Outdoor electronic equipment silicon waterproof glue and preparation method thereof

Abstract

The invention provides silicon waterproof glue for outdoor electronic equipment and a preparation method of the silicon waterproof glue, and belongs to the technical field of waterproof glue. The outdoor electronic equipment silicon waterproof glue is prepared from the following components in parts by weight: a component A: 20 to 30 parts of hydroxyl-terminated polydimethylsiloxane, 10 to 20 parts of methoxyl-terminated polydimethylsiloxane, 10 to 20 parts of a plasticizer and 30 to 50 parts of filler; the component B comprises 0.5-1 part of a catalyst, 30-50 parts of a curing agent and 10-20 parts of a coupling agent, and the specific components and the mass ratio of the components are controlled, so that the obtained waterproof glue has better mechanical properties, high temperature resistance, acid resistance and salt spray resistance while having better waterproofness.

Description

Technical Field

[0001] The invention belongs to the technical field of waterproof adhesives, and in particular relates to a silicone waterproof adhesive for outdoor electronic equipment and a preparation method thereof. Background Art

[0002] In recent years, the role of electronic products in our lives has been increasing. People's daily life depends on electronic products, such as digital cameras, laptops, smart phones, removable storage devices, etc. The core components of electronic products are composed of electronic components. Since water or water vapor can easily reduce or change the resistivity of insulators and semiconductors, it will affect the use of electronic or electrical equipment and even cause the risk of short circuit or equipment damage. Therefore, the waterproof level requirements of these devices are relatively high. In addition to sealing the electronic components and circuit parts, applying waterproof coatings is also an important waterproof measure.

[0003] For example, Chinese patent CN108359297A discloses an organic silicon nano waterproof coating and its preparation method, which includes the following raw materials by weight: 40-60 parts of silane monomer, 15-35 parts of pure acrylic emulsion, 6-15 parts of golden red titanium dioxide, 1-6 parts of emulsifier, 5-10 parts of nano titanium dioxide, 4-8 parts of nano zinc oxide, 7-13 parts of potassium titanate whiskers, 2-6 parts of nano carbon powder, 1-5 parts of plasticizer, 0.3-4.5 parts of leveling agent, 0.5-4 parts of defoaming agent, and 34-60 parts of deionized water. The coating of the invention has good hydrophobic properties, high viscosity, strong adhesion, uniform and stable properties, and the protective film formed is fine and smooth, with high film strength, not easy to break or leak, and excellent waterproof performance; the water vapor or water droplets on the surface of the protective layer are easy to condense into water droplets and slide down, and have certain self-cleaning properties. It has a wide range of applications and is suitable for coating the surfaces of all electrical and electronic equipment. It has excellent protective properties and excellent anti-aging and anti-corrosion properties.

[0004] For example, Chinese patent CN106833498A discloses a sealing waterproof adhesive and its preparation method and application, wherein the sealing waterproof adhesive is composed of the following components by mass: 30-70 parts of UV-curable resin, 4-10 parts of photoinitiator, 10-40 parts of active diluent, 2.5-5.5 parts of thixotropic agent, 1-4 parts of coupling agent, 0.5-8 parts of auxiliary agent, and 0.2-3 parts of pigment; wherein the UV-curable resin is one or more of polycarbonate polyurethane acrylate, polybutadiene polyurethane acrylate, polyester acrylate, modified epoxy acrylic resin or silicone acrylic resin. The sealing waterproof adhesive provided by the invention has good sealing and waterproof performance. Its application in the sealing and waterproof field of electronic products can replace the traditional hot melt adhesive process or sealing gasket, and can significantly improve production efficiency and reduce costs.

