Polyurethane primer with long-acting adhesion and preparation method thereof

Abstract

The invention discloses a polyurethane primer with long-acting adhesion and a preparation method thereof, and relates to the technical field of sealant adhesion, the polyurethane primer is composed of a first polymer, a second polymer, a water removal agent, carbon black, polyisocyanate, a wetting dispersant and other raw materials; the first polymer is obtained by carrying out catalytic reaction on bisphenol A modified polyether polyol and first diisocyanate; the content of isocyanato in the first polymer is 5-12%; the second polymer is obtained by reacting polycaprolactone polyol with second diisocyanate and then carrying out silane end capping; the polyurethane primer with long-acting adhesion has the advantages that the surface drying speed is high, a film can be quickly formed on the surface of a base material, and a paint film has good adhesion to polyurethane adhesive, ink glass, smooth glass and most metal base materials; it is guaranteed that the product can still be reliably bonded with polyurethane bonding glue after being brushed to the surface of a base material and placed for a long time, and long-acting adhesion of the polyurethane primer can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of sealant bonding, and specifically relates to a polyurethane primer with long-term adhesiveness and a preparation method thereof. Background Art

[0002] Polyurethane adhesives are widely used in the assembly process of vehicle windshields due to their excellent mechanical properties and aging resistance. Due to the characteristics of polyurethane adhesives themselves, their adhesiveness to non-porous substrates such as glass is poor. When in use, it is necessary to first treat the surface of the substrate with a primer to achieve reliable adhesion of the polyurethane adhesive to the substrate. The primer relies on the volatilization of organic solvents during use to quickly form a film on the surface of the substrate. Inevitably, some volatile organic solvents will be inhaled by the surrounding operators during this process, having a certain impact on health. Designing the brushing operation of the primer in a glass manufacturing enterprise can concentrate the brushing in a workshop equipped with a gas collection device, achieving the purpose of reducing volatile organic compounds in the vehicle final assembly line. At the same time, it can reduce the workstations on the final assembly line and improve production efficiency. However, this use process places higher requirements on the performance of the primer itself.

[0003] The effective time of the existing primer is generally within 24 hours after brushing. After more than 24 hours, there is a possibility of failure and re-brushing is required. And if the primer is brushed by a glass manufacturing enterprise, the time from glass transportation, storage to use needs to be considered. Therefore, there is an urgent need to design a polyurethane primer with long-term adhesiveness to meet the needs of glass transportation and storage. Summary of the Invention

[0004] To solve the above problems, the purpose of the present invention is to provide a polyurethane primer with long-term adhesiveness and a preparation method thereof, which can ensure that the primer still maintains good adhesiveness under two conditions: 3 months at 23°C and 50% RH, and 1 month at 40°C and 80% RH after brushing, realizing the long-term adhesive performance of the primer.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0006] A polyurethane primer with long-term adhesiveness, calculated by weight, is composed of the following raw materials: 20 - 30 parts of a first polymer, 15 - 25 parts of a second polymer, 1 - 2 parts of a water remover, 2 - 6 parts of carbon black, 2 - 5 parts of polyisocyanate, 0.05 - 0.3 parts of a second catalyst, 1 - 2 parts of a wetting and dispersing agent, and 35 - 55 parts of a third solvent;

[0007] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 5 - 12%;

[0008] The second polymer is obtained by reacting polycaprolactone polyol and a second diisocyanate, and then end-capping with silane.

[0009] Preferably, the first polymer is prepared according to the following steps:

[0010] Add bisphenol A-modified polyether polyol into a reaction kettle, heat up to 100 - 110 °C, vacuum dehydrate for at least half an hour, cool down to 55 - 65 °C, under stirring conditions, add a first diisocyanate, heat up to 80 - 85 °C, react for 1 - 3 hours under nitrogen protection, cool down to 70 - 75 °C, add a first catalyst, continue to react at 80 - 85 °C for 1.5 hours, sample and detect the isocyanate group content in the product. When the isocyanate group content is 5 - 12%, start to cool down. After the material cools down below 50 °C, add a first solvent, and continue to stir for 30 minutes to obtain a mixture for standby;

[0011] Wherein the mass ratio of bisphenol A-modified polyether polyol, the first diisocyanate, the first catalyst, and the first solvent is 4.5 - 15: 2.5 - 10.5: 0.0004 - 0.0006: 8 - 12;

[0012] The bisphenol A-modified polyether polyol is a bifunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content of not less than 20%;

[0013] The first diisocyanate is one or two of isophorone diisocyanate and hexamethylene diisocyanate;

[0014] The first catalyst is one of dibutyltin dilaurate and bis(morpholino)diethyl ether;

[0015] The first solvent is at least one of ethyl acetate, butyl acetate, toluene, acetone, or methyl ethyl ketone.

