Polyurethane (polyurethanes, abbreviated PU) is a kind of polymer with -NHCOO-repeat structural unit as the main chain. Isocyanate (monomer) is polymerized with a hydroxyl compound.Due to the strong polarity of the carbamate group, insoluble in non-polar groups, with good oil resistance, toughness, wear resistance, aging resistance and adhesion. Materials suitable for a wide temperature range (-50 -- 1500℃) can be prepared with different raw materials, including elastomer, thermoplastic resin and thermosetting resin. It is not resistant to hydrolysis or alkaline medium at high temperature. Adding polyurethane resin to the ink can improve the wettability of the ink to the pigment, and the film is good, the ink film is fast and wear-resistant, and it is used in the manufacturing of offset printing and water-based ink, but the price is higher. The polyurethane resin used for printing ink is generally made of polyester/polyether polyol and isocyanate reaction, molecular weight of about 20,000 ~ 40,000. Its solvent mainly to benzene, ketone, ester solvent as the main solvent. In the process of research and development according to the ink factory and printing plant environmental protection needs, using ketone ester solvent or alcohol ester solvent to prepare the corresponding benzene free ink resin. The characteristics of polyurethane resin for printing ink are as follows: ①Excellent yellowing resistance. The polyurethane resin for printing ink is synthesized by aliphatic polyester and aliphatic isocyanate as the main raw materials in the process of preparation. Compared with aromatic polyurethane, it has excellent optical stability, and the film has excellent yellow resistance. ②Excellent adhesion fastness to film substrates. Ink with polyurethane resin molecular chain segment contains carbamate, urea formate, ester bond, ether bond and other polar groups, and a variety of polar substrates PET, PA and other plastic surface polar groups to form hydrogen bonds, and then the formation of a certain connection strength of the joint. The polyurethane resin made of ink, printing on the surface of polar plastic substrate has good adhesion fastness. ③Good affinity and wettability with pigments/dyes. Polyurethane resin for printing ink is generally prepared by polyester or polyether polyols, aliphatic diisocyanate and diamine/diol chain extender. Due to the introduction of urea bond in PU resin, polyurethane monourea resin (PUU) is formed, which makes it have good dispersion wettability for pigments. ④Good resin compatibility. Ink with polyurethane resin and aldehyde-ketone resin, chloro-vinegar resin has a good compatibility, according to the actual situation in their own process formula appropriate to add, in order to improve the comprehensive performance of ink. ⑤Excellent film forming properties. Ink polyurethane resin and other fields of polyurethane resin used in the structure is different, the traditional polyurethane is mainly polyester polyol/polyethe...

Polyurethane adhesive is a kind of high-grade adhesive, with excellent flexibility, impact resistance, chemical resistance, wear resistance, and the most important is its low temperature resistance. Because of its series of advantages, polyurethane adhesives are widely used in the following fields. 1. Carpentry industry With the improvement of people's awareness of environmental protection, the wood processing industry has gradually used a new type of environmentally friendly polyurethane adhesive to replace the urea-formaldehyde resin, so as to reduce the pollution to the environment. One-component moisture-cured polyurethane adhesives used in the woodworking industry are liquid and used at room temperature. Usually, it has high bonding strength, good flexibility and water resistance, and can be bonded to many non-wood substrates (such as metal, plastic, rubber, etc.). The dry and wet strength of one component polyurethane adhesive is better than that of phenolic adhesive. Before bonding, coating hydroxymethyl resorcinol (HMR) coupling agent on the surface of bonding substrate can improve bonding strength. 2.Shoe industry Our country is always a large shoe-making country, and in recent years the preparation technology of water-based polyurethane is becoming mature. For some low-polarity shoe materials, such as SBS and other materials bonding, the peeling strength of polyurethane adhesive can not meet the requirements. Polyurethane adhesives for shoes with high crystallinity, high crystallization rate, high cohesion strength and good peeling strength can be developed by adding viscosifying resin. 3.Packaging industry Flexible packaging has surpassed hard packaging, such as plastic, glass bottles and cans, for its unique comprehensive performance such as light and convenient, long shelf life, sanitation, easy storage and transportation, easy to disassemble, less garbage and good shelf effect. Because of its excellent performance, polyurethane adhesive can bond film materials of different properties together to get cold resistance, oil resistance, drug resistance, transparent, wear resistance and other properties of flexible packaging composite film. At present, polyurethane adhesive has become the main adhesive for flexible packaging composite film processing in domestic and foreign markets. 4.Construction and paving industry In addition to the advantages of non-toxic, pollution-free, easy to use, polyurethane adhesive also has other incomparable advantages, that is, excellent low temperature resistance, solvent resistance, aging resistance, ozone resistance and bacteria resistance, in the application of building pavement materials plays an important role. It is widely used in elastic rubber floor MATS, hard rubber floor tiles and laying plastic track sports fields. The new two-component polyurethane adhesive breaks through the contradiction between the shear strength and the peeling strength of the traditional adhesive, and can make both of them ...

