Innoxious negative ion aqueous polyurethane and preparation method thereof

Abstract

The invention discloses a preparation method of innoxious negative ion aqueous polyurethane, and aqueous polyurethane prepared by the method. The method comprises the following steps: mixing dicyclohexyl methane diisocyanate and aliphatic diol according to a mol ratio of 2.5 to 4; carrying out reaction for 3 to 5 hours at 70 to 90 DEG C to obtain performed polymers; adding dimethylolbutyric acid with hydrophilic groups for taking the reaction for 3 to 5 hours; adding KOH water solution for emulsifying dispersion; and dripping diamine chain extenders for extending chains to obtain aqueous polyurethane latex emulsion. The invention adopts the aliphatic diisocyanate dicyclohexyl methane diisocyanate resin and the aliphatic polymeric diol, does not contain organic solvents such as NMP, acetone and the like often used for preparing the aqueous polyurethane, and does not contain common use neutralizing agents such as triethylamine and the like. The completely innoxious polyurethane material can be prepared, and the invention can be widely used in the fields of medical and health, food and household articles.

Description

technical field [0001] The invention relates to a method for preparing water-based polyurethane, in particular to a method for preparing non-toxic anionic water-based polyurethane and polyurethane obtained by the method. Background technique [0002] Water-based polyurethane uses water as the dispersion medium. Compared with solvent-based polyurethane, it has the advantages of non-combustibility, low odor, energy saving, and convenient operation. It has been widely used as leather finishing agent, coating and adhesive. [0003] Although compared with solvent-based polyurethane, there is still a gap in the product performance of water-based polyurethane, such as water resistance. In recent years, with people's increasing requirements for health and environmental protection and the promulgation of relevant national laws and regulations, there have been many reports on the preparation and research of waterborne polyurethane. [0004] Patents CN101003613A, CN1405196A, CN1930257...

AI Technical Summary

Problems solved by technology

The chronic action of N-methylpyrrolidone can cause dysfunction of the central nervous system, and cause lesions of respiratory organs, kidneys and vascular systems. However, N-methylpyrrolidone has a high boiling point and is difficult to remove in the end and stays in the material. biological toxicity

Secondly, water-based polyurethane usually uses tertiary amines such as triethylamine as a neutralizing agent, and triethylamine has a strong ammonia odor and has low solubility in water. This type of water-based polyurethane will emit amine odor, which is harmful to humans during production. and the environment will cause harm, and at the same time make the product somewhat toxic

Third, most of the previous patents used aromatic isocyanates such as HDI, IPDI and TDI as raw materials. On the one hand, isocyanates such as HDI, IPDI and TDI have high vapor pressure and are volatile. It is easy to cause harm to people and the environment, and polyurethane materials made of aromatic isocyanate TDI or MDI may decompose and produce carcinogenic aromatic amines during use

However, in order to avoid the use of co-solvent NMP, the invention does not use a hydrophilic monomer-containing chain extender, and directly adds water to the prepolymer during emulsification, while vigorously stirring to realize emulsification and dispersion, or does not use a co-solvent under the condition of using DMPA. Solvent is directly used for prepolymer chain extension. Because of its poor alcohol solubility, the prepolymerization system is turbid, which is unfavorable for chain extension reaction. The disadvantage of this invention is that the emulsion prepared by it has a large particle size, and the emulsion is unstable and easy to precipitate. layered