Two-component polyurethane corner combining glue

Abstract

The invention discloses a two-component polyurethane corner-combining adhesive which is composed of a component A and a component B, the component A comprises the following raw materials: polyether polyol, modified polyol, a plasticizer, a filler, molecular sieve activation powder, fumed silica, a defoaming agent and a catalyst; the component B comprises the following raw materials: isocyanate, a plasticizer, a filler, fumed silica and a defoaming agent; the raw materials of the modified polyol comprise long carbon chain dibasic acid, aromatic diol, castor oil and a catalyst, and the modified polyol contains a long carbon chain, a benzene ring and an ester group. According to the scheme, the modified polyol which can resist high temperature and keep flexibility at low temperature is synthesized and is used for preparing the two-component polyurethane corner combining adhesive, so that the two-component polyurethane corner combining adhesive can still keep higher mechanical strength after circulation of cold and hot impact, and the mechanical strength is reduced by less than 10%, so that the defects in the prior art are overcome.

Description

Technical Field

[0001] This invention relates to the field of polyurethane corner adhesive technology, and more particularly to a two-component polyurethane corner adhesive. Background Technology

[0002] Insulating glass, as an important energy-saving building material, is widely used in modern building doors, windows, curtain walls, and other fields due to its excellent thermal and sound insulation properties. Insulating glass typically consists of two or more panes of glass separated and sealed by spacers (such as aluminum spacers or warm edge strips) to form a sealed cavity. This cavity can be filled with dry air or inert gas to further enhance its thermal performance. To ensure the integrity and airtightness of the insulating glass structure, sealant is usually used to bond and seal the glass to the spacers. Polyurethane corner sealant is widely used in the sealing process of insulating glass due to its good bonding strength, flexibility, and processing performance.

[0003] However, in the cold regions of northern my country, the temperature difference between indoors and outdoors in winter is extremely large, reaching 40-60℃ or even higher. Under such extreme temperature conditions, the significant differences in the coefficients of linear expansion among the glass, spacer, and polyurethane corner sealant lead to substantial internal stress during temperature cycling. Currently available polyurethane corner sealants for insulated glass generally lack sufficient resistance to temperature differences, making it difficult to effectively adapt to such drastic thermal expansion and contraction. After prolonged use, delamination easily occurs at the interface between the sealant and the substrate, forming tiny gaps. Once these gaps appear, moisture can easily seep into the insulated glass during the rainy season or in high-humidity environments, causing the insulated cavity to fail, the glass to fog up, condensate, or even mold, severely impacting the lifespan and energy-saving performance of the insulated glass.

[0004] Currently, the industry commonly uses an additional coating of anti-leakage sealant on the outside of insulated glass as a remedial measure to prevent moisture intrusion. However, this method not only increases production process steps and material costs but also highly depends on the skill and meticulousness of the construction personnel. If local areas are not completely filled or have defects such as air bubbles or broken sealant, they may still become potential points of water leakage, failing to fundamentally solve the structural failure problem caused by the insufficient temperature difference resistance of polyurethane corner sealant.

[0005] Therefore, there is an urgent need to develop a new type of polyurethane corner sealant with excellent resistance to high and low temperature alternation, in order to effectively address the challenges posed by the large temperature difference environment in the frigid northern regions to the sealing reliability of insulated glass, thereby improving the overall durability and service life of insulated glass. Summary of the Invention

[0006] The purpose of this invention is to propose a two-component polyurethane corner adhesive. By synthesizing a modified polyol that can withstand high temperatures and maintain flexibility at low temperatures, and using it in the preparation of the two-component polyurethane corner adhesive, the adhesive can still maintain high mechanical strength after thermal shock cycles, with a decrease in mechanical strength of less than 10%, thus overcoming the shortcomings of the prior art.

[0007] To achieve this objective, the present invention adopts the following technical solution: A two-component polyurethane corner adhesive, consisting of component A and component B; The raw materials for component A include polyether polyol, modified polyol, plasticizer, filler, molecular sieve activated powder, fumed silica, defoamer, and catalyst; the raw materials for component B include isocyanate, plasticizer, filler, fumed silica, and defoamer. The raw materials for the modified polyol include long-chain dicarboxylic acids, aromatic diols, castor oil, and catalysts, and the modified polyol contains long-chain, benzene rings, and ester groups.

