Organic silicon modified polyurethane adhesive and preparation method thereof

Abstract

The invention relates to the field of polymer adhesive materials, and particularly discloses an organic silicon modified polyurethane adhesive and a preparation method thereof. The organic silicon modified polyurethane adhesive is prepared from the following raw materials in parts by weight: 70 to 100 parts of polyether polyol, 60 to 90 parts of isocyanate, 20 to 35 parts of an organic silicon monomer composite material, 1 to 5 parts of a catalyst, 2 to 8 parts of a chain extender, 2 to 5 parts of an anti-aging aid, 2 to 6 parts of nano filler and 1 to 2 parts of a de-foaming agent, the organic silicon monomer composite material is prepared from vinyl trimethylsilane composite liquid, amino silane composite liquid and hydroxyl silicone oil in a mass ratio of 1: (0.5-1): (1-2); the preparation method comprises the following steps: uniformly mixing the polyether polyol, the isocyanate and the chain extender to obtain a primary mixture; adding an organic silicon monomer composite material, a catalyst and a nano filler, and uniformly mixing to obtain a mixture; adding an anti-aging aid and a defoaming agent, uniformly mixing, and defoaming to obtain a finished product. Meanwhile, the adhesive has the advantages of high bonding strength and good aging resistance.

Description

Technical Field

[0001] The present invention relates to the field of polymer adhesive materials, and more specifically, to an organosilicon-modified polyurethane adhesive and a preparation method thereof. Background Art

[0002] Although traditional polyurethane adhesives have good bonding properties and certain weather resistance, their performance is easily affected under extreme environmental conditions, such as high temperature, strong ultraviolet radiation or long-term exposure to oxidative environments, leading to problems such as decreased adhesion and accelerated aging.

[0003] Silicone materials have excellent heat resistance, oxidation resistance and low surface energy properties, but when used alone they often cannot meet the requirements of high-strength bonding.

[0004] Therefore, developing a new adhesive that can maintain the high bonding strength of polyurethane and also have the aging resistance of silicone is a problem to be solved. Summary of the Invention

[0005] In order to prepare a polyurethane adhesive having both high bonding strength and good aging resistance, the present application provides a silicone-modified polyurethane adhesive and a preparation method thereof.

[0006] In the first aspect, the present application provides a silicone-modified polyurethane adhesive, which adopts the following technical solution: a silicone-modified polyurethane adhesive, comprising the following raw materials in parts by weight: 70-100 parts of polyether polyol, 60-90 parts of isocyanate, 20-35 parts of silicone monomer compound, 1-5 parts of catalyst, 2-8 parts of chain extender, 2-5 parts of aging-resistant additive, 2-6 parts of nanofiller, and 1-2 parts of defoaming agent; the silicone monomer compound is composed of vinyltrimethylsilane composite liquid, aminosilane composite liquid and hydroxy silicone oil in a mass ratio of 1:0.5-1:1-2.

[0007] By adopting the above technical solution, silicone monomer compounds are added to polyether polyols and isocyanates, and the silicone monomer compounds have better dispersion and cross-linking effects. The chain extender increases the length of the polyurethane molecular chain, and the thickening effect of the nanofiller is combined. The silicone monomer compound and the nanofiller have a higher cross-linking degree in the polyurethane adhesive, thereby making the polyurethane have a higher bonding strength.

[0008] The cross-linking effect of vinyltrimethylsilane, aminosilane and hydroxy silicone oil with polyether polyol and isocyanate improves the dispersion stability of the silicone monomer compound in polyurethane, ensuring the bonding strength. At the same time, the aging resistance of silane and silicone oil is utilized to make the polyurethane adhesive have better aging resistance.

[0009] Preferably, the vinyltrimethylsilane composite solution is composed of vinyltrimethylsilane, polycrystalline mullite whiskers and polyethylene glycol solution in a mass ratio of 10:1-1.5:0.5-1.

