Door and window sealing hot melt adhesive and production process thereof

Abstract

The invention discloses a door and window sealing hot melt adhesive and a production process thereof, and relates to the technical field of hot melt adhesives, the door and window sealing hot melt adhesive comprises the following components by mass: 30%-35% of weather-resistant modified EVA resin, 20%-25% of high weather-resistant terpene phenolic resin, 15%-20% of a polyester plasticizer, 0.5%-0.8% of an antioxidant compound, and 0.3%-0.5% of a light stabilizer, 25%-30% of a nano TiO2 and heavy calcium carbonate compound filler; through formula optimization, the special weather-resistant modified base resin, the high-weather-resistant tackifying resin, the weather-resistant plasticizer, the compound efficient antioxidant and the light stabilizer are adopted, and the nano TiO2 with the ultraviolet shielding function and the heavy calcium carbonate compound filler are added, so that the weather resistance of the hot melt adhesive is synergistically enhanced from multiple levels, and meanwhile, the hot melt adhesive has the advantages that the weather resistance is greatly improved, and the service life of the hot melt adhesive is prolonged. The improved production equipment ensures uniform mixing and accurate adding of all raw materials and auxiliaries and a stable production environment, and the consistency and stability of product quality are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt adhesives, and in particular to a door and window sealing hot melt adhesive and a production process thereof. Background Art

[0002] In the construction field, doors and windows are key components of enclosing structures, and their sealing performance is of vital importance. The weather resistance of sealing materials is the core to achieve long-term effective sealing. Currently, hot melt adhesive is a commonly used sealing material for doors and windows, but ordinary hot melt adhesive for sealing doors and windows has prominent weather resistance issues when used outdoors.

[0003] When exposed to the outdoors for a long time, hot melt adhesives are easily affected by ultraviolet rays, drastic temperature changes, humidity and other factors, and are prone to aging. Ultraviolet rays cause molecular chains to break and cross-link, resulting in degradation of physical properties, such as increased hardness and reduced flexibility. In terms of temperature, hot melt adhesives tend to flow and soften at high temperatures, causing deformation of the sealing structure and reduced sealing effect. At low temperatures, hot melt adhesives become brittle and crack, and cannot maintain sealing. Humidity accelerates hydrolysis reactions, destroys internal structures, and shortens service life.

[0004] From a production perspective, it is difficult to ensure the weather resistance of hot melt adhesives with existing equipment and processes. Traditional mixing equipment cannot ensure that additives such as antioxidants and light stabilizers are evenly dispersed in the hot melt adhesive system, resulting in insufficient weather resistance in some areas. The temperature control accuracy of ordinary reactors is poor, and slight temperature fluctuations affect the reaction process of raw materials, which in turn has an adverse effect on the weather resistance stability of the product. Conventional molding equipment may introduce impurities or cause internal stress concentration during hot melt adhesive molding. These defects will accelerate the aging and failure of hot melt adhesives in outdoor environments. Therefore, it is very necessary to develop door and window sealing hot melt adhesives with excellent weather resistance and targeted improvements in production equipment and processes. Summary of the invention

[0005] In order to solve the above technical problems, a door and window sealing hot melt adhesive and a production process thereof are provided, which solve the problem that the hot melt adhesive in the prior art has poor weather resistance.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a hot melt adhesive for sealing doors and windows, which is composed of the following components by mass percentage:

[0007] Weathering modified EVA resin 30%-35%, high weathering terpene phenolic resin 20%-25%, polyester plasticizer 15%-20%, antioxidant compound 0.5%-0.8%, light stabilizer 0.3%-0.5%, nano-TiO2 and heavy calcium carbonate compound filler 25%-30%;

[0008] Among them, polyester plasticizers have good thermal stability and migration resistance, and are not easy to volatilize or migrate in high and low temperature environments. They help maintain the flexibility and stability of hot melt adhesives under different temperature conditions and improve their weather resistance.