[0005] However, the waterproof adhesives disclosed in the prior art all have the problem of poor weather resistance and anti-aging performance, and therefore it is necessary to provide an outdoor electronic equipment silicone waterproof adhesive with better anti-aging and weather resistance and a preparation method thereof. Summary of the invention

[0006] Based on the deficiencies in the prior art, the present invention aims to provide a silicone waterproof adhesive for outdoor electronic equipment with better anti-aging and weather resistance and a preparation method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: A silicone waterproof adhesive for outdoor electronic equipment, comprising the following components by weight: Component A: 20-30 parts of hydroxyl-terminated polydimethylsiloxane, 10-20 parts of methoxy-terminated polydimethylsiloxane, 10-20 parts of plasticizer, and 30-50 parts of filler; Component B: 0.5-1 part of catalyst, 30-50 parts of curing agent, 10-20 parts of coupling agent.

[0008] Preferably, the outdoor electronic equipment silicone waterproof adhesive comprises the following components by weight: Component A: 22-28 parts of hydroxyl-terminated polydimethylsiloxane, 12-18 parts of methoxy-terminated polydimethylsiloxane, 12-15 parts of plasticizer, and 35-45 parts of filler; Component B: 0.5-0.8 parts of catalyst, 35-45 parts of curing agent, 15-18 parts of coupling agent.

[0009] As some preferred embodiments, the mass ratio of the hydroxyl-terminated polydimethylsiloxane to the methoxy-terminated polydimethylsiloxane is 1-3:1, preferably 1.8:1.

[0010] The plasticizer is selected from one or more of white oil, soybean oil, methyl silicone oil and epoxy soybean oil; Preferably, the plasticizer is a mixture of methyl silicone oil and epoxy soybean oil, and the mass ratio of the two is 1-3:1; preferably 2:1.

[0011] The filler is a mixture of attapulgite and attapulgite modified by silicon dioxide, and the mass ratio of the two is 3-5:1, preferably 4:1.

[0012] The preparation method of the silicon dioxide modified attapulgite is: (1) adding water to attapulgite to prepare an attapulgite solution with a mass fraction of 20-30%; (2) adding water to sodium silicate to prepare a sodium silicate solution with a mass fraction of 20-30%; (3) Add the sodium silicate solution to the attapulgite solution under stirring conditions, and adjust the pH to 8-9.5. After reacting at 50-60°C for 0.5-1h, adjust the pH to 5.5-6.5, continue the reaction for 3-5 hours, wash the reaction product, and dry it to obtain the silica-modified attapulgite.

[0013] The mass ratio of attapulgite to sodium silicate is 2-5:1, preferably 3:1.

[0014] The catalyst is dibutyltin dilaurate and dibutyltin diacetate in a mass ratio of 1:1.

[0015] The curing agent is aminoethylpiperazine.

[0016] The coupling agent is a mixture of epoxy silane and allyl trimethoxy silane, and the mass ratio of the two is 1:2-4; preferably 1:3.

[0017] As a preferred embodiment, the outdoor electronic equipment silicone waterproof adhesive comprises the following components by weight: Component A: 25.2 parts of hydroxyl-terminated polydimethylsiloxane, 14 parts of methoxy-terminated polydimethylsiloxane, 10 parts of methyl silicone oil, 5 parts of epoxy soybean oil, 32 parts of attapulgite, and 8 parts of silica-modified attapulgite prepared in the basic example; Component B: 0.3 parts of dibutyltin dilaurate, 0.3 parts of dibutyltin diacetate catalyst, 40 parts of aminoethylpiperazine, 4 parts of epoxysilane, and 12 parts of allyltrimethoxysilane.

[0018] The present invention also provides a method for preparing the above-mentioned silicone waterproof adhesive for outdoor electronic equipment, comprising the following steps: S1. Put the raw materials of component A into a vacuum kneader and blend them. Control the temperature to 160-180° C. and the vacuum degree to 0.02-0.05 MPa. Blend for 3-4 hours. After blending, bring the mixture to room temperature to obtain component A. S2. Put the raw materials of component B into a reaction kettle and stir and mix them for 20-40 minutes to obtain component B.

[0019] S3. During use, component A and component B are mixed evenly in a mass ratio of 1:1 to obtain the silicone waterproof adhesive for outdoor electronic equipment.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) In the implementation process of the present invention, a mixture of hydroxyl-terminated polydimethylsiloxane and methoxy-terminated polydimethylsiloxane is used as a base material, and organic tin is used as a catalyst. By controlling the mass ratio of hydroxyl-terminated polydimethylsiloxane to methoxy-terminated polydimethylsiloxane, the viscosity of the waterproof adhesive can be improved, so that the obtained waterproof adhesive has better mechanical properties, especially the tensile strength and elongation at break of the waterproof adhesive can be significantly improved.