[0016] Preferably, the second polymer is prepared according to the following steps:

[0017] Add polycaprolactone polyol into a reaction kettle, heat up to 100 - 110 °C, vacuum dehydrate for at least half an hour, cool down to 65 - 70 °C, under stirring conditions, add a second diisocyanate, heat up to 80 - 85 °C, react for 2 - 4 hours under nitrogen protection, sample and detect the isocyanate group content in the product. When the isocyanate group content is 3.5 - 10%, lower the material temperature to 50 °C, add a second solvent, dropwise add a silane end-capping agent, and continue to stir for 20 minutes after the dropping is completed to obtain a mixture for standby;

[0018] Wherein the mass ratio of polycaprolactone polyol, the second diisocyanate, the second solvent, and the silane end-capping agent is 4 - 15: 1.5 - 8: 4 - 6: 0.5 - 3.5;

[0019] The polycaprolactone polyol is a bifunctional polycaprolactone polyol with a molecular weight of less than 2000;

[0020] The second diisocyanate is one of diphenylmethane diisocyanate and toluene diisocyanate;

[0021] The silane capping agent is one or two of N-(n-butyl)-3-aminopropyltrimethoxysilane, anilinomethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, anilinomethylmethyldimethoxysilane or N-phenylaminopropyltrimethoxysilane;

[0022] The second solvent is at least one of ethyl acetate, butyl acetate or acetone.

[0023] Preferably, the water scavenger is p-toluenesulfonyl isocyanate, vinyltrimethoxysilane or trimethyl orthoacetate; the carbon black is pigment carbon black.

[0024] Preferably, the polyisocyanate is one or two of HDI biuret, HDI trimer, TDI trimer and IPDI trimer;

[0025] The wetting and dispersing agent is BYK9077, YCK-2170, HY-4010 or HY-9076.

[0026] Preferably, the second catalyst is one or two of organotin catalysts, bis(morpholino)diethyl ether, triethylenediamine, diazabicyclooctane or triethylamine

[0027] The third solvent is one or two of ethyl acetate, butyl acetate, acetone or methyl ethyl ketone.

[0028] Preferably, the organotin catalyst is dibutyltin dilaurate or stannous octoate.

[0029] The present invention also includes a preparation method of a polyurethane primer with long-term adhesiveness, comprising the following steps:

[0030] By weight, 35-55 parts of the third solvent, 2-6 parts of carbon black, 1-2 parts of water scavenger, and 1-2 parts of wetting and dispersing agent are added to a ball mill and ball milled for 3-5 hours, and then 20-30 parts of the first polymer, 15-25 parts of the second polymer, 2-5 parts of polyisocyanate, and 0.05-0.3 parts of the second catalyst are added and ball milled for 2-4 hours to obtain a polyurethane primer with long-term adhesiveness;

[0031] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 5-12%;

[0032] The second polymer is obtained by reacting polycaprolactone polyol and a second diisocyanate, and then end-capping with silane.

[0033] The present invention has the following advantages compared with the prior art:

[0034] The polyurethane primer with long-term adhesiveness of the present invention has a rapid surface drying rate and can quickly form a film on the surface of the substrate. The paint film has good adhesiveness to polyurethane adhesive, ink glass, smooth glass and most metal substrates. The paint film has good weather resistance and moisture resistance. It can ensure that after the product is applied to the surface of the substrate and placed at 23°C and 50% RH for 3 months, or at 40°C and 80% RH for 1 month, it can still achieve reliable adhesion with the polyurethane adhesive, and can achieve the long-term adhesiveness of the polyurethane primer. Detailed implementation mode

[0035] The purpose of the present invention is to provide a polyurethane primer with long-term adhesiveness and a preparation method thereof. The following is a further description of the present invention in combination with specific embodiments.

