A high temperature resistant two-component organosilicon composition and preparation method thereof

Abstract

The present invention relates to the field of silicone compositions, and in particular to a high-temperature resistant two-component silicone composition and a preparation method thereof. The high-temperature resistant two-component silicone composition comprises two components A and B; in parts by mass, the raw materials of component A include: 1 to 100 parts of a polysiloxane matrix, 5 to 150 parts of a particle additive, 0 to 10 parts of an adhesive aid, and 0 to 10 parts of a catalyst; the raw materials of component B include: 1 to 100 parts of a polysiloxane matrix, 5 to 150 parts of a particle additive, 1 to 20 parts of a cross-linking agent, and 0 to 1 part of an inhibitor. The present invention provides a high-temperature resistant two-component silicone composition, which has an excellent protective effect. When used in protective equipment for PTC heaters, it can effectively improve the waterproof, heat-resistant and aging-resistant properties of the PTC heater, and has excellent market significance.

Description

Technical Field

[0001] The present invention relates to the field of organosilicon compositions, and in particular to a high temperature resistant two-component organosilicon composition and a preparation method thereof. Background Art

[0002] New energy vehicles are the future direction of global automobile development, and are also the direction that my country's policy focuses on supporting. Since new energy vehicles do not have engines like traditional fuel and vehicles, the heat generated by the engine cannot meet the heating function in the car, and the heating of the whole vehicle becomes a problem, requiring additional heating equipment. The electric heating function of PTC ceramics just meets this demand.

[0003] As a positive temperature coefficient semiconductor material, PTC ceramics can generate heat by itself when powered on, and the temperature can reach above 260°C. It has the advantages of high heating efficiency and safety. Due to these advantages, it has become an option to use PTC as an assembly part to provide a heat source for air conditioning systems. With the introduction of relevant standards for electric vehicles in my country, there are strict requirements for the waterproof level of PTC air heaters, which generally have to reach IP67 waterproof level.

[0004] Due to its unique molecular structure, silicone rubber has excellent electrical properties and chemical inertness, and has good flame retardancy, excellent adhesion, high and low temperature resistance, heat resistance and moisture resistance. It can maintain elasticity for a long time in the range of -60 to 300°C and is an effective PTC air heater protective product.

[0005] Therefore, in order to solve the above problems, the present application provides a high temperature resistant silicone rubber, which can effectively improve the waterproof, heat resistance and aging resistance of the PTC heater and has excellent market significance. Summary of the invention

[0006] In order to solve the above problems, the first aspect of the present invention provides a high temperature resistant two-component silicone composition, comprising two components A and B; in parts by mass, the raw materials of component A include: 1 to 100 parts of polysiloxane matrix, 5 to 150 parts of particle additives, 0 to 10 parts of bonding aids, and 0 to 10 parts of catalysts;

[0007] In parts by mass, the raw materials of component B include: 1 to 100 parts of polysiloxane matrix, 5 to 150 parts of particle additive, 1 to 20 parts of cross-linking agent, and 0 to 1 part of inhibitor.

[0008] As a preferred solution, the polysiloxane matrix is ​​at least one of methyl polysiloxane, vinyl polysiloxane and chloropropyl polysiloxane; the viscosity of the polysiloxane matrix is ​​10 to 50,000 mPa·s at 25°C.

[0009] As a preferred solution, the viscosity of the polysiloxane matrix is ​​500-5000 mPa·s at 25°C.

[0010] As a preferred solution, the polysiloxane matrix is ​​vinyl polysiloxane; the vinyl polysiloxane has a structure shown in the following formula:

[0011] Wherein, m and n are positive integers ≥1.

[0012] As a preferred solution, the particle additive is at least one of metal oxides; the average particle size of the particle additive is 0.05 to 50 μm.

[0013] As a preferred solution, the average particle size of the particle additive is 0.5-10 μm.

[0014] As a preferred solution, the metal oxide is at least one of aluminum oxide, magnesium oxide, silicon dioxide, titanium dioxide, antimony dioxide, cerium oxide, zinc oxide, and iron oxide.

[0015] As a preferred solution, the metal oxide is aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, titanium oxide and cerium oxide.

[0016] As a preferred solution, in component A, the mass ratio of aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, titanium oxide and cerium oxide is 30-35:20-25:0-5:3-6:2-4:0-3.

[0017] As a preferred solution, in component B, the mass ratio of aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, titanium oxide and cerium oxide is 25-35:15-25:3-10:3-8:2-5:0-3.