[0008] Preferably, the modified polyol comprises, by mass percentage, 20-69.99% long-chain dicarboxylic acid, 10-43% aromatic diol, 20-40% castor oil, and 0.01-0.1% catalyst.

[0009] Preferably, the long-chain dicarboxylic acid includes any one or more combinations of dimer acids, sebacic acid, undecanoic acid, and dodecanoic acid; The aromatic diols include any one or more combinations of 4,4'-dihydroxydiphenylmethane, 1,2-diphenyl-1,2-ethylene glycol and 4,4'-biphenyldiol; The catalyst comprises any one or more combinations of tetrabutyl titanate, tetraisopropyl titanate, monobutyltin oxide, butyltin triisooctanoate, antimony glycolate, antimony trioxide, and zinc acetate.

[0010] Preferably, the method for preparing the modified polyol includes the following steps: A. In an inert gas environment, long-chain dicarboxylic acid, aromatic diol and catalyst are added to a reaction vessel, heated to the polycondensation reaction temperature, and then subjected to a heat preservation reaction to obtain polyester diol. B. Castor oil is added to the reactor and modified polyol is obtained through transesterification. In step A, the polycondensation reaction temperature is 180–270°C, and the heat preservation reaction time is 3–10 h. In step B, the transesterification reaction is carried out at a temperature of 130–200°C for 2–5 hours.

[0011] Preferably, by mass percentage, component A comprises 10-50% polyether polyol, 10-40% modified polyol, 1-20% plasticizer, 10-40% filler, 1-10% molecular sieve activated powder, 1-10% fumed silica, 0.1-2% defoamer, and 0.02-0.2% catalyst.

[0012] Preferably, in component A, the polyether polyol includes any one or a combination of polyether diol with a molecular weight of 1000, polyether diol with a molecular weight of 2000, polyether triol with a molecular weight of 500, polyether triol with a molecular weight of 1000, polyether triol with a molecular weight of 3000, and polyether triol with a molecular weight of 5000. The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate powder, modified light calcium carbonate powder, and modified silica powder; The molecular sieve activated powder includes any one or more combinations of 3A, 4A, 5A and 13X; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or a combination of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers; The catalyst includes any one or more combinations of organotin catalysts, organobismuth catalysts, organozinc catalysts, and organobismuth-zinc composite catalysts.

[0013] Preferably, by mass percentage, component B comprises 18-70% isocyanate, 1-20% plasticizer, 20-50% filler, 1-10% fumed silica, and 0.1-2% defoamer.

[0014] Preferably, in component B, the isocyanate includes any one or more combinations of TDI and its prepolymer, MDI and its prepolymer, IPDI and its prepolymer, HMDI and its prepolymer, HDI trimer and polymeric MDI; The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate, modified light calcium carbonate, and modified silica powder; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or more combinations of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers.

[0015] The technical solution provided by this invention may include the following beneficial effects: 1. This scheme synthesizes a special modified polyol, which causes the long-chain dicarboxylic acid in the raw material to condense with aromatic diols under the action of a catalyst to form a polyester diol, which is then transesterified with castor oil to generate a modified polyol. This modified polyol contains benzene rings, long carbon chains and ester groups, and combines heat resistance and low temperature resistance, which can ensure adhesion at high temperatures and flexibility at low temperatures.

[0016] 2. This solution applies modified polyols to polyurethane corner adhesives, enabling the polyurethane corner adhesives to maintain high mechanical strength even after thermal shock cycles, with a decrease in mechanical strength of less than 10%, thus overcoming the shortcomings of existing technologies. Detailed Implementation

[0017] This technical solution provides a two-component polyurethane corner adhesive, consisting of component A and component B; The raw materials for component A include polyether polyol, modified polyol, plasticizer, filler, molecular sieve activated powder, fumed silica, defoamer, and catalyst; the raw materials for component B include isocyanate, plasticizer, filler, fumed silica, and defoamer. The raw materials for the modified polyol include long-chain dicarboxylic acids, aromatic diols, castor oil, and catalysts, and the modified polyol contains long-chain, benzene rings, and ester groups.

[0018] To effectively address the challenges posed by the large temperature differences in the frigid northern regions to the sealing reliability of insulated glass, thereby improving the overall durability and service life of insulated glass, this technical solution proposes a two-component polyurethane corner adhesive. A special modified polyol is synthesized, which causes the long-chain dicarboxylic acid and aromatic diol in the raw materials to condense into a polyester diol under the action of a catalyst. This polyester diol is then transesterified with castor oil to generate a modified polyol containing benzene rings, long carbon chains, and ester groups. This modified polyol combines heat resistance and low-temperature resistance, ensuring both adhesion at high temperatures and flexibility at low temperatures.

