Two-component condensation deacidification type silicone adhesive with rapid deep curing and preparation method

Abstract

This invention relates to a rapid, deep-curing, two-component condensation-deacid-type silicone adhesive. The raw materials of this two-component deacid-type silicone adhesive include component A and component B. Component A consists of α,ω-dihydroxy polydimethylsiloxane, filler, and tungstate; component B consists of dimethyl silicone oil, filler, silicate, crosslinking agent, and catalyst. During the curing process, the condensation-deacidification and vulcanization of the silicone and the condensation-dehydration reaction of the inorganic heteropolyacids have a synergistic catalytic effect, ultimately achieving rapid, deep curing of the deacid-type silicone adhesive, with a curing depth ≥30mm within 24 hours. Simultaneously, the formed silicotungsten heteropolyacids can also act as inorganic tackifiers to enhance the adhesion of the silicone adhesive to the substrate. This adhesive is suitable for applications requiring rapid curing and good sealing and bonding, significantly improving work efficiency.

Description

Technical Field

[0001] This invention relates to a two-component condensation-deacid type silicone sealant that can be rapidly and deeply cured, belonging to the field of silicone sealants. Background Technology

[0002] Silicone sealants are widely used in construction, industry, aerospace, electronics, automobiles, new energy, photovoltaics and other fields due to their strong anti-aging ability, good weather resistance, excellent impact resistance, low shrinkage, and excellent electrical properties and insulation capabilities.

[0003] Condensation-type silicone sealants are typically formed by the vulcanization of α,ω-dihydroxy polydimethylsiloxane (commonly known as 107 silicone oil) and a crosslinking agent under the action of a catalyst. This process requires interaction with moisture in the air to form an elastomer. Depending on the crosslinking agent selected, condensation-type silicone sealants can be classified into deacidified, deoxime-de-alcoholized, deamined, deamided, and deketinated types, etc.

[0004] The curing effect of condensation-type silicone adhesives depends on temperature, humidity, and adhesive layer thickness. Under typical environmental conditions (temperature 25℃, humidity 50%RH), the adhesive layer can generally be surface-dry after 5-30 minutes, and a preliminary curing of an adhesive layer with a thickness of 0.1-2mm can be achieved within one day. However, as the curing depth increases, the rate at which the moisture required for the condensation reaction migrates from the surface to the interior becomes increasingly slower. A curing depth of more than 10mm and sufficient adhesion strength to the substrate often require more than a week. This drawback makes it unsuitable for rapid bonding, positioning, and sealing requirements, especially in applications emphasizing production efficiency such as home appliances and consumer electronics, which can severely impact customer work efficiency and thus limit the application and promotion of condensation-type silicone adhesives.

[0005] Therefore, it is essential to develop condensation-type silicone sealants that can cure rapidly at room temperature. The main idea of ​​patent CN201410296001.5 is to use low-viscosity hydroxyl silicone oil to undergo an organic dehydration condensation reaction under the catalysis of organotin to provide the moisture required for internal curing of silicone sealants. However, in order to provide sufficient moisture, more than 10,000 pppm of organotin catalyst needs to be added, resulting in serious heavy metal contamination. Other patents that achieve rapid curing of silicone sealants by introducing a dehydration condensation reaction are rarely reported. Summary of the Invention

[0006] This invention addresses the limitation of current condensation-type silicone adhesives in achieving rapid deep curing by developing a fast-curing two-component condensation-deacid-based silicone adhesive. During the curing process, the organosilicon condensation-deacidification and inorganic acid condensation-dehydration reactions synergistically catalyze each other, ultimately achieving rapid deep curing with a curing depth of ≥30mm within 24 hours. This adhesive is suitable for applications requiring rapid curing and good sealing adhesion, significantly improving work efficiency.

[0007] This invention is achieved through the following technical solution:

[0008] In the first aspect, the present invention provides a two-component condensation-deacidified silicone adhesive that can be rapidly and deeply cured:

[0009] A fast-curing, deep-curing, two-component condensation-deacid-type silicone sealant, comprising component A and component B, wherein:

[0010] Component A contains the following ingredients by weight percentage:

[0011] 107 silicone oil 45-60%

[0012] 25-40% filler

[0013] tungstate 10-25%

[0014] Component B contains the following components by weight percentage:

[0015]

[0016]

[0017] Preferably, the mass ratio of component A to component B is 4 to 10:1.