[0036] Example 1

[0037] A polyurethane primer with long-term adhesiveness is composed of the following raw materials: 20 kg of the first polymer, 15 kg of the second polymer, 1 kg of water scavenger p-toluenesulfonyl isocyanate, 2 kg of carbon black, 2 kg of HDI biuret, 0.05 kg of dimorpholinodiethyl ether, 1 kg of wetting and dispersing agent BYK9077, and 35 kg of ethyl acetate;

[0038] The first polymer is obtained by catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 5%;

[0039] The first polymer is prepared according to the following steps:

[0040] Add 9 kg of bisphenol A-modified polyether polyol into the reaction kettle, heat up to 100°C, vacuum dehydrate for 45 minutes under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 55°C, add 5 kg of isophorone diisocyanate under stirring conditions, heat up to 80°C, react for 3 hours under nitrogen protection, cool down to about 70°C, add 0.8 g of dibutyltin dilaurate, keep reacting at 80°C for 1.5 hours, sample and detect the isocyanate group content in the product. When the isocyanate group content is 5%, lower the material temperature below 50°C, add 16 kg of ethyl acetate, and continue stirring for 30 minutes to obtain a mixture for standby;

[0041] The bisphenol A-modified polyether polyol is a difunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content not less than 20%.

[0042] The second polymer is obtained by reacting polycaprolactone polyol with a second diisocyanate and then end-capping with silane. The specific steps are as follows:

[0043] Add 8 kg of polycaprolactone polyol to a reaction kettle, heat up to 100 °C, carry out vacuum dehydration for 45 minutes under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 65 °C, add 3 kg of diphenylmethane diisocyanate under stirring conditions, heat up to 80 °C, and react for 4 hours under nitrogen protection. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 3.5%, lower the material temperature to 50 °C, add 8 kg of ethyl acetate, dropwise add 1 kg of N-(n-butyl)-3-aminopropyltrimethoxysilane, and continue stirring for 20 minutes after the dropwise addition is completed to obtain a mixture for standby;

[0044] The polycaprolactone polyol is a bifunctional polycaprolactone polyol with a molecular weight of less than 2000.

[0045] Example 2

[0046] A polyurethane primer with long-term adhesiveness is composed of the following raw materials: 30 kg of the first polymer, 25 kg of the second polymer, 2 kg of water scavenger vinyltrimethoxysilane, 6 kg of carbon black, 5 kg of HDI trimer, 0.3 kg of triethylenediamine, 2 kg of wetting and dispersing agent YCK-2170, and 55 kg of butyl acetate;

[0047] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol with a first diisocyanate; the isocyanate group content of the first polymer is 12%;

[0048] The first polymer is prepared according to the following steps:

[0049] Add 15 kg of bisphenol A-modified polyether polyol to a reaction kettle, heat up to 110 °C, carry out vacuum dehydration for at least half an hour under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 65 °C, add 10.5 kg of hexamethylene diisocyanate under stirring conditions, heat up to 85 °C, and react for 1 hour under nitrogen protection. Cool down to 70 °C, add 0.6 g of bis(morpholino)diethyl ether, and continue reacting at 85 °C for 1.5 hours. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 12%, lower the material temperature below 50 °C, add 12 kg of butyl acetate, and continue stirring for 30 minutes to obtain a mixture for standby;

[0050] The bisphenol A-modified polyether polyol is a bifunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content of not less than 20%;

[0051] The second polymer is obtained by reacting polycaprolactone polyol with a second diisocyanate and then end-capping with silane. The specific steps are as follows:

[0052] Add 15 kg of polycaprolactone polyol to a reaction kettle, heat up to 110 °C, perform vacuum dehydration for half an hour under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 70 °C, add 8 kg of toluene diisocyanate under stirring conditions, heat up to 85 °C, and react for 2 hours under nitrogen protection. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 10%, lower the material temperature to 50 °C, add 6 kg of butyl acetate, dropwise add 3.5 kg of anilinomethyltrimethoxysilane, and continue stirring for 20 minutes after the dropping is completed to obtain a mixture for standby;

[0053] The polycaprolactone polyol is a bifunctional polycaprolactone polyol with a molecular weight of less than 2000.