[0018] As a preferred solution, the raw materials of the bonding aid include, by mass, 1 to 50 parts of vinyl cyclic siloxane and 1 to 50 parts of coupling agent.

[0019] As a more preferred solution, the raw materials of the bonding aid include, by weight, 5 to 20 parts of vinyl cyclic siloxane and 5 to 30 parts of coupling agent.

[0020] As a preferred solution, the vinyl cyclic siloxane is at least one of 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, and 1,3,5,7,9-pentaveinyl-1,3,5,7,9-pentamethylcyclopentasiloxane.

[0021] As a preferred solution, the coupling agent is a silane coupling agent and / or a titanate coupling agent.

[0022] As a preferred embodiment, the silane coupling agent is at least one of 3-(2,3-epoxypropyloxy)propyltrimethoxysilane, 3-(2,3-epoxypropyloxy)propyltriethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldiethoxysilane, [3-(methacryloxy)propyl]trimethoxysilane, 3-methacryloxypropyltriisopropoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 1,3,5-tris(trimethoxysilylpropyl)isocyanurate, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-[3-(trimethoxysilyl)propyl]ethylenediamine.

[0023] As a preferred solution, the titanate coupling agent is at least one of isopropyl tri(dioctyl phosphate) titanate, isopropyl tri(dioctyl pyrophosphate) ethylene titanate, tetra-n-butyl titanate, tetraisopropyl titanate, di(ethyl acetoacetate) diisopropyl titanate, and di(acetylacetonate) diisopropyl titanate.

[0024] As a preferred solution, the preparation method of the bonding aid includes: mixing vinyl cyclic siloxane and silane coupling agent, stirring and heating to 110-130°C, and reacting at this temperature for 4-5 hours, then removing low-boiling substances by reduced pressure distillation for 3-4 hours, and finally controlling the temperature to 40-60°C, adding titanate coupling agent, and continuing stirring for 3-4 hours to obtain the bonding aid.

[0025] As a preferred solution, in the component A, the mass ratio of the bonding aid to the polysiloxane matrix is ​​1-5:20-40.

[0026] As a preferred solution, in the component A, the mass ratio of the bonding aid to the polysiloxane matrix is ​​1.5-3:26.5-37.5.

[0027] In the present application, by adding a homemade bonding agent and compounding it with a polysiloxane matrix, the temperature resistance of the composition is effectively improved, and it can further maintain good elasticity and hydrophobic properties under high temperature conditions. The applicant believes that the bonding agent added in the present application can structurally intersperse the silicone composition through its good cross-linking network and multiple branches, thereby reducing the migration speed of active molecules in the silicone composition system under high temperature conditions, and on the other hand, the high cross-linking network can maintain a good degree of molecular chain connection at high temperatures, especially when the mass ratio of the bonding agent to the polysiloxane matrix is ​​1.5-3:26.5-37.5, the above effect is significantly improved.

[0028] As a preferred solution, the catalyst is any one of an alcohol solution of chloroplatinic acid, a platinum complex of 1,3-divinyl-1,3-diphenyl-dimethyldisiloxane and a platinum complex of 1,3-divinyltetramethyldisiloxane.

[0029] As a preferred solution, the cross-linking agent has a structure shown in the following formula:

[0030] Wherein, n is a positive integer ≥ 3, and its hydrogen content is 0.01-1%.

[0031] As a preferred solution, the inhibitor is at least one of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 3-phenyl-1-butyn-3-ol, and 1-ethynylcyclohexanol.

[0032] As a preferred solution, the mass ratio of the A and B components is 1-2:1-2.

[0033] As a preferred solution, the mass ratio of the A and B components is 1:1.

[0034] The second aspect of the present invention provides a method for preparing the above-mentioned high-temperature resistant two-component silicone composition, comprising the following steps: (1) heating a mixture containing a polysiloxane matrix and a particle additive to 100-140°C, vacuum dehydrating and mixing for 1-3 hours, then cooling to 30-70°C, adding an adhesive additive and a catalyst, and stirring and dispersing them uniformly at a vacuum degree of not less than -0.05-0.1Mpa to obtain component A; (2) stirring and dispersing the raw materials containing a polysiloxane matrix, a particle additive, a cross-linking agent and an inhibitor at a temperature of 30-70°C and a vacuum degree of not less than -0.05-0.1Mpa to obtain component B; (3) mixing components A and B uniformly in proportion to obtain the product.