[0018] In this invention, the 107 silicone oil is the base polymer, and its viscosity is preferably 500 to 50000 cP;

[0019] In this invention, the filler is one or more of the following: silica powder, alumina, calcium carbonate, talc, diatomaceous earth, and glass microspheres.

[0020] In this invention, the tungstate is selected from one or more of ammonium tungstate, calcium tungstate, sodium tungstate, cobalt tungstate, cadmium tungstate, and ferrous tungstate, with calcium tungstate being preferred;

[0021] In this invention, the dimethyl silicone oil is a plasticizer, and its viscosity is preferably 50-20000 cP;

[0022] In this invention, the crosslinking agent is one or more of methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, di-tert-butoxydiacetoxysilane, and phenyltriacetoxysilane in combination;

[0023] In this invention, the silicate is selected from one or more of ammonium silicate, sodium silicate, potassium silicate, and ferric silicate, with ammonium silicate being preferred;

[0024] In this invention, the catalyst is an organotin catalyst, including one or more of monobutyltin oxide, dibutyltin oxide, dimethyltin oxide, dibutyltin acetate, dibutyltin dilaurate, di(dodecylthio)dibutyltin, dibutyltin maleate, and stannous octoate.

[0025] In this invention, during the adhesive curing process, the small molecule acid X-COOH is released during the organosilicon condensation deacidification and vulcanization process, which can be used as an acid regulator in the heteropolyacid formation process.

[0026]

[0027] Silicates and tungstates condense to form heteropolyacid silicotungstate [α-SiW] 11 O 39 ] 8- The water released during the process can be used as an accelerator for the organosilicon condensation deacidification and sulfidation reaction:

[0028] 11[WO4] 2- +[SiO3] 2- +16H + →[α-SiW 11 O 39 ] 8- +8H2O

[0029] Through the synergistic catalytic effect of organosilicon condensation deacidification sulfurization and inorganic heteropolyacid condensation dehydration reaction, rapid deep curing was ultimately achieved; simultaneously, the generated [α-SiW 11 O 39 ] 8- It can also be used as an inorganic tackifier to improve the adhesion of silicone adhesives.

[0030] Secondly, the present invention provides a method for preparing the above-mentioned rapidly deep-curing two-component condensation-deacid-reducing silicone sealant:

[0031] A method for preparing a rapid, deep-curing, two-component condensation-deacid-type silicone sealant, comprising the following steps:

[0032] (1) Add 107 silicone oil and filler to a stirring vessel, stir at 10-20 rpm / min, disperse at 300-500 rpm / min, heat to 100-130℃ and keep warm while vacuum stirring for 1-3 hours, then cool down to below 40℃, add tungstate, stir at 20-30 rpm / min, disperse at 800-1000 rpm / min, vacuum stir for 10-20 minutes to obtain component A;

[0033] (2) Add dimethyl silicone oil, filler, silicate, crosslinking agent and catalyst to a stirred tank, stir at 10-20 rpm / min and disperse at 300-500 rpm / min, and vacuum mix thoroughly for 10-20 min to obtain component B;

[0034] The A component prepared in step (1) and the B component prepared in step (2) are respectively packaged into KIT packaging tubes and sealed for storage, thus obtaining a two-component condensation deacidification silicone sealant that can be rapidly and deeply cured.

[0035] The adhesive of the present invention is suitable for applications requiring rapid curing and good sealing and bonding, and can significantly improve work efficiency.

[0036] The present invention has the following advantages and beneficial effects compared with the prior art:

[0037] In the curing process of the adhesive of the present invention, the organosilicon condensation deacidification and vulcanization reaction and the inorganic acid condensation dehydration reaction can play a synergistic catalytic effect, ultimately achieving rapid curing of the deacidified organosilicon adhesive, which can achieve a curing depth of ≥30mm in 24 hours; the curing process is carried out simultaneously from the surface and the interior, and is basically unaffected by the ambient humidity.