[0054] Example 3

[0055] A polyurethane primer with long-term adhesiveness is composed of the following raw materials: 22 kg of the first polymer, 16 kg of the second polymer, 1.2 kg of trimethyl orthoacetate as a water scavenger, 3 kg of pigment carbon black, 3 kg of TDI trimer, 0.1 kg of diazabicyclo, 1.2 kg of wetting and dispersing agent HY-4010, and 38 kg of acetone;

[0056] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 6%;

[0057] The first polymer is prepared according to the following steps:

[0058] Add 10 kg of bisphenol A-modified polyether polyol to a reaction kettle, heat up to 105 °C, perform vacuum dehydration for at least half an hour under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 58 °C, add 5 kg of isophorone diisocyanate and 5 kg of hexamethylene diisocyanate under stirring conditions, heat up to 82 °C, and react for 1.5 hours under nitrogen protection. Cool down to about 70 °C, add 1 g of dibutyltin dilaurate, and continue to react at 82 °C for 1.5 hours. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 6%, lower the material temperature below 50 °C, add 20 kg of toluene, and continue stirring for 30 minutes to obtain a mixture for standby;

[0059] The bisphenol A-modified polyether polyol is a bifunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content of not less than 20%;

[0060] The second polymer is obtained by reacting polycaprolactone polyol with a second diisocyanate and then end-capping with silane; specifically, it includes the following steps:

[0061] Add 8 kg of polycaprolactone polyol to a reaction kettle, heat up to 105 °C, dehydrate under vacuum for half an hour under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 68 °C, add 3 kg of diphenylmethane diisocyanate under stirring conditions, heat up to 82 °C, and react for 3 hours under nitrogen protection. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 5%, lower the material temperature to 50 °C, add 4.5 kg of acetone, dropwise add 1 kg of 3-mercaptopropyltrimethoxysilane, and continue stirring for 20 minutes after the dropping is completed to obtain a mixture for standby;

[0062] The polycaprolactone polyol is a bifunctional polycaprolactone polyol with a molecular weight of less than 2000.

[0063] Example 4

[0064] A polyurethane primer with long-lasting adhesiveness is composed of the following raw materials: 24 kg of the first polymer, 24 kg of the second polymer, 1.8 kg of water scavenger p-toluenesulfonyl isocyanate, 5 kg of pigment carbon black, 4 kg of IPDI trimer, 0.2 kg of stannous octoate, 1.5 kg of wetting and dispersing agent HY-9076, and 40 kg of methyl ethyl ketone;

[0065] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol with a first diisocyanate; the isocyanate group content of the first polymer is 8%;

[0066] The first polymer is prepared according to the following steps:

[0067] Add 8 kg of bisphenol A-modified polyether polyol to a reaction kettle, heat up to 108 °C, dehydrate under vacuum for 40 minutes under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 60 °C, add 3 kg of isophorone diisocyanate and 4 kg of hexamethylene diisocyanate under stirring conditions, heat up to 84 °C, and react for 2.5 hours under nitrogen protection. Cool down to 70 °C, add 0.5 g of bis(morpholino)diethyl ether, keep reacting at 84 °C for 1.5 hours, take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 8%, lower the material temperature to below 50 °C, add 11 kg of acetone, and continue stirring for 30 minutes to obtain a mixture for standby;

[0068] The bisphenol A-modified polyether polyol is a bifunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content of not less than 20%;

[0069] The second polymer is obtained by reacting polycaprolactone polyol and a second diisocyanate, and then end-capping with silane, and specifically includes the following steps:

[0070] Add 12 kg of polycaprolactone polyol to a reaction kettle, heat up to 105 °C, carry out vacuum dehydration for half an hour under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 66 °C, add 6 kg of toluene diisocyanate under stirring conditions, heat up to 82 °C, and react for 2.5 hours under nitrogen protection. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 8%, lower the material temperature to 50 °C, add 2 kg of ethyl acetate and 3 kg of butyl acetate, dropwise add 3 kg of anilinomethylmethyldimethoxysilane, and continue stirring for 20 minutes after the dropping is completed to obtain a mixture for standby;

[0071] The polycaprolactone polyol is a difunctional polycaprolactone polyol with a molecular weight below 2000.