[0010] By adopting the above technical solution, the porous surface of the polycrystalline mullite whiskers is used to load vinyltrimethylsilane, and the silicon in the polycrystalline mullite whiskers is easily connected with the vinyltrimethylsilane. At the same time, the viscosity of the polyethylene glycol solution is used to further promote the adhesion of vinyltrimethylsilane to the surface of the polycrystalline mullite whiskers.

[0011] The silicon in the polycrystalline mullite whiskers is convenient for connecting with vinyltrimethylsilane, and the silicon hydroxyl groups on the surface of the polycrystalline mullite whiskers and the hydroxyl groups in the polyethylene glycol facilitate further cross-linking of the silicone monomer compound with the polyether polyol and isocyanate. With the polycrystalline mullite whiskers as the skeleton, a larger area is in contact with the polyether polyol and isocyanate, thereby improving the cross-linking density and cross-linking stability, so that the vinyltrimethylsilane is stably connected in the cross-linking network of the polyether polyol and isocyanate, thereby making the polyurethane adhesive have higher bonding strength and better compatibility and connectivity with the silicone monomer, thereby ensuring the aging resistance of the polyurethane adhesive.

[0012] Preferably, the aminosilane composite liquid is composed of aminosilane, hydroxyapatite whiskers and triethanolamine in a mass ratio of 10:1-2:0.5-1.

[0013] By adopting the above technical solution, the surface of the hydroxyapatite whisker is loaded with aminosilane, and the bonding effect of triethanolamine is utilized to further promote the attachment of aminosilane to the surface of the hydroxyapatite whisker.

[0014] The hydroxyl groups of the hydroxyapatite whiskers in the aminosilane composite liquid and the amino groups in the triethanolamine are utilized to promote further cross-linking of the aminosilane composite liquid with the vinyltrimethylsilane composite liquid, polyether polyol and isocyanate, thereby improving the cross-linking effect of the aminosilane with the polyether polyol and isocyanate with the hydroxyapatite whiskers as the supporting skeleton, so that the cross-linking density in the polyurethane adhesive is higher; at the same time, the cross-linking points in the polyurethane are increased, and the polyurethane molecular chain is further extended, so that the polyurethane adhesive has a higher bonding strength. The aminosilane composite liquid has good aging resistance and can also be uniformly cross-linked and dispersed in the polyurethane molecules, thereby ensuring that the polyurethane adhesive has high bonding strength while having good aging resistance.

[0015] Preferably, the nanofiller is composed of modified silica whiskers and cellulose fiber filaments in a mass ratio of 1:0.3-0.5.

[0016] By adopting the above technical solution, the cross-linking effect of silica whiskers with aminosilane and vinyltrimethylsilane is utilized, combined with the better flexible folding effect of cellulose fiber and its own hydroxyl group, the cross-linking effect of nanofillers with silicone monomer composites, polyether polyols, and isocyanates is further improved. The presence of the cross-linked network can effectively improve stress distribution, reduce stress concentration, and thus improve the bonding strength of the nanofillers.

[0017] Silica whiskers and cellulose fiber filaments have good aging resistance and can resist the erosion of harsh environments such as ultraviolet rays, high temperature and low temperature, thereby improving the aging resistance of polyurethane adhesives and extending their service life.

[0018] Preferably, the modified silica whiskers are prepared from silica whiskers and chitosan solution in a mass ratio of 1:0.2-0.3.

[0019] By adopting the above technical solution, the bonding effect of the chitosan solution is utilized to facilitate adhesion to the surface of the silica whisker, and the amino groups in the chitosan on the surface of the silica whisker are connected with the hydroxyl groups and amino groups in the polyether polyol, isocyanate and silicone monomer composite material, thereby improving the dispersion effect and cross-linking effect of the silica whisker in the polyurethane network structure, and combining with the aging resistance of the silica whisker to further improve the aging resistance of the polyurethane adhesive; at the same time, combining with the cross-linked network structure formed by the chitosan, the bonding strength of the polyurethane adhesive is further improved, thereby extending its service life.