[0019] Furthermore, the modified polyols described above are applied to polyurethane corner adhesives, enabling the polyurethane corner adhesives to maintain high mechanical strength even after undergoing thermal shock cycles, with a decrease in mechanical strength of less than 10%, thus overcoming the shortcomings of existing technologies.

[0020] To further explain, the modified polyol comprises, by mass percentage, 20-69.99% long-chain dicarboxylic acid, 10-43% aromatic diol, 20-40% castor oil, and 0.01-0.1% catalyst.

[0021] To further ensure that the polyurethane corner adhesive maintains high mechanical strength after thermal shock cycles with a decrease in mechanical strength of less than 10%, this solution also optimizes the raw material ratio of the modified polyol.

[0022] Specifically, while an excess of long-chain dicarboxylic acids maintains flexibility at low temperatures and provides good low-temperature mechanical properties, insufficient rigidity can lead to poor high-temperature resistance. A smaller amount provides good high-temperature resistance but results in poor flexibility at low temperatures and a higher rate of mechanical degradation. An excess of aromatic diols leads to a high benzene ring content and good high-temperature resistance, but excessive rigidity can result in poor low-temperature resistance and a significant decrease in mechanical properties at low temperatures. A smaller amount provides sufficient flexibility but insufficient rigidity and unsatisfactory high-temperature performance. The catalyst selection is based on cost and minimizing side reactions. A smaller amount results in a slower reaction, longer reaction time, higher energy consumption, and higher costs; a larger amount results in a faster reaction rate but also introduces the risk of side reactions. The castor oil selection is based on the optimal hydroxyl value of the reaction between the long-chain dicarboxylic acid and the aromatic diol. Excessive castor oil can lead to excess castor oil, which, due to its long-chain groups, can negatively impact high-temperature resistance. Insufficient castor oil can lead to incomplete transesterification and excessive rigidity, resulting in poor low-temperature resistance.

[0023] To further clarify, the long-chain dicarboxylic acid includes any one or more combinations of dimer acids, sebacic acid, undecanoic acid, and dodecanoic acid; The aromatic diols include any one or more combinations of 4,4'-dihydroxydiphenylmethane, 1,2-diphenyl-1,2-ethylene glycol and 4,4'-biphenyldiol; The catalyst comprises any one or more combinations of tetrabutyl titanate, tetraisopropyl titanate, monobutyltin oxide, butyltin triisooctanoate, antimony glycolate, antimony trioxide, and zinc acetate.

[0024] Preferably, the long-chain dicarboxylic acid includes any one or more combinations of dimer acids and dodecanoic acid; The aromatic diols include any one or more combinations of 4,4'-dihydroxydiphenylmethane and 1,2-diphenyl-1,2-ethylene glycol; The catalyst includes any one or more combinations of tetrabutyl titanate and zinc acetate.

[0025] To further explain, the preparation method of the modified polyol includes the following steps: A. In an inert gas environment, long-chain dicarboxylic acid, aromatic diol and catalyst are added to a reaction vessel, heated to the polycondensation reaction temperature, and then subjected to a heat preservation reaction to obtain polyester diol. B. Castor oil is added to the reactor and modified polyol is obtained through transesterification. In step A, the polycondensation reaction temperature is 180–270°C, and the heat preservation reaction time is 3–10 h. In step B, the transesterification reaction is carried out at a temperature of 130–200°C for 2–5 hours.

[0026] Based on considerations of production costs and reducing side reactions, this scheme also optimizes relevant parameters in the preparation process of modified polyols to simultaneously balance product quality and production energy consumption.

[0027] Preferably, in step A, the inert gas includes any one of argon, nitrogen, and helium; the polycondensation reaction temperature is 220–250°C, and the reaction time of the heat preservation reaction is 6–8 h; in step B, the transesterification reaction temperature is 160–190°C, and the reaction time is 3–5 h.

[0028] To further explain, by mass percentage, component A comprises 10-50% polyether polyol, 10-40% modified polyol, 1-20% plasticizer, 10-40% filler, 1-10% molecular sieve activated powder, 1-10% fumed silica, 0.1-2% defoamer, and 0.02-0.2% catalyst.