Acrylic resin is made of acrylic ester and methacrylate and other alene monomers copolymerization resin, through the selection of different resin structure, different formula, production process and solvent composition, can be synthesized different types, different performance and different application of acrylic resin, Acrylic resin can be divided into thermoplastic acrylic resin and thermosetting acrylic resin according to the difference of structure and film forming mechanism. The main absorption peak of acrylic resin synthesized by copolymerization of acrylic ester and methacrylate monomer is outside the range of solar spectrum, so the acrylic resin paint has excellent light resistance and outdoor aging performance. Thermoplastic acrylic resin in the film forming process does not occur further crosslinking, so its relative molecular weight is larger, has good light and color preservation, water and chemical resistance, fast drying, convenient construction, easy construction recoating and rework, aluminum powder preparation of aluminum powder whiteness, good positioning. Thermoplastic acrylic resin is widely used in automobile, electrical appliance, machinery, construction and other fields. Thermosetting acrylic resin refers to a certain functional group in the structure, in the paint through and added amino resin, epoxy resin, polyurethane and other functional groups reaction to form a network structure, thermosetting resin is generally relatively low molecular weight. Thermosetting acrylic coatings have excellent fullness, gloss, hardness, solvent resistance, weather resistance, no color change in high temperature baking, no yellowing. The most important application is to make amino acrylic paint with amino resin, which is widely used in cars, motorcycles, bicycles, coil steel and other products. According to the mode of production, it can be divided into: 1.Emulsion polymerization is through monomer, initiator and its reaction solvent reaction polymerization, the general resin for solid content of 50% resin solution! Is containing about 50% of the solvent resin, the general reaction with the solution of benzene (toluene or xylene), esters (ethyl acetate, butyl acetate), is generally single or mixed! Solid emulsion type acrylic resin has solvent immutability! Generally due to the choice of solvents and the product performance is not the same! Generally have a certain color number! The glass transition temperature is low, because the reaction is usually done with no methyl acrylate! Solid this type of resin can have a higher solid content, up to 80%! Can do high solid paint, production is simple! But because of solvent immutability, transportation is not convenient! 2, suspension polymerization is a more complex production process, is generally used as a method for the production of solid resin! Solid acrylic resin, which is generally used with methyl acrylate down reaction polymerization! Acrylates without methyl are generally with a certain...

Preparation method of waterborne acrylic emulsion 1.The preparation of water-based acrylic emulsion: the raw materials including acrylic hard monomer, acrylic soft monomer and acrylic functional monomer all acrylic monomer, emulsifier, water added to the pre-emulsifying kettle, emulsifying 30 ~ 40min.A non-stratified emulsion is obtained. Then the remaining water, remaining emulsifier and buffer are added into the polymerization reactor, and the temperature is raised to 78 ~ 80℃. The emulsion is put in, and the initiator is added for 20 ~ 30min. The remaining emulsion and remaining initiator are added, and the droplets are finished in 3 ~ 4h. Then the polymerization reactor was heated to 85 ~ 90℃ to hold heat for 1 ~ 2 hours, and the temperature was lowered to 45 ~ 50℃. pH regulator was added to adjust the PH value of the reaction system to between 6 ~ 7. That is to prepare water-based acrylic emulsion. 2.Common equipment required for the preparation of water-based acrylic emulsion preemulsification kettle → drip adding kettle → reaction kettle → vertical condenser → filter → stirring kettle → filling machine → need a vacuum system, nitrogen system, water cooling system, pure water equipment Water-based acrylic emulsion features 1.Water-based acrylic emulsion is commonly used in thermosetting resin, the amount of thermosetting resin is relatively large, and widely used. Water-based acrylic emulsion also has many modifiers, accelerators, additives, etc., can be composed of a variety of combinations, so as to obtain different properties of epoxy curing system, to meet the requirements of various properties and processes 2.The stability of water-based acrylic emulsion is affected by temperature. The stability of emulsion is better at low temperature. 3.Water-based acrylic emulsion in the polymerization process to water as a solvent, to avoid the use of expensive organic solvents and recovery solvent trouble, but also reduce the risk of fire and pollution. It is cheap, pollution-free, safe and convenient, energy saving and other advantages make emulsion polymerization more and more widely used.