[0035] Beneficial effects:

[0036] 1. The present application provides a high-temperature resistant two-component silicone composition, which has excellent protective effects. When used in protective equipment for PTC heaters, it can effectively improve the waterproof, heat-resistant and aging-resistant properties of PTC heaters, and has excellent market significance.

[0037] 2. The present application provides a high-temperature resistant two-component silicone composition, which effectively improves the temperature resistance of the composition by adding a homemade bonding aid and compounding it with a polysiloxane matrix, and can further maintain good elasticity and hydrophobic properties under high temperature conditions. DETAILED DESCRIPTION

[0038] Example 1

[0039] Embodiment 1 A first aspect provides a high temperature resistant two-component silicone composition, the components of which include:

[0040]

[0041] The raw materials of the bonding aid include, by mass, 15 parts of vinyl cyclic siloxane (2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane) and 15 parts of a coupling agent (3-(2,3-epoxypropoxy)propyltrimethoxysilane and isopropyl tri(dioctylphosphoyl)titanate, 2:1).

[0042] Preparation method of bonding agent: After mixing vinyl cyclic siloxane and silane coupling agent, stir and heat to 120°C, react at this temperature for 4.5 hours, then remove low boiling points by vacuum distillation for 3.5 hours, finally control to 55°C, add titanate coupling agent, continue stirring for 3.5 hours to obtain.

[0043] The second aspect of this embodiment provides a method for preparing the above-mentioned high-temperature resistant two-component silicone composition, comprising the following steps: (1) heating a mixture containing a polysiloxane matrix and a particle additive to 130°C, vacuum dehydrating and mixing for 2 hours, then cooling to 50°C, adding an adhesive additive and a catalyst, and stirring and dispersing them uniformly at a vacuum degree of not less than -0.08Mpa to obtain component A; (2) stirring and dispersing the raw materials containing a polysiloxane matrix, a particle additive, a cross-linking agent and an inhibitor at a temperature of 50°C and a vacuum degree of not less than -0.08Mpa to obtain component B; (3) mixing components A and B uniformly in proportion to obtain the result.

[0044] Example 2

[0045] The specific implementation of this embodiment is the same as that of Embodiment 1, except that:

[0046]

[0047] Example 3

[0048] The specific implementation of this embodiment is the same as that of Embodiment 1, except that:

[0049] Comparative Example 1

[0050] The specific implementation of this comparative example is the same as that of Example 1, except that:

[0051]

[0052] Performance Evaluation

[0053] Table 1

[0054]

[0055] It can be seen from Examples 1 to 3, Comparative Example 1 and Table 1 that the high temperature resistant two-component silicone composition provided by the present invention has excellent protective effect. When used in protective equipment for PTC heaters, it can effectively improve the waterproof, heat-resistant and aging-resistant properties of the PTC heater, and has excellent market significance.

Claims

1. A high temperature resistant two-component silicone composition, characterized in that: The ingredients include two components A and B; the formula is shown in the table below; The raw materials of the AD adhesion promoter include, by mass, 15 parts of vinyl cyclic siloxane and 15 parts of coupling agent; The vinyl cyclic siloxane is 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane; the coupling agent is 3-(2,3-epoxypropoxy)propyltrimethoxysilane and isopropyl tri(dioctylphosphoyloxy) titanate in a ratio of 2:1; Preparation method: After mixing vinyl cyclic siloxane and silane coupling agent, stir and heat to 120°C, and react at this temperature for 4.5 hours, then remove low-boiling products by reduced pressure distillation for 3.5 hours, finally control the temperature to 55°C, add titanate coupling agent, and continue stirring for 3.5 hours to obtain.

2. A method for preparing the high temperature resistant two-component silicone composition according to claim 1, characterized in that: The following steps are involved: (1) The raw materials of component A, which include vinyl polysiloxane with a viscosity of 500 mPa·s, aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, titanium oxide, and cerium oxide, are mixed, heated to 100-140°C, and then vacuum-dehydrated and mixed for 1-3 hours, and then cooled to 30-70°C, and AD adhesion promoter and platinum complex of 1,3-divinyltetramethyldisiloxane are added, and the mixture is stirred and dispersed uniformly at a vacuum degree of not less than -0.05 MPa to obtain component A; (2) The raw materials of component B, which include vinyl polysiloxane with a viscosity of 500 mPa·s, aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, titanium oxide, cerium oxide, a crosslinking agent, and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane are mixed, and the mixture is stirred and dispersed uniformly at a temperature of 30-70°C and a vacuum degree of not less than -0.05 MPa to obtain component B; (3) Components A and B are mixed uniformly in proportion to obtain the obtained product.

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