[0029] Preferably, by mass percentage, component A comprises 20-40% polyether polyol, 15-30% modified polyol, 5-12% plasticizer, 23-35% filler, 3-5% molecular sieve activated powder, 3-5% fumed silica, 0.2-1% defoamer, and 0.06-0.12% catalyst.

[0030] To further clarify, in component A, the polyether polyol includes any one or a combination of polyether diol with a molecular weight of 1000, polyether diol with a molecular weight of 2000, polyether triol with a molecular weight of 500, polyether triol with a molecular weight of 1000, polyether triol with a molecular weight of 3000, and polyether triol with a molecular weight of 5000. The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate powder, modified light calcium carbonate powder, and modified silica powder; The molecular sieve activated powder includes any one or more combinations of 3A, 4A, 5A and 13X; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or a combination of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers; The catalyst includes any one or more combinations of organotin catalysts, organobismuth catalysts, organozinc catalysts, and organobismuth-zinc composite catalysts.

[0031] It should be noted that the specific types of raw materials in component A are all conventional raw materials in this field. Further explanation is needed regarding the plasticizers: DIBP refers to diisobutyl phthalate, DOP refers to dioctyl phthalate, DINP refers to diisononyl phthalate, DOTP refers to dioctyl terephthalate, DOA refers to dioctyl adipate, DOS refers to dioctyl sebacate, DOZ refers to dioctyl azelate, and TXIB refers to 2,2,4-trimethyl-1,3-pentanediol diisobutyrate. In the molecular sieve activation powder, 3A, 4A, 5A, and 13X refer to four common types of molecular sieves. In the fillers, modified heavy calcium carbonate powder refers to surface-modified heavy calcium carbonate, and modified light calcium carbonate powder refers to surface-modified light calcium carbonate.

[0032] Preferably, in component A, the polyether polyol includes a polyether diol with a molecular weight of 1000, a polyether triol with a molecular weight of 500, and a polyether triol with a molecular weight of 3000. The plasticizer includes any one or more combinations of DINP and DOA; The filler includes any one or more combinations of modified light calcium carbonate and modified silica powder; The molecular sieve activated powder includes any one or more combinations of 4A and 5A; The defoamer includes any one or more combinations of silicone defoamers and modified acrylate defoamers; The catalyst includes any one or more combinations of organobismuth catalysts and organozinc catalysts.

[0033] To further explain, by mass percentage, component B comprises 18-70% isocyanate, 1-20% plasticizer, 20-50% filler, 1-10% fumed silica, and 0.1-2% defoamer.

[0034] Preferably, by mass percentage, component B comprises 40-55% isocyanate, 5-12% plasticizer, 33-45% filler, 3-5% fumed silica, and 0.2-1% defoamer.

[0035] To further clarify, in component B, the isocyanate includes any one or more combinations of TDI and its prepolymer, MDI and its prepolymer, IPDI and its prepolymer, HMDI and its prepolymer, HDI trimer and polymeric MDI; The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate, modified light calcium carbonate, and modified silica powder; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or more combinations of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers.

[0036] It should be noted that the specific types of raw materials in component B are all conventional raw materials in this field. Further explanation is needed: in isocyanates, TDI refers to toluene diisocyanate, MDI refers to diphenylmethane diisocyanate, IPDI refers to isophorone diisocyanate, HMDI refers to hexamethylene diisocyanate, HDI trimer refers to hexamethylene diisocyanate trimer, and polymeric MDI refers to polymeric diphenylmethane diisocyanate.

[0037] Preferably, in component B, the isocyanate is polymeric MDI; The plasticizer includes any one or more combinations of DINP and DOA; The filler includes any one or more combinations of modified light calcium carbonate and modified silica powder; The defoamer includes any one or more combinations of silicone defoamers and modified acrylate defoamers.

[0038] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0039] Example 1 (1) Preparation of modified polyols Clean the 1000L reactor thoroughly, purge it with nitrogen once, then evacuate it to below -0.095MPa, and purge it with nitrogen again. Repeat this process three times, and finally return it to atmospheric pressure with nitrogen on the last purging.

[0040] Add 318g of dimer acid, 132g of 4,4'-dihydroxydiphenylmethane, and 0.24g of tetrabutyl titanate. Then, purge with nitrogen for 5 minutes, stir, and slowly raise the temperature to 220°C at a rate of 3°C / min. Start timing and maintain the temperature for the reaction. When there are no more water droplets at the outlet after about 3 hours of reaction, use a vacuum pump to maintain a vacuum level between -0.05MPa and -0.07MPa. Continue to maintain the temperature for about 2 hours until there are no more water droplets. Then, evacuate to a vacuum level below -0.095MPa and continue the reaction for 2 hours.

