High-solid-content low-viscosity odorless hydroxyl polyurethane resin as well as preparation method and application thereof

Abstract

The invention discloses high-solid-content low-viscosity odorless hydroxyl polyurethane resin as well as a preparation method and application thereof. The preparation method comprises the following steps of: mixing micro-molecular polyol, acid anhydride, a catalyst I and an organic solvent, carrying out heat preservation reaction at 115-125 DEG C for 2-3 hours, adding an epoxy compound and a catalyst II, carrying out heat preservation at 105-115 DEG C for 5-7 hours, cooling to 90 DEG C or below, and carrying out reduced pressure distillation to obtain hydroxyl polyol with a star-shaped branched structure; and adding the hydroxyl polyol with the star-shaped branched structure generated in the step 1, micro-molecular polyol, polyether polyol, polyisocyanate and an organic solvent into a reaction kettle, and keeping the temperature of 75-85 DEG C for 4-5 hours to obtain the high-solid-content low-viscosity odorless hydroxyl polyurethane resin. The hydroxyl polyurethane resin prepared by the method has the advantages that the solid content can reach more than 90%, the viscosity is less than 2000mPa. S, the reaction temperature is low, the side reaction is less, high-temperature esterification reaction is not needed, the loss of micromolecular polyol is avoided, the structure and the performance of the resin are easy to control and adjust, and the like.

Description

technical field [0001] The invention belongs to the technical field of two-component polyurethane wood lacquer, and relates to a hydroxy polyurethane resin, in particular to a preparation method and application of a high-solid-content, low-viscosity, clean-odor hydroxy polyurethane resin. Background technique [0002] Two-component polyurethane wood coatings have excellent physical and chemical properties and are widely used in wooden furniture and wooden floors. According to the different components containing hydroxyl groups, it can be divided into acrylic polyurethane, alkyd polyurethane, polyacid polyurethane, polyether polyurethane, epoxy polyurethane and other varieties. [0003] With the improvement of people's living standards, the restrictive regulations on the emission of volatile organic compounds (VOC) in two-component polyurethane wood paints are becoming more and more stringent. Higher requirements; due to the slow release rate and long release period of the s...

AI Technical Summary

Problems solved by technology

However, the cross-linking density of wood alkyd resin and curing agent in this technology is small, resulting in a surface dry time of more than 40 minutes, a longer time for the paint film and volatile gas, and a poorer compactness of the paint film, and it will last for a long time Still contains residual odor, in addition its production cost is higher

[0005] Chinese invention patent CN102286246A discloses a short-oil alkyd resin and a low-odor polyurethane paint including the alkyd resin. Adipic acid long-chain structure is added to the resin design, and two kinds of trifunctional alcohol and tetrafunctional alcohol are used. Alcohols with different structures strengthen the three-dimensional structure of the resin molecular chain, improve the release property of the product during film formation, greatly reduce the odor of furniture products, and release the odor within 24 hours of normal drying, but due to the selected short Oily alkyd resin itself has a strong odor and strong polarity. During the process of cross-linking and curing with the curing agent to form a film, due to the strong polarity of the alkyd resin, it is tightly adsorbed with the wood substrate. Make the smell not easy to volatilize in a short time, so that this technology does not achieve the real clean taste of the product

[0006] Chinese invention patent CN105399934A discloses a two-step process for synthesizing low-odor alkyd resins, adding soybean oleic acid, pentaerythritol, additives, and solvents, feeding nitrogen to replace the internal air, raising the temperature to 205-215 ° C, and keeping it warm for 1 Hours, cool down to 120°C, add ethylene glycol, neopentyl glycol, phthalic anhydride, maleic anhydride, solvent, heat up to 160-170°C, keep warm for 1 hour, then heat up to 180-190°C, Keep warm for one hour, then raise the temperature to 205-215°C, keep warm for esterification until the viscosity and acid value are qualified, then cool down, add solvent, dilute and filter out the material. When the prepared resin is used for wood varnish and top coat, the film-forming and odor-cleaning effect is good. It has good solvent volatility, good gloss stability, and excellent scratch resistance, which can meet the requirements of suite and hotel furniture manufacturing industries, but its synthesis process temperature is high, the maximum temperature reaches 215 ° C, the cost is high, and the reaction is accompanied by a large number of side effects. product

[0007] To sum up, there are still big problems in the existing technology to completely solve the problem of residual odor after furniture coating paint dries, and the comprehensive performance of the coating film needs to be improved

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