• Study on the application of waterborne polyurethane in textile finishing
    Study on the application of waterborne polyurethane in textile finishing

    2023-06-09

    Environmental protection pressure has prompted some traditional solvent-based products to gradually withdraw from the market and replace them with water-based, high solid content, powder products, etc.Waterborne polyurethane, as an important member of waterborne products, is facing unprecedented development opportunities with its unique excellent properties.In addition to the leather industry, it is used in textile finishing, coatings, medical materials, glass fiber, plastic parts, automotive interior parts, card production and other industries.The research topic related to waterborne polyurethane is becoming a hot topic in recent years. There are more and more research projects related to waterborne polyurethane, and more and more scientific research institutions and universities are participating in the exploration. Their work is mainly reflected in the following aspects.There are more and more research projects related to waterborne polyurethane, and more and more scientific research institutions and universities are participating in the exploration. Their work is mainly reflected in the following aspects. Crosslinked modified waterborne polyurethane is mostly linear structure, its water resistance, solvent resistance and heat resistance is relatively poor, the introduction of crosslinked structure, can be effectively improved.According to the internal crosslinking method, partial branching and crosslinking structures can be formed by introducing three functional compounds.This kind of method can improve the performance of the film, its main disadvantage is that the molecular weight of the prepolymerization is large, resulting in emulsification difficulties, difficult to produce water-based polyurethane with high solid content, so the drying performance is relatively poor. The more feasible is to use the diplomatic association method, although the method is more troublesome in application, but it is really effective, and can significantly enhance the drying speed, and the improvement of performance is especially obvious.In which the key cross-linker cured at room temperature is water, which can disperse polyisocyanate and polyaziridine. In recent years, there are many researches on water-dispersible polyisocyanates, but not many have been published. Some domestic manufacturers are trying to launch, but the performance stability needs to be improved. Another kind of crosslinked modified product is closed waterborne polyurethane. The synthesis of this type of product is difficult to control, and the products produced are not stable, but it will be a key direction in the future, especially in the textile function finishing, paint printing and other industries have great room for display.

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  • Guidelines for the use of surfactants in pesticides
    Guidelines for the use of surfactants in pesticides

    2023-06-08

    Surfactants are now used not only in herbicides but in all forms of pesticides. Surfactants can be used to make pesticide preparations that can not be used directly. As a pesticide additive applied to pesticides, it can not only improve the use effect of pesticides, but also reduce the amount of pesticides, reduce the impact of pesticides on the environment, and bring great benefits to agricultural production. However, since pesticides are a class of special chemicals with strong biological activity, and their control objects, protection objects and environmental conditions are very complex, the surfactant in pesticides must be selected and formulated according to the nature and characteristics of the original drug, but also consider the impact of the surfactant itself on the target organism. The following highlights the guidelines for the use of three surfactants. Solubilizer Using the micelle action of surfactants, the solubility of the insoluble agent in the solvent is significantly increased, which is solubilization. Surfactants with HLB=15-18 can be used as solubilizers, but only when the concentration of solubilizers is higher than the critical micelle concentration. At this time, the insoluble drug is contained or adsorbed in the rubber by the lipophilic group of the solubilizer, the hydrophilic group of the solubilizer is in water, and the non-polar drug is soluble in water. Dispersant Dispersants can hinder or prevent the aggregation of solid or liquid particles in the dispersion system, and keep them uniformly dispersed for a long time. The dispersant is adsorbed at the oil-water interface or on the surface of solid particles, forming a charge or steric barrier around the particles, which helps to prevent the re-aggregation of pesticide particles during mixing and storage. Generally used as a dispersant is a polycyclic anionic surfactant, such as alkyl naphthalene sulfonate and naphthalene sulfonate formaldehyde condensation of sodium salt, lignosulfonate, etc. Polymer dispersants (such as sodium polycarboxylate) are particularly important in the preparation of aqueous suspension because of their adsorption properties and their ability to charge dispersed particles and have large spatial barriers. Suspoemulsion(SE) The mixed dosage form is popular because it is convenient and ensures that users use the correct amount of various pesticide ingredients, while avoiding the inhomogeneity that usually occurs when mixing in barrels. It uses a solid pesticide of insoluble water and another liquid pesticide of insoluble water to prepare a suspended mixed dispersion solution by relying on surfactant as the medium of water, which can generally be regarded as a combination of SC and EW. The commonly used surfactants mainly include emulsifiers, dispersants and thickeners. The flocculation of particles and oil droplets in SC and EW formulations is not only a problem, but also a wide range of cold and hot storage tests are necessary.