[0009] Among them, the vinyl acetate (VA) content of the weather-resistant modified EVA resin is 30%-32%, and the melt index is 180-220 g / 10 min. The weather-resistant modified EVA resin enhances the resistance to ultraviolet rays and oxidation environment through molecular structure optimization;

[0010] The antioxidant complex is compounded by antioxidant 1010 and antioxidant 168 in a ratio of 2:1. Antioxidant 1010 captures free radicals and inhibits oxidation reactions, while antioxidant 168 decomposes hydroperoxides. Their synergistic effect prolongs the oxidation induction period of the hot melt adhesive in the outdoor environment and improves weather resistance.

[0011] Preferably, the softening point of the highly weather-resistant terpene phenolic resin is 100-105 °C. This tackifying resin can not only significantly improve the initial tack and holding power of the hot melt adhesive, but also maintain stable adhesion performance in the outdoor environment and is not easily aged to reduce the bonding strength with door and window materials.

[0012] Preferably, the light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate. The light stabilizer can effectively absorb ultraviolet energy and convert it into heat energy, capture free radicals generated by ultraviolet irradiation, prevent photooxidative degradation reactions, and enhance the stability of the hot melt adhesive under light conditions.

[0013] Preferably, in the nano-TiO2 and heavy calcium carbonate composite filler, nano-TiO2 is surface-treated with a coupling agent, and heavy calcium carbonate is surface-modified. Their mass ratio is 1:3-1:5. Nano-TiO2 has excellent ultraviolet shielding performance, can reflect and scatter ultraviolet rays, reduce its penetration into the hot melt adhesive, and at the same time fill microscopic pores, enhancing density and mechanical properties. After surface modification, heavy calcium carbonate has better compatibility with other raw materials, can reduce costs, improve hardness, wear resistance and dimensional stability. The two are compounded in a mass ratio of 1:3-1:5 to further enhance the weather resistance of the hot melt adhesive.

[0014] A production process for a door and window sealing hot melt adhesive includes the following steps:

[0015] S1. Pretreatment of raw materials: Use a combination of a high-precision vibrating screen and a cyclone separator to pretreat solid raw materials such as weather-resistant modified EVA resin, highly weather-resistant terpene phenolic resin, and heavy calcium carbonate. The vibrating screen can accurately screen out raw material particles that meet the particle size requirements, and the cyclone separator efficiently removes light impurities in the raw materials, ensuring the purity of the raw materials entering the production process and reducing the negative impact of impurities on the weather resistance of the hot melt adhesive. For nano-TiO2, use a high-speed stirring and ultrasonic dispersion integrated machine for dispersion treatment, uniformly disperse it in an appropriate amount of organic solvent to form a stable nano-dispersion liquid, ensure its uniform distribution in the hot melt adhesive system, and give full play to its ultraviolet shielding effect;

[0016] S2. Mixing and stirring: Equip a reactor with efficient stirring and precise temperature control functions. After heating to 140 - 150 °C to completely melt the EVA resin, stir at a high speed of 200 - 250 r / min. First, add the high weather-resistant terpene phenolic resin and stir for 20 - 30 min, then slowly add the polyester plasticizer and stir for 15 - 20 min. This stirring method and equipment can ensure that all raw materials are fully mixed evenly in a short time, making additives such as antioxidants and light stabilizers more evenly dispersed in the hot melt adhesive system, and improving the uniformity of the product's weather resistance;

[0017] S3. Adding additives and fillers: Use a feeding system with a precise quantitative adding device to accurately add the compounded antioxidant and light stabilizer into the reactor in sequence, and stir for 10 - 15 min to make them evenly dispersed. Then, slowly add the compounded filler of nano-TiO₂ and heavy calcium carbonate through a screw conveyor. The screw conveyor can precisely control the adding speed and uniformity of the filler. The adding process lasts for 30 - 40 min. After adding, continue to stir for 60 - 90 min to ensure that all raw materials are fully mixed to form a uniform and stable hot melt adhesive mixture, maximizing the improvement of weather resistance by each component;

[0018] S4. Filtration: Adopt a multi-stage filtration system. First, remove larger particle impurities through a 200-mesh coarse filter screen, and then further filter tiny particles and undispersed agglomerates using a 500-mesh fine filter screen. The filtering equipment is equipped with an automatic backwashing device;