[0020] Preferably, the chain extender consists of polyethylene glycol 600 and propylene glycol in a mass ratio of 1:1-2.

[0021] By adopting the above technical solution, polyethylene glycol 600 and propylene glycol utilize their hydroxyl groups to promote the cross-linking of polyether polyol and isocyanate, thereby extending the polyurethane molecular chain. The long-chain polyurethane increases the bonding strength and aging resistance of the polyurethane adhesive.

[0022] Preferably, the anti-aging additive is composed of an ultraviolet absorber, an antioxidant and a light stabilizer in a mass ratio of 1:0.5-1:0.5-1.

[0023] By adopting the above technical solution, the ultraviolet absorber, antioxidant and light stabilizer are combined to further improve the aging resistance of the polyurethane adhesive.

[0024] In a second aspect, the present application provides a method for preparing a silicone-modified polyurethane adhesive, which adopts the following technical solution: A method for preparing a silicone-modified polyurethane adhesive comprises the following steps: S1. Mix polyether polyol, isocyanate, and chain extender uniformly, and treat at 80-85° C. for 1-2 hours to obtain a primary mixture; S2. Add organosilicon monomer composite, catalyst, and nanofiller to the primary mixture and continue treating for 1-2 hours to obtain a mixture; S3. Add anti-aging additives and defoaming agents to the mixture, mix and stir evenly, and vacuum degas to obtain the finished product.

[0025] By adopting the above technical solution, the prepared polyurethane adhesive has the advantages of high bonding strength and good aging resistance.

[0026] Preferably, the vinyltrimethylsilane composite liquid in the organosilicon monomer composite is prepared by the following method: immersing and dispersing polycrystalline mullite whiskers in vinyltrimethylsilane, then adding polyethylene glycol solution to the vinyltrimethylsilane, and continuing to immerse and disperse to obtain a finished product.

[0027] By adopting the above technical solution, the polycrystalline mullite whiskers are porous and the pores are interconnected, ensuring that vinyltrimethylsilane enters the porous structure and attaches to the pore surface. Combined with the viscosity of the polyethylene glycol solution, the vinyltrimethylsilane is further adhered to the surface of the polycrystalline mullite whiskers. The large specific surface area of the polycrystalline mullite whiskers is utilized in combination with the hydroxyl groups of the polyethylene glycol to promote the cross-linking of the vinyltrimethylsilane composite liquid with the polyether polyol and isocyanate, thereby improving the bonding strength of the polyurethane adhesive.

[0028] The higher cross-linking density, combined with the better weather resistance of the silicone in vinyltrimethylsilane and the better aging resistance of the polycrystalline mullite whiskers, further improves the aging resistance of the polyurethane adhesive.

[0029] Preferably, the aminosilane composite liquid in the organosilicon monomer composite is prepared by the following method: The hydroxyapatite whiskers are etched, then immersed and dispersed in aminosilane, and then triethanolamine is added to the aminosilane, and the immersion and dispersion treatment is continued to obtain a finished product.

[0030] By adopting the above technical solution, the surface roughness of the hydroxyapatite whiskers is increased after etching, and then they are immersed in aminosilane. The amino groups in the aminosilane and the hydroxyl and amino groups in the triethanolamine are utilized to further facilitate the attachment of the aminosilane to the pores and surface of the hydroxyapatite whiskers. The large specific surface area of the hydroxyapatite whiskers is utilized in combination with the amino and hydroxyl groups attached to their surfaces to further increase the crosslinking degree between the aminosilane composite liquid and the polyether polyol and isocyanate, thereby improving the bonding strength of the polyurethane adhesive.

[0031] Hydroxyapatite whiskers have high strength and good aging resistance. Combined with the good aging resistance and cross-linking effect of aminosilane and the role of triethanolamine in improving the cross-linking network, they further improve the mechanical strength and aging resistance of polyurethane adhesives and extend their service life.

