing agent, 1-5 parts of a silane coupling agent, 1-5 parts of alkali metal oxide, 1-5 parts of a heat-resistant agent and 0.1-0.5 part of a release agent. According to the high-tear-resistance and low-pressure-change silicone rubber for the new energy cable and the preparation method of the silicone rubber, the low-hydrogen-content silicone oil is introduced to obtain a cross-linked structure with a longer link number during vulcanization, the direction of force is changed when the cross-linked structure encounters external force, and the low-hydrogen-content silicone oil is introduced to enable the vulcanization degree to be more complete, so that better tear resistance is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone rubber material manufacturing, and in particular to a silicone rubber with high tear resistance and low pressure deformation for new energy cables and a preparation method thereof. Background Art

[0002] With the rapid development of the new energy vehicle market in recent years, the demand for silicone rubber cables for new energy vehicles has gradually increased. Due to the harsh use environment, there are strict requirements on the material's resistance to high and low temperatures, electrical insulation, sealing, wear resistance, compression permanent deformation resistance, tear resistance, aging resistance and other properties, and silicone rubber is just suitable. Therefore, it is widely used in the fields of automotive parts, new energy vehicle cables, high-strength cables, and high-strength low-pressure variable seals for auto parts. However, in the field of new energy cables, the low-pressure variable performance of high-hardness glue mostly adopts the idea of ​​centralized cross-linking, which is inconsistent with the requirement of high tear strength in the cross-linking structure. The tear performance of low-pressure variable silicone rubber used for most wires and cables on the market is not high, and cannot meet the needs of some structural parts or high-strength cables. For this reason, we propose a high-tear and low-pressure variable silicone rubber for new energy cables and its preparation method. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a silicone rubber with high tear resistance and low pressure deformation for new energy cables and a preparation method thereof, which solves the problems raised in the above-mentioned background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical scheme: a silicone rubber with high tear resistance and low pressure deformation for new energy cables, whose components are calculated by weight: 100 parts of methyl vinyl silicone rubber, 2 to 10 parts of hydroxy silicone oil, 1 to 5 parts of silazane, 20 to 100 parts of fumed silica, 0.1 to 1 part of low hydrogen silicone oil, 2 to 10 parts of vulcanizing agent, 1 to 5 parts of silane coupling agent, 1 to 5 parts of alkali metal oxide, 1 to 5 parts of heat resistant agent, and 0.1 to 0.5 parts of release agent.

[0005] Furthermore, the molecular weight of the methyl vinyl silicone rubber is between 600,000 and 700,000, and the molar percentage of vinyl in the methyl vinyl silicone rubber is between 0.04% and 3.0%.

[0006] Furthermore, hydroxy silicone oil refers to a hydroxy-terminated polydimethylsiloxane having a viscosity of 30-35 mm2 / s at 25°C, a hydroxyl content of 8-10%, and a pH value of 6.5-7.5.

[0007] Furthermore, the silane coupling agent is one or more of γ-[(2,3)-glycidoxy]propyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

[0008] Furthermore, the specific surface area of ​​the fumed silica is 190-210 m2 / g, the average particle size is 7-40 nm, and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0009] Furthermore, the low hydrogen silicone oil is polymethyl pendant hydrogen siloxane, which has a viscosity of 10-60 mm2 / s at 25°C and a hydrogen content of 0.5-1.0%.

[0010] Furthermore, the alkali metal oxide is one or more of calcium oxide, zinc oxide and magnesium oxide.

[0011] Furthermore, the heat-resistant agent is a mixture of cerium oxide and titanium oxide.

[0012] Furthermore, the release agent is a mixture of zinc stearate and stearic acid.

[0013] Furthermore, a method for preparing a silicone rubber with high tear resistance and low pressure change for new energy cables as described in the claims is characterized in that the steps are as follows:

[0014] S1: Add methyl vinyl silicone rubber, hydroxy silicone oil, hexamethyldisilazane, silane coupling agent, low hydrogen silicone oil and release agent into a kneader and stir at room temperature for 10-20 minutes, then add fumed silica into the kneader in 5 equal parts, knead the rubber into a mass each time and then add silica;

[0015] S2: The material obtained in S1 is heated to 120-160°C, and vacuumed for 1-3 hours at a constant temperature, with a vacuum degree of -0.08-0.1 MPa;

[0016] S3: After the stirring in S2 is completed, cooling water is passed to cool the material to below 50° C., and a heat-resistant agent and an alkali metal oxide are added to the material and stirred for 60 minutes to obtain a silicone rubber masterbatch;

[0017] S4: adding a vulcanizing agent to the silicone rubber masterbatch obtained in S3 and stirring for 30 minutes to obtain the silicone rubber with high tear resistance and low compression permanent deformation.