[0019] S5. Molding and packaging: Use an extruder with precise temperature control and pressure control functions for hot melt adhesive molding. During the extrusion process, precisely control the temperature at 130 - 140 °C and the pressure at 5 - 8 MPa to ensure that the hot melt adhesive is extruded smoothly and maintains good molding quality, avoiding damage to the molecular structure of the hot melt adhesive due to temperature and pressure problems during the extrusion process, which affects the weather resistance. The molded hot melt adhesive is quickly transferred to a cooling device equipped with dual cooling functions of cold air and water mist. The combination of cold air and water mist can achieve rapid and uniform cooling, reducing internal stress caused by uneven cooling. The cooled hot melt adhesive is packaged in an aluminum-plastic composite film with high barrier performance and vacuum-packed through a vacuum packaging device to reduce its contact with external air, moisture, and ultraviolet rays, further extending its storage life and weather resistance.

[0020] Preferably, the stirring paddle in the reactor in step S2 has a multi-layer, multi-angle, variable-frequency speed regulation paddle structure, and the precise temperature control system can control the temperature fluctuation within ±1 °C, avoiding the influence of unstable temperature on the reaction and mixing effect of raw materials, and thus affecting the weather resistance.

[0021] Preferably, the filtration system in step S4 is also equipped with an automatic backwashing device, which can regularly clean the filter screen during the filtration process, prevent impurities from clogging the filter screen, ensure the continuity and stability of the filtration effect, ensure the purity of the hot melt adhesive, reduce the aging risk caused by impurities, and improve the weather resistance.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] (1) Through formula optimization, using a special weather-resistant modified base resin, a highly weather-resistant tackifying resin, a weather-resistant plasticizer, compounding a high-efficiency antioxidant and a light stabilizer, and adding a nano-TiO2 and heavy calcium carbonate compound filler with ultraviolet shielding function, the weather resistance of the hot melt adhesive is enhanced synergistically from multiple levels. At the same time, the improved production equipment ensures the uniform mixing, precise addition of various raw materials and auxiliaries, and a stable production environment, effectively improving the consistency and stability of product quality. After outdoor natural aging test, after 24 months of exposure, the hot melt adhesive can still maintain good physical properties and sealing effect. Compared with traditional door and window sealing hot melt adhesives, the weather resistance is increased by at least 1 time.

[0024] (2) On the premise of ensuring the high performance of the hot melt adhesive, by reasonably using relatively inexpensive fillers such as heavy calcium carbonate, the production cost is effectively reduced. At the same time, due to the high weather resistance and long service life of the product, the replacement frequency and maintenance cost of the door and window sealant are reduced. In the long run, it has significant economic benefits and improves the market competitiveness of the product. Detailed implementation manners

[0025] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variants.

[0026] Example 1

[0027] S1. Raw material preparation: By mass percentage, weigh 32 kg of weather-resistant modified EVA resin (VA content is 31%, melt index is 200 g / 10 min), 22 kg of highly weather-resistant terpene phenolic resin (softening point is 102 °C), 18 kg of polyester plasticizer, 0.3 kg of antioxidant 1010, 0.15 kg of antioxidant 168, 0.35 kg of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 5 kg of nano-TiO2 surface-treated with a coupling agent, and 22.2 kg of surface-modified heavy calcium carbonate;

[0028] Use a high-precision vibrating screen and a cyclone separator to pre-treat the solid raw materials, and use a high-speed stirring and ultrasonic dispersion integrated machine to disperse the nano-TiO2.

[0029] S2. Mixing and Stirring: Add the weather-resistant modified EVA resin into a reaction kettle equipped with special stirring blades and a precise temperature control system, heat it up to 145 °C to completely melt the EVA resin. Turn on the stirring device and stir at a speed of 220 r / min, add the highly weather-resistant terpene phenolic resin, and stir for 25 min. Then slowly add the polyester plasticizer and continue stirring for 18 min.