[0032] In summary, this application has the following beneficial effects: 1. Adding silicone monomer compound to polyether polyol and isocyanate, taking advantage of the better dispersion and cross-linking effect of silicone monomer compound, chain extender increases the length of polyurethane molecular chain, combined with the thickening effect of nano filler, so that the silicone monomer compound and nano filler have a higher cross-linking degree in polyurethane adhesive, thereby making the polyurethane have higher bonding strength.

[0033] 2. In the silicone monomer compound, the hydroxyl groups in the polyethylene glycol and the amino groups in the triethanolamine in the silicone monomer compound are used to form a cross-linked structure supported by polycrystalline mullite whiskers and hydroxyapatite whiskers with polyether polyols and isocyanates, which promotes the extension of the polyurethane molecular chain, thereby enhancing the continuity of the polyurethane, increasing the length of the molecular chain while increasing the cross-linking points, further promoting the formation of a cross-linked network, and thus improving the bonding strength of the polyurethane adhesive.

[0034] 3. The chitosan and cellulose fiber in the nanofiller are combined, and the amino and hydroxyl groups in the chitosan are combined with the hydroxyl groups in the cellulose fiber to improve the cross-linking effect between the nanofiller and the polyether polyol and isocyanate. The larger specific surface area of the silica whiskers further promotes the formation of the cross-linking network. The flexibility of the cellulose fiber further increases the cross-linking density and the cross-linking point, thereby improving the bonding strength and mechanical strength of the polyurethane adhesive.

[0035] 4. The hydroxyl groups on the surface of polycrystalline mullite whiskers cooperate with the amino groups of aminosilane and the hydroxyl groups of hydroxy silicone oil to further promote the crosslinking of vinyltrimethylsilane composite liquid with aminosilane composite liquid, hydroxy silicone oil, polyether polyol and isocyanate, thereby improving the crosslinking effect and coordinating with the aging resistance of silane and silicone oil, so that the polyurethane adhesive has higher bonding strength and better aging resistance. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the embodiments.

[0037] Preparation Example of Vinyltrimethylsilane Composite Liquid The vinyltrimethylsilane in the following raw materials was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.; other raw materials were commercially available.

[0038] Preparation Example 1: Vinyltrimethylsilane composite liquid was prepared by the following method: 1 kg of polycrystalline mullite whiskers are immersed in 10 kg of vinyltrimethylsilane, where the average length of the polycrystalline mullite whiskers is 15 μm. Ultrasonic dispersion is carried out at 20 kHz for 20 minutes, and the average open porosity of the polycrystalline mullite whiskers is 30%-35%. Then, 1 kg of polyethylene glycol solution is added to the vinyltrimethylsilane, where the polyethylene glycol solution is a polyethylene glycol ethanol solution with a mass fraction of 10%, and the polyethylene glycol is polyethylene glycol 20000. The soaking and dispersion is continued for 20 minutes to obtain a finished product.

[0039] Preparation Example 2: This preparation example differs from Preparation Example 1 in that: 1.5 kg of polycrystalline mullite whiskers were immersed in 10 kg of vinyltrimethylsilane and ultrasonically dispersed at 20 kHz for 20 minutes. The average open porosity of the polycrystalline mullite whiskers was 30%-35%. Then, 0.5 kg of polyethylene glycol solution was added to the vinyltrimethylsilane and the immersion and dispersion were continued for 20 minutes to obtain a finished product.

[0040] Preparation example of aminosilane composite liquid The aminosilane in the following raw materials was purchased from Guangzhou Longkai Chemical Co., Ltd. as aminosilane KH-A1130; other raw materials were commercially available.

[0041] Preparation Example 3: The aminosilane composite liquid was prepared by the following method: 1 kg of hydroxyapatite whiskers were laser etched, with an average surface porosity of 8%-10% and an average length of 20 μm. The whiskers were then immersed in 10 kg of aminosilane and ultrasonically dispersed at 20 kHz for 20 minutes. 1 kg of triethanolamine was then added to the aminosilane and the immersion and dispersion process was continued for another 20 minutes to obtain a finished product.

