Hydrolysis-resistant polyester polyol and preparation method thereof

Abstract

The invention provides hydrolysis-resistant polyester polyol which is prepared by the following components in parts by weight: 20-50 parts of aliphatic dicarboxylic acid or carboxylic acid anhydride, 5-20 parts of aromatic dibasic acid or ester, 15-50 parts of polyol, and 0-0.002 parts of assistant. Polyester polyol is good in reactivity, compatibility and hydrolysis resistance. When 10-100% of polyester polyol is added for preparing a flexibly packaged adhesive, the adhesive strength, heat resistance and weather resistance of the adhesive can be improved significantly, and meanwhile the initial adhesion of the adhesive can be enhanced.

Description

technical field [0001] The invention belongs to the field of chemical products, and in particular relates to a hydrolysis-resistant polyester polyol used in a solvent-free polyurethane adhesive, and also relates to a preparation method of the hydrolysis-resistant polyester polyol. Background technique [0002] At present, solvent-free polyurethane adhesives include one-component adhesives and two-component polyurethane adhesives. [0003] Since there is no small molecule of solvent in the solvent-free polyurethane adhesive, the intermolecular force is strong, and hydrogen bonds are easily formed, so the viscosity of the adhesive is very high at room temperature. Although the viscosity can be effectively reduced by raising the temperature, too high a temperature will easily cause the adhesive to gel and form a high-molecular-weight resin, resulting in difficulty in coating or uneven coating. Therefore, it is very important to control the temperature of adhesive coating. Usua...

AI Technical Summary

Problems solved by technology

Since polyester polyols can provide greater intermolecular forces, polyester two-component polyurethane adhesives have good mechanical properties and good heat resistance. Poor compatibility, especially the viscosity of the prepared high-temperature-resistant solvent-free adhesive cannot be controlled, resulting in difficulty in sizing, poor adhesion and other quality problems; when used in solvent-free adhesives, the viscosity of the adhesive is often too high High, poor compatibility with other additives, resulting in difficulty in sizing, poor adhesion and other quality problems

However, the polyether-type two-component polyurethane adhesive is poor in bonding performance and high temperature resistance.

The mixed two-component polyurethane adhesive includes a mixture of polyester and polyether, its heat resistance is still not good, and the compatibility of polyester and polyether is poor

[0007] Aromatic polyester polyols have appeared in the existing market, which can produce phthalic anhydride polyesters with low viscosity and good compatibility with polyether polyols by introducing ethylene oxide or propylene oxide at the end of polycondensation synthesis , but the activity of this system is not high, the initial adhesion is not good, and the addition amount is low, and the hydrolysis resistance is not good

[0008] Solvent-free adhesives used in flexible packaging usually require low viscosity and good compatibility with other components. However, existing polyester polyols usually have high viscosity and poor hydrolysis resistance. Poor compatibility leads to poor adhesive performance, poor bonding performance and poor hydrolysis resistance of the cured adhesive layer

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