[0030] S3. Adding Auxiliaries and Fillers: Sequentially add antioxidant 1010, antioxidant 168, and light stabilizer through a precise quantitative adding device, stir for 12 min, and then slowly add the nano-TiO₂ dispersion and heavy calcium carbonate through a screw conveyor while stirring. The adding process lasts for 35 min, and after the addition, continue stirring for 70 min.

[0031] S4. Filtration: Pass the mixed hot-melt adhesive mixture through a multi-stage filtration system equipped with an automatic backwashing device, first through a 200-mesh coarse filter screen, and then through a 500-mesh fine filter screen for filtration.

[0032] S5. Shaping and Packaging: Extrude the filtered hot-melt adhesive into a glue stick through an extruder with precise temperature control and pressure control functions, extrude it at 135 °C and 6 MPa, cool it with a cooling device combining cold air and water mist, and then vacuum package it with an aluminum-plastic composite film through a vacuum packaging device.

[0033] Performance Testing

[0034] Weather Resistance Testing: Place the sealed door and window specimens in the outdoor natural environment for 24 months. The hot-melt adhesive only shows slight discoloration, without obvious aging or cracking phenomena, and has excellent weather resistance.

[0035] High and Low Temperature Performance Testing: Place the sealed door and window specimens in a high-temperature environment of 80 °C for 24 hours and a low-temperature environment of -30 °C for 24 hours respectively. The hot-melt adhesive does not flow or deform in the high-temperature environment, and does not crack or fall off in the low-temperature environment. The high and low temperature performance is stable.

[0036] Sealing Performance Testing: Use the prepared hot-melt adhesive for door and window sealing. After simulated wind and rain testing, there is no leakage at the door and window sealing parts, and the sealing performance is good.

[0037] Example 2

[0038] S1. Raw material preparation: Weigh 30 kg of weather-resistant modified EVA resin (VA content is 30%, melt index is 180 g / 10 min), 23 kg of highly weather-resistant terpene phenolic resin (softening point is 100 °C), 17 kg of polyester plasticizer, 0.28 kg of antioxidant 1010, 0.14 kg of antioxidant 168, 0.32 kg of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 4 kg of nano-TiO₂ surface-treated with coupling agent, and 25.26 kg of surface-modified heavy calcium carbonate by mass percentage, and conduct corresponding pretreatment on the raw materials.

[0039] S2. Mixing and stirring: Add the weather-resistant modified EVA resin into the reaction kettle, heat up to 140 °C to completely melt the EVA resin, turn on the stirring device, stir at a speed of 200 r / min, add the highly weather-resistant terpene phenolic resin, stir for 30 min, and then slowly add the polyester plasticizer and continue stirring for 20 min.

[0040] S3. Adding additives and fillers: Use a precise quantitative feeding system to sequentially add antioxidant 1010, antioxidant 168, and light stabilizer, and stir for 10 min. Then slowly add the nano-TiO₂ dispersion and heavy calcium carbonate through a screw conveyor while stirring. The adding process lasts for 40 min, and continue stirring for 80 min after the addition is completed.

[0041] S4. Filtration: Filter the mixed hot melt adhesive mixture through a multi-stage filtration system.

[0042] S5. Molding and packaging: Extrude the filtered hot melt adhesive into pellets through an extruder, extrude at 130 °C and 5 MPa, cool with a cooling device combining cold air and water mist, and then conduct vacuum packaging with an aluminum-plastic composite film through a vacuum packaging device.

[0043] Performance testing

[0044] Weather resistance test: Place the sealed door and window specimens in the outdoor natural environment for 24 months. The performance of the hot melt adhesive is stable and the weather resistance is good.

[0045] High and low temperature performance test: Place the sealed door and window specimens in a high temperature environment of 80 °C for 24 hours and a low temperature environment of -30 °C for 24 hours respectively. The hot melt adhesive does not flow or deform in the high temperature environment, and does not crack or fall off in the low temperature environment. The high and low temperature performance is stable.