[0038] [α-SiW] generated during the curing process 11 O 39 ] 8- It can also be used as an inorganic tackifier to improve the adhesion of silicone adhesives.

[0039] This adhesive has promising applications in scenarios where production efficiency is paramount, such as home appliances and consumer electronics. Detailed Implementation

[0040] To facilitate understanding of the present invention, preferred embodiments are provided below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] Example 1

[0042] Add 5690g of 5000cp 107 silicone oil and 3240g of silicon micro powder to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min. Heat to 120℃ and hold under vacuum for 2 hours. Then cool down to below 40℃ and add 1070g of calcium tungstate. Stir at 20 rpm / min and disperse at 800 rpm / min under vacuum for 10 minutes to obtain component A.

[0043] Add 357g of 1000cP dimethyl silicone oil, 418.2g of silica powder, 133.8g of ammonium silicate, 89g of methyltriacetoxysilane, and 2g of dibutyltin dilaurate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min under vacuum for 20 minutes to obtain component B.

[0044] Component A and Component B are separately bottled into 10:1 KIT packaging tubes and sealed for storage to obtain Example Sample 1.

[0045] Example 2

[0046] Add 5690g of 1500cp 107 silicone oil and 2740g of calcium carbonate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min. Heat to 120℃, keep warm, and stir under vacuum for 2 hours. Then cool down to below 40℃, add 1570g of sodium tungstate, stir at 20 rpm / min and disperse at 800 rpm / min, and stir under vacuum for 10 minutes to obtain component A.

[0047] Add 377g of 100cP dimethyl silicone oil, 368.5g of calcium carbonate, 183.5g of sodium silicate, 68g of ethyltriacetoxysilane, and 3g of dibutyltin maleate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min. Vacuum and mix thoroughly for 20 minutes to obtain component B.

[0048] Component A and Component B are separately packaged into 10:1 KIT tubes and sealed for storage to obtain Example Sample 2.

[0049] Example 3

[0050] Add 4690g of 10000cp 107 silicone oil and 3240g of alumina powder to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min. Heat to 120℃ and hold under vacuum for 2 hours. Then cool to below 40℃ and add 2070g of ammonium tungstate. Stir at 20 rpm / min and disperse at 800 rpm / min. Vacuum stir for 10 minutes to obtain component A.

[0051] Add 307g of 5000cP dimethyl silicone oil, 348.6g of alumina powder, 233.4g of ammonium silicate, 107g of phenyltriacetoxysilane, and 4g of dibutyltin maleate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min under vacuum for 20 minutes to obtain component B.

[0052] Components A and B are separately packaged into 10:1 KIT tubes and sealed for storage to obtain Example Sample 3.

[0053] Example 4

[0054] Add 4950g of 10000cp 107 silicone oil and 2840g of alumina powder to a double planetary mixer. Stir at 15rpm / min and disperse at 500rpm / min. Heat to 120℃ and hold under vacuum for 2 hours. Then cool to below 40℃ and add 2210g of ammonium tungstate. Stir at 20rpm / min and disperse at 800rpm / min under vacuum for 10 minutes to obtain component A.

[0055] Add 307g of 3000cP dimethyl silicone oil, 394g of alumina powder, 197g of ammonium silicate, 100g of phenyltriacetoxysilane, and 2g of dibutyltin dilaurate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min under vacuum for 20 minutes to obtain component B.

[0056] Take component A and component B and put them into 6:1 KIT packaging tubes and seal them for storage to obtain sample 4 of example.

[0057] Comparative Example 1

[0058] Add 5690g of 5000cp 107 silicone oil and 4310g of silicon micro powder to a double planetary mixer. Stir at 15rpm / min and disperse at 500rpm / min. Heat to 120℃ and keep warm under vacuum for 2 hours. Then cool to room temperature to obtain component A.

[0059] Add 357g of 1000cP dimethyl silicone oil, 552g of silicon micro powder, 89g of methyltriacetoxysilane, and 2g of dibutyltin dilaurate to a double planetary mixer. Stir at 15 rpm / min and disperse at 500 rpm / min. Vacuum and mix thoroughly for 20 minutes to obtain component B.