[0042] Preparation Example 4: This preparation example differs from Preparation Example 3 in that: 2 kg of hydroxyapatite whiskers were laser etched, with an average surface porosity of 8%-10% and an average length of 20 μm. The whiskers were then immersed in 10 kg of aminosilane and dispersed at 20 kHz for 20 minutes. 0.5 kg of triethanolamine was then added to the aminosilane and the mixture was immersed and dispersed for another 20 minutes to obtain a finished product.

[0043] Preparation example of modified silica whiskers The following raw materials are all commercially available.

[0044] Preparation Example 5: Modified silica whiskers were prepared by the following method: 0.3 kg of chitosan solution was evenly sprayed on the surface of 1 kg of silica whiskers. The average length of the silica whiskers was 500 nm. The chitosan solution was a 1% chitosan acetic acid solution with an acetic acid concentration of 2%. The solution was dried and broken up until the silica whiskers did not stick to each other and agglomerated to obtain modified silica whiskers.

[0045] Preparation Example 6: This preparation example differs from Preparation Example 5 in that: 0.2 kg of chitosan solution was evenly sprayed on the surface of 1 kg of silica whiskers. The average length of the silica whiskers was 500 nm. The chitosan solution was a 1% chitosan acetic acid solution with an acetic acid concentration of 2%. The product was obtained by drying and breaking up the silica whiskers until they were no longer adhered to each other. Example

[0046] Among the following raw materials, polyether polyol was purchased from Shandong Tianhe Chemical Co., Ltd.; isocyanate was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.; UV absorber was purchased from Qingdao Jidejia New Material Technology Co., Ltd. as UV absorber UV571; antioxidant was purchased from Nanjing Milan New Materials Co., Ltd., model 5057; light stabilizer was purchased from Fujian Disheng Technology Co., Ltd., model UV-123; other raw materials are all commonly available on the market.

[0047] Example 1: A silicone-modified polyurethane adhesive: 85kg of polyether polyol, 80kg of isocyanate, 30kg of organosilicon monomer compound, 3kg of catalyst, 5kg of chain extender, 4kg of anti-aging agent, 5kg of nanofiller, and 1kg of defoamer; the organosilicon monomer compound consists of the vinyltrimethylsilane composite liquid prepared in Preparation Example 1, the aminosilane composite liquid prepared in Preparation Example 3, and hydroxy silicone oil in a mass ratio of 1:1:2; the catalyst is dibutyltin dilaurate; the chain extender consists of polyethylene glycol 600 and propylene glycol in a mass ratio of 1:1; the anti-aging agent consists of an ultraviolet absorber, an antioxidant, and a light stabilizer in a mass ratio of 1:1:1; the nanofiller consists of modified silica whiskers prepared in Preparation Example 5 and cellulose fiber filaments in a mass ratio of 1:0.4, and the average length of the cellulose fiber filaments is 300nm; the defoamer is an organosilicon defoamer; The preparation method is as follows: S1. Mix polyether polyol, isocyanate and chain extender evenly, and treat at 80°C for 2 hours to obtain a primary mixture; S2, adding the organosilicon monomer composite, catalyst, and nanofiller to the primary mixture and continuing the process for 2 hours to obtain a mixture; S3. Add anti-aging additives and defoaming agents to the mixture and mix for 30 minutes. After stirring evenly, vacuum degassing is performed to obtain the finished product.

