Study on Properties of Polyurethane Adhesives for Ink (I)

Foreword

Printing as a means of information transmission and beautification plays a very important role in modern society. Among the determinants of various properties of the printing ink, the nature of the ink resin is the main factor. Polyurethane resin has excellent abrasion resistance, scratch resistance, solvent resistance, adhesive properties, good low temperature performance, high gloss, gloss retention, and its application performance has a wide range of adjustability, can meet each Different kinds of requirements. Therefore, the use of polyurethane resin in ink has become increasingly active and has become one of the most important resin materials. This work used differential scanning calorimetry (DSC), atomic force microscopy (AFM), tensile testing machines, and screen printers to test and analyze the polymer polyol type on the micro-morphology, mechanical properties and printability and Adhesion and other properties, in order to provide a reference for the development and application of polyurethane ink.

1 Experimental section

1.1 The main raw materials and reagents

IPDI: Industrial grade, Degussa-Höls company; Polytetrahydrofuran ether glycol (PTMEG): Mn=2000, Yantai Huada Chemical Co., Ltd.; Polybutylene Adipatediol (PBA): Mn=2000, Yantai Huada Chemical Co., Ltd.; Isophorone Diamine (IPDA): Industrial grade, Degussa-H櫣ls company; Di-n-butylamine (Bu2NH): Chemically pure, Shanghai Chemical Reagent Co.; methyl ethyl ketone, isopropyl alcohol: chemical Pure, Shanghai Feida Industry and Trade Co., Ltd.

1.2 Synthesis Methods

In a four-necked flask equipped with electric stirring and nitrogen protection, polyether or polyester diols and diisocyanate are added, and the reaction temperature is controlled at 60 to 100° C. so that the content of -NCO reaches a predetermined value (dibutylamine titration analysis [ 1]) Preparation of prepolymers; chain extender diluted with solvent, and reacted at 50°C for 30-60 min; then chain terminating agent is added, temperature control reaction is continued for 1 to 2 hours to obtain proper solid content and viscosity One-component solvent-based polyurethane resin.

1.3 Film production

The resin solution is poured into a horizontal glass mold, naturally air-dried and placed in an oven at 60° C. for 3 to 4 hours, and then processed in a vacuum drying oven at 80 to 100° C. for 2 to 4 hours with a film thickness of 0.3 to 0.6 mm.

1.4 Analysis and Test

(1) DSC analysis: Amplitude-modulated differential scanning calorimetry (TAModulated DSC2910) with a temperature range of -130 to 250°C and a heating rate of 15°C/min.

(2) Atomic force microscope (AFM) analysis: NanoScope IIIa (Digital Instruments), test mode is tapping mode. The scan size was 5 μm and the scan rate was 1 001 Hz.

(3) Mechanical properties: Japan Shimadzu AG-2000AR2 testing machine, tensile rate 200mm/min;

(4) Printing adaptability: The resin is prepared into ink, printed on a nylon cloth by a screen printing machine, and the permeation performance of the ink on the printing screen is examined; and the printed film is completely dried and then bundled at 30 to 70°C. Laminate (pressurize) and examine its adhesion.

(5) Adhesion: The printed coating film was completely dried at 30 to 70° C., an adhesive tape was applied to the printed film, and the film was rapidly peeled after being uniformly kneaded to examine the surface state of the printed film after peeling off. The visual measurement standards were: Good ○: More than 90% of printed film remained; Accepted □: 60 to 90% of printed film remained; Bad Δ: Residual of printed film was 60% or less.