[0041] The mixture was cooled to 180℃, 150g of castor oil was added, and nitrogen was pumped at a rate of 0.01L / min to maintain the temperature for 3.5h. Then the mixture was cooled to 120℃ and stirred under vacuum for 0.5h. The mixture was then cooled and removed from the reactor to obtain modified polyol ①.

[0042] (2) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of modified polyol ①, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0043] (3) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0044] Example 2 (1) Preparation of modified polyols Clean the 1000L reactor thoroughly, purge it with nitrogen once, then evacuate it to below -0.095MPa, and purge it with nitrogen again. Repeat this process three times, and finally return it to atmospheric pressure with nitrogen on the last purging.

[0045] Add 318g of dimer acid, 141g of 1,2-diphenyl-1,2-ethylene glycol, and 0.24g of tetrabutyl titanate. Then, purge with nitrogen for 5 minutes, stir, and slowly raise the temperature to 220°C at a rate of 3°C / min. Start timing and maintain the temperature for the reaction. When there are no more water droplets at the outlet after about 3 hours of reaction, use a vacuum pump to maintain a vacuum level between -0.05MPa and -0.07MPa. Continue to maintain the temperature for about 2 hours until there are no more water droplets. Then, evacuate to a vacuum level below -0.095MPa and continue the reaction for 2 hours.

[0046] The temperature was lowered to 180℃, 150g of castor oil was added, and nitrogen was blown at a rate of 0.01L / min to keep the reaction at this temperature for 3.5h. Then the temperature was lowered to 120℃ and stirred under vacuum for 0.5h. The mixture was then cooled and removed from the reactor to obtain modified polyol ②.

[0047] (2) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of modified polyol ②, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degassing for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0048] (3) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0049] Example 3 (1) Preparation of modified polyols Clean the 1000L reactor thoroughly, purge it with nitrogen once, then evacuate it to below -0.095MPa, and purge it with nitrogen again. Repeat this process three times, and finally return it to atmospheric pressure with nitrogen on the last purging.

[0050] Add 318g of dimer acid, 66g of 4,4'-dihydroxydiphenylmethane, 70.5g of 1,2-diphenyl-1,2-ethylene glycol, and 0.24g of tetrabutyl titanate. Then purge with nitrogen for 5 minutes, stir, and slowly raise the temperature to 220°C at a rate of 3°C / min. Start timing and maintain the temperature for the reaction. When there are no more water droplets at the outlet after about 3 hours of reaction, use a vacuum pump to maintain a vacuum level between -0.05MPa and -0.07MPa. Continue to maintain the temperature for about 2 hours until there are no more water droplets. Then, evacuate to a vacuum level below -0.095MPa and continue the reaction for 2 hours.

[0051] The temperature was lowered to 180℃, 150g of castor oil was added, and nitrogen was blown at a rate of 0.01L / min to keep the reaction at this temperature for 3.5h. The temperature was then lowered to 120℃ and stirred under vacuum for 0.5h. The modified polyol ③ was obtained by cooling and removing the product from the reactor.

[0052] (2) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of modified polyol ③, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0053] (3) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0054] Example 4 (1) Preparation of modified polyols Clean the 1000L reactor thoroughly, purge it with nitrogen once, then evacuate it to below -0.095MPa, and purge it with nitrogen again. Repeat this process three times, and finally return it to atmospheric pressure with nitrogen on the last purging.

[0055] Add 189.9g of dodecanoic acid, 192g of 4,4'-dihydroxydiphenylmethane, and 0.24g of tetrabutyl titanate. Then, purge with nitrogen for 5 minutes, stir, and slowly raise the temperature to 220°C at a rate of 3°C / min. Start timing and maintain the temperature for the reaction. When there are no more water droplets at the outlet after about 3 hours of reaction, use a vacuum pump to maintain a vacuum level between -0.05MPa and -0.07MPa. Continue to maintain the temperature for about 2 hours until there are no more water droplets. Then, evacuate to a vacuum level below -0.095MPa and continue the reaction for 2 hours.