[0018] The invention provides a silicone rubber with high tear resistance and low compression deformation for new energy cables and a preparation method thereof, which has the following beneficial effects: a cross-linked structure with a longer number of links is obtained during vulcanization by introducing low-hydrogen silicone oil, and the direction of the force is changed when encountering an external force, and the introduction of the low-hydrogen silicone oil can make the vulcanization degree more complete, thereby obtaining better tearing performance; the fully vulcanized silicone rubber limits the movement of white carbon black during cable use, and the hydrolyzate generated by the reaction of alkali metal oxides and silane coupling agents with water acts on the exposed silanol groups to inhibit the weak interaction force generated by the hydrolyzate, and inhibits the breakage of the siloxane main chain in an acidic environment, thereby obtaining lower compression permanent deformation performance; and a heat-resistant agent is used to reduce the degradation and breakage of the siloxane main chain of the silicone rubber at high temperature and the free radicals generated by the oxidation of the side groups, resulting in excessive concentration of crosslinking and making the rubber brittle, thereby improving the aging resistance, so that the material has excellent tearing performance, lower compression permanent deformation performance, good aging resistance, high mechanical strength, simple preparation process, and good application in the field of new energy wires and cables. DETAILED DESCRIPTION

[0019] The following examples are used to illustrate the present invention, but they are not intended to limit the scope of the present invention.

[0020] Example 1

[0021] S1: 90kg of methyl vinyl silicone rubber with a vinyl content of 0.04, 10kg of methyl vinyl silicone rubber with a vinyl content of 3.0, 3kg of hydroxy silicone oil, 2kg of hexamethyldisilazane, 0.5kg of γ-(methacryloyloxy)propyltrimethoxysilane, 1kg of polymethyl side hydrogen siloxane with a hydrogen content of 0.75, 0.5kg of vinyltrimethoxysilane, 0.1kg of zinc stearate, and 0.1kg of stearic acid are added to a kneader and stirred at room temperature for 15min, and then 70kg of 200-ratio fumed silica is evenly divided into 14kg, 14kg, 14kg, 14kg, and 14kg and added to the kneader, and the rubber material is kneaded into a mass each time and then the silica is added;

[0022] S2: The material obtained in S1 was heated to 160°C and vacuumed for 3 hours at a constant temperature, with a vacuum degree of -0.08 MPa;

[0023] S3: After the stirring in S2 is completed, cool the material to below 50°C by cooling water, add 1kg cerium oxide, 0.5kg titanium oxide, 1kg calcium oxide, and 0.5kg zinc oxide into the rubber and stir for 60min to obtain a silicone rubber masterbatch, and cool the material to room temperature by cooling water again for standby use;

[0024] S4: adding 1.3 kg of dichloromethane to the silicone rubber masterbatch obtained in S3 and stirring for 30 min to obtain the silicone rubber with high tear resistance and low compression permanent deformation;

[0025] Vulcanization conditions 175℃5min Hardness Shore A 72 Tensile strength mpa 9.1 Elongation % 280 Right angle tear KN / m 41.8 Plasticity 275 Compression set 175℃*22h 13.6

[0026] Example 2

[0027] S1: 95kg of methyl vinyl silicone rubber with a vinyl content of 0.04, 5kg of methyl vinyl silicone rubber with a vinyl content of 3.0, 2kg of hydroxy silicone oil, 2kg of hexamethyldisilazane, 0.5kg of γ-(methacryloyloxy)propyltrimethoxysilane, 1.5kg of polymethyl side hydrogen siloxane with a hydrogen content of 0.5, 0.5kg of vinyltrimethoxysilane, 0.08kg of zinc stearate, and 0.07kg of stearic acid are added to a kneader and stirred at room temperature for 15min, and then 50kg of 200-ratio fumed silica is evenly divided into 10kg, 10kg, 10kg, 10kg, and 10kg and added to the kneader, and the rubber material is kneaded into a mass each time and then the silica is added;

[0028] S2: The material obtained in S1 was heated to 160°C and vacuumed for 3 hours at a constant temperature, with a vacuum degree of -0.08 MPa;

[0029] S3: After the stirring in S2 is completed, cool the material to below 50°C by cooling water, add 1.5kg cerium oxide, 0.5kg titanium oxide, 1kg calcium oxide, 0.25kg zinc oxide, and 0.25kg magnesium oxide into the rubber and stir for 60min to obtain a silicone rubber masterbatch, and cool the material to room temperature by cooling water again for standby use;

[0030] S4: adding 1.2 kg of dichloromethane to the silicone rubber masterbatch obtained in S3 and stirring for 30 min to obtain the silicone rubber with high tear resistance and low compression permanent deformation;

