Toluene-diisocyanate-modified alkyd resin and preparation method thereof

Abstract

The invention discloses toluene-diisocyanate-modified alkyd resin and a preparation method thereof; the toluene-diisocyanate-modified alkyd resin is prepared from 15-17% of dry or semidry vegetable oleic acid, 9-11% of pentaerythritol, 3-5% of a tribasic alcohol, 12-14% of phthalic anhydride, 8-10% of benzoic acid, 0.05-0.15% of a color reducer, 2-5% of toluene diisocyanate, 0.03-0.05% of an organic tin catalyst, 1-3% of xylene, and 40-49% of an organic solvent. The toluene-diisocyanate-modified alkyd resin prepared with the above raw materials has light color, good adhesion, high drying speed, high hardness, high paint film gloss, good watertightness and good viscosity stability, the defects of the prior art can be overcome, and good technical advantages are achieved.

Description

Technical field [0001] The invention relates to a resin, in particular to a toluene diisocyanate modified alkyd resin with strong environmental protection, superior performance, good dryness and storage stability, and a preparation method thereof, belonging to the technical field of polymer materials. Background technique [0002] The application of toluene diisocyanate (TDI) modified alkyd resin is the same as that of ordinary air-drying alkyd resin, mainly by adding a drier to automatically oxidize and dry in the air to form a film, which can be made into varnish, color paint, and various coatings And auxiliary materials become alkyd resin paint system. Due to the introduction of urethane bonds in the resin, the paint film has better drying properties, hardness and wear resistance than ordinary air-drying alkyd resins. [0003] The mainstream practice in the industry now is to use vegetable oils and polyols after alcoholysis and esterification with phthalic anhydride into alkyd ...

AI Technical Summary

Problems solved by technology

[0004] 1. It is made by alcoholysis method, and the color of the resin is relatively dark, which limits the application field of the resin, for example, it cannot be applied to white enamel with high requirements

[0005] 2. The oil length of the resin is relatively long, generally above 45%, and it is diluted with 200# of aliphatic hydrocarbon, the molecular weight of the resin is low, the softening point is low, and the dryness and hardness of the resin are not very ideal

[0006] 3. The viscosity of the resin will increase after storage for a period of time. The main reason is that the ratio of -OH in the alkyd resin oligomer to -NCO in the added TDI is generally 1-1.1:1 (traditionally, it is believed that the excess of hydroxyl groups is good for water resistance) , the excess of hydroxyl groups is small, when it reacts with isocyanate bonds in TDI, it will not completely react to form urethane bonds, and there is residual -NCO in the resin. As the storage time increases, the viscosity of the resin will increase.

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