[0060] Components A and B were separately bottled into 10:1 KIT packaging tubes and sealed for storage to obtain control sample 1.

[0061] The above examples and comparative examples were tested at the same temperature and humidity (temperature 25±2℃, humidity 50±5%RH) for different time periods at room temperature (total adhesive layer height 40mm). Simultaneously, the shear strength of the samples against PC was tested at different time periods. The relevant comparative results are as follows:

[0062] Curing depth test method: After mixing components A and B, pour the mixture into a disposable plastic cup, control the adhesive layer thickness to 40mm, place the sample in a standard environment (temperature 25±2℃, humidity 50±5%RH), and take it out at different time periods to test the thickness of the cured adhesive layer.

[0063] Shear strength test method: GB / T 7124-2008 Determination of tensile shear strength of adhesives (rigid material to rigid material) standard.

[0064] Table 1 Comparison of Curing Depth of Two-Component Deacid-Reducing Silicone Adhesives

[0065]

[0066] Table 2 Comparison of Bonding Strength of Two-Component Deacidified Silicone Adhesive PC

[0067]

[0068] Comparing the performance data of the silicone sealants in the above examples and comparative examples, the deep curing speed of Examples 1, 2, 3, and 4 is significantly faster than that of Comparative Example 1, which did not introduce the inorganic heteropoly acid condensation dehydration reaction. Examples 1, 2, 3, and 4 can achieve a maximum curing depth of ≥30mm after 24 hours. At the same time, comparing the bonding effect on PC material, Examples 1, 2, 3, and 4 can achieve a very high bonding strength in a short time compared to Comparative Example 1, and can reach the final bonding strength in 24 hours. The above proves that the condensation deacidification type silicone sealant has the effects of rapid deep curing, rapid positioning, and sealing.

[0069] The above description is only a preferred embodiment of the present invention and is 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 within the protection scope of the present invention.

Claims

1. A two-component condensation-deacidified silicone sealant capable of rapid deep curing, characterized in that, Includes component A and component B: Component A contains the following ingredients by weight percentage: 107 silicone oil 45-60% 25-40% filler tungstate 10-25% Component B contains the following components by weight percentage: Dimethyl silicone oil 20-40% 30-50% filler Silicate 10-25% Crosslinking agent 5-15% Catalyst 0.1-0.5%; The mass ratio of component A to component B is 4~10:

1.

2. The silicone sealant according to claim 1, wherein, The viscosity of the 107 silicone oil is 500~50000 cP.

3. The silicone sealant according to claim 1, wherein, The filler is one or more of the following: silica powder, alumina, calcium carbonate, talc, diatomaceous earth, and glass microspheres.

4. The silicone sealant according to claim 1, wherein, The tungstate is selected from one or more of ammonium tungstate, calcium tungstate, sodium tungstate, cobalt tungstate, cadmium tungstate, and ferrous tungstate.

5. The silicone sealant according to claim 1, wherein, The viscosity of the dimethyl silicone oil is 50-20000 cP.

6. The silicone sealant according to claim 1, wherein, The silicate is selected from one or more of ammonium silicate, sodium silicate, potassium silicate, and iron silicate.

7. The silicone sealant according to claim 1, wherein, The crosslinking agent is one or more of methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, di-tert-butoxydiacetoxysilane, and phenyltriacetoxysilane.

8. The silicone sealant according to claim 1, wherein, The catalyst is an organotin catalyst.

9. The silicone sealant according to claim 8, wherein, The catalyst is one or more of monobutyltin oxide, dibutyltin oxide, dimethyltin oxide, dibutyltin acetate, dibutyltin dilaurate, di(dodecylthio)dibutyltin, dibutyltin maleate, and stannous octoate.

10. A method for preparing silicone sealant according to any one of claims 1-9, comprising: (1) Add 107 silicone oil and filler to a stirring vessel, heat to 100-130℃, keep warm and stir under vacuum, then cool down to below 40℃, add tungstate, stir under vacuum, and obtain component A; (2) Add dimethyl silicone oil, filler, silicate, crosslinking agent and catalyst into a stirring vessel and stir. Vacuum the mixture thoroughly to obtain component B.

Images