[0048] Example 2: This example differs from Example 1 in that: 70kg of polyether polyol, 60kg of isocyanate, 20kg of organosilicon monomer compound, 1kg of catalyst, 2kg of chain extender, 2kg of anti-aging agent, 2kg of nanofiller, and 1kg of defoamer; the organosilicon monomer compound consists of the vinyltrimethylsilane composite liquid prepared in Preparation Example 2, the aminosilane composite liquid prepared in Preparation Example 4, and hydroxy silicone oil in a mass ratio of 1:0.5:1; the catalyst is dibutyltin dilaurate; the chain extender consists of polyethylene glycol 600 and propylene glycol in a mass ratio of 1:2; the anti-aging agent consists of an ultraviolet absorber, an antioxidant, and a light stabilizer in a mass ratio of 1:0.5:0.5; the nanofiller consists of modified silica whiskers prepared in Preparation Example 6 and cellulose fiber filaments in a mass ratio of 1:0.3, and the average length of the cellulose fiber filaments is 300nm; the defoamer is an organosilicon defoamer; The preparation method is as follows: S1. Mix polyether polyol, isocyanate and chain extender evenly, and treat at 85°C for 1 hour to obtain a primary mixture; S2, adding the organosilicon monomer composite, catalyst, and nanofiller to the primary mixture and continuing the treatment for 1 hour to obtain a mixture; S3. Add anti-aging additives and defoaming agents to the mixture and mix for 30 minutes. After stirring evenly, vacuum degassing is performed to obtain the finished product.

[0049] Example 3: This example differs from Example 1 in that: 100kg of polyether polyol, 90kg of isocyanate, 35kg of organosilicon monomer compound, 5kg of catalyst, 8kg of chain extender, 5kg of anti-aging additive, 6kg of nanofiller, and 2kg of defoamer; the organosilicon monomer compound consists of the vinyltrimethylsilane composite liquid prepared in Preparation Example 1, the aminosilane composite liquid prepared in Preparation Example 3, and hydroxy silicone oil in a mass ratio of 1:1:2; the catalyst is dibutyltin dilaurate; the chain extender consists of polyethylene glycol 600 and propylene glycol in a mass ratio of 1:2; the nanofiller consists of modified silica whiskers prepared in Preparation 5 and cellulose fiber filaments in a mass ratio of 1:0.5, and the average length of the cellulose fiber filaments is 300nm; the defoamer is an organosilicon defoamer; The preparation method is as follows: S1. Mix polyether polyol, isocyanate and chain extender evenly, and treat at 85°C for 1 hour to obtain a primary mixture; S2, adding the organosilicon monomer composite, catalyst, and nanofiller to the primary mixture and continuing the treatment for 1 hour to obtain a mixture; S3. Add anti-aging additives and defoaming agents to the mixture and mix for 30 minutes. After stirring evenly, vacuum degassing is performed to obtain the finished product.

[0050] Example 4: This example differs from Example 1 in that: No polycrystalline mullite whiskers were added during the preparation of the vinyltrimethylsilane composite solution, and no hydroxyapatite whiskers were added during the preparation of the aminosilane composite solution.

[0051] Example 5: This example differs from Example 1 in that: No polyethylene glycol solution was added during the preparation of the vinyltrimethylsilane composite solution, and no triethanolamine was added during the preparation of the aminosilane composite solution.

[0052] Example 6: This example differs from Example 1 in that: No cellulose fibers were added to the nanofiller.

[0053] Example 7: This example differs from Example 1 in that: The modified silica whiskers are replaced by silica whiskers of equal mass in the nanofiller.

[0054] Comparative Example Comparative Example 1: The difference between this comparative example and Example 1 is that: The organic silicon monomer compound is replaced by methyl silicone oil of equal mass in the raw materials.

[0055] Comparative Example 2: This comparative example differs from Example 1 in that: No nanofillers are added to the raw materials.

[0056] Performance testing 1. Bond strength test Polyurethane adhesives were prepared using the methods of Examples 1-7 and Comparative Examples 1-2, respectively. The shear strength was tested with reference to GB / T7124-2008 "Determination of tensile shear strength of adhesives". The glass plate substrate size was 100 mm × 25 mm, and the adhesive layer thickness was controlled to be 0.2 mm. After curing, the adhesive was placed in a standard environment at an ambient temperature of 23°C and a relative humidity of 50% for 7 days before testing. The test speed was 5 mm / min, and the data was recorded.

