Precautions for using two-component polyurethane adhesives 1.Before applying the adhesive, the surface of the adherend must be clean, dry and free of grease. 2.The resin and curing agent should be mixed in the required ratio. 3.When scraping the glue, please try to scrape it carefully as it has a defoaming effect. 4.Store adhesive in (> 10, <50 * C) and dry place 5.Run out of the mixed glue within the specified operating time. If it is used for more than the opening time, it may cause the risk of degumming and strength reduction, and even the glue cannot be scraped at all. 6.Understand that the main agent and curing agent of the adhesive are more sensitive to water (especially the curing agent). The polyurethane curing agent will react with water to generate carbon dioxide. Do not wash the surface of the substrate with oil, and be careful not to allow a large amount of glue Moisture.Epoxy resins and curing agents are more sensitive to moisture than polyurethane, but they also cannot allow excessive moisture on the bonding surface. 7. It is recommended that users use certain personal safety products, such as operating with gloves. Sinograce Chemical's water based polyurethane glue emulsion has a high viscosity. visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone             :+86 0551 63459511

Development trend of waterborne polyurethane: Nowadays, with the stricter requirements of environmental protection policies, the environmental protection requirements for the performance of adhesives will become higher and higher. Therefore, the greening and environmental protection of composite materials will be more and more important. There will be even more urgency.Therefore, the points mentioned below will definitely become the future development trend of water-based polyurethane. (1) Improve the bonding strength of water-based polyurethane, especially the initial bonding strength, and reduce the gap between it and traditional solvent-based PU.In the process of synthesizing water-based polyurethane, less or no organic solvent is used at all, thereby truly meeting the requirements of environmental protection, increasing the solid content of the synthetic water-based polyurethane, and reducing the cost of transportation and use. (2) Use of biomass resources to modify water-based polyurethanes, such as natural polymer compounds and natural rosin resins.Natural high-molecular compounds are mainly cellulose, starch, and so on. As a kind of degradable and renewable biomass resource, cellulose has received great attention in aerospace and medicine.In recent years, how to use cellulose more fully and efficiently has become the focus of attention of many scientists. Therefore, the use of biomass resources to modify water-based polyurethane will become one of the future trends of modified water-based polyurethane. (3)Use functional graphene materials as modifiers to modify waterborne polyurethane.Since graphene is a two-dimensional carbon atom crystal with a single-layer atomic thickness and a special honeycomb structure, it is currently one of the thinnest materials in the world. Therefore, graphene is expected to rely on its excellent electrical, thermal, and mechanical properties. Become a high-quality filler for polymer-based composite materials, and give polymer-based composite materials excellent properties, thereby expanding their application fields.In addition, using graphene as a filler to compound with water-based polyurethane can not only give it relatively good mechanical properties and thermal stability, but also make it have good electrical conductivity. (4)In recent years, hyperbranched polymers, especially macromolecular polymers with three-dimensional structures and a large number of special end groups, have gradually developed.Due to the special structure of hyperbranched polymers, they have a wide range of applications in the fields of polymer modification, drug release, and adhesives.Among them, the hydroxyl-terminated hyperbranched polymer has high chemical reactivity with isocyanate. As a modifier of water-based polyurethane, it is expected to produce a modified water-based polyurethane material with excellent comprehensive properties and the advantages of both a hyperbranched structure and water-based polyurethane. For more deta...

Current problems with waterborne polyurethane adhesives: (1) Low solid content: At present, the solid content of water-based polyurethane (WPU) can reach 45%. Fewer systems lead to higher drying and transportation costs. Increasing the solid content leads to an increase in the viscosity of the system, which makes emulsification and dispersion difficult. Reduced emulsion stability. (2) Slow drying and curing speed: The specific heat capacity and latent heat of evaporation of water are high, so the volatilization and drying of water are slow, resulting in long curing time of the adhesive, increasing energy consumption, and reducing production efficiency. (3) Poor wetting performance: The surface tension of water is three times greater than that of ordinary solvents. Using water as a solvent has poor wetting ability on low-energy surfaces. (4) Poor initial adhesion performance: The unmodified water-based polyurethane adhesive has a lower initial viscosity than the modified one, and has a greater impact on construction. (5) Poor water resistance and heat resistance: Most water-based polyurethane adhesives are linear thermoplastics, and their molecular chains contain hydrophilic groups, which results in poor water resistance and heat resistance. (6) Poor storage stability: The storage stability becomes worse as the solid content of the water-based polyurethane adhesive system increases and the degree of cross-linking increases. Sinograce Chemical is professional in the field of polyurethane coating, the quality is worthy of guarantee, the technology is worthy of trust. visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511

Water based polyurethane resin refers to a binary colloidal system in which a polyurethane resin is dissolved or dispersed in water.Water-based polyurethane resin has the advantages of easy to use, stable performance, strong adhesion, excellent gloss, good heat resistance, etc. It can be suitable for various printing methods, especially suitable for screen printing, plastic packaging and composite films. The water-based polyurethane used in the ink industry requires good gloss, high bonding strength to materials, and good blocking resistance at a certain temperature.According to these performance requirements, there are the following requirements for the structural characteristics, functionality, synthetic formula, and process of polyurethane:(1) Select appropriate polyacids and polyols to synthesize polyester polyols with temperature resistance;(2) the introduction of polar groups with strong adhesion to the material;(3) Selecting suitable raw materials to improve the crystallinity of polyurethane;(4) Use coupling agents and other auxiliaries to improve the moisture and heat resistance of water-based polyurethane adhesives for inks. At present, water-based polyurethane inks have been commercialized, can meet a variety of performance requirements, and are receiving increasing attention.The application of water-based polyurethane inks is mainly flexographic printing and gravure printing. Water-based polyurethane inks widely used abroad have good environmental protection, stable ink properties, high viscosity, strong tinting power, and high fastness. need. Sinograce chemical produces polyurethane resin for various polyurethane coatings, such as water-based glue and water-based polyurethane waterproof coating visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511