Reactive self-delustering waterborne polyurethane resin, and preparation method and application thereof

Abstract

The invention discloses a reactive self-delustering waterborne polyurethane resin, and a preparation method and application thereof. The reactive self-delustering waterborne polyurethane resin has luster of no more than 20 at 60 DEG C when in a dry state and is prepared through reaction among the following components: 1, at least one aliphatic diisocyanate; 2, at least one carboxylic acid type hydrophilic dihydric alcohol; 3, at least one polymerized dihydric alcohol containing a water-dispersable group; 4, a catalyst used for synthesis of waterborne polyurethane; 5, at least one neutralizer; 6, at least one sulfonic acid type hydrophilic chain extender containing active hydrogen; and 7, at least one small molecule compound containing active hydrogen. The reactive self-delustering waterborne polyurethane resin has solid content of 25 to 40% and an average particle size of 500 to 5000 nm; no delustering agent is needed, and controllable generation of particles in certain particle size distribution can be realized in the process of synthesis; and the particles shrink after drying and dehydration of a film, which leads to increase of microscopic surface roughness and reduction in glossiness.

Description

technical field [0001] The invention relates to a novel self-delustering coating and a preparation method thereof, in particular to a reaction self-delustering water-based polyurethane resin and a preparation method and application thereof. Background technique [0002] Matting resin generally refers to the resin with obvious atomization and low gloss (matte) on the surface after film formation, which is mainly used in coating. Existing matting resins are mainly obtained by reacting self-matting and externally adding matting agents. Gloss is related to the ability of a surface to reflect more light in some directions than others. High-gloss surfaces reflect most of the light that hits them, while low-gloss surfaces reflect very little of the light that hits them, mostly internal refraction, absorption. The directions associated with mirror reflections generally have the highest reflectivity, and measurements by this test method correlate with visual observations of surface...

AI Technical Summary

Problems solved by technology

Although this way of adding a matting agent can achieve the purpose of matting, its disadvantages are also obvious: the cost of using a large amount of matting agent is high; the composition coagulates resulting in a multi-seed appearance; the coating is more brittle and easy to break and fall off ; Precipitation of matting agent leads to uneven mixing before application, resulting in differences in gloss throughout the coating; Reduced resistance to rubbing, flexing and rubbing

In order to avoid some defects caused by externally added matting agent, Chinese patent CN104193946A discloses a preparation method of self-dulling polyurethane resin, which includes the use of light-absorbing acrylic grafted substances for sealing, a large amount of acetone for viscosity reduction, and the use of Distillation treatment, acetone is difficult to remove, easy to have residue

CN103626930A describes a method for preparing a water-based acrylic polyurethane matting resin with a phase-separated structure. First, it is necessary to prepare two kinds of polyurethanes, anionic and nonionic, and then carry out seed emulsion polymerization of the acrylate mixture in the two polyurethanes, and prepare The polyurethane process requires end-capping treatment, a large amount of acetone is used as a diluent, and the entire synthesis step is cumbersome and time-consuming. It is difficult to produce in an industrialized assembly line.

CN104293165A discloses a low-color UV-curable matting coating for woodware. The purpose of matting is achieved by adding 2-hydroxyanisole sulfide to change the refractive index, but the system adds many benzenes or ketones, etc. Toxic additives and alcohol ether solvents, a large amount of organic compounds are volatile, and do not meet the low VOC emission standards of my country's new environmental protection law