[0072] Example 5

[0073] A polyurethane primer with long-term adhesiveness is composed of the following raw materials: 28 kg of the first polymer, 20 kg of the second polymer, 1.6 kg of water scavenger vinyltrimethoxysilane, 4 kg of pigment carbon black, 1.5 kg of HDI trimer, 1.5 kg of TDI trimer, 0.1 kg of dimorpholinodiethyl ether, 0.15 kg of triethylenediamine, 1.8 kg of wetting and dispersing agent YCK-2170, 20 kg of butyl acetate, and 25 kg of acetone;

[0074] The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 10%;

[0075] The first polymer is prepared according to the following steps:

[0076] Add 12 kg of bisphenol A-modified polyether polyol to a reaction kettle, heat up to 102 °C, carry out vacuum dehydration for 35 minutes under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 62 °C, add 9 kg of isophorone diisocyanate under stirring conditions, heat up to 82 °C, and react for 2.5 hours under nitrogen protection. Cool down to 72 °C, add 5 g of dibutyltin dilaurate, and continue reacting at 82 °C for 1.5 hours. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 10%, lower the material temperature below 50 °C, add 12 kg of methyl ethyl ketone, and continue stirring for 30 minutes to obtain a mixture for standby;

[0077] The bisphenol A-modified polyether polyol is a difunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content not less than 20%;

[0078] The second polymer is obtained by reacting polycaprolactone polyol and a second diisocyanate, and then end-capping with silane; specifically, it includes the following steps:

[0079] Add 12 kg of polycaprolactone polyol to the reaction kettle, heat up to 108 °C, carry out vacuum dehydration for 40 minutes under the condition that the vacuum degree is not less than 0.092 MPa, cool down to 68 °C, add 7 kg of toluene diisocyanate under stirring conditions, heat up to 82 °C, and react for 2.5 hours under nitrogen protection. Take a sample to detect the isocyanate group content in the product. When the isocyanate group content is 6%, lower the material temperature to 50 °C, add 1 kg of butyl acetate and 4 kg of acetone, dropwise add 2 kg of N-phenylaminopropyltrimethoxysilane, and continue stirring for 20 minutes after the dropping is completed to obtain a mixture for standby;

[0080] Among them, the mass ratio of polycaprolactone polyol, the second diisocyanate, the second solvent, and the silane end-capping agent is 12:7:5:2;

[0081] The polycaprolactone polyol is a difunctional polycaprolactone polyol with a molecular weight of less than 2000.

[0082] Example 6

[0083] A preparation method of a polyurethane primer with long-term adhesiveness described in Example 1 includes the following steps:

[0084] Add 35 kg of ethyl acetate, 2 kg of carbon black, 1 kg of water scavenger p-toluenesulfonyl isocyanate, and 1 kg of wetting and dispersing agent BYK9077 to the ball mill and ball mill for 3 hours, and then add 20 kg of the first polymer, 15 kg of the second polymer, 2 kg of HDI biuret, and 0.05 kg of dimorpholinodiethyl ether and ball mill for 2 hours to obtain a polyurethane primer with long-term adhesiveness.

[0085] Example 7

[0086] A preparation method of a polyurethane primer with long-term adhesiveness described in Example 2 includes the following steps:

[0087] Add 55 kg of butyl acetate, 2 kg of water scavenger vinyltrimethoxysilane, 6 kg of carbon black, and 2 kg of wetting and dispersing agent YCK-2170 to the ball mill and ball mill for 5 hours, and then add 30 kg of the first polymer, 25 kg of the second polymer, 5 kg of HDI trimer, and 0.3 kg of triethylenediamine and ball mill for 4 hours to obtain a polyurethane primer with long-term adhesiveness.