[0021] (2) The present invention uses a mixture of methyl silicone oil and epoxy soybean oil as a plasticizer. On the one hand, epoxy soybean oil has good heat resistance and light resistance, and is environmentally friendly. On the other hand, during the implementation of the present invention, it was found that using methyl silicone oil and epoxy soybean oil in a mass ratio of 1-3:1 as plasticizers can improve the mechanical properties of the waterproof adhesive.

[0022] (3) The present invention uses a mixture of attapulgite and silica-modified attapulgite as a filler, and controls the mass ratio of the two to be 3-5:1. The obtained waterproof glue has better high temperature resistance and salt spray erosion resistance, so that the waterproof glue still has good tensile strength and elongation at break after long-term use at room temperature.

[0023] (4) The present invention uses a mixture of epoxy silane and allyl trimethoxy silane as a coupling agent, and controls the mass ratio thereof to be 1:2-4, which can significantly improve the interaction between the filler and the organic matrix, effectively improve the activity of the material surface, enable a better mixing reaction between the components of component A and the components of component B, and improve the waterproof performance of the waterproof glue. DETAILED DESCRIPTION

[0024] The following will be combined with the tables in 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.

[0025] Hereinafter, examples and comparative examples of the present invention will be shown to explain the composition of the present invention in more detail, but the present invention is not limited thereto.

[0026] The present invention does not limit the sources of the raw materials used. Unless otherwise specified, the raw materials used in the present invention are common commercial products in the technical field.

[0027] The hydroxyl-terminated polydimethylsiloxane: CAS No. 70131-67-8, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number P304442; The methoxy-terminated polydimethylsiloxane: CAS No. 68951-97-3, purchased from Shanghai Myrel Biochemical Technology Co., Ltd., product number GEL-DMS-XM11.

[0028] Basic Example: The preparation method of silica-modified attapulgite is: (1) Add water to attapulgite to prepare an attapulgite solution with a mass fraction of 25%; (2) Add water to sodium silicate to prepare a sodium silicate solution with a mass fraction of 25%; (3) Adding the sodium silicate solution to the attapulgite solution under stirring, the mass ratio of the attapulgite to the sodium silicate being 3:1, and adjusting the pH to 9. After reacting at 60° C. for 1 hour, adjusting the pH to 6, and continuing the reaction for 5 hours, washing the reaction product, and drying it to obtain the silica-modified attapulgite.

[0029] Example 1 A silicone waterproof adhesive for outdoor electronic equipment The components by weight are as follows: Component A: 20 parts of hydroxyl-terminated polydimethylsiloxane, 10 parts of methoxy-terminated polydimethylsiloxane, 5 parts of methyl silicone oil, 5 parts of epoxy soybean oil, 22.5 parts of attapulgite, and 7.5 parts of silica-modified attapulgite prepared in the basic example; Component B: 0.25 parts of dibutyltin dilaurate, 0.25 parts of dibutyltin diacetate catalyst, 30 parts of aminoethylpiperazine, 4 parts of epoxysilane, and 8 parts of allyltrimethoxysilane.

[0030] The preparation method is: S1. Put the raw materials of component A into a vacuum kneader and blend them. Control the temperature to 170° C. and the vacuum degree to 0.05 MPa. Blend for 3 hours. After blending, bring the mixture to room temperature to obtain component A. S2. Put the raw materials of component B into a reaction kettle and stir and mix them for 30 minutes to obtain component B.

[0031] S3. During use, component A and component B are mixed evenly in a mass ratio of 1:1 to obtain the silicone waterproof adhesive for outdoor electronic equipment.