[0056] The temperature was lowered to 180℃, 218g of castor oil was added, and nitrogen was blown at a rate of 0.01L / min to keep the reaction at this temperature for 3.5h. The temperature was then lowered to 120℃ and stirred under vacuum for 0.5h. The mixture was then cooled and removed from the reactor to obtain the modified polyol ④.

[0057] (2) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of modified polyol ④, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0058] (3) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0059] Example 5 (1) Preparation of modified polyols Clean the 1000L reactor thoroughly, purge it with nitrogen once, then evacuate it to below -0.095MPa, and purge it with nitrogen again. Repeat this process three times, and finally return it to atmospheric pressure with nitrogen on the last purging.

[0060] Add 159g of dimer acid, 95g of dodecanoic acid, 192g of 4,4'-dihydroxydiphenylmethane, and 0.24g of tetrabutyl titanate. Then, purge with nitrogen for 5 minutes, stir, and slowly raise the temperature to 220°C at a rate of 3°C / min. Start timing and maintain the temperature for the reaction. When there are no more water droplets at the outlet after about 3 hours of reaction, use a vacuum pump to maintain a vacuum level between -0.05MPa and -0.07MPa. Continue to maintain the temperature for about 2 hours until there are no more water droplets. Then, evacuate to a vacuum level below -0.095MPa and continue the reaction for 2 hours.

[0061] The temperature was lowered to 180℃, 218g of castor oil was added, and the reaction was carried out under nitrogen at a rate of 0.01L / min for 3.5h. The temperature was then lowered to 120℃ and stirred under vacuum for 0.5h. The modified polyol was obtained by cooling and removing it from the reactor.

[0062] (2) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of modified polyol ⑤, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degassing for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0063] (3) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0064] Comparative Example 1 (1) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of castor oil, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5 hours. Then add 40g of 4A molecular sieve activation powder, 0.3g of organic bismuth catalyst, and 0.5g of organic zinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10 minutes. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0065] (2) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0066] Comparative Example 2 (1) Preparation of component A Add 130g of 1000 molecular weight polyether glycol, 50g of 500 molecular weight polyether triol, 160g of 3000 molecular weight polyether triol, 180g of phthalic anhydride polyester polyol with a hydroxyl value of 168mg KOH / g, 70g of plasticizer DINP, and 5g of modified organosilicon defoamer to the reactor, and start slow stirring. In the dispersed state, add 34.2g of hydrophobic fumed silica and 330g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degassing for 1.5h. Then add 40g of 4A molecular sieve activation powder, 0.3g of organobismuth catalyst, and 0.5g of organozinc catalyst. Continue stirring and dispersing evenly, then vacuum for 10min. Press the material out of the reactor and fill it into tube A of the two-component tube.

[0067] (2) Preparation of component B Add 520g of polymeric MDI, 70g of plasticizer DINP, and 5g of modified silicone defoamer to the reactor, and start slow stirring. In the dispersed state, add 40g of hydrophobic fumed silica and 365g of modified light calcium carbonate powder in batches. After stirring and dispersing evenly, vacuum degas for 1.5h, press out of the reactor, and fill into tube B of the two-component tube.

[0068] Sample preparation After sandblasting and polishing, the 3-series aluminum was cleaned with ethyl acetate, dried in an oven at 50°C, and then cooled to room temperature in a drying oven. Samples were prepared, sheared, and maintained according to JC / T 2560-2020 standard, and then performance tests were conducted. The results are shown in Table 1 below.

[0069] Table 1 Performance test results of Examples 1-5 and Comparative Examples 1-2

[0070] The performance test results of Examples 1-5 show that the modified polyols in this solution are applied to polyurethane corner adhesives, which enables the polyurethane corner adhesives to maintain high mechanical strength after thermal shock cycles, with a decrease in mechanical strength of less than 10%, thus overcoming the shortcomings of the prior art.

[0071] Furthermore, in Comparative Example 1, castor oil was used to replace the modified polyol in this scheme. Although castor oil contains a long carbon chain structure, has good flexibility, and maintains good mechanical properties at low temperatures, its lack of a rigid structure leads to poor high-temperature resistance and a high rate of mechanical degradation at high temperatures. In Comparative Example 2, phthalic anhydride polyester polyol was used to replace the modified polyol in this scheme. Although phthalic anhydride polyester polyol contains a benzene ring structure, has high rigidity, and good high-temperature resistance, maintaining good strength at high temperatures, its lack of a long carbon chain structure and excessive rigidity lead to poor low-temperature resistance and a large rate of mechanical degradation at low temperatures. The results of Comparative Examples 1 and 2 show that the modified polyol in this scheme contains both benzene rings and long carbon chain structures, ensuring both rigidity and flexibility, enabling the adhesive to withstand high temperatures while maintaining minimal mechanical degradation at low temperatures.