[0088] Example 8

[0089] A preparation method of a polyurethane primer with long-term adhesiveness described in Example 3 includes the following steps:

[0090] 38 kg of acetone, 1.2 kg of trimethyl orthoacetate as water remover, 3 kg of pigment carbon black, and 1.2 kg of wetting and dispersing agent HY-4010 were added to a ball mill and milled for 3.5 hours. Then, 22 kg of the first polymer, 16 kg of the second polymer, 3 kg of TDI trimer, and 0.1 kg of diazabicyclo were added and milled for 2.5 hours to obtain a polyurethane primer with long-lasting adhesiveness.

[0091] Example 9

[0092] A method for preparing a polyurethane primer with long-lasting adhesiveness as described in Example 4, comprising the following steps:

[0093] 40 kg of methyl ethyl ketone, 5 kg of pigment carbon black, 1.8 kg of p-toluenesulfonyl isocyanate as water remover, and 1.5 kg of wetting and dispersing agent HY-9076 were added to a ball mill and milled for 4.5 hours. Then, 24 kg of the first polymer, 24 kg of the second polymer, 4 kg of IPDI trimer, and 0.2 kg of stannous octoate were added and milled for 3.5 hours to obtain a polyurethane primer with long-lasting adhesiveness.

[0094] Example 10

[0095] A method for preparing a polyurethane primer with long-lasting adhesiveness as described in Example 5, comprising the following steps:

[0096] 25 kg of acetone, 4 kg of pigment carbon black, 1.6 kg of vinyltrimethoxysilane as water remover, and 1.8 kg of wetting and dispersing agent YCK-2170 were added to a ball mill and milled for 3 - 5 hours. Then, 28 kg of the first polymer, 20 kg of the second polymer, 1.5 kg of HDI trimer, 1.5 kg of TDI trimer, 0.1 kg of dimorpholinodiethyl ether, and 0.15 kg of triethylenediamine were added and milled for 3 hours to obtain a polyurethane primer with long-lasting adhesiveness.

[0097] The products of Examples 6 - 10 were compared and tested with the commercially available DT-01 primer. After applying the primer on the surface of ink and smooth glass, according to the method B of the finger-touch method in GB / T 1728-1979 for measuring the surface drying time, the surface drying time was measured. After the film was surface dry, the specimens were placed for 7 days at 23°C and 50% RH, for 3 months at 23°C and 50% RH, and for 1 month at 40°C and 80% RH. After taking out, AM-140E polyurethane adhesive was applied on the film surface. Then, the specimens after applying the adhesive were placed for 7 days at 23°C and 50% RH. After taking out, the peel adhesiveness test was carried out, and the test method referred to method B in Appendix D.1.2 of GB 16776-2005, and the hand-pulling test (non-product destruction method) was performed. The test results are shown in Table 1.

[0098] Table 1 Test Results of Primer

[0099]

[0100] It can be seen from the data in Table 1 that the polyurethane primer product with long-lasting adhesiveness of the present invention has a faster surface drying time compared with conventional products, has good long-term effectiveness after being applied to the substrate surface, and can maintain good adhesiveness after being placed for 3 months at 23°C and 50% RH, and after being placed for 1 month under the humid heat condition of 40°C and 80% RH.

Claims

1. A polyurethane primer with long-lasting adhesiveness, characterized in that: Composed of the following raw materials by weight parts: 20 - 30 parts of the first polymer, 15 - 25 parts of the second polymer, 1 - 2 parts of water scavenger, 2 - 6 parts of carbon black, 2 - 5 parts of polyisocyanate, 0.05 - 0.3 parts of the second catalyst, 1 - 2 parts of wetting and dispersing agent, and 35 - 55 parts of the third solvent; The first polymer is obtained by a catalytic reaction of bisphenol A - modified polyether polyol and the first diisocyanate; the isocyanate group content of the first polymer is 5 - 12%; The second polymer is obtained by reacting polycaprolactone polyol and the second diisocyanate, and then end - capping with silane.