[0046] Sealing performance test: Use the prepared hot melt adhesive for door and window sealing. After simulated wind and rain tests, there is no leakage at the door and window sealing parts, and the sealing performance is good.

[0047] Example 3

[0048] S1. Raw material preparation: Weigh 34 kg of weather-resistant modified EVA resin (VA content is 32%, melt index is 220 g / 10 min), 21 kg of highly weather-resistant terpene phenolic resin (softening point is 105 °C), 19 kg of polyester plasticizer, 0.32 kg of antioxidant 1010, 0.16 kg of antioxidant 168, 0.38 kg of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, 6 kg of nano-TiO₂ surface-treated with coupling agent, and 19.14 kg of surface-modified heavy calcium carbonate by mass percentage. Use a high-precision vibrating screen and a cyclone separator to pre-treat solid raw materials such as weather-resistant modified EVA resin, highly weather-resistant terpene phenolic resin, and heavy calcium carbonate to remove impurities and particles that do not meet the particle size requirements;

[0049] For nano-TiO₂, use a high-speed stirring and ultrasonic dispersion integrated machine to uniformly disperse it in an appropriate amount of organic solvent to form a stable nano-dispersion.

[0050] S2. Mixing and stirring: Add the weather-resistant modified EVA resin to a reaction kettle equipped with special stirring blades and a precise temperature control system, heat up to 150 °C to completely melt the EVA resin, turn on the stirring device, stir at a speed of 250 r / min, add the highly weather-resistant terpene phenolic resin, and stir for 20 min to fully mix the two. Then slowly add the polyester plasticizer and continue to stir for 15 min to ensure that the plasticizer is uniformly dispersed in the system.

[0051] S3. Adding additives and fillers: Through a feeding system with a precise quantitative adding device, add antioxidant 1010, antioxidant 168, and light stabilizer in sequence, stir for 15 min to uniformly disperse the additives in the hot melt adhesive system. Then slowly add the nano-TiO₂ dispersion and heavy calcium carbonate through a screw conveyor while stirring. The adding process lasts for 30 min. After adding, continue to stir for 90 min to ensure that all raw materials are fully mixed evenly to form a uniform and stable hot melt adhesive mixture.

[0052] S4. Filtration: Pass the mixed hot melt adhesive mixture through a multi-stage filtration system equipped with an automatic backwashing device. First, pass through a 200-mesh coarse filter screen to preliminarily remove larger particle impurities, and then pass through a 500-mesh fine filter screen for fine filtration to remove fine particles and unevenly dispersed aggregates to ensure the purity of the hot melt adhesive.

[0053] S5. Molding and Packaging: The filtered hot-melt adhesive is extruded into strips through an extruder with precise temperature control and pressure control functions. It is extruded under the conditions of 140°C and 8 MPa to ensure the smooth extrusion of the hot-melt adhesive and good molding quality. A cooling device combining cold air and water mist is used to rapidly cool the molded hot-melt adhesive to reduce the internal stress caused by uneven cooling. The cooled hot-melt adhesive is packaged in an aluminum-plastic composite film with high barrier properties and vacuum-packed through a vacuum packaging device to prevent it from contacting with external air, moisture, and ultraviolet rays.

[0054] Performance Testing

[0055] Weather Resistance Testing: The sealed window and door specimens are placed outdoors in the natural environment for 24 months. There are no obvious signs of aging on the surface of the hot-melt adhesive, only slight discoloration, and it still maintains good flexibility and adhesiveness, showing excellent weather resistance.

[0056] High and Low Temperature Performance Testing: The sealed window and door specimens are placed in a high-temperature environment of 80°C for 24 hours and a low-temperature environment of -30°C for 24 hours respectively. In the high-temperature environment, the hot-melt adhesive does not show phenomena such as flowing and deformation. In the low-temperature environment, the hot-melt adhesive does not crack or fall off, and the high and low temperature performance is stable and reliable.

[0057] Sealing Performance Testing: The prepared hot-melt adhesive is used for window and door sealing. After the simulated wind and rain test, there is no leakage at the window and door sealing parts, effectively blocking the intrusion of wind and rain, and the sealing performance is good.