[0057] 2. UV resistance test Polyurethane adhesives were prepared using the methods of Examples 1-7 and Comparative Examples 1-2, respectively. The polyurethane adhesives were coated on glass plates and, after curing, placed in a standard environment at 23° C. and 50% relative humidity for 7 days. The adhesive layer had a size of 100 mm × 25 mm and an average thickness of 0.2 mm after curing. Then irradiate the glass plate with a UV lamp at a wavelength of 350nm for 24 hours, with the UV lamp 30cm away from the glass plate. Then, refer to GB / T7124-2008 "Determination of tensile shear strength of adhesives" to test the shear strength at a test speed of 5mm / min, and record the data. 3. High temperature resistance test Polyurethane adhesives were prepared using the methods of Examples 1-7 and Comparative Examples 1-2, respectively. The polyurethane adhesives were coated on glass plates and, after curing, placed in a standard environment at 23° C. and 50% relative humidity for 7 days. The adhesive layer had a size of 100 mm × 25 mm and an average thickness of 0.2 mm after curing. Then irradiate at 100°C for 240 hours, and then test the shear strength with reference to GB / T7124-2008 "Determination of tensile shear strength of adhesives" at a test speed of 5 mm / min, and record the data.

[0058] Table 1 Performance test table It can be seen from Examples 1-3 and Table 1 that the polyurethane adhesive prepared in the present application has high bonding strength, and even after ultraviolet radiation and high temperature treatment, it still has high bonding strength, thereby ensuring the service life of the polyurethane adhesive.

[0059] From Example 1 and Examples 4-7 and Table 1, it can be seen that no polycrystalline mullite whiskers were added during the preparation of the vinyltrimethylsilane composite liquid in Example 4, and no hydroxyapatite whiskers were added during the preparation of the aminosilane composite liquid. Compared with Example 1, the shear strength of Example 4 is lower than that of Example 1; this indicates that the polycrystalline mullite whiskers and hydroxyapatite whiskers are matched to utilize their larger specific surface area to increase the crosslinking point and improve the stress distribution, thereby improving the bonding strength of the polyurethane adhesive. At the same time, the polycrystalline mullite whiskers and hydroxyapatite whiskers have good aging resistance, can improve the aging resistance of the polyurethane adhesive, and extend its service life.

[0060] In the preparation process of the vinyltrimethylsilane composite liquid of Example 5, no polyethylene glycol solution was added, and no triethanolamine was added during the preparation process of the aminosilane composite liquid. Compared with Example 1, the shear strength of Example 5 is lower than that of Example 1; this indicates that the hydroxyl groups and amino groups in polyethylene glycol and triethanolamine can further promote the crosslinking of polycrystalline mullite whiskers and hydroxyapatite whiskers with polyether polyols and isocyanates, thereby further increasing the crosslinking density, thereby improving the bonding strength and aging resistance of the polyurethane adhesive.

[0061] No cellulose fiber filaments were added to the nanofiller in Example 6. Compared with Example 1, the shear strength of Example 6 was lower than that of Example 1, indicating that the hydroxyl groups of the cellulose fiber filaments can be cross-linked with polyether polyols and isocyanates, thereby further increasing the degree of cross-linking and improving stress concentration points, thereby improving the bonding strength and aging resistance of the polyurethane adhesive.

[0062] In Example 7, the modified silica whiskers were replaced with silica whiskers of equal mass in the nanofiller. Compared with Example 1, the shear strength of Example 7 was lower than that of Example 1, indicating that the amino and hydroxyl groups in chitosan can be cross-linked with polyether polyols and isocyanates, thereby further improving the degree of cross-linking, improving stress concentration points, and at the same time amplifying the cross-linking points and extending the length of the polyurethane molecular chain, thereby further improving the bonding strength and aging resistance of the polyurethane adhesive.