2. The polyurethane primer with long-lasting adhesiveness according to claim 1, characterized in that: The first polymer is prepared according to the following steps: Add bisphenol A - modified polyether polyol into a reaction kettle, heat up to 100 - 110 °C, vacuum dehydrate for at least half an hour, cool down to 55 - 65 °C, add the first diisocyanate under stirring conditions, heat up to 80 - 85 °C, react for 1 - 3 hours under nitrogen protection, cool down to 70 - 75 °C, add the first catalyst, keep reacting at 80 - 85 °C for another 1.5 hours, sample and detect the isocyanate group content in the product. When the isocyanate group content is 5 - 12%, start to cool down. After the material cools down below 50 °C, add the first solvent, and continue stirring for 30 minutes to obtain a mixture for standby; Wherein the mass ratio of bisphenol A - modified polyether polyol, the first diisocyanate, the first catalyst, and the first solvent is 4.5 - 15:2.5 - 10.5:0.0004 - 0.0006:8 - 12; The bisphenol A - modified polyether polyol is a difunctional polyether polyol with a molecular weight below 1000 and a bisphenol A content of not less than 20%; The first diisocyanate is one or two of isophorone diisocyanate and hexamethylene diisocyanate; The first catalyst is one of dibutyltin dilaurate and bis(morpholino)diethyl ether; The first solvent is at least one of ethyl acetate, butyl acetate, toluene, acetone, or methyl ethyl ketone.

3. The polyurethane primer with long-lasting adhesiveness according to claim 1, characterized in that: The second polymer is prepared according to the following steps: Add polycaprolactone polyol into a reaction kettle, heat up to 100 - 110 °C, vacuum dehydrate for at least half an hour, cool down to 65 - 70 °C, add the second diisocyanate under stirring conditions, heat up to 80 - 85 °C, react for 2 - 4 hours under nitrogen protection, sample and detect the isocyanate group content in the product. When the isocyanate group content is 3.5 - 10%, lower the temperature of the material to 50 °C, add the second solvent, drop - wise add the silane end - capping agent, and continue stirring for 20 minutes after the dropping is completed to obtain a mixture for standby; Wherein the mass ratio of polycaprolactone polyol, the second diisocyanate, the second solvent, and the silane end - capping agent is 4 - 15:1.5 - 8:4 - 6:0.5 - 3.5; The polycaprolactone polyol is a difunctional polycaprolactone polyol with a molecular weight below 2000; The second diisocyanate is one of diphenylmethane diisocyanate and toluene diisocyanate. The silane capping agent is one or two of N-(n-butyl)-3-aminopropyltrimethoxysilane, anilinomethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, anilinomethylmethyldimethoxysilane or N-phenylaminopropyltrimethoxysilane; The second solvent is at least one of ethyl acetate, butyl acetate or acetone.

4. The polyurethane primer with long-acting adhesiveness according to claim 1, characterized in that: The water scavenger is p-toluenesulfonyl isocyanate, vinyltrimethoxysilane or trimethyl orthoacetate; the carbon black is pigment carbon black.

5. A polyurethane primer with long-term adhesiveness according to claim 1, characterized in that: The polyisocyanate is one or two of HDI biuret, HDI trimer, TDI trimer, IPDI trimer; The wetting and dispersing agent is BYK9077, YCK-2170, HY-4010 or HY-9076.

6. A polyurethane primer with long-term adhesiveness according to claim 1, characterized in that: The second catalyst is one or two of organotin catalysts, bis(morpholino)diethyl ether, triethylenediamine, diazabicyclo or triethylamine The third solvent is one or two of ethyl acetate, butyl acetate, acetone or methyl ethyl ketone.

7. A polyurethane primer with long-term adhesiveness according to claim 6, characterized in that: The organotin catalyst is dibutyltin dilaurate or stannous octoate.

8. The preparation method of a polyurethane primer with long-lasting adhesiveness according to claim 1, characterized in that: It includes the following steps: By weight, 35-55 parts of the third solvent, 2-6 parts of carbon black, 1-2 parts of water scavenger, and 1-2 parts of wetting and dispersing agent are added to a ball mill and ball milled for 3-5 hours, and then 20-30 parts of the first polymer, 15-25 parts of the second polymer, 2-5 parts of polyisocyanate, and 0.05-0.3 parts of the second catalyst are added and ball milled for 2-4 hours to obtain a polyurethane primer with long-term adhesiveness; The first polymer is obtained by a catalytic reaction of bisphenol A-modified polyether polyol and a first diisocyanate; the isocyanate group content of the first polymer is 5-12%; The second polymer is obtained by reacting polycaprolactone polyol and a second diisocyanate, and then capped with silane.

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