High solid content and low viscosity net odor hydroxyl polyurethane resin and its preparation method and application

Abstract

The invention discloses high-solid-content, low-viscosity, clean-odor hydroxyl polyurethane resin and its preparation method and application. The preparation method is: mixing small molecular polyol, acid anhydride, catalyst one and organic solvent at 115-125°C for 2-3 Hours, add epoxy compound and catalyst two, keep warm at 105-115°C for 5-7 hours, lower the temperature below 90°C, and distill under reduced pressure to obtain hydroxy polyols with star-shaped branched structure; add the first step to the reaction kettle Hydroxy polyols, small molecule polyols, polyether polyols, polyisocyanates and organic solvents with a star-shaped branched structure are kept at 75-85°C for 4-5 hours to obtain high-solid-content, low-viscosity, and clean-odour hydroxyl polyurethane resin. The hydroxyl polyurethane resin prepared by the present invention has a solid content of more than 90%, a viscosity below 2000mPa.s, a low reaction temperature, few side reactions, no high-temperature esterification reaction, no loss of small molecule polyols, and easy resin structure and performance. Adjustable control etc.

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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