[0032] Example 2 A silicone waterproof adhesive for outdoor electronic equipment The components by weight are as follows: Component A: 30 parts of hydroxyl-terminated polydimethylsiloxane, 20 parts of methoxy-terminated polydimethylsiloxane, 15 parts of methyl silicone oil, 5 parts of epoxy soybean oil, 40 parts of attapulgite, and 8 parts of silica-modified attapulgite prepared in the basic example; Component B: 0.5 parts of dibutyltin dilaurate, 0.5 parts of dibutyltin diacetate catalyst, 50 parts of aminoethylpiperazine, 4 parts of epoxysilane, and 16 parts of allyltrimethoxysilane.

[0033] The preparation method is: S1. Put the raw materials of component A into a vacuum kneader and blend them. Control the temperature to 170° C. and the vacuum degree to 0.05 MPa. Blend for 3 hours. After blending, bring the mixture to room temperature to obtain component A. S2. Put the raw materials of component B into a reaction kettle and stir and mix them for 30 minutes to obtain component B.

[0034] S3. During use, component A and component B are mixed evenly in a mass ratio of 1:1 to obtain the silicone waterproof adhesive for outdoor electronic equipment.

[0035] Example 3: Silicone waterproof adhesive for outdoor electronic equipment The components by weight are as follows: Component A: 25.2 parts of hydroxyl-terminated polydimethylsiloxane, 14 parts of methoxy-terminated polydimethylsiloxane, 10 parts of methyl silicone oil, 5 parts of epoxy soybean oil, 32 parts of attapulgite, and 8 parts of silica-modified attapulgite prepared in the basic example; Component B: 0.3 parts of dibutyltin dilaurate, 0.3 parts of dibutyltin diacetate catalyst, 40 parts of aminoethylpiperazine, 4 parts of epoxysilane, and 12 parts of allyltrimethoxysilane.

[0036] The preparation method is: S1. Put the raw materials of component A into a vacuum kneader and blend them. Control the temperature to 170° C. and the vacuum degree to 0.05 MPa. Blend for 3 hours. After blending, bring the mixture to room temperature to obtain component A. S2. Put the raw materials of component B into a reaction kettle and stir and mix them for 30 minutes to obtain component B.

[0037] S3. During use, component A and component B are mixed evenly in a mass ratio of 1:1 to obtain the silicone waterproof adhesive for outdoor electronic equipment.

[0038] Comparative Example 1 The difference from Example 3 is that only hydroxyl-terminated polydimethylsiloxane is used as the base material, namely 39.2 parts of hydroxyl-terminated polydimethylsiloxane, and the rest is the same as Example 3.

[0039] Comparative Example 2 The difference from Example 3 is that the mass ratio of hydroxyl-terminated polydimethylsiloxane to methoxy-terminated polydimethylsiloxane is 1:3, that is, 14 parts of hydroxyl-terminated polydimethylsiloxane and 25.2 parts of methoxy-terminated polydimethylsiloxane, and the rest is the same as Example 3.

[0040] Comparative Example 3 The difference from Example 3 is that the filler is only attapulgite, that is, 40 parts of attapulgite, and the rest is the same as Example 3.

[0041] Comparative Example 4 The difference from Example 3 is that the silica-modified attapulgite is replaced with light calcium carbonate powder, and the rest is the same as Example 3.

[0042] Comparative Example 5 The difference from Example 3 is that the mass ratio of attapulgite to silica-modified attapulgite is 1:4, i.e., 82 parts of attapulgite and 32 parts of silica-modified attapulgite prepared in the basic example, and the rest is the same as Example 3.

[0043] Comparative Example 6 The difference from Example 3 is that the coupling agent is only epoxy silane, and the rest is the same as Example 3.

[0044] Effect experiment: 1. Mechanical properties test Under standard environmental conditions (temperature 23℃±2℃, humidity 50%±5%), components A and B were mixed in a mass ratio of 1:1 to form a flat film with a thickness of 2.0 mm±0.2 mm. After curing for 28 days under this condition, the dumbbell-shaped specimens required for the experiment were prepared according to the Type I sample preparation method in GB / T528-2009.

