Patent display(6) A microfiber containing polyurethane resin for dipping

Technical field

The present invention relates to a polyurethane resin, in particular a polyurethane resin used in the preparation process of microfiber fabrics.

Background

Microfiber is a typical representative of the new synthetic fiber that chemical fibers develop in the direction of high technology and high simulation, and can be made into simulated silk, imitation peach velvet, imitation suede, imitation wool and high-density products.Microfiber has opened up an unprecedented way out in the textile field, and its application range is very wide, from shoes, bags, sofas, leather goods to clothing, etc. all of which are sold as high-end products. The preparation process of microfiber fabric is:

The use of ultra-fine island fiber non-woven fabric as the base fabric, the fiber using nylon or polyester and polystyrene mixed spinning, stretched with a solvent to extract polystyrene and prepared, the microfiber is cut short, comb cotton auxiliary mesh, needle into non-woven fabric, this non-woven fabric by polyvinyl alcohol treatment, drying with a grinder after grinding flat, with polyurethane slurry for impregnation, coating and water solidification, washing, toluene extraction method or alkali reduction method to extract polystyrene and other processes.Since polystyrene needs to be extracted with toluene or strong alkali in the preparation process of microfiber fabrics, the polyurethane resin slurry requires that it cannot be dissolved in toluene or strong alkali or cause performance degradation.The raw material formulation of polyurethane slurry in the prior art is usually composed of polyester polyols, polyether polyols, chain spreaders, isocyanates, organic solvents, chain terminators and antioxidants and other additives, mainly using a two-step method (prepolymer method) synthesis. However, the polyurethane resin in the prior art as a whole, solvent resistance and acid and alkali resistance are poor, and can not meet the requirements of microfiber impregnation.

Contents of the Invention

The technical problem to be solved by the present invention is to provide a microfiber impregnated polyurethane resin, which has excellent solvent resistance and acid and alkali resistance.

To solve the above technical problems, the present invention takes the following technical solution:

A microfiber containing impregnated polyurethane resin, the raw material formulation consists of polyester polyols, polyether polyols, chain spreaders, isocyanates, organic solvents, chain terminators and antioxidants, in particular, the Polyester Polyol is a molecular weight of 2000 polyethylene glycol butanediol adipate diol, the polyether polyol is a molecular weight of 2000 polytetrahydrofuranether glycol,the chain extender is ethylene glycol, the isocyanate is 4,4-diphenylmethane-2-isocyanate, in terms of the total mass of the polyurethane resin, the mass content of the above components is as follows:

Polyester polyols 5.5 to 6%;

Polyether polyols 14~20%;

Chain expander 6 to 8%;

Isocyanate 4~5.8%;

Antioxidant 0.08~0.1%;

Organic solvent 63~75%;

Chain terminator 0.2~0.4%.

The above organic solvent is preferably dimethylformamide. The chain terminator is preferably methanol.

The polyurethane resin may be prepared using conventional polyurethane preparation process.

As a preferred embodiment, the polyurethane resin is prepared by the following synthesis process:

(1) Synthetic prepolymer: Polyester polyols, polyether polyols, chain spreaders, organic solvents and antioxidants were added to the reactor according to the formula, and the prepolymer was obtained at a temperature of 70 to 80 °C and reacted at atmospheric pressure for 3 to 5 hours;

(2) Chain expansion reaction: to the above prepolymer to add a amount of chain spreader for chain expansion reaction, the temperature of the chain expansion reaction is 70 ~ 80 ° C, under atmospheric pressure, the chain expansion reaction is carried out for 6 to 8 hours, the chain terminator is added to terminate the reaction, filtered, to obtain the microfibers containing impregnated polyurethane resin.

Due to the embodiment of the above technical solution, the present invention has the following advantages compared to the prior art:

For polyurethane resin, its acid and alkali resistance and solvent resistance are contradictory pairs of properties, usually, the ether bond contained in the polyether resin is better than the ester bond contained in the polyester resin, but too good acid and alkali resistance will cause the wet resin containing the soaking to surround the microfibers, when the toluene is withdrawn, the toluene is blocked outside, which is not conducive to the extraction of polystyrene, even if it is withdrawn, the feel will be hard, and the polyester resin containing the appropriate proportion in the formula, when the toluene is withdrawn, Some polyester resins will swell, which is conducive to the extraction of polystyrene, and the wear resistance of microfiber leather will be improved after extraction.The choice and proportion of polyester / polyether of the present invention is appropriate, thus having excellent solvent resistance while having excellent acid and alkali resistance.