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  • Water based adhesive
    Water based adhesive

    2023-06-03

    Water based adhesive Water-based adhesive refers to the water-soluble polymer dissolved into appropriate concentration of aqueous solution, or insoluble polymer dispersed into micro-particles (emulsion) in water with the help of surfactant in the general term of adhesives;In simple terms, adhesives made of materials that can be dispersed or dissolved in water are aqueous adhesives and are often referred to as water-based adhesives. classification Water-based adhesives can be divided into the following categories: 1. Aqueous solution, such as starch or dextrin, cellulose and protein natural adhesives, polyvinyl alcohol, phenolic resin, urea-formaldehyde resin, melamine resin and other synthetic adhesives; 2. Emulsion or water dispersion, such as PVAc, EVA emulsion, polyacrylate emulsion, epoxy resin emulsion, butylbenzene, nitrile, neoprene latex, polyurethane emulsion, etc. 3. Aqueous dispersion, such as water-based reclaimed rubber or butyl rubber, etc. Application area Automobile industry: With the development of automobile industry, the relationship between automobile and adhesive is more and more close. Firstly, the "three leaks" (air leakage, rain leakage and dust leakage) of the car are solved, and the comfort of the whole car is improved. Secondly, it not only plays the role of heat insulation and vibration reduction, enhancement of automobile structure and interior and exterior decoration, but also simplifies the automobile manufacturing process, and plays a more and more important role in automobile energy saving and consumption reduction, lightweight and extension of service life. Therefore, the amount of adhesive on the car is increasing. Packaging industry: in our country's flexible packaging industry, the proportion of water-based adhesives is still relatively high. In the past, solve-based adhesives were used, but there are serious organic solvent volatilization and residue problems in solve-based adhesives, which not only pollutes the environment, but also has a variety of health and safety risks. Today, when the green wind swept through the whole packaging and printing industry, the industry turned its attention to more environmentally friendly water-based adhesives and solvless adhesives, especially the water-based adhesives gave high hopes. Construction industry: in the internal structure decoration, there are many building materials in the process of manufacturing and production also need to be used. At present, in order to solve the problems of pollution and the key to the human body, the construction field has gradually begun to use more environmentally friendly water-based adhesives. Footwear industry: With the human pursuit of environmental protection and health and environmental protection policy requirements, ool-based adhesive because of a large number of volatile solvents, with heavy odor, sensitization, environmental pollution, toxic components and other shortcomings, non-toxic, pollution-free, environmentall...

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  • Adhesive increases effectiveness——TK series water-based viscosifying emulsion
    Adhesive increases effectiveness——TK series water-based viscosifying emulsion

    2023-06-01

    Water-based viscosifying emulsion plays a very important role in water-based acrylic pressure sensitive adhesive, which can improve the bonding strength and initial adhesion of pressure sensitive adhesive on high and low energy surfaces, so as to achieve the best balance point, and can improve the application range and grade of pressure sensitive products. Today, we will take you to understand the application of water-based viscous emulsion in water-based pressure sensitive adhesive. The adhesive emulsion plays a very important role in the pressure sensitive adhesive. It has a significant effect on the improvement of the peeling strength and initial viscosity of the adhesive. Depending on the adhesive polymer, different tackifying emulsions should be selected. Aqueous rosin viscosification emulsion is a rosin modified emulsion dispersion with 55% high solid content, 100% solvent free and APE free. It has a very narrow particle size distribution interval and a small average particle size, which is used to improve the adhesive properties of waterborne pressure sensitive adhesives/adhesives.It has excellent low foamability, storage and mechanical stability. It has excellent compatibility with common polymers such as acrylic acid, SBR and NR. Water-based adhesive emulsion is used for pressure sensitive adhesive, paper adhesive, industrial tape, film adhesive and other water-based adhesive. Best Products TK series water-based viscosifying emulsion I.Overview This series of products are made of modified rosin polyester and polymer surfactant as raw materials, and emulsified by special homogenization process. The products and the preparation process do not use any organic solvent, which is a green water-based tackifying agent. Due to the use of polymer emulsifier, it has a significant viscosity effect and a wide range of compatibility, can be widely used in all kinds of water-based adhesives to increase viscosity or thickening. II.Characteristics 1.Unique polymer surfactant, making the product viscosity effect is significant, good compatibility, wide compatibility, suitable for many varieties. 2.Special emulsification process, narrow particle size distribution, stable quality, long storage period. 3.Rosin modified polyester can be suitable for a wide PH value, can be used in near neutral or weak alkaline conditions. 4.Low surface tension, small foam, uniform coating. 5.After addition, it can significantly improve the initial viscosity value, holding viscosity, peeling strength, and make it reach the best balance point. 6.The preparation uses water as solvent, does not contain any organic solvent, green and environmentally friendly. III.technical indicator Appearance: White emulsion pH:6-8 solid content:50~55 % Particle size: ≤0.5μm Ionic type: anion Stability (25℃) : three months Hard water resistance: stable in hard water IV.Hard water resistance: stable in hard water 1.Acrgeic: mutual tolerance 2.Styrene-butadiene rubber (SBR) : mutual tolerance 3.Chl...

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