[0045] Tensile strength and elongation at break: tested according to GB / T 528-2009; Standard performance: the specimen is subjected to tensile test using an electronic tensile testing machine under standard conditions; High temperature resistance: The sample was placed in a 200℃ high temperature oven, taken out after 168 hours, placed under standard conditions for 24 hours, and subjected to a tensile test using an electronic tensile testing machine; Acid resistance: The sample was immersed in a 30% sulfuric acid solution for 168 hours, taken out and placed for 24 hours, and a tensile test was performed using an electronic tensile machine; Salt spray resistance: The sample was placed in a salt spray test chamber and subjected to a 1000-hour test cycle in accordance with GB / T 10125-2012. The sample was then taken out and placed under standard conditions for 24 hours, and a tensile test was performed using an electronic tensile testing machine.

[0046] The test results are shown in Tables 1-4 below.

[0047] Table 1 Tensile strength and elongation at break test According to the test results in Table 1 above, it can be seen that the outdoor electronic equipment silicone waterproof adhesive prepared in Examples 1-3 of the present invention has greater tensile strength and elongation at break. In the comparative example, changing the type of components or the ratio between the components will affect the mechanical properties of the waterproof adhesive to a certain extent, thereby reducing the tensile strength and elongation at break of the waterproof adhesive.

[0048] Table 2 High temperature resistance test According to the test results in Table 2 above, it can be seen that the outdoor electronic equipment silicone waterproof adhesive prepared in Examples 1-3 of the present invention has good high temperature resistance. Changing the type of components or the ratio between the components in the comparative examples will affect the high temperature resistance of the waterproof adhesive to a certain extent. In particular, changing the type or ratio of fillers in Comparative Examples 3-5 will significantly affect the high temperature resistance of the waterproof adhesive. After being treated at 200°C for 168h, the tensile strength and elongation at break of the waterproof adhesive are significantly reduced.

[0049] Table 3 Acid resistance test According to the test results in Table 3 above, it can be seen that the outdoor electronic equipment silicone waterproof adhesive prepared in Examples 1-3 of the present invention has good acid resistance. Changing the types of components or the ratios between the components in the comparative examples will affect the acid resistance of the waterproof adhesive to a certain extent. In particular, in Comparative Examples 1 and 6, only using hydroxyl-terminated polydimethylsiloxane as the base material, or changing the type of coupling agent, will significantly affect the acid resistance of the waterproof adhesive. After soaking in 30% sulfuric acid for 168 hours, the elongation at break of the waterproof adhesive is significantly reduced.

[0050] Table 4 According to the test results in Table 4 above, it can be seen that the silicone waterproof adhesive for outdoor electronic equipment prepared in Examples 1-3 of the present invention has good salt spray resistance. Changing the type of components or the ratio between the components in the comparative examples will affect the salt spray resistance of the waterproof adhesive to a certain extent. In particular, in Comparative Example 1 and Comparative Examples 3-5, only hydroxyl-terminated polydimethylsiloxane is used as the base material, or the type or ratio of the filler is changed, which will significantly affect the salt spray resistance of the waterproof adhesive. The tensile strength of the waterproof adhesive is significantly reduced after salt spray treatment.

[0051] 2. Waterproof performance The water vapor transmission rate was tested with reference to GB / T 1037-2021. The test results are shown in Table 5 below.

[0052] Table 5 Water vapor transmission rate test According to the test results in Table 5 above, it can be seen that the outdoor electronic equipment silicone waterproof adhesive prepared in Examples 1-3 of the present invention has a low water vapor permeability. Changing the types of components or the ratios between the components in the comparative examples will affect the waterproof effect of the waterproof adhesive to a certain extent. In particular, in Comparative Examples 1, 3 and 6, only hydroxyl-terminated polydimethylsiloxane is used as the base material, or the type of filler is changed, or the type of coupling agent is changed, which will significantly affect the waterproof performance of the waterproof adhesive and increase the water vapor permeability.