[0063] Combining Example 1 and Comparative Examples 1-2 and Table 1, it can be seen that the organic silicone monomer composite material in Comparative Example 1 is replaced by methyl silicone oil of equal mass. Compared with Example 1, the shear strength of Comparative Example 1 is lower than that of Example 1; this shows that the combination of vinyltrimethylsilane composite liquid and aminosilane composite liquid can improve the bonding strength and aging resistance of the polyurethane adhesive.

[0064] No nanofiller was added to the raw materials of Comparative Example 2. Compared with Example 1, the shear strength of Comparative Example 2 was lower than that of Example 1, indicating that the addition of nanofillers can increase the cross-linking points and utilize its nanofilling effect to further improve the bonding strength and aging resistance of the polyurethane adhesive.

[0065] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A silicone-modified polyurethane adhesive, characterized in that: The invention comprises the following raw materials in parts by weight: 70-100 parts of polyether polyol, 60-90 parts of isocyanate, 20-35 parts of organosilicon monomer compound, 1-5 parts of catalyst, 2-8 parts of chain extender, 2-5 parts of anti-aging additive, 2-6 parts of nanofiller, and 1-2 parts of defoaming agent; the organosilicon monomer compound is composed of vinyltrimethylsilane composite liquid, aminosilane composite liquid and hydroxy silicone oil in a mass ratio of 1:0.5-1:1-2.

2. The organosilicon-modified polyurethane adhesive according to claim 1, characterized in that: The vinyltrimethylsilane composite liquid consists of vinyltrimethylsilane, polycrystalline mullite whiskers and polyethylene glycol solution in a mass ratio of 10:1-1.5:0.5-1.

3. The organosilicon-modified polyurethane adhesive according to claim 1, characterized in that: The aminosilane composite liquid consists of aminosilane, hydroxyapatite whiskers and triethanolamine in a mass ratio of 10:1-2:0.5-1.

4. The organosilicon-modified polyurethane adhesive according to claim 1, characterized in that: The nano filler consists of modified silicon dioxide whiskers and cellulose fiber filaments in a mass ratio of 1:0.3-0.

5.

5. The organosilicon-modified polyurethane adhesive according to claim 4, characterized in that: The modified silicon dioxide whisker is prepared from silicon dioxide whisker and chitosan solution in a mass ratio of 1:0.2-0.

3.

6. The organosilicon-modified polyurethane adhesive according to claim 1, characterized in that: The chain extender consists of polyethylene glycol 600 and propylene glycol in a mass ratio of 1:1-2.

7. The organosilicon-modified polyurethane adhesive according to claim 1, characterized in that: The anti-aging auxiliary agent consists of an ultraviolet absorber, an antioxidant and a light stabilizer in a mass ratio of 1:0.5-1:0.5-1.

8. The method for preparing a silicone-modified polyurethane adhesive according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Mix polyether polyol, isocyanate and chain extender evenly, and treat at 80-85°C for 1-2 hours to obtain a primary mixture; S2. Adding the organosilicon monomer composite, catalyst, and nanofiller to the primary mixture and continuing the process for 1-2 hours to obtain a mixture; S3. Add anti-aging additives and defoaming agents to the mixture, mix and stir evenly, and vacuum degas to obtain the finished product.

9. The method for preparing a silicone-modified polyurethane adhesive according to claim 8, characterized in that: The vinyltrimethylsilane composite liquid in the organosilicon monomer composite is prepared by the following method: The polycrystalline mullite whiskers are immersed and dispersed in vinyltrimethylsilane, and then a polyethylene glycol solution is added to the vinyltrimethylsilane, and the immersion and dispersion are continued to obtain a finished product.

10. The method for preparing a silicone-modified polyurethane adhesive according to claim 8, characterized in that: The aminosilane composite liquid in the organosilicon monomer composite is prepared by the following method: The hydroxyapatite whiskers are etched, then immersed and dispersed in aminosilane, and then triethanolamine is added to the aminosilane, and the immersion and dispersion treatment is continued to obtain a finished product.

Images