| Reflective materials are favored by people because they can reflect light back to the light source and have a good warning effect.Reflective materials can be found everywhere in our lives,such as traffic signs,warning suits,packaging,etc.However,the optical element of the reflective material is inevitably exposed to the outside,and is highly susceptible to corrosion,abrasion,damage,and falling off,resulting in deterioration of the retroreflective effect.Therefore,an adhesive having excellent properties is required to enable the optical member to be firmly fixed to the substrate.However,in recent years,the country's advocacy of green environmental protection and people's awareness of environmental protection,the development of a high-performance green and environmentally friendly adhesives for reflective materials has become a major problem that needs to be solved.Waterborne polyurethane adhesive is water dispersant,which has no harm to the environment and has become one of the development directions of adhesives.Therefore,it is of great significance to study the synthesis and application of waterborne polyurethane adhesives in reflective materials.In order to study the structure and amount of hydrophilic end group capping agent(MPEG),crosslinker(such as TMP)and dendritic chain extender(such as H103),the water resistance and heat resistance of waterborne polyurethane adhesive film are studied.The influence of alkalinity,peeling strength,pH of washing powder solution,formulation of WPU adhesive,silane coupling agent and reflective cloth on the adhesion of glass beads and aluminum silver layer,especially Slow down the corrosion of aluminum-silver layer and the water-washing resistance of reflective cloth.Characterization and detection were carried out by scanning electronmicroscopy(SEM),optical microscopy,Fourier transform infrared spectroscopy(FT-IR),high and low temperature double column tensile testing machine and retroreflective coefficient detector.The glass bead film,aluminum silver film and reflective cloth made of silane coupling agent modified WPU adhesive were washed and detected,and the silane coupling agent was bonded to the microbead,the aluminum silver layer was protected,and the reflective cloth was washed with water.Sexual influence.the result shows:(1)The increase of the hydrophilic end group content improves the peeling strength of the water-based polyurethane adhesive,and the water resistance and the heat-resistant alkalitity of the film are significantly decreased.When the content of the crosslinking agent is increased,the water resistance and the heat-resistant alkalinity of the film are remarkably improved,and the peeling strength reaches a peak value of0.9 KN/m at TMP=0.2 wt.%.The degree of branching is improved,the water absorption rate and the gel fraction are firstly converted and then inverted.At H103=5.3 wt.%,the film has good water resistance and heat resistance.The peel strength tends to change with the increase of H103 content.(2)The higher the pH of the aqueous medium and the higher the pH of the WPU adhesive,the less the interfacial adhesion,the shedding of the glass beads and the erosion of the aluminum-silver layer.The waterborne polyurethane adhesive modified by the silane coupling agent has good wettability and good adhesion to the glass microspheres and the aluminum silver layer and protects the alkaline environment to the aluminum silver layer to some extent.Erosion,which slows down the decreasing trend of the reflective strength of the reflective cloth,makes the water-washing resistance of the reflective cloth significantly improved,and is superior to the reflective cloth made by the company's current adhesive.In addition,when the reflective material is made,the pH of the WPU7 adhesive is adjusted to neutral,and5% of the 3025 curing agent is added,and the reverse heating is combined at 80 ° C,and the water-washing performance of the obtained reflective cloth material can be significantly improved.improve. |
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