[0053] The above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A silicone waterproof adhesive for outdoor electronic equipment, characterized in that: The components are as follows by weight: Component A: 20-30 parts of hydroxyl-terminated polydimethylsiloxane, 10-20 parts of methoxy-terminated polydimethylsiloxane, 10-20 parts of plasticizer, and 30-50 parts of filler; Component B: 0.5-1 part of catalyst, 30-50 parts of curing agent, 10-20 parts of coupling agent; The mass ratio of the hydroxyl-terminated polydimethylsiloxane to the methoxy-terminated polydimethylsiloxane is 1-3:

1.

2. The outdoor electronic equipment waterproof silicone adhesive according to claim 1, characterized in that: The components are as follows by weight: Component A: 22-28 parts of hydroxyl-terminated polydimethylsiloxane, 12-18 parts of methoxy-terminated polydimethylsiloxane, 12-15 parts of plasticizer, and 35-45 parts of filler; Component B: 0.5-0.8 parts of catalyst, 35-45 parts of curing agent, 15-18 parts of coupling agent.

3. The outdoor electronic equipment waterproof silicone adhesive according to claim 1, characterized in that: The mass ratio of the hydroxyl-terminated polydimethylsiloxane to the methoxy-terminated polydimethylsiloxane is 1.8:

1.

4. The outdoor electronic equipment waterproof silicone adhesive according to claim 1, characterized in that: The plasticizer is selected from one or more of white oil, soybean oil, methyl silicone oil and epoxy soybean oil.

5. The outdoor electronic equipment waterproof silicone adhesive according to claim 4, characterized in that: The plasticizer is a mixture of methyl silicone oil and epoxy soybean oil, and the mass ratio of the two is 1-3:

1.

6. The outdoor electronic equipment waterproof silicone adhesive according to claim 1, characterized in that: The filler is a mixture of attapulgite and attapulgite modified by silicon dioxide, and the mass ratio of the two is 3-5:

1.

7. The outdoor electronic equipment waterproof silicone adhesive according to claim 6, characterized in that: The preparation method of the silicon dioxide modified attapulgite is: (1) adding water to attapulgite to prepare an attapulgite solution with a mass fraction of 20-30%; (2) adding water to sodium silicate to prepare a sodium silicate solution with a mass fraction of 20-30%; (3) adding the sodium silicate solution to the attapulgite solution under stirring conditions, adjusting the pH to 8-9.5; reacting at 50-60° C. for 0.5-1 h, adjusting the pH to 5.5-6.5, continuing the reaction for 3-5 hours, washing the reaction product, and drying it to obtain the silica-modified attapulgite; The mass ratio of attapulgite to sodium silicate is 2-5:

1.

8. The outdoor electronic equipment waterproof silicone adhesive according to claim 1, characterized in that: The coupling agent is a mixture of epoxy silane and allyl trimethoxy silane, and the mass ratio of the two is 1:2-4.

9. The outdoor electronic equipment waterproof silicone adhesive according to any one of claims 1 to 8, characterized in that: The components are as follows by weight: Component A: 25.2 parts of hydroxyl-terminated polydimethylsiloxane, 14 parts of methoxy-terminated polydimethylsiloxane, 10 parts of methyl silicone oil, 5 parts of epoxy soybean oil, 32 parts of attapulgite, and 8 parts of silica-modified attapulgite prepared in the basic example; Component B: 0.3 parts of dibutyltin dilaurate, 0.3 parts of dibutyltin diacetate catalyst, 40 parts of aminoethylpiperazine, 4 parts of epoxysilane, and 12 parts of allyltrimethoxysilane.

10. The method for preparing the silicone waterproof adhesive for outdoor electronic equipment according to any one of claims 1 to 9, characterized in that: The steps include: S1. Put the raw materials of component A into a vacuum kneader and blend them. Control the temperature to 160-180° C. and the vacuum degree to 0.02-0.05 MPa. Blend for 3-4 hours. After blending, bring the mixture to room temperature to obtain component A. S2. Put the raw materials of component B into a reaction kettle and stir and mix them for 20-40 minutes to obtain component B. S3. During use, component A and component B are mixed evenly in a mass ratio of 1:1 to obtain the silicone waterproof adhesive for outdoor electronic equipment.

Images