A water-based polyurethane-acrylic resin emulsion modified by silicone resin and preparation method thereof

Abstract

The invention discloses silicon resin-modified waterborne polyurethane-acrylic resin emulsion. The silicon resin-modified waterborne polyurethane-acrylic resin emulsion is prepared from the followingraw materials: acrylic resin monomers, isocyanate, vinyl silicone resin, double bond-containing polyester polyol, saturated polyester polyol, castor oil, N,N-dimethylformamide, ethanediamine, an initiating agent, a catalyst, a cross-linking agent, a hydrophilic chain-extending agent, a neutralizing agent, a negative-nonionic reactive emulsifying agent and water. A preparation method for the silicon resin-modified waterborne polyurethane-acrylic resin emulsion comprises the following steps: (1) preparation of a polyol mixture; (2) preparation of polyurethane prepolymer; (3) preparation of a polyurethane intermediate; (4) preparation of a pre-emulsion; (5) preparation of the silicon resin-modified waterborne polyurethane-acrylic resin emulsion. The silicon resin-modified waterborne polyurethane-acrylic resin emulsion disclosed by the invention is high in stability, environment-friendly, safe and low in cost; a coating obtained by the silicon resin-modified waterborne polyurethane-acrylicresin emulsion has good adhesion property, wear resistance, high lustre, high plumpness, excellent adhesion resistance and high drying speed.

Description

technical field [0001] The invention relates to a water-based polyurethane-acrylic resin emulsion modified by silicone resin and a preparation method thereof. Background technique [0002] Coatings and inks used on plastic products are generally solvent-based, and organic solvents are used as diluents. After painting, a large amount of organic solvents will volatilize into the air, which not only pollutes the atmosphere and damages human health, but also wastes Lots of resources. With the improvement of environmental protection laws and regulations in various countries and the enhancement of people's awareness of environmental protection, traditional solvent-based coatings and inks can no longer meet the needs of environmental protection. Water-based coatings and inks are current research hotspots. They use water as the dispersion medium and contain no or only a small amount of organic solvents. They have the advantages of non-toxic, non-flammable, non-polluting, safe and r...

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Problems solved by technology

At present, many researchers have carried out relevant research, but the prepared products all have obvious defects and are difficult to be applied industrially, for example:

[0004] D.Dieterich disclosed in the review (D.Dieterich, Prog.Org.Coatings, 9,281 (1981)) the method that polyacrylate dispersion and polyurethane dispersion are carried out physical blending, but in the blend that this method obtains There are obvious phase regions of acrylic and polyurethane, and the stability is poor;

[0005] DE A1953348, EP A167188, EP A189945 and EP A308115 disclose free-radical polymerization of acrylate monomers in aqueous polyurethane dispersions, which result in intimate mixing of the two polymer chains, polyurethane and acrylic acid, at the molecular level. It is a hybrid dispersion with inter-chain intertwining and secondary molecular interactions. Its physical and mechanical properties and stability are superior to physical blends, but its heat resistance and solvent resistance are poor, and it is difficult to industrialize. application;

[0006] CN 102786637A discloses a composite modified water-based polyurethane resin and a preparation method thereof. The polyurethane resin is compositely modified by using castor oil, epoxy resin, acrylate, etc., and the coating prepared by the composite modified water-based polyurethane resin is used in During the film forming process, the cross-linking density is high, the film hardness is high, the gloss is high, the water resistance is good, and the solvent resistance is good, but the viscosity of the prepolymer is too high, which makes it difficult to disperse during emulsification and the particle size of the emulsion is large;

[0007] CN 101280053A discloses a method for preparing acrylic acid-modified water-based polyurethane from renewable polyols. After polyurethane prepolymer and acrylic monomer are mixed and emulsified, polyurethane emulsion with network interpenetrating structure is prepared by emulsion polymerization , this kind of emulsion has the advantages of high weather resistance, chemical resistance and water resistance, but the particle size of the emulsion is large and the storage stability is poor;

[0008] CN 105418870A discloses a castor oil / acrylic acid composite modified water-based polyurethane emulsion and its preparation method. The water-based polyurethane is modified by castor oil and polyhydroxy acrylic resin to obtain a solid content of 30%wt-35%wt, with cross-linking A modified water-based polyurethane emulsion with a linked structure, which has excellent mechanical properties, dryness and water resistance, and is resistant to heat and humidity, but its solvent resistance is poor.

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