[0058] It can be seen from the above three embodiments that the hot-melt adhesive for window and door sealing prepared by the present invention performs excellently in terms of weather resistance, high and low temperature performance, and sealing performance. Moreover, the production process is feasible, the product quality is stable, and it has good application prospects.

[0059] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot-melt adhesive for door and window sealing, characterized in that It consists of the following components by mass percentage: Weather-resistant modified EVA resin: 30%-35%, highly weather-resistant terpene phenolic resin: 20%-25%, polyester plasticizer: 15%-20%, antioxidant complex: 0.5%-0.8%, light stabilizer: 0.3%-0.5%, nano-TiO2 and heavy calcium carbonate compound filler: 25%-30%; Among them, the vinyl acetate (VA) content of the weather-resistant modified EVA resin is 30%-32%, and the melt index is 180-220 g / 10 min; The antioxidant complex is compounded by antioxidant 1010 and antioxidant 168 in a ratio of 2:

1.

2. The hot-melt adhesive for door and window sealing according to claim 1 and its production process are characterized in that, The softening point of the highly weather-resistant terpene phenolic resin is 100-105 °C.

3. A kind of door and window sealing hot melt adhesive and its production process according to claim 1, characterized in that, The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.

4. A kind of door and window sealing hot melt adhesive and its production process according to claim 1, characterized in that, In the nano-TiO2 and heavy calcium carbonate compound filler, the nano-TiO2 is surface-treated with a coupling agent, and the heavy calcium carbonate is surface-modified. The mass ratio of the two is 1:3-1:

5.

5. The production process of the hot melt adhesive for door and window sealing according to any one of claims 1-4, characterized in that, It includes the following steps: S1. Pretreatment of raw materials: Use a combination of a high-precision vibrating screen and a cyclone separator to pretreat solid raw materials such as weather-resistant modified EVA resin, highly weather-resistant terpene phenolic resin, and heavy calcium carbonate. Use a high-speed stirring and ultrasonic dispersion integrated machine to disperse nano-TiO2 and uniformly disperse it in an appropriate amount of organic solvent to form a stable nano-dispersion liquid; S2. Mixing and stirring: Add the weather-resistant modified EVA resin to a reaction kettle equipped with special stirring blades and precise temperature control functions. Heat up to 140-150 °C to completely melt the EVA resin, stir at a speed of 200-250 r / min, first add the highly weather-resistant terpene phenolic resin and stir for 20-30 min, and then slowly add the polyester plasticizer and stir for 15-20 min; S3. Adding additives and fillers: Use a feeding system with a precise quantitative adding device to accurately add the compounded antioxidant and light stabilizer to the reaction kettle in sequence, stir for 10-15 min to make them uniformly dispersed, and then slowly add the nano-TiO2 and heavy calcium carbonate compound filler through a screw conveyor. The adding process lasts for 30-40 min. After the adding is completed, continue to stir for 60-90 min; S4. Filtration: Use a multi-stage filtration system. First, remove larger particle impurities through a 200-mesh coarse filter screen, and then use a 500-mesh fine filter screen to further filter out fine particles and unevenly dispersed aggregates; S5. Molding and packaging: Use an extruder with precise temperature control and pressure control functions to carry out hot melt adhesive molding. During the extrusion process, control the temperature at 130-140 °C and the pressure at 5-8 MPa. The formed hot melt adhesive is quickly transferred to a cooling device equipped with dual cooling functions of cold air and water mist for cooling. The cooled hot melt adhesive is packaged in an aluminum-plastic composite film with high barrier performance and vacuum-packed by a vacuum packaging device.

6. The production process of a hot-melt adhesive for door and window sealing according to claim 5, characterized in that: The stirring blades in the reaction kettle in step S2 are of a multi-layer, multi-angle, variable-frequency speed regulation blade structure, and the precise temperature control system can control the temperature fluctuation within ±1 °C.

7. The production process of a hot-melt adhesive for door and window sealing according to claim 5, characterized in that, The filtration system in step S4 is also equipped with an automatic backwashing device.