[0072] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A two-component polyurethane corner adhesive, characterized in that: It consists of component A and component B; The raw materials for component A include polyether polyol, modified polyol, plasticizer, filler, molecular sieve activated powder, fumed silica, defoamer, and catalyst; the raw materials for component B include isocyanate, plasticizer, filler, fumed silica, and defoamer. The raw materials for the modified polyol include long-chain dicarboxylic acids, aromatic diols, castor oil, and catalysts, and the modified polyol contains long-chain, benzene rings, and ester groups.

2. The two-component polyurethane corner adhesive according to claim 1, characterized in that: The modified polyol comprises, by mass percentage, 20-69.99% long-chain dicarboxylic acid, 10-43% aromatic diol, 20-40% castor oil, and 0.01-0.1% catalyst.

3. The two-component polyurethane corner adhesive according to claim 1, characterized in that: The long-chain dicarboxylic acid includes any one or more combinations of dimer acids, sebacic acid, undecanoic acid, and dodecanoic acid. The aromatic diols include any one or more combinations of 4,4'-dihydroxydiphenylmethane, 1,2-diphenyl-1,2-ethylene glycol and 4,4'-biphenyldiol; The catalyst comprises any one or more combinations of tetrabutyl titanate, tetraisopropyl titanate, monobutyltin oxide, butyltin triisooctanoate, antimony glycolate, antimony trioxide, and zinc acetate.

4. The two-component polyurethane corner adhesive according to claim 1, characterized in that: The method for preparing the modified polyol includes the following steps: A. In an inert gas environment, long-chain dicarboxylic acid, aromatic diol and catalyst are added to a reaction vessel, heated to the polycondensation reaction temperature, and then subjected to a heat preservation reaction to obtain polyester diol. B. Castor oil is added to the reactor and modified polyol is obtained through transesterification. In step A, the polycondensation reaction temperature is 180–270°C, and the heat preservation reaction time is 3–10 h. In step B, the transesterification reaction is carried out at a temperature of 130–200°C for 2–5 hours.

5. The two-component polyurethane corner adhesive according to claim 1, characterized in that: According to the mass percentage, component A includes 10-50% polyether polyol, 10-40% modified polyol, 1-20% plasticizer, 10-40% filler, 1-10% molecular sieve activated powder, 1-10% fumed silica, 0.1-2% defoamer and 0.02-0.2% catalyst.

6. The two-component polyurethane corner adhesive according to claim 1, characterized in that: In component A, the polyether polyol includes any one or a combination of polyether diol with a molecular weight of 1000, polyether diol with a molecular weight of 2000, polyether triol with a molecular weight of 500, polyether triol with a molecular weight of 1000, polyether triol with a molecular weight of 3000, and polyether triol with a molecular weight of 5000. The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate powder, modified light calcium carbonate powder, and modified silica powder; The molecular sieve activated powder includes any one or more combinations of 3A, 4A, 5A and 13X; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or a combination of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers; The catalyst includes any one or more combinations of organotin catalysts, organobismuth catalysts, organozinc catalysts, and organobismuth-zinc composite catalysts.

7. The two-component polyurethane corner adhesive according to claim 1, characterized in that: According to the mass percentage, component B includes 18-70% isocyanate, 1-20% plasticizer, 20-50% filler, 1-10% fumed silica and 0.1-2% defoamer.

8. The two-component polyurethane corner adhesive according to claim 1, characterized in that: In component B, the isocyanate includes any one or more combinations of TDI and its prepolymer, MDI and its prepolymer, IPDI and its prepolymer, HMDI and its prepolymer, HDI trimer and polymeric MDI; The plasticizer includes any one or more combinations of DIBP, DOP, DINP, DOTP, DOA, DOS, DOZ and TXIB; The filler includes any one or more combinations of modified heavy calcium carbonate, modified light calcium carbonate, and modified silica powder; The fumed silica is hydrophobic fumed silica; The defoamer includes any one or more combinations of silicone defoamers, modified silicone defoamers, acrylate defoamers, modified acrylate defoamers, organofluorine defoamers, and modified organofluorine defoamers.

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