[0031]

[0032]

[0033] Example 3

[0034] S1: 98kg of methyl vinyl silicone rubber with a vinyl content of 0.04, 2kg of methyl vinyl silicone rubber with a vinyl content of 3.0, 1.5kg of hydroxy silicone oil, 1.0kg of hexamethyldisilazane, 0.5kg of γ-(methacryloyloxy)propyltrimethoxysilane, 1.0kg of polymethyl side hydrogen siloxane with a hydrogen content of 1.0, 0.5kg of γ-[(2,3)-glycidoxy]propyltrimethoxysilane, 0.06kg of zinc stearate, and 0.06kg of stearic acid are added to a kneader and stirred at room temperature for 15min, and then 35kg of 200-ratio fumed silica is added to the kneader in an average of 7kg, 7kg, 7kg, 7kg, and 7kg, and the rubber material is kneaded into a mass each time and then the silica is added;

[0035] S2: The material obtained in S1 was heated to 160°C and vacuumed for 3 hours at a constant temperature, with a vacuum degree of -0.08 MPa;

[0036] S3: After the stirring in S2 is completed, cool the material to below 50°C by cooling water, add 1.2kg cerium oxide, 0.4kg titanium oxide, 1kg calcium oxide, and 0.25kg zinc oxide into the rubber and stir for 60min to obtain a silicone rubber masterbatch, and cool the material to room temperature by cooling water again for standby use;

[0037] S4: adding 1 kg of dichloroethylene to the silicone rubber masterbatch obtained in S3 and stirring for 30 min to obtain the silicone rubber with high tear resistance and low compression permanent deformation;

[0038]

[0039]

[0040] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A high tear resistance and low pressure deformation silicone rubber for new energy cables, characterized by: The composition is calculated by weight as follows: 100 parts of methyl vinyl silicone rubber, 2-10 parts of hydroxy silicone oil, 1-5 parts of silazane, 20-100 parts of fumed silica, 0.1-1 part of low hydrogen silicone oil, 2-10 parts of vulcanizing agent, 1-5 parts of silane coupling agent, 1-5 parts of alkali metal oxide, 1-5 parts of heat resistant agent and 0.1-0.5 parts of release agent.

2. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 1, characterized in that: The molecular weight of the methyl vinyl silicone rubber is between 600,000 and 700,000, and the molar percentage of vinyl in the methyl vinyl silicone rubber is between 0.04% and 3.0%.

3. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 2, characterized in that: Hydroxy silicone oil refers to terminal hydroxyl polydimethylsiloxane with a viscosity of 30-35 mm2 / s at 25°C, a hydroxyl content of 8-10%, and a pH value of 6.5-7.

5.

4. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 3, characterized in that: The silane coupling agent is one or more of γ-[(2,3)-glycidoxy]propyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

5. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 4, characterized in that: The specific surface area of ​​fumed silica is 190-210 m2 / g, the average particle size is 7-40 nm, and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

6. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 5, characterized in that: Low hydrogen silicone oil is polymethyl pendant hydrogen siloxane with a viscosity of 10-60 mm2 / s at 25°C and a hydrogen content of 0.5-1.0%.

7. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 6, characterized in that: The alkali metal oxide is one or more of calcium oxide, zinc oxide and magnesium oxide.

8. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 7, characterized in that: The heat-resistant agent is a mixture of cerium oxide and titanium oxide.

9. The high tear resistance and low pressure deformation silicone rubber for new energy cables according to claim 8, characterized in that: The release agent is a mixture of zinc stearate and stearic acid.

10. A method for preparing a silicone rubber with high tear resistance and low pressure deformation for new energy cables according to claim 9, characterized in that: The steps are: S1: Add methyl vinyl silicone rubber, hydroxy silicone oil, hexamethyldisilazane, silane coupling agent, low hydrogen silicone oil and release agent into a kneader and stir at room temperature for 10-20 minutes, then add fumed silica into the kneader in 5 equal parts, knead the rubber into a mass each time and then add silica; S2: The material obtained in S1 is heated to 120-160°C, and vacuumed for 1-3 hours at a constant temperature, with a vacuum degree of -0.08-0.1 MPa; S3: After the stirring in S2 is completed, cooling water is passed to cool the material to below 50° C., and a heat-resistant agent and an alkali metal oxide are added to the material and stirred for 60 minutes to obtain a silicone rubber masterbatch; S4: adding a vulcanizing agent to the silicone rubber masterbatch obtained in S3 and stirring for 30 minutes to obtain the silicone rubber with high tear resistance and low compression permanent deformation.

Images